retro tek htlv p19 antigen elisa kit  (ZeptoMetrix corporation)

Journal: Retrovirology

Article Title: Intra- pol proviral open region of HTLV-1 controls the transcription from both long terminal repeats

doi: 10.1186/s12977-025-00671-4

Figure Lengend Snippet: Repressive effect of IPOR on viral production and transcription from the integrated provirus. A Diagram illustrating the experimental workflow for quantitative determination of HTLV-1 p19 and measurement of tax expression using HTLV-1-WT or Mut molecular clones. B Production of viral-protein p19 measured with ELISA method. C Relative mRNA expression of tax in HTLV-1-WT- or Mut- infected JET cells. ΔΔCt correcting values ( tax /18S rRNA) by RT-qPCR were adjusted to PVL. At least two independent experiments were performed. Technical triplicate data is presented as mean ± SD. p values were calculated by Welch’s t test

Article Snippet: After 48 h, p19 levels in the virus-containing supernatants were quantified using the RETRO-TEK HTLV p19 Antigen ELISA Kit (ZeptoMetrix).

Techniques: Expressing, Clone Assay, Enzyme-linked Immunosorbent Assay, Infection, Quantitative RT-PCR

Journal: Nature Communications

Article Title: The Human T-cell Leukemia Virus capsid protein is a potential drug target

doi: 10.1038/s41467-025-65899-2

Figure Lengend Snippet: a Graph comparing the infectivity of WT-A and WT-C packaging constructs as measured by GFP reporter expression in a replication dependent infection system. Results are displayed from 8 independent experiments. Statistical analysis was performed using an unpaired two-tailed t-test. Bar graph displaying infectivity of HIV-1 ( b ) and HTLV-1c ( c ) as measured by GFP reporter expression in a replication dependent infection system in the presence of increasing amounts of lenacapavir. Results are displayed as the mean +/− SD from 4 independent experiments. Statistical analysis was performed using an unpaired two-tailed t-test. d Bar graph displaying relative infectivity (grey bars) and p19 production (white bars) of 21 HTLV-1c CA mutants, compared to the WT construct, which is set at 100%. Results are displayed as the mean +/- SD from 3 independent experiments. Shaded areas contain residues in the CA intra-hexamer interface (pale green, e ), CA NTD trimeric interface (pale purple, f ), SO 4/ PO 4 binding pocket (pale orange, g ) and CA CTD trimer of dimers interface (pale blue, h ). i HTLV-1c CA mutants, shown in ( d ), mapped onto the structure of the monomeric full-length CA protein, with mutated residues coloured according to infection and virus production phenotypes. Representative gating strategy for the FACS data is provided in Supplementary Fig. . Source data are provided as a Source Data file.

Article Snippet: Virus production was measured using a p19 antigen ELISA kit (Zeptometrix) according to the manufacturer’s instructions.

Techniques: Infection, Construct, Expressing, Two Tailed Test, Binding Assay, Virus

Journal: Journal of Virology

Article Title: Establishment of a novel human T-cell leukemia virus type 1 infection model using cell-free virus

doi: 10.1128/jvi.01862-23

Figure Lengend Snippet: Establishment of HTLV-1 cell-free infection model ( A ) Determination of the optimal amount of pX1 MT-M, an infectious molecular clone of HTLV-1, for in vitro viral production. Approximately 0.5 × 10 6 Lenti-X 293T cells were transfected with 0.125–3.0 µg of pX1 MT-M for 48 hours. HTLV-1-containing culture supernatants of transfected cells were harvested and quantified by HTLV-1 p19 ELISA. ( B ) Morphological evaluation of the obtained virions by transmission electron microscopy (TEM). HTLV-1 particles were negatively stained with 2% uranyl acetate. Scale bar = 300 nm. Similar images of HTLV-1 particles were obtained in two independent experiments. ( C ) Particle size distribution shown by the maximum diameters of spherical or oval virions obtained in TEM analysis. Diameters of 93 particles were measured by the ImageJ software, and the number of particles in each 20 nm range is shown. ( D and E ) Proviral load (PVL) of infected adherent and suspended cells using the cell-free infection model. The PVLs were analyzed at 48 hours post-infection (hpi) for the adherent cells shown in panel D and at 24, 48, and 72 hpi for the suspended cells shown in panel E. ( F ) The PVL of four suspended cell lines depending on the amount of virion. Virus levels were quantified by HTLV-1 p19 ELISA. The PVLs were analyzed at 48 hpi. ( G ) HTLV-1 Env-dependent infection was assessed by neutralizing assay. MOLT4 cells were infected using the cell-free infection model in the presence or absence of HTLV-1 envelope-specific neutralizing antibody (LAT-27, 10 or 20 µg/mL). The PVLs were analyzed at 48 hpi. In panels E and G, asterisks represent significant differences versus the data for MOLT4 and LAT-27(–), respectively (** P < 0.01 by one-way analysis of variance (ANOVA) followed by Dunnett's multiple comparison test). In panels D–G, the data are the means ± SD of three independent experiments.

Article Snippet: The amount of HTLV-1 p19 antigen in culture supernatant was quantified using the HTLV-1 p19 Antigen ELISA Kit (ZeptoMetrix, Buffalo, NY) according to the manufacturer's instructions with the following three modifications.

