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    Native Antigen Inc mouse anti flavivirus envelope protein monoclonal antibody
    Effect of RRM2 knockdown on DENV RNA replication and infectious virus production (A) Schematic representation of the experimental protocol. Briefly, HuH-7, HepG2, and A549 cells were transfected with RRM2 siRNA or non-targeting control siRNA (Ctrl.si) one day before infection with DENV-1 and DENV-2 at a MOI of 0.1. Cells and culture supernatants were harvested 72 h later to measure intracellular and extracellular DENV RNA levels using RT-qPCR and quantify infectious virus titers in culture supernatants via a focus-forming assay. Created using Biorender.com. (B) SDS-PAGE and western blotting were utilized to assess the efficiency of RRM2 knockdown in HepG2, HuH-7, and A549 cells after treatment with specific RRM2 siRNA for 96 h at final concentrations of 10, 20, 5, and 5 nM, respectively. The expression levels of other RR subunits, RRM1 and p53R2, were also characterized. β-actin served as a loading control. (C–E) Intracellular and extracellular DENV RNA copy numbers were measured 72 h post-transfection (hpi) via RT-qPCR in HuH-7, HepG2, and A549 cells. Intracellular DENV RNA levels were normalized to GAPDH mRNA levels. Results are presented as mean+/-standard deviation (SD). p values were assessed using Student’s t test. (F–H) Infectious virus titers in culture supernatants from non-transfected and siRNA-transfected HuH-7, HepG2, and A549 cells were determined using a fluorescent focus assay on BHK-21 cells. Results are presented as mean +/- SD. p values were evaluated by Student’s t test. (I) Viability of HuH-7, HepG2, and A549 cells following treatment with RRM2 siRNA. Cells were seeded in 96-well plates and transfected with the indicated final concentrations of RRM2 siRNA. At 96 h post-transfection, cell viability was assessed using the 2(2-methyl-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2, 4disulfophenyl)-2H-tetrazolium, monosodium salt (WST)-8 assay (OD 450 ). The percentage of viability was calculated and compared to the untreated control (100% viability). (J) Immunofluorescence microscopy was conducted to evaluate the infection efficiency of DENV particles released from RRM2 or control siRNA-transfected and non-treated cells. Schematic representation of the experimental procedure. Culture supernatants harvested from non-transfected and siRNA-transfected DENV-infected HuH-7 and HepG2 cells were used to infect naive cell lines at an MOI of 1 (left). Three days post-infection, cell monolayers were analyzed by immunofluorescence for DENV envelope (E) protein expression using <t>anti-flavivirus</t> <t>monoclonal</t> antibody <t>4G2,</t> followed by Alexa Fluor 488-conjugated goat anti-mouse IgG. Representative immunofluorescence images (400× magnification) depicting DENV-E protein expression in HuH-7 and HepG2 cells. Cell nuclei were stained with DAPI, and cells were observed under a BZ-X700 fluorescence microscope (Keyence Co., Osaka, Japan). White squares indicate enlarged insets. Scale bars, 50 μm (right).
    Mouse Anti Flavivirus Envelope Protein Monoclonal Antibody, supplied by Native Antigen Inc, used in various techniques. Bioz Stars score: 91/100, based on 7 PubMed citations. ZERO BIAS - scores, article reviews, protocol conditions and more
    https://www.bioz.com/product/mouse+anti+flavivirus+envelope+protein+monoclonal+antibody/Mouse+Anti-Flavivirus+Envelope+Protein+Antibody+(4G2)/pmc12670889-339-51-59
    Average 91 stars, based on 7 article reviews
    mouse anti flavivirus envelope protein monoclonal antibody - by Bioz Stars, 2026-09
    91/100 stars

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    1) Product Images from "Ribonucleotide reductase subunit M2 mediates the mTOR pathway to recruit furin endoprotease and promote maturation of dengue virus"

    Article Title: Ribonucleotide reductase subunit M2 mediates the mTOR pathway to recruit furin endoprotease and promote maturation of dengue virus

    Journal: iScience

    doi: 10.1016/j.isci.2025.113998

    Effect of RRM2 knockdown on DENV RNA replication and infectious virus production (A) Schematic representation of the experimental protocol. Briefly, HuH-7, HepG2, and A549 cells were transfected with RRM2 siRNA or non-targeting control siRNA (Ctrl.si) one day before infection with DENV-1 and DENV-2 at a MOI of 0.1. Cells and culture supernatants were harvested 72 h later to measure intracellular and extracellular DENV RNA levels using RT-qPCR and quantify infectious virus titers in culture supernatants via a focus-forming assay. Created using Biorender.com. (B) SDS-PAGE and western blotting were utilized to assess the efficiency of RRM2 knockdown in HepG2, HuH-7, and A549 cells after treatment with specific RRM2 siRNA for 96 h at final concentrations of 10, 20, 5, and 5 nM, respectively. The expression levels of other RR subunits, RRM1 and p53R2, were also characterized. β-actin served as a loading control. (C–E) Intracellular and extracellular DENV RNA copy numbers were measured 72 h post-transfection (hpi) via RT-qPCR in HuH-7, HepG2, and A549 cells. Intracellular DENV RNA levels were normalized to GAPDH mRNA levels. Results are presented as mean+/-standard deviation (SD). p values were assessed using Student’s t test. (F–H) Infectious virus titers in culture supernatants from non-transfected and siRNA-transfected HuH-7, HepG2, and A549 cells were determined using a fluorescent focus assay on BHK-21 cells. Results are presented as mean +/- SD. p values were evaluated by Student’s t test. (I) Viability of HuH-7, HepG2, and A549 cells following treatment with RRM2 siRNA. Cells were seeded in 96-well plates and transfected with the indicated final concentrations of RRM2 siRNA. At 96 h post-transfection, cell viability was assessed using the 2(2-methyl-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2, 4disulfophenyl)-2H-tetrazolium, monosodium salt (WST)-8 assay (OD 450 ). The percentage of viability was calculated and compared to the untreated control (100% viability). (J) Immunofluorescence microscopy was conducted to evaluate the infection efficiency of DENV particles released from RRM2 or control siRNA-transfected and non-treated cells. Schematic representation of the experimental procedure. Culture supernatants harvested from non-transfected and siRNA-transfected DENV-infected HuH-7 and HepG2 cells were used to infect naive cell lines at an MOI of 1 (left). Three days post-infection, cell monolayers were analyzed by immunofluorescence for DENV envelope (E) protein expression using anti-flavivirus monoclonal antibody 4G2, followed by Alexa Fluor 488-conjugated goat anti-mouse IgG. Representative immunofluorescence images (400× magnification) depicting DENV-E protein expression in HuH-7 and HepG2 cells. Cell nuclei were stained with DAPI, and cells were observed under a BZ-X700 fluorescence microscope (Keyence Co., Osaka, Japan). White squares indicate enlarged insets. Scale bars, 50 μm (right).
    Figure Legend Snippet: Effect of RRM2 knockdown on DENV RNA replication and infectious virus production (A) Schematic representation of the experimental protocol. Briefly, HuH-7, HepG2, and A549 cells were transfected with RRM2 siRNA or non-targeting control siRNA (Ctrl.si) one day before infection with DENV-1 and DENV-2 at a MOI of 0.1. Cells and culture supernatants were harvested 72 h later to measure intracellular and extracellular DENV RNA levels using RT-qPCR and quantify infectious virus titers in culture supernatants via a focus-forming assay. Created using Biorender.com. (B) SDS-PAGE and western blotting were utilized to assess the efficiency of RRM2 knockdown in HepG2, HuH-7, and A549 cells after treatment with specific RRM2 siRNA for 96 h at final concentrations of 10, 20, 5, and 5 nM, respectively. The expression levels of other RR subunits, RRM1 and p53R2, were also characterized. β-actin served as a loading control. (C–E) Intracellular and extracellular DENV RNA copy numbers were measured 72 h post-transfection (hpi) via RT-qPCR in HuH-7, HepG2, and A549 cells. Intracellular DENV RNA levels were normalized to GAPDH mRNA levels. Results are presented as mean+/-standard deviation (SD). p values were assessed using Student’s t test. (F–H) Infectious virus titers in culture supernatants from non-transfected and siRNA-transfected HuH-7, HepG2, and A549 cells were determined using a fluorescent focus assay on BHK-21 cells. Results are presented as mean +/- SD. p values were evaluated by Student’s t test. (I) Viability of HuH-7, HepG2, and A549 cells following treatment with RRM2 siRNA. Cells were seeded in 96-well plates and transfected with the indicated final concentrations of RRM2 siRNA. At 96 h post-transfection, cell viability was assessed using the 2(2-methyl-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2, 4disulfophenyl)-2H-tetrazolium, monosodium salt (WST)-8 assay (OD 450 ). The percentage of viability was calculated and compared to the untreated control (100% viability). (J) Immunofluorescence microscopy was conducted to evaluate the infection efficiency of DENV particles released from RRM2 or control siRNA-transfected and non-treated cells. Schematic representation of the experimental procedure. Culture supernatants harvested from non-transfected and siRNA-transfected DENV-infected HuH-7 and HepG2 cells were used to infect naive cell lines at an MOI of 1 (left). Three days post-infection, cell monolayers were analyzed by immunofluorescence for DENV envelope (E) protein expression using anti-flavivirus monoclonal antibody 4G2, followed by Alexa Fluor 488-conjugated goat anti-mouse IgG. Representative immunofluorescence images (400× magnification) depicting DENV-E protein expression in HuH-7 and HepG2 cells. Cell nuclei were stained with DAPI, and cells were observed under a BZ-X700 fluorescence microscope (Keyence Co., Osaka, Japan). White squares indicate enlarged insets. Scale bars, 50 μm (right).

