Journal: Journal of molecular medicine (Berlin, Germany)

Article Title: Host and Pathogen Hyaluronan Signal Through Human Siglec-9 to Suppress Neutrophil Activation

doi: 10.1007/s00109-015-1341-8

Figure Lengend Snippet: Specific recognition of hyaluronan by the Ig-like-V-set domain of hSiglec-9. (a) Immobilized high molecular weight-hyaluronan (HMW-HA) was probed with human Siglec–Fc and CD44–Fc chimeras and binding evaluated by using an anti-human IgG-HRP. (b) Binding of hSiglec-9–Fc to immobilized HMW-HA was performed in the presence of increasing concentrations of HMW-HA, heparan sulfate, chondroitin sulfate or heparin. (c, d) To map the hSiglec-9 domain responsible for HA recognition, binding of hSiglec-9–Fc to immobilized HMW-HA was compared to binding of hSiglec-9–Fc with an Arg→Ala mutation in the V-set domain (hSiglec-9R120K), a fusion protein construct of the hSiglec-9 V-set domain + the second Ig-like domain (C2-set) of hSiglec-7 + human IgG Fc tail (hSiglec-9V-7C2–Fc), a fusion protein construct encompassing V-set domain of hSiglec-7 + C2-set of hSiglec-9 + human IgG Fc tail (Siglec-7V-9C2–Fc), a fusion protein construct of the hSiglec-9 V-set domain + first C2-set domain + human IgG Fc tail (Siglec-9–Fc 2D). Results are expressed as the mean ± SD. All experiments were performed in triplicate, repeated 3 times (a, d) or 2 times (b). One-way ANOVA with Dunnett’s multiple comparison test; P < 0.001 (***).

Article Snippet: Siglec-Fc proteins were purified from culture supernatant by adsorption to protein A-Sepharose (GE Healthcare); human CD44–Fc chimera was purchased from R&D Systems. hSiglecs-Fc and CD44–Fc were treated with 25 mU and 5 mU of Arthrobacter ureafaciens sialidase (AUS) for 60 min to remove Sias, prior to elution from the protein A-Sepharose.

Techniques: Molecular Weight, Binding Assay, Mutagenesis, Construct, Comparison

Journal: Journal of molecular medicine (Berlin, Germany)

Article Title: Host and Pathogen Hyaluronan Signal Through Human Siglec-9 to Suppress Neutrophil Activation

doi: 10.1007/s00109-015-1341-8

Figure Lengend Snippet: High molecular weight hyaluronan (HMW-HA) is recognized by hSiglec-9 on human neutrophils. (a) To evaluate the molecular size of hyaluronan (HA) responsible for binding to hSiglec-9, high molecular weigh HA (HMW-HA; >1,000 kDa), low molecular weigh (200 – 300 kDa-HA and 25 – 75 kDa-HA), nano-HA (nonamers) and oligo-HA (hexamers) fragments were added to compete with binding of hSiglec-9–Fc to immobilized HMW-HA plates. Binding was evaluated using an anti-human IgG-HRP. Experiment performed in triplicate and repeated 3 times; results are expressed as mean ± SD. (b) Flow cytometry reveals constitutive expression of Siglec-9 and CD44 on human neutrophils from 9 different donors; geometric mean ± 95% confidence interval. (c) Binding of FITC-labeled HMW-HA to neutrophils of these donors was evaluated by flow cytometry; geometric mean ± 95% confidence interval. (d) Human neutrophils were pretreated with anti-Siglec-9 monoclonal antibodies, anti-human CDw329 (BD Pharmingen, #550906) and anti-human Siglec-9 (R&D Systems, #BAF1139) and effects on binding to FITC-labeled HMW-HA determined. CDw329 Ab blocked binding of HMW-HA, but not GBS capsule (Fig. 5b) and was designated “α-Sig-9(HA)”; in contrast, the R&D Systems Ab blocked recognition of GBS capsule (Fig. 5b), but did not interfere with binding to HMW-HA, and was thus designated “α-Sig-9(Sia)”. Data pooled from five independent experiments in triplicate; data represent the mean ± SD. (e, f) Calcein-labeled human neutrophils were pretreated with α-Sig-9(HA), α-Sig-9(Sia) and α-CD44 mAbs, added to wells coated with immobilized HMW-HA to facilitate adherence, then unbound neutrophils washed away. Remaining neutrophils were lifted and enumerated. Experiment performed in triplicate and repeated 5 times; results are expressed as mean ± SD. One-way ANOVA with Dunnett’s multiple comparison test; P < 0.001 (***).