Techniques: Infection, In Vitro, Transfection, Enzyme-linked Immunosorbent Assay, Transmission Assay, Electron Microscopy, Staining, Software, Virus, Neutralizing Assay, Comparison

Journal: Journal of Virology

Article Title: Establishment of a novel human T-cell leukemia virus type 1 infection model using cell-free virus

doi: 10.1128/jvi.01862-23

Figure Lengend Snippet: HTLV-1-associated viral biofilms contribute to the infectivity of cell-free infection model ( A and B ) Effect of filtration on virus levels and infectivity in the culture supernatant. After filtration with two pore sizes (0.45 and 0.20 µm), virus levels were quantified by HTLV-1 p19 ELISA and shown in panel A. MOLT4 cells were infected with unfiltered or filtered culture supernatants with the equivalent of 20 ng of HTLV-1 p19. The PVLs were analyzed at 48 hpi and shown in panel B. ( C and D ) Morphological evaluation of the virus assemblies by TEM. Unfiltered culture supernatants and filtered culture supernatants with a pore size of 0.20 µm were negatively stained with 2% uranyl acetate. Representative lower and higher magnification images of two independent experiments are shown in panels C and D, respectively. Black arrowheads show mature virus particles with electron-dense cores in panel D. Scale bars in panels C and one side of the square in panel D represent 500 nm. ( E ) Effect of filtration on the total collagen levels. After filtration with two pore sizes (0.45 and 0.20 µm), the amount of total collagen in the culture supernatant was quantified. ( F ) Kinetics analysis of the HTLV-1 p19 antigen levels and the amount of total collagen in culture supernatants. Approximately 3.5 × 10 6 Lenti-X 293T cells were transfected with 20 µg of pX1 MT-M. Culture supernatants were harvested every 24 hours until 96 hours post-transfection. The HTLV-1 p19 antigen levels and the amount of total collagen were quantified and data are shown on the left and right y-axes, respectively. ( G ) Effect of collagenase treatment on infectivity in the culture supernatant. Unfiltered culture supernatants and filtered culture supernatants with a pore size of 0.20 µm were incubated at 37°C for 1 hour with or without recombinant collagenase (100 U/mL). After incubation, MOLT4 cells were infected with these culture supernatants with the equivalent of 20 ng of HTLV-1 p19. The PVLs were analyzed at 48 hpi. Asterisks in panels A, B, and E represent significant differences versus the data for unfiltered culture supernatant (** P < 0.01 by one-way ANOVA followed by Dunnett’s multiple comparison test). In panel G, significant differences were calculated with one-way ANOVA followed by Tukey’s multiple comparison test (* P < 0.05; ** P < 0.01; and NS, not significant). In panels A, B, E, F, and G, the data are the means ± SD of three independent experiments.

Article Snippet: The amount of HTLV-1 p19 antigen in culture supernatant was quantified using the HTLV-1 p19 Antigen ELISA Kit (ZeptoMetrix, Buffalo, NY) according to the manufacturer's instructions with the following three modifications.

Techniques: Infection, Filtration, Virus, Enzyme-linked Immunosorbent Assay, Pore Size, Staining, Transfection, Incubation, Recombinant, Comparison

Journal: Journal of Virology

Article Title: Establishment of a novel human T-cell leukemia virus type 1 infection model using cell-free virus

doi: 10.1128/jvi.01862-23

Figure Lengend Snippet: Cell-free HTLV-1 virions can induce de novo infection in vivo ( A ) Schematic of the experimental schedule. All NOJ mice were reconstituted with a human immune system by the intrahepatic transplantation of human CD133 + hematopoietic stem cells into newborn mice. After humanization, 12 mice were divided into three groups and inoculated intraperitoneally with HTLV-1-containing culture supernatants or Dulbecco’s Modified Eagle Medium as a control (p19 50 ng/mouse group, n = 4; p19 10 ng/mouse group, n = 4; control group, n = 4). Black arrowheads indicate the timepoints of blood collection. ( B ) Quantification of HTLV-1 PVL in the peripheral blood of inoculated mice. HTLV-1 PVL was determined by real-time PCR at 0-, 21-, 35-, 49-, 70-, and 91-day post-infection. One dot represents the result of an individual mouse. ( C ) Human CD45 + leucocytes, CD3 + lymphocytes, total CD4 + T cells, and CD25 + T cells were routinely analyzed by flow cytometry. One dot represents the result of an individual mouse. The absolute numbers of human CD45 + , CD3 + , CD4 + , and CD25 + leucocytes are shown in panel C. CD3 + lymphocytes were gated to analyze the populations of CD4 + and CD25 + T cells. Asterisks in panel B represent significant differences between groups given p19 50 ng and p19 10 ng per mouse (* P < 0.05 by Mann–Whitney U -test). Asterisks represent significant differences among three groups in panel C (** P < 0.01 by Kruskal–Wallis test followed by Dunn’s multiple-comparisons test).

Article Snippet: The amount of HTLV-1 p19 antigen in culture supernatant was quantified using the HTLV-1 p19 Antigen ELISA Kit (ZeptoMetrix, Buffalo, NY) according to the manufacturer's instructions with the following three modifications.

Techniques: Infection, In Vivo, Transplantation Assay, Modification, Control, Real-time Polymerase Chain Reaction, Flow Cytometry, MANN-WHITNEY