    Techniques Used: Knockdown, Virus, Transfection, Control, Infection, Quantitative RT-PCR, Focus Forming Assay, SDS Page, Western Blot, Expressing, Standard Deviation, Immunofluorescence, Microscopy, Staining, Fluorescence

    RRM2 knockdown reduced furin protein levels in the cells, decreasing cleavage of DENV prM protein (A) RT-qPCR analysis of RRM2 mRNA levels in HuH-7 cells either mock-infected or infected with DENV-1 or DENV-2 at an MOI of 0.1. RRM2 mRNA levels were normalized to GAPDH mRNA levels. Data are expressed as mean ± standard deviation (SD) of triplicate measurements. p values were assessed using Student’s t test. n.s., not significant. (B) DENV infection increased RRM2 protein levels. HuH-7 cells were mock-infected or infected with DENV-1 or DENV-2 at an MOI of 0.1. Cells were harvested at the indicated time points (24, 48, and 72 hpi) and analyzed by western blotting using anti-RRM2, anti-p53R2, and mouse monoclonal anti-flavivirus E (4G2) antibodies. Endogenous β-actin expression served as an internal control. Protein levels were quantified using ImageJ software and normalized to β-actin levels. Densitometric p53R2/actin and RRM2/actin ratios are shown below the blots. (C) Representative western blot images depict RRM2, DENV envelope (E), DENV capsid, and DENV prM protein expression levels in HuH-7 cells that were transfected with RRM2 siRNA or control (Ctrl) siRNA (5 nM). HuH-7 cells were either non-transfected or transfected with siRNAs one day prior to infection with DENV-1 or DENV-2 at an MOI of 0.1. At 72 hpi, cells were harvested and subjected to western blot analysis under non-reducing conditions using anti-prM, anti-capsid, anti-flavivirus E (4G2), and anti-RRM2 antibodies. β-actin was utilized as a loading control. (D) Determination of viral maturation was carried out by calculating the ratio of prM to E protein expression, normalized to non-transfected DENV-infected HuH-7 cells. Detected signals of DENV E and prM proteins in (C) were quantified using ImageJ software, and prM-to-E ratios are plotted as bar graphs. Numbers indicate n -fold increase compared to non-transfected cells. (E) Western blot analysis of prM and pr proteins in culture supernatants of non-transfected, control siRNA or RRM2 siRNA-transfected DENV-1 infected HuH-7 cells (C) under reducing conditions using an anti-pr mouse mAb. (F) Analysis of DENV E protein glycosylation status. Mock infected (−) or DENV (+) infected and siRNA-transfected HuH-7 cell lysates were treated with PNGaseF (+) or buffer control (−), then subjected to non-reducing SDS-PAGE and western blotting with anti-E 4G2, anti-RRM2, and anti-actin antibodies. Arrows indicate the positions of undigested and glycosylated E (2N) protein and deglycosylated forms (1N and 0N) of E protein. 0N, 1N, and 2N correspond to the number of N-linked glycans on E protein. β-actin was utilized as a loading control. (G) Quantification of endogenous furin mRNA levels relative to GAPDH in HuH-7 cells that were non-transfected or transfected with RRM2 siRNA or control siRNA (Ctrl si) (5 nM) for 96 h. Data are expressed as mean ± SD of triplicate measurements. (H) Effect of RRM2 knockdown on furin protein expression. HuH-7 cells were either non-transfected or transfected with control siRNA or RRM2 siRNA one day before mock infection or infection with DENV-1 or DENV-2 at an MOI of 0.1. At 72 hpi, cells were harvested and analyzed by western blotting using anti-furin, anti-RRM2, and anti-DENV-E proteins. β-actin served as a loading control. Protein band intensities were analyzed using ImageJ software. Densitometric furin/actin ratios are shown below the blots. (I) Furin protein levels in HuH-7 and A549 cells with or without transfection of furin expression plasmid (myc-DDK-tagged human furin, 4 μg) and those non-transfected or transfected with control or RRM2 siRNA (5 nM). Densitometric furin/actin ratios are shown below the blots. (J) A549 cells were seeded in 60 mm dishes, and after 24 h, cells were transfected with the furin expression plasmid (4 μg) alone or co-transfected with RRM2 or control siRNA. The following day, the cells were infected with DENV-2 at an MOI of 0.1. At 72 hpi, cells were harvested and subjected to western blot analysis under non-reducing conditions using anti-furin, anti-RRM2, anti-prM, anti-flavivirus E (4G2), and anti-actin antibodies. Densitometric prM/actin ratios are shown below the blots (left). Determination of viral maturation was carried out by calculating prM to E protein expression ratios normalized to those of control siRNA-transfected A549 cells. Detected signals of DENV E and prM proteins were quantified using ImageJ software as described in . prM-to-E ratios are plotted as bar graphs. Number indicates n -fold increase compared to Ctrl siRNA-transfected cells (right).
    Figure Legend Snippet: RRM2 knockdown reduced furin protein levels in the cells, decreasing cleavage of DENV prM protein (A) RT-qPCR analysis of RRM2 mRNA levels in HuH-7 cells either mock-infected or infected with DENV-1 or DENV-2 at an MOI of 0.1. RRM2 mRNA levels were normalized to GAPDH mRNA levels. Data are expressed as mean ± standard deviation (SD) of triplicate measurements. p values were assessed using Student’s t test. n.s., not significant. (B) DENV infection increased RRM2 protein levels. HuH-7 cells were mock-infected or infected with DENV-1 or DENV-2 at an MOI of 0.1. Cells were harvested at the indicated time points (24, 48, and 72 hpi) and analyzed by western blotting using anti-RRM2, anti-p53R2, and mouse monoclonal anti-flavivirus E (4G2) antibodies. Endogenous β-actin expression served as an internal control. Protein levels were quantified using ImageJ software and normalized to β-actin levels. Densitometric p53R2/actin and RRM2/actin ratios are shown below the blots. (C) Representative western blot images depict RRM2, DENV envelope (E), DENV capsid, and DENV prM protein expression levels in HuH-7 cells that were transfected with RRM2 siRNA or control (Ctrl) siRNA (5 nM). HuH-7 cells were either non-transfected or transfected with siRNAs one day prior to infection with DENV-1 or DENV-2 at an MOI of 0.1. At 72 hpi, cells were harvested and subjected to western blot analysis under non-reducing conditions using anti-prM, anti-capsid, anti-flavivirus E (4G2), and anti-RRM2 antibodies. β-actin was utilized as a loading control. (D) Determination of viral maturation was carried out by calculating the ratio of prM to E protein expression, normalized to non-transfected DENV-infected HuH-7 cells. Detected signals of DENV E and prM proteins in (C) were quantified using ImageJ software, and prM-to-E ratios are plotted as bar graphs. Numbers indicate n -fold increase compared to non-transfected cells. (E) Western blot analysis of prM and pr proteins in culture supernatants of non-transfected, control siRNA or RRM2 siRNA-transfected DENV-1 infected HuH-7 cells (C) under reducing conditions using an anti-pr mouse mAb. (F) Analysis of DENV E protein glycosylation status. Mock infected (−) or DENV (+) infected and siRNA-transfected HuH-7 cell lysates were treated with PNGaseF (+) or buffer control (−), then subjected to non-reducing SDS-PAGE and western blotting with anti-E 4G2, anti-RRM2, and anti-actin antibodies. Arrows indicate the positions of undigested and glycosylated E (2N) protein and deglycosylated forms (1N and 0N) of E protein. 0N, 1N, and 2N correspond to the number of N-linked glycans on E protein. β-actin was utilized as a loading control. (G) Quantification of endogenous furin mRNA levels relative to GAPDH in HuH-7 cells that were non-transfected or transfected with RRM2 siRNA or control siRNA (Ctrl si) (5 nM) for 96 h. Data are expressed as mean ± SD of triplicate measurements. (H) Effect of RRM2 knockdown on furin protein expression. HuH-7 cells were either non-transfected or transfected with control siRNA or RRM2 siRNA one day before mock infection or infection with DENV-1 or DENV-2 at an MOI of 0.1. At 72 hpi, cells were harvested and analyzed by western blotting using anti-furin, anti-RRM2, and anti-DENV-E proteins. β-actin served as a loading control. Protein band intensities were analyzed using ImageJ software. Densitometric furin/actin ratios are shown below the blots. (I) Furin protein levels in HuH-7 and A549 cells with or without transfection of furin expression plasmid (myc-DDK-tagged human furin, 4 μg) and those non-transfected or transfected with control or RRM2 siRNA (5 nM). Densitometric furin/actin ratios are shown below the blots. (J) A549 cells were seeded in 60 mm dishes, and after 24 h, cells were transfected with the furin expression plasmid (4 μg) alone or co-transfected with RRM2 or control siRNA. The following day, the cells were infected with DENV-2 at an MOI of 0.1. At 72 hpi, cells were harvested and subjected to western blot analysis under non-reducing conditions using anti-furin, anti-RRM2, anti-prM, anti-flavivirus E (4G2), and anti-actin antibodies. Densitometric prM/actin ratios are shown below the blots (left). Determination of viral maturation was carried out by calculating prM to E protein expression ratios normalized to those of control siRNA-transfected A549 cells. Detected signals of DENV E and prM proteins were quantified using ImageJ software as described in . prM-to-E ratios are plotted as bar graphs. Number indicates n -fold increase compared to Ctrl siRNA-transfected cells (right).

    Techniques Used: Knockdown, Quantitative RT-PCR, Infection, Standard Deviation, Western Blot, Expressing, Control, Software, Transfection, Glycoproteomics, SDS Page, Plasmid Preparation

    Related Articles

    Staining:

    Article Title: Ribonucleotide reductase subunit M2 mediates the mTOR pathway to recruit furin endoprotease and promote maturation of dengue virus
    Article Snippet: .. Cells were stained to visualize foci of viral infection using a mouse anti-flavivirus envelope protein monoclonal antibody (clone 4G2, The Native Antigen Company) and anti-mouse Alexa Fluor 488 secondary antibody (Thermo Fisher Scientific). .. Fluorescent foci were counted manually using a BZ-X700 fluorescence microscope (Keyence Co., Osaka, Japan), and infectious virus titers were expressed as fluorescent focus units per mL.