Article Snippet: Siglec-Fc proteins were purified from culture supernatant by adsorption to protein A-Sepharose (GE Healthcare); human CD44–Fc chimera was purchased from R&D Systems. hSiglecs-Fc and CD44–Fc were treated with 25 mU and 5 mU of Arthrobacter ureafaciens sialidase (AUS) for 60 min to remove Sias, prior to elution from the protein A-Sepharose.

Techniques: Molecular Weight, Binding Assay, Flow Cytometry, Expressing, Labeling, Comparison

Journal: Journal of molecular medicine (Berlin, Germany)

Article Title: Host and Pathogen Hyaluronan Signal Through Human Siglec-9 to Suppress Neutrophil Activation

doi: 10.1007/s00109-015-1341-8

Figure Lengend Snippet: Group A Streptococcus (GAS) engages hSiglec-9 via its surface hyaluronan capsule. (a) Human Siglec-9–Fc was immobilized to ELISA wells using protein A, and binding of FITC-labeled forms of WT GAS, its isogenic HA capsule-deficient mutant (ΔhasA), an animal-passaged hyperencapsulated (AP) derivative and its isogenic HA capsule-deficient mutant (AP ΔhasA) were evaluated; results are expressed as mean ± SD and repeated 5 times in triplicate with similar results; representative experiment shown. One-Way ANOVA with Dunnett’s multiple comparison test; P < 0.001 (***) (b) Human Siglec-9–Fc chimera was immobilized to ELISA wells via protein A in the presence of α-Sig-9(HA), α-Sig-9(Sia) or isotype control Abs and binding of FITC-labeled WT GAS or sialic acid-expressing serotype III group B Streptococcus (GBS) evaluated. (c) Human Siglec-9/9R120K/5/6/7/11 and human CD44-Fc chimera were immobilized to ELISA wells via protein A. Binding of FITC-labeled WT GAS was evaluated. Results represent mean ± SD; triplicate wells, representative experiment depicted of 5 independent repeats with similar results, performed in triplicate. (d) hSiglec-9–Fc was immobilized to ELISA plates using protein A, then wells were pretreated with HMW-HA, HMW-heparan sulfate or heparin over the indicated range of concentrations. Binding of FITC-labeled WT GAS was evaluated.

Article Snippet: Siglec-Fc proteins were purified from culture supernatant by adsorption to protein A-Sepharose (GE Healthcare); human CD44–Fc chimera was purchased from R&D Systems. hSiglecs-Fc and CD44–Fc were treated with 25 mU and 5 mU of Arthrobacter ureafaciens sialidase (AUS) for 60 min to remove Sias, prior to elution from the protein A-Sepharose.

Techniques: Enzyme-linked Immunosorbent Assay, Binding Assay, Labeling, Mutagenesis, Comparison, Expressing

Journal: Journal of molecular medicine (Berlin, Germany)

Article Title: Host and Pathogen Hyaluronan Signal Through Human Siglec-9 to Suppress Neutrophil Activation

doi: 10.1007/s00109-015-1341-8

Figure Lengend Snippet: HMW-HA binding to hSiglec-9 induces SHP-1 recruitment and blunts neutrophil NET production and oxidative burst. (a) 1.2 × 107 human neutrophils were incubated for 30 min + 10 µg/ml of high molecular weight hyaluronan (HMW-HA) + 25 nM PMA. Cell lysates were immunoprecipitated with α-Siglec9 and SHP-1 recruitment was visualized by western blot analysis; results were repeated 2 times with similar results; representative experiment with relative densitometry values is shown. (b) Neutrophils were pretreated with α-Sig-9(HA), α-Sig-9(Sia) or α-CD44 Abs, incubated with 10 µg/ml of HMW-HA and activated for 30 min with PMA. Reactive oxygen species (ROS) release was measured with the OxyBURST Green H2HFF BSA probe and results expressed as mean fluorescence intensity (MFI) ± SD; experiment repeated 5 times with similar results; representative experiment is shown. (c) Neutrophils were pretreated α-Sig-9(HA), α-Sig-9(Sia), or α-CD44 mAbs, then incubated with 10 µg/ml of HMW-HA and activated with PMA for 3 h; production of neutrophil extracellular traps (NETs) visualized by staining for DAPI (DNA, blue) + anti-myeloperoxidase/AlexaFluor488 (green); representative fields at 20x magnification is shown; experiment performed in triplicate and repeated 5 times. (d) NET production was quantified by Quant-iT™ PicoGreen® assay for extracellular DNA; results are expressed as mean ± SD; experiment repeated 3 times in triplicate with similar results; representative experiment shown. One-way ANOVA with Dunnett’s multiple comparison test; P < 0.001 (***).

