siga  (Valiant)

Journal:

Article Title: Impact of the Molecular Form of Immunoglobulin A on Functional Activity in Defense against Streptococcus pneumoniae ▿

doi: 10.1128/IAI.01758-06

Figure Lengend Snippet: (A) Affinity-purified MAb 2A01 supernatant (inset; lane A) was fractionated by gel filtration to yield mIgA (inset; lane B) and pIgA (inset; lane C). AU, absorbance units. (B) Enhanced opsonophagocytosis with MAb 2A01 (IgA2) pIgA and SIgA compared to

Article Snippet: Standards included serum IgA and SIgA (MP Biomedicals, Aurora, IL).

Techniques: Affinity Purification, Filtration

Journal:

Article Title: Impact of the Molecular Form of Immunoglobulin A on Functional Activity in Defense against Streptococcus pneumoniae ▿

doi: 10.1128/IAI.01758-06

Figure Lengend Snippet: Solid-phase ELISA was used to examine affinity and avidity for the three molecular forms of IgA. Antibody binding curves for mIgA, pIgA, and SIgA of one IgA2 (MAb 2A01) and two IgA1s (MAb 6BA01 and MAb 8A01). (A) ELISA binding curves show similar antigen

Article Snippet: Standards included serum IgA and SIgA (MP Biomedicals, Aurora, IL).

Techniques: Enzyme-linked Immunosorbent Assay, Binding Assay

Journal:

Article Title: Impact of the Molecular Form of Immunoglobulin A on Functional Activity in Defense against Streptococcus pneumoniae ▿

doi: 10.1128/IAI.01758-06

Figure Lengend Snippet: IgA1 proteases from H. influenzae type 1 and S. pneumoniae inhibit IgA-mediated opsonophagocytosis of S. pneumoniae in the presence of complement. (A) Digestion of hMAb 2A02 pIgA and SIgA with H. influenzae IgA1 protease before use in opsonophagocytosis

Article Snippet: Standards included serum IgA and SIgA (MP Biomedicals, Aurora, IL).

Techniques:

Journal: Journal of Virology

Article Title: Rare Detection of Antiviral Functions of Polyclonal IgA Isolated from Plasma and Breast Milk Compartments in Women Chronically Infected with HIV-1

doi: 10.1128/JVI.02084-18

Figure Lengend Snippet: Env antigen-specific IgA and IgG responses in milk and plasma seldom correlate with other Env antigen-specific responses in HIV-infected lactating women. To determine whether immune responses to the various HIV-1 antigens were associated with each other, correlations between binding scores for selected antigen specificities were tested for plasma IgA (A), plasma IgG (B), breast milk (BM) IgA (C), and breast milk IgG (D). Kendall’s tau values and corresponding corrected P values (see Materials and Methods) are reported. Boldface P values indicate significant correlations at a P value of

Article Snippet: To test IgA binding to TZM-bl/FcαRI-expressing cells, human IgA1(κ), IgA2(κ) (Athens Research and Technology, Athens GA), purified human secretory IgA (MP Biomedicals, LLC, Solon, Ohio), and FITC-conjugated goat anti-human IgA (Sigma) were used.

Techniques: Infection, Binding Assay

Journal: Journal of Virology

Article Title: Rare Detection of Antiviral Functions of Polyclonal IgA Isolated from Plasma and Breast Milk Compartments in Women Chronically Infected with HIV-1

doi: 10.1128/JVI.02084-18

Figure Lengend Snippet: Lack of detectable milk IgA-mediated phagocytosis despite increasing IgA concentration. To determine if lack of milk IgA phagocytosis activity was due to lower HIV-1 specific activity in IgA than that in IgG, higher concentrations of IgA and IgG were purified from the milk of an HIV-positive lactating woman recruited in the United states. Breast milk (BM) IgG, breast milk IgA, and a control antibody, CH31 mIgA2, were tested for phagocytosis of HIV ConS gp140-coated beads at 5-fold dilutions as indicated, and flow cytometry diagrams indicative of the phagocytosis results are shown. The red traces indicate sample antibody setup while black traces indicate the no-antibody control setup, and gray fill indicates the no-target control setup. Antibody-mediated phagocytosis is indicated by a greater area under the curve for the red trace than that for the black trace. Milk IgG and CH31 mIgA2 showed antibody-mediated phagocytosis activity down to 2 μg/ml, while milk IgA showed no antibody-mediated phagocytosis activity even at 250 μg/ml.

Article Snippet: To test IgA binding to TZM-bl/FcαRI-expressing cells, human IgA1(κ), IgA2(κ) (Athens Research and Technology, Athens GA), purified human secretory IgA (MP Biomedicals, LLC, Solon, Ohio), and FITC-conjugated goat anti-human IgA (Sigma) were used.