    Article Title: Ribonucleotide reductase subunit M2 mediates the mTOR pathway to recruit furin endoprotease and promote maturation of dengue virus
    Article Snippet: .. Following two washes with PBS, the cells were stained with a mouse anti-flavivirus envelope protein monoclonal antibody (clone 4G2, The Native Antigen Company) in PBS/0.2% BSA for 1 h, washed three times with PBS/0.2% BSA, incubated with anti-mouse Alexa Fluor 488 secondary antibody (Thermo Fisher Scientific) for 1 h, then washed three times with PBS/0.2% BSA. ..

    Infection:

    Article Title: Ribonucleotide reductase subunit M2 mediates the mTOR pathway to recruit furin endoprotease and promote maturation of dengue virus
    Article Snippet: .. Cells were stained to visualize foci of viral infection using a mouse anti-flavivirus envelope protein monoclonal antibody (clone 4G2, The Native Antigen Company) and anti-mouse Alexa Fluor 488 secondary antibody (Thermo Fisher Scientific). .. Fluorescent foci were counted manually using a BZ-X700 fluorescence microscope (Keyence Co., Osaka, Japan), and infectious virus titers were expressed as fluorescent focus units per mL.

    Western Blot:

    Article Title: Ribonucleotide reductase subunit M2 mediates the mTOR pathway to recruit furin endoprotease and promote maturation of dengue virus
    Article Snippet: Plasmid DNA transfections were conducted using Lipofectamine LTX reagent (Invitrogen) or Lipofectamine 2000 transfection reagent (Invitrogen) following the manufacturer’s instructions. .. Antibodies against the following proteins were used in the immunoblots: mouse anti-RRM2 clone 1E1 (cat# WH0006241M1; Sigma-Aldrich), rabbit anti-RRM2 (cat# GTX103193; GeneTex, Irvine, CA, USA), rabbit anti-furin (cat# PA1-062, Thermo Fisher Scientific), rabbit anti-RRM1 (cat# ab137114; Abcam, Cambridge, MA, USA), goat anti-p53R2 ( N -16, sc-10840, Santa Cruz Biotechnology, CA, USA), mouse anti-flavivirus envelope protein monoclonal antibody (clone 4G2; The Native Antigen Company, Oxford, UK), rabbit anti-dengue virus capsid protein (cat# GTX103343; GeneTex), rabbit anti-dengue virus prM protein (cat# GTX128093; GeneTex), mouse anti-dengue virus prM protein (clone CC5.A9.E10; The Native Antigen Company), mouse anti-dengue virus pr monoclonal antibody (cat# LDG0013YA; LEADGENE), mouse anti-dengue virus NS1 monoclonal antibody (cat# ab41490; Abcam), rabbit anti-mTOR (cat# GTX101557; GeneTex), rabbit anti-LC3I/II (cat# PM036; MBL International, Woburn, MA, USA), rabbit anti-4E-BP1 (cat# 9452; Cell Signaling Technology, Danvers, MA, USA), rabbit anti-phospho-4E-BP1 (Ser65) (cat# 9451; Cell Signaling Technology), rabbit anti-phospho-4E-BP1 (Thr70) (cat# 9455; Cell Signaling Technology), and mouse anti-actin antibody (cat# A2228; Sigma-Aldrich). .. The appropriate horseradish peroxidase-conjugated secondary antibodies (Dako) were then applied.

    Virus:

    Article Title: Ribonucleotide reductase subunit M2 mediates the mTOR pathway to recruit furin endoprotease and promote maturation of dengue virus
    Article Snippet: Plasmid DNA transfections were conducted using Lipofectamine LTX reagent (Invitrogen) or Lipofectamine 2000 transfection reagent (Invitrogen) following the manufacturer’s instructions. .. Antibodies against the following proteins were used in the immunoblots: mouse anti-RRM2 clone 1E1 (cat# WH0006241M1; Sigma-Aldrich), rabbit anti-RRM2 (cat# GTX103193; GeneTex, Irvine, CA, USA), rabbit anti-furin (cat# PA1-062, Thermo Fisher Scientific), rabbit anti-RRM1 (cat# ab137114; Abcam, Cambridge, MA, USA), goat anti-p53R2 ( N -16, sc-10840, Santa Cruz Biotechnology, CA, USA), mouse anti-flavivirus envelope protein monoclonal antibody (clone 4G2; The Native Antigen Company, Oxford, UK), rabbit anti-dengue virus capsid protein (cat# GTX103343; GeneTex), rabbit anti-dengue virus prM protein (cat# GTX128093; GeneTex), mouse anti-dengue virus prM protein (clone CC5.A9.E10; The Native Antigen Company), mouse anti-dengue virus pr monoclonal antibody (cat# LDG0013YA; LEADGENE), mouse anti-dengue virus NS1 monoclonal antibody (cat# ab41490; Abcam), rabbit anti-mTOR (cat# GTX101557; GeneTex), rabbit anti-LC3I/II (cat# PM036; MBL International, Woburn, MA, USA), rabbit anti-4E-BP1 (cat# 9452; Cell Signaling Technology, Danvers, MA, USA), rabbit anti-phospho-4E-BP1 (Ser65) (cat# 9451; Cell Signaling Technology), rabbit anti-phospho-4E-BP1 (Thr70) (cat# 9455; Cell Signaling Technology), and mouse anti-actin antibody (cat# A2228; Sigma-Aldrich). .. The appropriate horseradish peroxidase-conjugated secondary antibodies (Dako) were then applied.

    Incubation:

    Article Title: Ribonucleotide reductase subunit M2 mediates the mTOR pathway to recruit furin endoprotease and promote maturation of dengue virus
    Article Snippet: .. Following two washes with PBS, the cells were stained with a mouse anti-flavivirus envelope protein monoclonal antibody (clone 4G2, The Native Antigen Company) in PBS/0.2% BSA for 1 h, washed three times with PBS/0.2% BSA, incubated with anti-mouse Alexa Fluor 488 secondary antibody (Thermo Fisher Scientific) for 1 h, then washed three times with PBS/0.2% BSA. ..