Article Snippet: Siglec-Fc proteins were purified from culture supernatant by adsorption to protein A-Sepharose (GE Healthcare); human CD44–Fc chimera was purchased from R&D Systems. hSiglecs-Fc and CD44–Fc were treated with 25 mU and 5 mU of Arthrobacter ureafaciens sialidase (AUS) for 60 min to remove Sias, prior to elution from the protein A-Sepharose.

Techniques: Binding Assay, Incubation, Molecular Weight, Immunoprecipitation, Western Blot, Fluorescence, Staining, Picogreen Assay, Comparison

Journal: Journal of molecular medicine (Berlin, Germany)

Article Title: Host and Pathogen Hyaluronan Signal Through Human Siglec-9 to Suppress Neutrophil Activation

doi: 10.1007/s00109-015-1341-8

Figure Lengend Snippet: Group A Streptococcus (GAS) binding to hSiglec-9 via its surface HMW-HA capsule blunts neutrophil oxidative burst, NET responses and bactericidal activity. (a, b) Neutrophils were labeled with OxyBURST Green H2HFF BSA in the presence of α-Sig-9(HA), α-Sig-9(Sia) or α-CD44 mAbs, infected with WT or isogenic ΔhasA GAS at MOI = 20 for 30 min and oxidative burst measured by FACS; results are expressed as MFI ±SD and repeated twice with similar results; representative experiment is shown. (c) PMA-stimulated neutrophils (5 × 105 cells) were pretreated with α-Sig-9(HA), α-Sig-9(Sia), or α-CD44 mAbs and exposed for 3 h to MOI = 10 of GAS (DNase mutant) that had been pretreated or not with hyaluronidase to remove HA capsule and NET production visualized by staining for DAPI (DNA, blue) + anti-myeloperoxidase/AlexaFluor488 (green); results are repeated 5 times in triplicate, representative fields at 32 × magnification is shown. (d) NET production was quantified by Quant-iT™ PicoGreen® assay for extracellular DNA; results are expressed as mean ± SD and repeated 2 times with similar results; representative experiment shown. (e) Neutrophils were pretreated with α-Sig-9(HA), α-Sig-9(Sia) or α-CD44 mAbs, infected with WT or isogenic ΔhasA GAS at multiplicity of infection (MOI) = 10 for 30 min, then cells lysed and dilutions plated on agar for enumeration of colony forming units to evaluate neutrophil killing of GAS. Data represent the mean + SD of triplicates; repeated 4 times with similar results; representative experiment shown. One-Way ANOVA with Dunnett’s multiple comparison test; P < 0.001 (***) or P < 0.05 (*).

Article Snippet: Siglec-Fc proteins were purified from culture supernatant by adsorption to protein A-Sepharose (GE Healthcare); human CD44–Fc chimera was purchased from R&D Systems. hSiglecs-Fc and CD44–Fc were treated with 25 mU and 5 mU of Arthrobacter ureafaciens sialidase (AUS) for 60 min to remove Sias, prior to elution from the protein A-Sepharose.

Techniques: Binding Assay, Activity Assay, Labeling, Infection, Mutagenesis, Staining, Picogreen Assay, Comparison

Journal: Oncotarget

Article Title: Increasing TIMP3 expression by hypomethylating agents diminishes soluble MICA, MICB and ULBP2 shedding in acute myeloid leukemia, facilitating NK cell-mediated immune recognition

doi: 10.18632/oncotarget.16657

Figure Lengend Snippet: ( A ) AML cell lines (KG1a and NB4 cells) were treated with DMSO (Ctrl), DAC (1 and 5 μM) or AZA (1 and 5 μM) for 48 hours. Soluble levels of MICA, MICB, ULBP1, ULBP2 and ULBP3 ligands were quantified by sandwich ELISA. Each bar represents the mean ± SEM of at least four independent experiments. * p < 0.05 and * p < 0.001. ( B ) KG1a and NB4 cells were treated with 5 μM of DAC for 48 hours. Before and after treatment, cell surface expression of NKG2DL was analyzed by flow cytometry using monoclonal antibodies specific to each NKG2DL (MICA, MICB, ULBP1, ULBP2 and ULBP3), followed by incubation with FITC-conjugated goat anti-mouse IgG. The white histograms represent the isotype control antibody and shaded grey histograms show the NKG2DL expression. Dotted vertical lines indicate mean fluorescence intensity value in untreated samples.