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    Effect of RRM2 knockdown on DENV RNA replication and infectious virus production (A) Schematic representation of the experimental protocol. Briefly, HuH-7, HepG2, and A549 cells were transfected with RRM2 siRNA or non-targeting control siRNA (Ctrl.si) one day before infection with DENV-1 and DENV-2 at a MOI of 0.1. Cells and culture supernatants were harvested 72 h later to measure intracellular and extracellular DENV RNA levels using RT-qPCR and quantify infectious virus titers in culture supernatants via a focus-forming assay. Created using Biorender.com. (B) SDS-PAGE and western blotting were utilized to assess the efficiency of RRM2 knockdown in HepG2, HuH-7, and A549 cells after treatment with specific RRM2 siRNA for 96 h at final concentrations of 10, 20, 5, and 5 nM, respectively. The expression levels of other RR subunits, RRM1 and p53R2, were also characterized. β-actin served as a loading control. (C–E) Intracellular and extracellular DENV RNA copy numbers were measured 72 h post-transfection (hpi) via RT-qPCR in HuH-7, HepG2, and A549 cells. Intracellular DENV RNA levels were normalized to GAPDH mRNA levels. Results are presented as mean+/-standard deviation (SD). p values were assessed using Student’s t test. (F–H) Infectious virus titers in culture supernatants from non-transfected and siRNA-transfected HuH-7, HepG2, and A549 cells were determined using a fluorescent focus assay on BHK-21 cells. Results are presented as mean +/- SD. p values were evaluated by Student’s t test. (I) Viability of HuH-7, HepG2, and A549 cells following treatment with RRM2 siRNA. Cells were seeded in 96-well plates and transfected with the indicated final concentrations of RRM2 siRNA. At 96 h post-transfection, cell viability was assessed using the 2(2-methyl-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2, 4disulfophenyl)-2H-tetrazolium, monosodium salt (WST)-8 assay (OD 450 ). The percentage of viability was calculated and compared to the untreated control (100% viability). (J) Immunofluorescence microscopy was conducted to evaluate the infection efficiency of DENV particles released from RRM2 or control siRNA-transfected and non-treated cells. Schematic representation of the experimental procedure. Culture supernatants harvested from non-transfected and siRNA-transfected DENV-infected HuH-7 and HepG2 cells were used to infect naive cell lines at an MOI of 1 (left). Three days post-infection, cell monolayers were analyzed by immunofluorescence for DENV envelope (E) protein expression using <t>anti-flavivirus</t> <t>monoclonal</t> antibody <t>4G2,</t> followed by Alexa Fluor 488-conjugated goat anti-mouse IgG. Representative immunofluorescence images (400× magnification) depicting DENV-E protein expression in HuH-7 and HepG2 cells. Cell nuclei were stained with DAPI, and cells were observed under a BZ-X700 fluorescence microscope (Keyence Co., Osaka, Japan). White squares indicate enlarged insets. Scale bars, 50 μm (right).
    Mouse Anti Flavivirus Envelope Protein Monoclonal Antibody, supplied by Native Antigen Inc, used in various techniques. Bioz Stars score: 91/100, based on 1 PubMed citations. ZERO BIAS - scores, article reviews, protocol conditions and more
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    Effect of RRM2 knockdown on DENV RNA replication and infectious virus production (A) Schematic representation of the experimental protocol. Briefly, HuH-7, HepG2, and A549 cells were transfected with RRM2 siRNA or non-targeting control siRNA (Ctrl.si) one day before infection with DENV-1 and DENV-2 at a MOI of 0.1. Cells and culture supernatants were harvested 72 h later to measure intracellular and extracellular DENV RNA levels using RT-qPCR and quantify infectious virus titers in culture supernatants via a focus-forming assay. Created using Biorender.com. (B) SDS-PAGE and western blotting were utilized to assess the efficiency of RRM2 knockdown in HepG2, HuH-7, and A549 cells after treatment with specific RRM2 siRNA for 96 h at final concentrations of 10, 20, 5, and 5 nM, respectively. The expression levels of other RR subunits, RRM1 and p53R2, were also characterized. β-actin served as a loading control. (C–E) Intracellular and extracellular DENV RNA copy numbers were measured 72 h post-transfection (hpi) via RT-qPCR in HuH-7, HepG2, and A549 cells. Intracellular DENV RNA levels were normalized to GAPDH mRNA levels. Results are presented as mean+/-standard deviation (SD). p values were assessed using Student’s t test. (F–H) Infectious virus titers in culture supernatants from non-transfected and siRNA-transfected HuH-7, HepG2, and A549 cells were determined using a fluorescent focus assay on BHK-21 cells. Results are presented as mean +/- SD. p values were evaluated by Student’s t test. (I) Viability of HuH-7, HepG2, and A549 cells following treatment with RRM2 siRNA. Cells were seeded in 96-well plates and transfected with the indicated final concentrations of RRM2 siRNA. At 96 h post-transfection, cell viability was assessed using the 2(2-methyl-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2, 4disulfophenyl)-2H-tetrazolium, monosodium salt (WST)-8 assay (OD 450 ). The percentage of viability was calculated and compared to the untreated control (100% viability). (J) Immunofluorescence microscopy was conducted to evaluate the infection efficiency of DENV particles released from RRM2 or control siRNA-transfected and non-treated cells. Schematic representation of the experimental procedure. Culture supernatants harvested from non-transfected and siRNA-transfected DENV-infected HuH-7 and HepG2 cells were used to infect naive cell lines at an MOI of 1 (left). Three days post-infection, cell monolayers were analyzed by immunofluorescence for DENV envelope (E) protein expression using <t>anti-flavivirus</t> <t>monoclonal</t> antibody <t>4G2,</t> followed by Alexa Fluor 488-conjugated goat anti-mouse IgG. Representative immunofluorescence images (400× magnification) depicting DENV-E protein expression in HuH-7 and HepG2 cells. Cell nuclei were stained with DAPI, and cells were observed under a BZ-X700 fluorescence microscope (Keyence Co., Osaka, Japan). White squares indicate enlarged insets. Scale bars, 50 μm (right).
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    Effect of RRM2 knockdown on DENV RNA replication and infectious virus production (A) Schematic representation of the experimental protocol. Briefly, HuH-7, HepG2, and A549 cells were transfected with RRM2 siRNA or non-targeting control siRNA (Ctrl.si) one day before infection with DENV-1 and DENV-2 at a MOI of 0.1. Cells and culture supernatants were harvested 72 h later to measure intracellular and extracellular DENV RNA levels using RT-qPCR and quantify infectious virus titers in culture supernatants via a focus-forming assay. Created using Biorender.com. (B) SDS-PAGE and western blotting were utilized to assess the efficiency of RRM2 knockdown in HepG2, HuH-7, and A549 cells after treatment with specific RRM2 siRNA for 96 h at final concentrations of 10, 20, 5, and 5 nM, respectively. The expression levels of other RR subunits, RRM1 and p53R2, were also characterized. β-actin served as a loading control. (C–E) Intracellular and extracellular DENV RNA copy numbers were measured 72 h post-transfection (hpi) via RT-qPCR in HuH-7, HepG2, and A549 cells. Intracellular DENV RNA levels were normalized to GAPDH mRNA levels. Results are presented as mean+/-standard deviation (SD). p values were assessed using Student’s t test. (F–H) Infectious virus titers in culture supernatants from non-transfected and siRNA-transfected HuH-7, HepG2, and A549 cells were determined using a fluorescent focus assay on BHK-21 cells. Results are presented as mean +/- SD. p values were evaluated by Student’s t test. (I) Viability of HuH-7, HepG2, and A549 cells following treatment with RRM2 siRNA. Cells were seeded in 96-well plates and transfected with the indicated final concentrations of RRM2 siRNA. At 96 h post-transfection, cell viability was assessed using the 2(2-methyl-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2, 4disulfophenyl)-2H-tetrazolium, monosodium salt (WST)-8 assay (OD 450 ). The percentage of viability was calculated and compared to the untreated control (100% viability). (J) Immunofluorescence microscopy was conducted to evaluate the infection efficiency of DENV particles released from RRM2 or control siRNA-transfected and non-treated cells. Schematic representation of the experimental procedure. Culture supernatants harvested from non-transfected and siRNA-transfected DENV-infected HuH-7 and HepG2 cells were used to infect naive cell lines at an MOI of 1 (left). Three days post-infection, cell monolayers were analyzed by immunofluorescence for DENV envelope (E) protein expression using <t>anti-flavivirus</t> <t>monoclonal</t> antibody <t>4G2,</t> followed by Alexa Fluor 488-conjugated goat anti-mouse IgG. Representative immunofluorescence images (400× magnification) depicting DENV-E protein expression in HuH-7 and HepG2 cells. Cell nuclei were stained with DAPI, and cells were observed under a BZ-X700 fluorescence microscope (Keyence Co., Osaka, Japan). White squares indicate enlarged insets. Scale bars, 50 μm (right).
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    Effect of RRM2 knockdown on DENV RNA replication and infectious virus production (A) Schematic representation of the experimental protocol. Briefly, HuH-7, HepG2, and A549 cells were transfected with RRM2 siRNA or non-targeting control siRNA (Ctrl.si) one day before infection with DENV-1 and DENV-2 at a MOI of 0.1. Cells and culture supernatants were harvested 72 h later to measure intracellular and extracellular DENV RNA levels using RT-qPCR and quantify infectious virus titers in culture supernatants via a focus-forming assay. Created using Biorender.com. (B) SDS-PAGE and western blotting were utilized to assess the efficiency of RRM2 knockdown in HepG2, HuH-7, and A549 cells after treatment with specific RRM2 siRNA for 96 h at final concentrations of 10, 20, 5, and 5 nM, respectively. The expression levels of other RR subunits, RRM1 and p53R2, were also characterized. β-actin served as a loading control. (C–E) Intracellular and extracellular DENV RNA copy numbers were measured 72 h post-transfection (hpi) via RT-qPCR in HuH-7, HepG2, and A549 cells. Intracellular DENV RNA levels were normalized to GAPDH mRNA levels. Results are presented as mean+/-standard deviation (SD). p values were assessed using Student’s t test. (F–H) Infectious virus titers in culture supernatants from non-transfected and siRNA-transfected HuH-7, HepG2, and A549 cells were determined using a fluorescent focus assay on BHK-21 cells. Results are presented as mean +/- SD. p values were evaluated by Student’s t test. (I) Viability of HuH-7, HepG2, and A549 cells following treatment with RRM2 siRNA. Cells were seeded in 96-well plates and transfected with the indicated final concentrations of RRM2 siRNA. At 96 h post-transfection, cell viability was assessed using the 2(2-methyl-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2, 4disulfophenyl)-2H-tetrazolium, monosodium salt (WST)-8 assay (OD 450 ). The percentage of viability was calculated and compared to the untreated control (100% viability). (J) Immunofluorescence microscopy was conducted to evaluate the infection efficiency of DENV particles released from RRM2 or control siRNA-transfected and non-treated cells. Schematic representation of the experimental procedure. Culture supernatants harvested from non-transfected and siRNA-transfected DENV-infected HuH-7 and HepG2 cells were used to infect naive cell lines at an MOI of 1 (left). Three days post-infection, cell monolayers were analyzed by immunofluorescence for DENV envelope (E) protein expression using anti-flavivirus monoclonal antibody 4G2, followed by Alexa Fluor 488-conjugated goat anti-mouse IgG. Representative immunofluorescence images (400× magnification) depicting DENV-E protein expression in HuH-7 and HepG2 cells. Cell nuclei were stained with DAPI, and cells were observed under a BZ-X700 fluorescence microscope (Keyence Co., Osaka, Japan). White squares indicate enlarged insets. Scale bars, 50 μm (right).

    Journal: iScience

    Article Title: Ribonucleotide reductase subunit M2 mediates the mTOR pathway to recruit furin endoprotease and promote maturation of dengue virus

    doi: 10.1016/j.isci.2025.113998

    Figure Lengend Snippet: Effect of RRM2 knockdown on DENV RNA replication and infectious virus production (A) Schematic representation of the experimental protocol. Briefly, HuH-7, HepG2, and A549 cells were transfected with RRM2 siRNA or non-targeting control siRNA (Ctrl.si) one day before infection with DENV-1 and DENV-2 at a MOI of 0.1. Cells and culture supernatants were harvested 72 h later to measure intracellular and extracellular DENV RNA levels using RT-qPCR and quantify infectious virus titers in culture supernatants via a focus-forming assay. Created using Biorender.com. (B) SDS-PAGE and western blotting were utilized to assess the efficiency of RRM2 knockdown in HepG2, HuH-7, and A549 cells after treatment with specific RRM2 siRNA for 96 h at final concentrations of 10, 20, 5, and 5 nM, respectively. The expression levels of other RR subunits, RRM1 and p53R2, were also characterized. β-actin served as a loading control. (C–E) Intracellular and extracellular DENV RNA copy numbers were measured 72 h post-transfection (hpi) via RT-qPCR in HuH-7, HepG2, and A549 cells. Intracellular DENV RNA levels were normalized to GAPDH mRNA levels. Results are presented as mean+/-standard deviation (SD). p values were assessed using Student’s t test. (F–H) Infectious virus titers in culture supernatants from non-transfected and siRNA-transfected HuH-7, HepG2, and A549 cells were determined using a fluorescent focus assay on BHK-21 cells. Results are presented as mean +/- SD. p values were evaluated by Student’s t test. (I) Viability of HuH-7, HepG2, and A549 cells following treatment with RRM2 siRNA. Cells were seeded in 96-well plates and transfected with the indicated final concentrations of RRM2 siRNA. At 96 h post-transfection, cell viability was assessed using the 2(2-methyl-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2, 4disulfophenyl)-2H-tetrazolium, monosodium salt (WST)-8 assay (OD 450 ). The percentage of viability was calculated and compared to the untreated control (100% viability). (J) Immunofluorescence microscopy was conducted to evaluate the infection efficiency of DENV particles released from RRM2 or control siRNA-transfected and non-treated cells. Schematic representation of the experimental procedure. Culture supernatants harvested from non-transfected and siRNA-transfected DENV-infected HuH-7 and HepG2 cells were used to infect naive cell lines at an MOI of 1 (left). Three days post-infection, cell monolayers were analyzed by immunofluorescence for DENV envelope (E) protein expression using anti-flavivirus monoclonal antibody 4G2, followed by Alexa Fluor 488-conjugated goat anti-mouse IgG. Representative immunofluorescence images (400× magnification) depicting DENV-E protein expression in HuH-7 and HepG2 cells. Cell nuclei were stained with DAPI, and cells were observed under a BZ-X700 fluorescence microscope (Keyence Co., Osaka, Japan). White squares indicate enlarged insets. Scale bars, 50 μm (right).

    Article Snippet: Mouse anti-flavivirus envelope protein monoclonal antibody (D1-4G2-4-15) , ATCC , CVCL_J890.

    Techniques: Knockdown, Virus, Transfection, Control, Infection, Quantitative RT-PCR, Focus Forming Assay, SDS Page, Western Blot, Expressing, Standard Deviation, Immunofluorescence, Microscopy, Staining, Fluorescence

    RRM2 knockdown reduced furin protein levels in the cells, decreasing cleavage of DENV prM protein (A) RT-qPCR analysis of RRM2 mRNA levels in HuH-7 cells either mock-infected or infected with DENV-1 or DENV-2 at an MOI of 0.1. RRM2 mRNA levels were normalized to GAPDH mRNA levels. Data are expressed as mean ± standard deviation (SD) of triplicate measurements. p values were assessed using Student’s t test. n.s., not significant. (B) DENV infection increased RRM2 protein levels. HuH-7 cells were mock-infected or infected with DENV-1 or DENV-2 at an MOI of 0.1. Cells were harvested at the indicated time points (24, 48, and 72 hpi) and analyzed by western blotting using anti-RRM2, anti-p53R2, and mouse monoclonal anti-flavivirus E (4G2) antibodies. Endogenous β-actin expression served as an internal control. Protein levels were quantified using ImageJ software and normalized to β-actin levels. Densitometric p53R2/actin and RRM2/actin ratios are shown below the blots. (C) Representative western blot images depict RRM2, DENV envelope (E), DENV capsid, and DENV prM protein expression levels in HuH-7 cells that were transfected with RRM2 siRNA or control (Ctrl) siRNA (5 nM). HuH-7 cells were either non-transfected or transfected with siRNAs one day prior to infection with DENV-1 or DENV-2 at an MOI of 0.1. At 72 hpi, cells were harvested and subjected to western blot analysis under non-reducing conditions using anti-prM, anti-capsid, anti-flavivirus E (4G2), and anti-RRM2 antibodies. β-actin was utilized as a loading control. (D) Determination of viral maturation was carried out by calculating the ratio of prM to E protein expression, normalized to non-transfected DENV-infected HuH-7 cells. Detected signals of DENV E and prM proteins in (C) were quantified using ImageJ software, and prM-to-E ratios are plotted as bar graphs. Numbers indicate n -fold increase compared to non-transfected cells. (E) Western blot analysis of prM and pr proteins in culture supernatants of non-transfected, control siRNA or RRM2 siRNA-transfected DENV-1 infected HuH-7 cells (C) under reducing conditions using an anti-pr mouse mAb. (F) Analysis of DENV E protein glycosylation status. Mock infected (−) or DENV (+) infected and siRNA-transfected HuH-7 cell lysates were treated with PNGaseF (+) or buffer control (−), then subjected to non-reducing SDS-PAGE and western blotting with anti-E 4G2, anti-RRM2, and anti-actin antibodies. Arrows indicate the positions of undigested and glycosylated E (2N) protein and deglycosylated forms (1N and 0N) of E protein. 0N, 1N, and 2N correspond to the number of N-linked glycans on E protein. β-actin was utilized as a loading control. (G) Quantification of endogenous furin mRNA levels relative to GAPDH in HuH-7 cells that were non-transfected or transfected with RRM2 siRNA or control siRNA (Ctrl si) (5 nM) for 96 h. Data are expressed as mean ± SD of triplicate measurements. (H) Effect of RRM2 knockdown on furin protein expression. HuH-7 cells were either non-transfected or transfected with control siRNA or RRM2 siRNA one day before mock infection or infection with DENV-1 or DENV-2 at an MOI of 0.1. At 72 hpi, cells were harvested and analyzed by western blotting using anti-furin, anti-RRM2, and anti-DENV-E proteins. β-actin served as a loading control. Protein band intensities were analyzed using ImageJ software. Densitometric furin/actin ratios are shown below the blots. (I) Furin protein levels in HuH-7 and A549 cells with or without transfection of furin expression plasmid (myc-DDK-tagged human furin, 4 μg) and those non-transfected or transfected with control or RRM2 siRNA (5 nM). Densitometric furin/actin ratios are shown below the blots. (J) A549 cells were seeded in 60 mm dishes, and after 24 h, cells were transfected with the furin expression plasmid (4 μg) alone or co-transfected with RRM2 or control siRNA. The following day, the cells were infected with DENV-2 at an MOI of 0.1. At 72 hpi, cells were harvested and subjected to western blot analysis under non-reducing conditions using anti-furin, anti-RRM2, anti-prM, anti-flavivirus E (4G2), and anti-actin antibodies. Densitometric prM/actin ratios are shown below the blots (left). Determination of viral maturation was carried out by calculating prM to E protein expression ratios normalized to those of control siRNA-transfected A549 cells. Detected signals of DENV E and prM proteins were quantified using ImageJ software as described in . prM-to-E ratios are plotted as bar graphs. Number indicates n -fold increase compared to Ctrl siRNA-transfected cells (right).

    Journal: iScience

    Article Title: Ribonucleotide reductase subunit M2 mediates the mTOR pathway to recruit furin endoprotease and promote maturation of dengue virus

    doi: 10.1016/j.isci.2025.113998

    Figure Lengend Snippet: RRM2 knockdown reduced furin protein levels in the cells, decreasing cleavage of DENV prM protein (A) RT-qPCR analysis of RRM2 mRNA levels in HuH-7 cells either mock-infected or infected with DENV-1 or DENV-2 at an MOI of 0.1. RRM2 mRNA levels were normalized to GAPDH mRNA levels. Data are expressed as mean ± standard deviation (SD) of triplicate measurements. p values were assessed using Student’s t test. n.s., not significant. (B) DENV infection increased RRM2 protein levels. HuH-7 cells were mock-infected or infected with DENV-1 or DENV-2 at an MOI of 0.1. Cells were harvested at the indicated time points (24, 48, and 72 hpi) and analyzed by western blotting using anti-RRM2, anti-p53R2, and mouse monoclonal anti-flavivirus E (4G2) antibodies. Endogenous β-actin expression served as an internal control. Protein levels were quantified using ImageJ software and normalized to β-actin levels. Densitometric p53R2/actin and RRM2/actin ratios are shown below the blots. (C) Representative western blot images depict RRM2, DENV envelope (E), DENV capsid, and DENV prM protein expression levels in HuH-7 cells that were transfected with RRM2 siRNA or control (Ctrl) siRNA (5 nM). HuH-7 cells were either non-transfected or transfected with siRNAs one day prior to infection with DENV-1 or DENV-2 at an MOI of 0.1. At 72 hpi, cells were harvested and subjected to western blot analysis under non-reducing conditions using anti-prM, anti-capsid, anti-flavivirus E (4G2), and anti-RRM2 antibodies. β-actin was utilized as a loading control. (D) Determination of viral maturation was carried out by calculating the ratio of prM to E protein expression, normalized to non-transfected DENV-infected HuH-7 cells. Detected signals of DENV E and prM proteins in (C) were quantified using ImageJ software, and prM-to-E ratios are plotted as bar graphs. Numbers indicate n -fold increase compared to non-transfected cells. (E) Western blot analysis of prM and pr proteins in culture supernatants of non-transfected, control siRNA or RRM2 siRNA-transfected DENV-1 infected HuH-7 cells (C) under reducing conditions using an anti-pr mouse mAb. (F) Analysis of DENV E protein glycosylation status. Mock infected (−) or DENV (+) infected and siRNA-transfected HuH-7 cell lysates were treated with PNGaseF (+) or buffer control (−), then subjected to non-reducing SDS-PAGE and western blotting with anti-E 4G2, anti-RRM2, and anti-actin antibodies. Arrows indicate the positions of undigested and glycosylated E (2N) protein and deglycosylated forms (1N and 0N) of E protein. 0N, 1N, and 2N correspond to the number of N-linked glycans on E protein. β-actin was utilized as a loading control. (G) Quantification of endogenous furin mRNA levels relative to GAPDH in HuH-7 cells that were non-transfected or transfected with RRM2 siRNA or control siRNA (Ctrl si) (5 nM) for 96 h. Data are expressed as mean ± SD of triplicate measurements. (H) Effect of RRM2 knockdown on furin protein expression. HuH-7 cells were either non-transfected or transfected with control siRNA or RRM2 siRNA one day before mock infection or infection with DENV-1 or DENV-2 at an MOI of 0.1. At 72 hpi, cells were harvested and analyzed by western blotting using anti-furin, anti-RRM2, and anti-DENV-E proteins. β-actin served as a loading control. Protein band intensities were analyzed using ImageJ software. Densitometric furin/actin ratios are shown below the blots. (I) Furin protein levels in HuH-7 and A549 cells with or without transfection of furin expression plasmid (myc-DDK-tagged human furin, 4 μg) and those non-transfected or transfected with control or RRM2 siRNA (5 nM). Densitometric furin/actin ratios are shown below the blots. (J) A549 cells were seeded in 60 mm dishes, and after 24 h, cells were transfected with the furin expression plasmid (4 μg) alone or co-transfected with RRM2 or control siRNA. The following day, the cells were infected with DENV-2 at an MOI of 0.1. At 72 hpi, cells were harvested and subjected to western blot analysis under non-reducing conditions using anti-furin, anti-RRM2, anti-prM, anti-flavivirus E (4G2), and anti-actin antibodies. Densitometric prM/actin ratios are shown below the blots (left). Determination of viral maturation was carried out by calculating prM to E protein expression ratios normalized to those of control siRNA-transfected A549 cells. Detected signals of DENV E and prM proteins were quantified using ImageJ software as described in . prM-to-E ratios are plotted as bar graphs. Number indicates n -fold increase compared to Ctrl siRNA-transfected cells (right).