Article Snippet: After blocking, 100 μl of sera or supernatant samples and recombinant human (rh) Fc chimera proteins specific for each NKG2DL (rhMICA Ref: 1300-MA, rhMICB Ref: 1599-MB, rhULBP1 Ref: 1380-UL, rhULBP2 Ref: 1298-UL,and rhULBP3 Ref: 1517-UL all from R&D Systems) were added for 2 hours at RT.

Techniques: Sandwich ELISA, Expressing, Flow Cytometry, Bioprocessing, Incubation, Control, Fluorescence

Journal: Oncotarget

Article Title: Increasing TIMP3 expression by hypomethylating agents diminishes soluble MICA, MICB and ULBP2 shedding in acute myeloid leukemia, facilitating NK cell-mediated immune recognition

doi: 10.18632/oncotarget.16657

Figure Lengend Snippet: ( A ) NKL cells were co-cultured with cell-free supernatants (sn) obtained from KG1a and NB4 cells untreated (sn-DMSO) or treated with 1 μM DAC for 48 hours (sn-DAC). NKL cells grow in culture medium were considered as a control (Ctrl). NKG2D expression was analyzed by flow cytometry and represented as mean fluorescence intensity (MFI). Each bar represents the mean ± SEM of three independent experiments. * versus control and p < 0.01; # versus sn-DMSO and p < 0.05. ( B ) NKL cells were co-cultured with K562 cells at the indicated E:T ratio in a cell lysis assay, in the absence (Ctrl) or presence of cellular supernatant derived from KG1a (left panel) and NB4 (middle panel) cells previously treated with DMSO (sn-DMSO) or 1 μM DAC (sn-DAC) for 48 hours. Specificity of the NKG2D-NKG2DL interaction was corroborated using an anti-NKG2D blocking mAb and the effect of DAC was assayed to analyze the non-specific effects on the lytic capacity of NKL cells (right panel). Measurements were made in duplicate and the mean ± SEM of the two independent experiments are shown. * versus control and p < 0.05; * versus control and p < 0.01; # versus sn-DMSO and p < 0.05.

Article Snippet: After blocking, 100 μl of sera or supernatant samples and recombinant human (rh) Fc chimera proteins specific for each NKG2DL (rhMICA Ref: 1300-MA, rhMICB Ref: 1599-MB, rhULBP1 Ref: 1380-UL, rhULBP2 Ref: 1298-UL,and rhULBP3 Ref: 1517-UL all from R&D Systems) were added for 2 hours at RT.

Techniques: Cell Culture, Control, Expressing, Flow Cytometry, Fluorescence, Lysis, Derivative Assay, Blocking Assay

Journal: Oncotarget

Article Title: Increasing TIMP3 expression by hypomethylating agents diminishes soluble MICA, MICB and ULBP2 shedding in acute myeloid leukemia, facilitating NK cell-mediated immune recognition

doi: 10.18632/oncotarget.16657

Figure Lengend Snippet: ( A ) KG1a and NB4 cells were treated with inhibitors specific to ADAM17 (10 μM GW280264X) and ADAM10 (50 μM of GI254023X) for 48 hours. Levels of soluble NKG2DL (sMICA/B and sULBPs1-3) were quantified by sandwich ELISA. Values are the mean ± SEM of at least three independent experiments. * p < 0.05 and * p < 0.01. ( B ) KG1a and NB4 cells were treated with DMSO (Ctrl) or DAC (1 μM) for 48 hours. After treatment, cell surface expression of ADAM17 was analyzed by flow cytometry using anti-human ADAM17 monoclonal antibody, followed by incubation with FITC-conjugated goat anti-mouse IgG. The white histograms represent the isotype control antibody and the shaded grey histograms show the ADAM17 expression. ( C ) ADAM17 activity in KG1a and NB4 cells was measured in whole-cell lysates after treatment with DMSO (Ctrl) or DAC (5 μM) for 48 hours. Data are expressed as relative fluorescence units (RLU) at Ex/Em=490/520 nm absorbance normalized with respect to micrograms of total protein (RLU/μg). Values are the mean ± SEM of three independent experiments. * p < 0.05 and * p < 0.01.