    Article Snippet: Mouse anti-flavivirus envelope protein monoclonal antibody (D1-4G2-4-15) , ATCC , CVCL_J890.

    Techniques: Knockdown, Quantitative RT-PCR, Infection, Standard Deviation, Western Blot, Expressing, Control, Software, Transfection, Glycoproteomics, SDS Page, Plasmid Preparation

    Effect of RRM2 knockdown on DENV RNA replication and infectious virus production (A) Schematic representation of the experimental protocol. Briefly, HuH-7, HepG2, and A549 cells were transfected with RRM2 siRNA or non-targeting control siRNA (Ctrl.si) one day before infection with DENV-1 and DENV-2 at a MOI of 0.1. Cells and culture supernatants were harvested 72 h later to measure intracellular and extracellular DENV RNA levels using RT-qPCR and quantify infectious virus titers in culture supernatants via a focus-forming assay. Created using Biorender.com. (B) SDS-PAGE and western blotting were utilized to assess the efficiency of RRM2 knockdown in HepG2, HuH-7, and A549 cells after treatment with specific RRM2 siRNA for 96 h at final concentrations of 10, 20, 5, and 5 nM, respectively. The expression levels of other RR subunits, RRM1 and p53R2, were also characterized. β-actin served as a loading control. (C–E) Intracellular and extracellular DENV RNA copy numbers were measured 72 h post-transfection (hpi) via RT-qPCR in HuH-7, HepG2, and A549 cells. Intracellular DENV RNA levels were normalized to GAPDH mRNA levels. Results are presented as mean+/-standard deviation (SD). p values were assessed using Student’s t test. (F–H) Infectious virus titers in culture supernatants from non-transfected and siRNA-transfected HuH-7, HepG2, and A549 cells were determined using a fluorescent focus assay on BHK-21 cells. Results are presented as mean +/- SD. p values were evaluated by Student’s t test. (I) Viability of HuH-7, HepG2, and A549 cells following treatment with RRM2 siRNA. Cells were seeded in 96-well plates and transfected with the indicated final concentrations of RRM2 siRNA. At 96 h post-transfection, cell viability was assessed using the 2(2-methyl-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2, 4disulfophenyl)-2H-tetrazolium, monosodium salt (WST)-8 assay (OD 450 ). The percentage of viability was calculated and compared to the untreated control (100% viability). (J) Immunofluorescence microscopy was conducted to evaluate the infection efficiency of DENV particles released from RRM2 or control siRNA-transfected and non-treated cells. Schematic representation of the experimental procedure. Culture supernatants harvested from non-transfected and siRNA-transfected DENV-infected HuH-7 and HepG2 cells were used to infect naive cell lines at an MOI of 1 (left). Three days post-infection, cell monolayers were analyzed by immunofluorescence for DENV envelope (E) protein expression using anti-flavivirus monoclonal antibody 4G2, followed by Alexa Fluor 488-conjugated goat anti-mouse IgG. Representative immunofluorescence images (400× magnification) depicting DENV-E protein expression in HuH-7 and HepG2 cells. Cell nuclei were stained with DAPI, and cells were observed under a BZ-X700 fluorescence microscope (Keyence Co., Osaka, Japan). White squares indicate enlarged insets. Scale bars, 50 μm (right).

    Journal: iScience

    Article Title: Ribonucleotide reductase subunit M2 mediates the mTOR pathway to recruit furin endoprotease and promote maturation of dengue virus

    doi: 10.1016/j.isci.2025.113998

    Figure Lengend Snippet: Effect of RRM2 knockdown on DENV RNA replication and infectious virus production (A) Schematic representation of the experimental protocol. Briefly, HuH-7, HepG2, and A549 cells were transfected with RRM2 siRNA or non-targeting control siRNA (Ctrl.si) one day before infection with DENV-1 and DENV-2 at a MOI of 0.1. Cells and culture supernatants were harvested 72 h later to measure intracellular and extracellular DENV RNA levels using RT-qPCR and quantify infectious virus titers in culture supernatants via a focus-forming assay. Created using Biorender.com. (B) SDS-PAGE and western blotting were utilized to assess the efficiency of RRM2 knockdown in HepG2, HuH-7, and A549 cells after treatment with specific RRM2 siRNA for 96 h at final concentrations of 10, 20, 5, and 5 nM, respectively. The expression levels of other RR subunits, RRM1 and p53R2, were also characterized. β-actin served as a loading control. (C–E) Intracellular and extracellular DENV RNA copy numbers were measured 72 h post-transfection (hpi) via RT-qPCR in HuH-7, HepG2, and A549 cells. Intracellular DENV RNA levels were normalized to GAPDH mRNA levels. Results are presented as mean+/-standard deviation (SD). p values were assessed using Student’s t test. (F–H) Infectious virus titers in culture supernatants from non-transfected and siRNA-transfected HuH-7, HepG2, and A549 cells were determined using a fluorescent focus assay on BHK-21 cells. Results are presented as mean +/- SD. p values were evaluated by Student’s t test. (I) Viability of HuH-7, HepG2, and A549 cells following treatment with RRM2 siRNA. Cells were seeded in 96-well plates and transfected with the indicated final concentrations of RRM2 siRNA. At 96 h post-transfection, cell viability was assessed using the 2(2-methyl-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2, 4disulfophenyl)-2H-tetrazolium, monosodium salt (WST)-8 assay (OD 450 ). The percentage of viability was calculated and compared to the untreated control (100% viability). (J) Immunofluorescence microscopy was conducted to evaluate the infection efficiency of DENV particles released from RRM2 or control siRNA-transfected and non-treated cells. Schematic representation of the experimental procedure. Culture supernatants harvested from non-transfected and siRNA-transfected DENV-infected HuH-7 and HepG2 cells were used to infect naive cell lines at an MOI of 1 (left). Three days post-infection, cell monolayers were analyzed by immunofluorescence for DENV envelope (E) protein expression using anti-flavivirus monoclonal antibody 4G2, followed by Alexa Fluor 488-conjugated goat anti-mouse IgG. Representative immunofluorescence images (400× magnification) depicting DENV-E protein expression in HuH-7 and HepG2 cells. Cell nuclei were stained with DAPI, and cells were observed under a BZ-X700 fluorescence microscope (Keyence Co., Osaka, Japan). White squares indicate enlarged insets. Scale bars, 50 μm (right).

    Article Snippet: Antibodies against the following proteins were used in the immunoblots: mouse anti-RRM2 clone 1E1 (cat# WH0006241M1; Sigma-Aldrich), rabbit anti-RRM2 (cat# GTX103193; GeneTex, Irvine, CA, USA), rabbit anti-furin (cat# PA1-062, Thermo Fisher Scientific), rabbit anti-RRM1 (cat# ab137114; Abcam, Cambridge, MA, USA), goat anti-p53R2 ( N -16, sc-10840, Santa Cruz Biotechnology, CA, USA), mouse anti-flavivirus envelope protein monoclonal antibody (clone 4G2; The Native Antigen Company, Oxford, UK), rabbit anti-dengue virus capsid protein (cat# GTX103343; GeneTex), rabbit anti-dengue virus prM protein (cat# GTX128093; GeneTex), mouse anti-dengue virus prM protein (clone CC5.A9.E10; The Native Antigen Company), mouse anti-dengue virus pr monoclonal antibody (cat# LDG0013YA; LEADGENE), mouse anti-dengue virus NS1 monoclonal antibody (cat# ab41490; Abcam), rabbit anti-mTOR (cat# GTX101557; GeneTex), rabbit anti-LC3I/II (cat# PM036; MBL International, Woburn, MA, USA), rabbit anti-4E-BP1 (cat# 9452; Cell Signaling Technology, Danvers, MA, USA), rabbit anti-phospho-4E-BP1 (Ser65) (cat# 9451; Cell Signaling Technology), rabbit anti-phospho-4E-BP1 (Thr70) (cat# 9455; Cell Signaling Technology), and mouse anti-actin antibody (cat# A2228; Sigma-Aldrich).

    Techniques: Knockdown, Virus, Transfection, Control, Infection, Quantitative RT-PCR, Focus Forming Assay, SDS Page, Western Blot, Expressing, Standard Deviation, Immunofluorescence, Microscopy, Staining, Fluorescence

    RRM2 knockdown reduced furin protein levels in the cells, decreasing cleavage of DENV prM protein (A) RT-qPCR analysis of RRM2 mRNA levels in HuH-7 cells either mock-infected or infected with DENV-1 or DENV-2 at an MOI of 0.1. RRM2 mRNA levels were normalized to GAPDH mRNA levels. Data are expressed as mean ± standard deviation (SD) of triplicate measurements. p values were assessed using Student’s t test. n.s., not significant. (B) DENV infection increased RRM2 protein levels. HuH-7 cells were mock-infected or infected with DENV-1 or DENV-2 at an MOI of 0.1. Cells were harvested at the indicated time points (24, 48, and 72 hpi) and analyzed by western blotting using anti-RRM2, anti-p53R2, and mouse monoclonal anti-flavivirus E (4G2) antibodies. Endogenous β-actin expression served as an internal control. Protein levels were quantified using ImageJ software and normalized to β-actin levels. Densitometric p53R2/actin and RRM2/actin ratios are shown below the blots. (C) Representative western blot images depict RRM2, DENV envelope (E), DENV capsid, and DENV prM protein expression levels in HuH-7 cells that were transfected with RRM2 siRNA or control (Ctrl) siRNA (5 nM). HuH-7 cells were either non-transfected or transfected with siRNAs one day prior to infection with DENV-1 or DENV-2 at an MOI of 0.1. At 72 hpi, cells were harvested and subjected to western blot analysis under non-reducing conditions using anti-prM, anti-capsid, anti-flavivirus E (4G2), and anti-RRM2 antibodies. β-actin was utilized as a loading control. (D) Determination of viral maturation was carried out by calculating the ratio of prM to E protein expression, normalized to non-transfected DENV-infected HuH-7 cells. Detected signals of DENV E and prM proteins in (C) were quantified using ImageJ software, and prM-to-E ratios are plotted as bar graphs. Numbers indicate n -fold increase compared to non-transfected cells. (E) Western blot analysis of prM and pr proteins in culture supernatants of non-transfected, control siRNA or RRM2 siRNA-transfected DENV-1 infected HuH-7 cells (C) under reducing conditions using an anti-pr mouse mAb. (F) Analysis of DENV E protein glycosylation status. Mock infected (−) or DENV (+) infected and siRNA-transfected HuH-7 cell lysates were treated with PNGaseF (+) or buffer control (−), then subjected to non-reducing SDS-PAGE and western blotting with anti-E 4G2, anti-RRM2, and anti-actin antibodies. Arrows indicate the positions of undigested and glycosylated E (2N) protein and deglycosylated forms (1N and 0N) of E protein. 0N, 1N, and 2N correspond to the number of N-linked glycans on E protein. β-actin was utilized as a loading control. (G) Quantification of endogenous furin mRNA levels relative to GAPDH in HuH-7 cells that were non-transfected or transfected with RRM2 siRNA or control siRNA (Ctrl si) (5 nM) for 96 h. Data are expressed as mean ± SD of triplicate measurements. (H) Effect of RRM2 knockdown on furin protein expression. HuH-7 cells were either non-transfected or transfected with control siRNA or RRM2 siRNA one day before mock infection or infection with DENV-1 or DENV-2 at an MOI of 0.1. At 72 hpi, cells were harvested and analyzed by western blotting using anti-furin, anti-RRM2, and anti-DENV-E proteins. β-actin served as a loading control. Protein band intensities were analyzed using ImageJ software. Densitometric furin/actin ratios are shown below the blots. (I) Furin protein levels in HuH-7 and A549 cells with or without transfection of furin expression plasmid (myc-DDK-tagged human furin, 4 μg) and those non-transfected or transfected with control or RRM2 siRNA (5 nM). Densitometric furin/actin ratios are shown below the blots. (J) A549 cells were seeded in 60 mm dishes, and after 24 h, cells were transfected with the furin expression plasmid (4 μg) alone or co-transfected with RRM2 or control siRNA. The following day, the cells were infected with DENV-2 at an MOI of 0.1. At 72 hpi, cells were harvested and subjected to western blot analysis under non-reducing conditions using anti-furin, anti-RRM2, anti-prM, anti-flavivirus E (4G2), and anti-actin antibodies. Densitometric prM/actin ratios are shown below the blots (left). Determination of viral maturation was carried out by calculating prM to E protein expression ratios normalized to those of control siRNA-transfected A549 cells. Detected signals of DENV E and prM proteins were quantified using ImageJ software as described in . prM-to-E ratios are plotted as bar graphs. Number indicates n -fold increase compared to Ctrl siRNA-transfected cells (right).

    Journal: iScience

    Article Title: Ribonucleotide reductase subunit M2 mediates the mTOR pathway to recruit furin endoprotease and promote maturation of dengue virus

    doi: 10.1016/j.isci.2025.113998

    Figure Lengend Snippet: RRM2 knockdown reduced furin protein levels in the cells, decreasing cleavage of DENV prM protein (A) RT-qPCR analysis of RRM2 mRNA levels in HuH-7 cells either mock-infected or infected with DENV-1 or DENV-2 at an MOI of 0.1. RRM2 mRNA levels were normalized to GAPDH mRNA levels. Data are expressed as mean ± standard deviation (SD) of triplicate measurements. p values were assessed using Student’s t test. n.s., not significant. (B) DENV infection increased RRM2 protein levels. HuH-7 cells were mock-infected or infected with DENV-1 or DENV-2 at an MOI of 0.1. Cells were harvested at the indicated time points (24, 48, and 72 hpi) and analyzed by western blotting using anti-RRM2, anti-p53R2, and mouse monoclonal anti-flavivirus E (4G2) antibodies. Endogenous β-actin expression served as an internal control. Protein levels were quantified using ImageJ software and normalized to β-actin levels. Densitometric p53R2/actin and RRM2/actin ratios are shown below the blots. (C) Representative western blot images depict RRM2, DENV envelope (E), DENV capsid, and DENV prM protein expression levels in HuH-7 cells that were transfected with RRM2 siRNA or control (Ctrl) siRNA (5 nM). HuH-7 cells were either non-transfected or transfected with siRNAs one day prior to infection with DENV-1 or DENV-2 at an MOI of 0.1. At 72 hpi, cells were harvested and subjected to western blot analysis under non-reducing conditions using anti-prM, anti-capsid, anti-flavivirus E (4G2), and anti-RRM2 antibodies. β-actin was utilized as a loading control. (D) Determination of viral maturation was carried out by calculating the ratio of prM to E protein expression, normalized to non-transfected DENV-infected HuH-7 cells. Detected signals of DENV E and prM proteins in (C) were quantified using ImageJ software, and prM-to-E ratios are plotted as bar graphs. Numbers indicate n -fold increase compared to non-transfected cells. (E) Western blot analysis of prM and pr proteins in culture supernatants of non-transfected, control siRNA or RRM2 siRNA-transfected DENV-1 infected HuH-7 cells (C) under reducing conditions using an anti-pr mouse mAb. (F) Analysis of DENV E protein glycosylation status. Mock infected (−) or DENV (+) infected and siRNA-transfected HuH-7 cell lysates were treated with PNGaseF (+) or buffer control (−), then subjected to non-reducing SDS-PAGE and western blotting with anti-E 4G2, anti-RRM2, and anti-actin antibodies. Arrows indicate the positions of undigested and glycosylated E (2N) protein and deglycosylated forms (1N and 0N) of E protein. 0N, 1N, and 2N correspond to the number of N-linked glycans on E protein. β-actin was utilized as a loading control. (G) Quantification of endogenous furin mRNA levels relative to GAPDH in HuH-7 cells that were non-transfected or transfected with RRM2 siRNA or control siRNA (Ctrl si) (5 nM) for 96 h. Data are expressed as mean ± SD of triplicate measurements. (H) Effect of RRM2 knockdown on furin protein expression. HuH-7 cells were either non-transfected or transfected with control siRNA or RRM2 siRNA one day before mock infection or infection with DENV-1 or DENV-2 at an MOI of 0.1. At 72 hpi, cells were harvested and analyzed by western blotting using anti-furin, anti-RRM2, and anti-DENV-E proteins. β-actin served as a loading control. Protein band intensities were analyzed using ImageJ software. Densitometric furin/actin ratios are shown below the blots. (I) Furin protein levels in HuH-7 and A549 cells with or without transfection of furin expression plasmid (myc-DDK-tagged human furin, 4 μg) and those non-transfected or transfected with control or RRM2 siRNA (5 nM). Densitometric furin/actin ratios are shown below the blots. (J) A549 cells were seeded in 60 mm dishes, and after 24 h, cells were transfected with the furin expression plasmid (4 μg) alone or co-transfected with RRM2 or control siRNA. The following day, the cells were infected with DENV-2 at an MOI of 0.1. At 72 hpi, cells were harvested and subjected to western blot analysis under non-reducing conditions using anti-furin, anti-RRM2, anti-prM, anti-flavivirus E (4G2), and anti-actin antibodies. Densitometric prM/actin ratios are shown below the blots (left). Determination of viral maturation was carried out by calculating prM to E protein expression ratios normalized to those of control siRNA-transfected A549 cells. Detected signals of DENV E and prM proteins were quantified using ImageJ software as described in . prM-to-E ratios are plotted as bar graphs. Number indicates n -fold increase compared to Ctrl siRNA-transfected cells (right).