Article Snippet: After blocking, 100 μl of sera or supernatant samples and recombinant human (rh) Fc chimera proteins specific for each NKG2DL (rhMICA Ref: 1300-MA, rhMICB Ref: 1599-MB, rhULBP1 Ref: 1380-UL, rhULBP2 Ref: 1298-UL,and rhULBP3 Ref: 1517-UL all from R&D Systems) were added for 2 hours at RT.

Techniques: Sandwich ELISA, Expressing, Flow Cytometry, Incubation, Control, Activity Assay, Fluorescence

Journal: Oncotarget

Article Title: Increasing TIMP3 expression by hypomethylating agents diminishes soluble MICA, MICB and ULBP2 shedding in acute myeloid leukemia, facilitating NK cell-mediated immune recognition

doi: 10.18632/oncotarget.16657

Figure Lengend Snippet: ( A ) KG1a and NB4 cells were treated with DMSO (Ctrl) or DAC (0.25, 0.5 and 1 μM) for 48 hours, and TIMP3 expression was analyzed by qRT-PCR. Each bar represents the relative expression of TIMP3 normalized with respect to the reference gene (GAPDH), using the 2 −ΔCt method. MICA transcription levels in the KG1a cell line untreated (DMSO, Ctrl) or treated with DAC at different concentrations were used as a positive control. Results are summarized as the mean ± SEM of five independent experiments. * p < 0.05 and * p < 0.01. ( B ) TIMP3 protein levels were evaluated by western blot in KG1a and NB4 cells after treatment with DMSO (Ctrl) or DAC (1 μM or 5 μM) for 48 hours. * p < 0.05. ( C ) The TIMP3 methylation pattern was quantified by pyrosequencing in AML cell lines (KG1a and NB4 cells) before and after treatment with 1 μM or 5 μM DAC. Pie charts show the average percentage of methylation for the CpGs analyzed in the TIMP3 gene. ( D ) TIMP3 expression was inhibited by transfection of KG1a cells previously treated with DAC (1 μM) with a TIMP3-specific siRNA or nonspecific scramble siRNA (200 nM). * p < 0.05 ( E ) Soluble NKG2DL were quantified by sandwich ELISA after TIMP3 inhibition. Values shown are the mean ± SEM of three independent experiments. * versus control and p < 0.05; * versus control and p < 0.01 # versus nonspecific scramble siRNA and p < 0.05.

Article Snippet: After blocking, 100 μl of sera or supernatant samples and recombinant human (rh) Fc chimera proteins specific for each NKG2DL (rhMICA Ref: 1300-MA, rhMICB Ref: 1599-MB, rhULBP1 Ref: 1380-UL, rhULBP2 Ref: 1298-UL,and rhULBP3 Ref: 1517-UL all from R&D Systems) were added for 2 hours at RT.

Techniques: Expressing, Quantitative RT-PCR, Positive Control, Western Blot, Methylation, Transfection, Sandwich ELISA, Inhibition, Control

Journal: Oncotarget

Article Title: Increasing TIMP3 expression by hypomethylating agents diminishes soluble MICA, MICB and ULBP2 shedding in acute myeloid leukemia, facilitating NK cell-mediated immune recognition

doi: 10.18632/oncotarget.16657

Figure Lengend Snippet: ( A ) Soluble NKG2DL were quantified by sandwich ELISA in sera from twelve AML patients before and after Vidaza ® treatment. Lines represent the levels of each sNKG2DL (ng/mL) before and after treatment of each individual AML patient. ( B ) Expression of NKG2DL on the cell surface of blasts from five AML patients before and after Vidaza ® treatment (left panel). The right panel shows dot plots of NKG2DL expression on the cell surface of blats from a representative patient. Numbers included in the figure quadrants indicate the percentage of positive cells for each NKG2DL.

Article Snippet: After blocking, 100 μl of sera or supernatant samples and recombinant human (rh) Fc chimera proteins specific for each NKG2DL (rhMICA Ref: 1300-MA, rhMICB Ref: 1599-MB, rhULBP1 Ref: 1380-UL, rhULBP2 Ref: 1298-UL,and rhULBP3 Ref: 1517-UL all from R&D Systems) were added for 2 hours at RT.

Techniques: Sandwich ELISA, Expressing