    Article Snippet: Antibodies against the following proteins were used in the immunoblots: mouse anti-RRM2 clone 1E1 (cat# WH0006241M1; Sigma-Aldrich), rabbit anti-RRM2 (cat# GTX103193; GeneTex, Irvine, CA, USA), rabbit anti-furin (cat# PA1-062, Thermo Fisher Scientific), rabbit anti-RRM1 (cat# ab137114; Abcam, Cambridge, MA, USA), goat anti-p53R2 ( N -16, sc-10840, Santa Cruz Biotechnology, CA, USA), mouse anti-flavivirus envelope protein monoclonal antibody (clone 4G2; The Native Antigen Company, Oxford, UK), rabbit anti-dengue virus capsid protein (cat# GTX103343; GeneTex), rabbit anti-dengue virus prM protein (cat# GTX128093; GeneTex), mouse anti-dengue virus prM protein (clone CC5.A9.E10; The Native Antigen Company), mouse anti-dengue virus pr monoclonal antibody (cat# LDG0013YA; LEADGENE), mouse anti-dengue virus NS1 monoclonal antibody (cat# ab41490; Abcam), rabbit anti-mTOR (cat# GTX101557; GeneTex), rabbit anti-LC3I/II (cat# PM036; MBL International, Woburn, MA, USA), rabbit anti-4E-BP1 (cat# 9452; Cell Signaling Technology, Danvers, MA, USA), rabbit anti-phospho-4E-BP1 (Ser65) (cat# 9451; Cell Signaling Technology), rabbit anti-phospho-4E-BP1 (Thr70) (cat# 9455; Cell Signaling Technology), and mouse anti-actin antibody (cat# A2228; Sigma-Aldrich).

    Techniques: Knockdown, Quantitative RT-PCR, Infection, Standard Deviation, Western Blot, Expressing, Control, Software, Transfection, Glycoproteomics, SDS Page, Plasmid Preparation

    Non-human VeroE6 cells were infected with MR766 MC or the chimeric MR766 MC virus with NS1 ZIKV-15555 (MR766 MC chimera) at an m.o.i. of 0.1. In ( A ), virus progeny production (PFU.mL -1 ) was determined by plaque-forming assay. In ( B ), intracellular viral RNA production was determined by RT-qPCR at 48 h p.i. I n ( C ), the percentage of ZIKV-infected cells based on FACS analysis using anti-E mAb 4G2. In ( D ), LDH activity were measured at 48h p.i and expressed as a percentage relative to mock-infected cells (control). Asterisks indicate that the differences between experimental samples are statistically significant, using an unpaired t test (**** p < 0.0001, ** p < 0.01, * p < 0.05).

    Journal: PLOS Neglected Tropical Diseases

    Article Title: The NS1 protein of contemporary West African Zika virus potentiates viral replication and reduces innate immune activation

    doi: 10.1371/journal.pntd.0012146

    Figure Lengend Snippet: Non-human VeroE6 cells were infected with MR766 MC or the chimeric MR766 MC virus with NS1 ZIKV-15555 (MR766 MC chimera) at an m.o.i. of 0.1. In ( A ), virus progeny production (PFU.mL -1 ) was determined by plaque-forming assay. In ( B ), intracellular viral RNA production was determined by RT-qPCR at 48 h p.i. I n ( C ), the percentage of ZIKV-infected cells based on FACS analysis using anti-E mAb 4G2. In ( D ), LDH activity were measured at 48h p.i and expressed as a percentage relative to mock-infected cells (control). Asterisks indicate that the differences between experimental samples are statistically significant, using an unpaired t test (**** p < 0.0001, ** p < 0.01, * p < 0.05).

    Article Snippet: The purified mouse anti- pan flavivirus envelope E protein monoclonal antibody (mAb) 4G2 was provided by RD Biotech (Besançon, France).

    Techniques: Infection, Virus, Quantitative RT-PCR, Activity Assay, Control

    Human A549 cells were infected with MR766 MC or chimeric MR766 MC virus with NS1 CWA protein (MR766 MC chimera) at an m.o.i. of 1. In ( A ), virus progeny production (PFU.mL -1 ) was examined using a conventional plaque-forming assay. In ( B ), intracellular viral RNA production was determined by RT-qPCR at 48 h p.i. In ( C ), the percentage of ZIKV-infected cells based on FACS analysis using anti-E mAb 4G2. In ( D ), LDH activity was measured at 48h p.i and expressed as a percentage relative to mock-infected cells (control). Asterisks indicate that the differences between experimental samples are statistically significant, using an unpaired t test (*** p < 0.001, ** p < 0.01, * p < 0.05).

    Journal: PLOS Neglected Tropical Diseases

    Article Title: The NS1 protein of contemporary West African Zika virus potentiates viral replication and reduces innate immune activation

    doi: 10.1371/journal.pntd.0012146

    Figure Lengend Snippet: Human A549 cells were infected with MR766 MC or chimeric MR766 MC virus with NS1 CWA protein (MR766 MC chimera) at an m.o.i. of 1. In ( A ), virus progeny production (PFU.mL -1 ) was examined using a conventional plaque-forming assay. In ( B ), intracellular viral RNA production was determined by RT-qPCR at 48 h p.i. In ( C ), the percentage of ZIKV-infected cells based on FACS analysis using anti-E mAb 4G2. In ( D ), LDH activity was measured at 48h p.i and expressed as a percentage relative to mock-infected cells (control). Asterisks indicate that the differences between experimental samples are statistically significant, using an unpaired t test (*** p < 0.001, ** p < 0.01, * p < 0.05).

    Article Snippet: The purified mouse anti- pan flavivirus envelope E protein monoclonal antibody (mAb) 4G2 was provided by RD Biotech (Besançon, France).

    Techniques: Infection, Virus, Quantitative RT-PCR, Activity Assay, Control

    A549 cells were infected with MR766 MC or chimeric MR766 MC virus with NS1 CWA protein (MR766 MC chimera) or mock-infected (no virus) for 24 h or 48 h at an m.o.i. of 1. In ( A ), visualization of intracellular rNS1 protein. Cells infected for 24h were stained with anti-E mAb 4G2 or anti-NS1 mAb 4G4 as primary antibody (green) for confocal immunofluorescence analysis. Nuclei were stained with DAPI (blue). The same magnification was used throughout. Scale bar, 25 μM. In ( B ), cell supernatant samples from three independent infections (exp. 1 to exp. 3) were analyzed in duplicates (A, B) by dot-blotting using mAb 4G4. The mean of signal intensity of each duplicate was determined using Image J software to estimate the relative amounts of secreted soluble NS1 protein. Results are the mean (± SEM) of three independent assays. Asterisks indicate that the differences between experimental samples are statistically significant, using an unpaired t test (** p < 0.01).

    Journal: PLOS Neglected Tropical Diseases

    Article Title: The NS1 protein of contemporary West African Zika virus potentiates viral replication and reduces innate immune activation

    doi: 10.1371/journal.pntd.0012146

    Figure Lengend Snippet: A549 cells were infected with MR766 MC or chimeric MR766 MC virus with NS1 CWA protein (MR766 MC chimera) or mock-infected (no virus) for 24 h or 48 h at an m.o.i. of 1. In ( A ), visualization of intracellular rNS1 protein. Cells infected for 24h were stained with anti-E mAb 4G2 or anti-NS1 mAb 4G4 as primary antibody (green) for confocal immunofluorescence analysis. Nuclei were stained with DAPI (blue). The same magnification was used throughout. Scale bar, 25 μM. In ( B ), cell supernatant samples from three independent infections (exp. 1 to exp. 3) were analyzed in duplicates (A, B) by dot-blotting using mAb 4G4. The mean of signal intensity of each duplicate was determined using Image J software to estimate the relative amounts of secreted soluble NS1 protein. Results are the mean (± SEM) of three independent assays. Asterisks indicate that the differences between experimental samples are statistically significant, using an unpaired t test (** p < 0.01).

    Article Snippet: The purified mouse anti- pan flavivirus envelope E protein monoclonal antibody (mAb) 4G2 was provided by RD Biotech (Besançon, France).

    Techniques: Infection, Virus, Staining, Immunofluorescence, Software

    A549 cells were infected with MR766 MC or the chimeric MR766 MC with NS1 ZIKV-15555 (MR766 MC chimera) at an m.o.i. of 1. In ( A ), the relative abundance of IFN-β and ISG mRNA was determined at 48 h p.i. by RT-qPCR. Housekeeping gene RPLPO36B4 mRNA served as an internal reference. The results are the mean (± S.D.) of three replicates. Asterisks indicate that the differences between MR766 MC and MR766 MC chimera for each cellular factor are statistically significant, using an unpaired t test (**** p < 0.0001, *** p < 0.001, ** p < 0.01, * p < 0.05). In ( B ), Immunoblot assay was performed on cell lysates using anti-ISG15 or anti-IFIT1 antibodies as indicated. Anti-E mAb 4G2 was used to detect ZIKV E protein. β-actin was detected as protein-loading control for lysate samples.

    Journal: PLOS Neglected Tropical Diseases

    Article Title: The NS1 protein of contemporary West African Zika virus potentiates viral replication and reduces innate immune activation

    doi: 10.1371/journal.pntd.0012146

    Figure Lengend Snippet: A549 cells were infected with MR766 MC or the chimeric MR766 MC with NS1 ZIKV-15555 (MR766 MC chimera) at an m.o.i. of 1. In ( A ), the relative abundance of IFN-β and ISG mRNA was determined at 48 h p.i. by RT-qPCR. Housekeeping gene RPLPO36B4 mRNA served as an internal reference. The results are the mean (± S.D.) of three replicates. Asterisks indicate that the differences between MR766 MC and MR766 MC chimera for each cellular factor are statistically significant, using an unpaired t test (**** p < 0.0001, *** p < 0.001, ** p < 0.01, * p < 0.05). In ( B ), Immunoblot assay was performed on cell lysates using anti-ISG15 or anti-IFIT1 antibodies as indicated. Anti-E mAb 4G2 was used to detect ZIKV E protein. β-actin was detected as protein-loading control for lysate samples.

    Article Snippet: The purified mouse anti- pan flavivirus envelope E protein monoclonal antibody (mAb) 4G2 was provided by RD Biotech (Besançon, France).

    Techniques: Infection, Quantitative RT-PCR, Western Blot, Control