Techniques: Concentration Assay, Activity Assay, Purification, Flow Cytometry, Cytometry

Journal: Journal of Virology

Article Title: Rare Detection of Antiviral Functions of Polyclonal IgA Isolated from Plasma and Breast Milk Compartments in Women Chronically Infected with HIV-1

doi: 10.1128/JVI.02084-18

Figure Lengend Snippet: Breast milk and plasma IgAs may inhibit C.1086 HIV-1 virion binding to epithelial cells. Inhibition of binding to the colonic epithelial cell line HT-29 was assessed using the tier 2 clade C virus HIV-1 C.1086, with 7 to 12 replicates performed over three independent experiments. VRC01 IgA was used as a positive control, and HIV-negative colostrum IgA and anti-influenza virus CH65 IgA were used as negative controls. A dotted line indicates the mean percent inhibition (MPI) cutoff of 31%, calculated as 2 standard deviations plus the MPI of anti-influenza virus hemagglutinin MAb CH65 IgA relative to that of the no-antibody condition.

Article Snippet: To test IgA binding to TZM-bl/FcαRI-expressing cells, human IgA1(κ), IgA2(κ) (Athens Research and Technology, Athens GA), purified human secretory IgA (MP Biomedicals, LLC, Solon, Ohio), and FITC-conjugated goat anti-human IgA (Sigma) were used.

Techniques: Binding Assay, Inhibition, Positive Control

Journal: Journal of Virology

Article Title: Rare Detection of Antiviral Functions of Polyclonal IgA Isolated from Plasma and Breast Milk Compartments in Women Chronically Infected with HIV-1

doi: 10.1128/JVI.02084-18

Figure Lengend Snippet: Milk and plasma IgG, but not IgA, mediate tier 1 HIV MW965 neutralization. To identify HIV-1 neutralization function in antibody fractions of milk and plasma, we determined the neutralization IC 50 in TZM-bl cells for IgA and IgG antibodies isolated from milk and plasma samples of 20 participants. HIV-specific neutralization activities against the clade C tier 1 HIV variants MW965 (and also S0032 for selected samples) are shown, as well as nonspecific antiviral neutralization activities against murine leukemia virus (MLV). Eight HIV-negative controls are also shown, as well as positive-control recombinant monoclonal antibodies (b12 and VRC01, CD4 binding site broadly neutralizing antibodies) in IgA and IgG backbones. No milk IgA samples neutralized HIV-1 MW965 or HIV-1 S0032 , whereas three plasma IgA samples had detectable neutralization.

Article Snippet: To test IgA binding to TZM-bl/FcαRI-expressing cells, human IgA1(κ), IgA2(κ) (Athens Research and Technology, Athens GA), purified human secretory IgA (MP Biomedicals, LLC, Solon, Ohio), and FITC-conjugated goat anti-human IgA (Sigma) were used.

Techniques: Neutralization, Isolation, Positive Control, Recombinant, Binding Assay

Journal: Journal of Virology

Article Title: Rare Detection of Antiviral Functions of Polyclonal IgA Isolated from Plasma and Breast Milk Compartments in Women Chronically Infected with HIV-1

doi: 10.1128/JVI.02084-18

Figure Lengend Snippet: Env antigen specificities of milk IgG and IgA and plasma and milk IgAs do not correlate, while milk and plasma IgG Env antigen-specificities are strongly correlated. (A, C, D, F and H) For 16 HIV-1 + lactating women, milk and plasma samples were obtained, and IgA and IgG were purified from both sample types. For IgA (A) and sIgA (D), binding scores to gp41, gp41 PID, gp140, and gp120 antigens are shown (see Materials and Methods for antigens and calculation). For IgA, scores for binding to gp70 V1/V2, linear V2, linear V3, and linear C5 antigen subspecificities are also shown (C). For IgG, scores are shown for binding to Env gp41, gp41 PID, gp140, and gp120, as well as Gag p24 antigens (F), and to gp70 V1/V2, linear V2, gp70 V3, and linear C5 antigen subspecificities (H). Background-subtracted MFI values below 0 are shown with a value of 0.01. (B, E, G, I, J and K) Correlations between compartments for each antigen specificity or antigen specificity ratio. Kendall’s tau values and corresponding corrected P values (see Materials and Methods) are reported. Boldface P values indicate significant correlations at a P value of

Article Snippet: To test IgA binding to TZM-bl/FcαRI-expressing cells, human IgA1(κ), IgA2(κ) (Athens Research and Technology, Athens GA), purified human secretory IgA (MP Biomedicals, LLC, Solon, Ohio), and FITC-conjugated goat anti-human IgA (Sigma) were used.

Techniques: Purification, Binding Assay

Journal: Journal of Virology

Article Title: Rare Detection of Antiviral Functions of Polyclonal IgA Isolated from Plasma and Breast Milk Compartments in Women Chronically Infected with HIV-1

doi: 10.1128/JVI.02084-18

Figure Lengend Snippet: Breast milk and plasma IgGs, but not IgAs, mediate phagocytosis of HIV-1 virions and Env-coated beads. To determine the phagocytosis function in antibody fractions of breast milk (BM) and plasma (PL), we tested IgA and IgG from milk and plasma of 16 HIV + women for phagocytosis of beads coated with HIV-1 Env ConS gp140 (A), beads coated with HIV-1 Env 1086.C gp140 (B), and fully infectious fluorescent HIV-1 virions (HIV-1 92Th023 -Tomato) (C). Antibodies from an additional five HIV-negative women were also tested as negative controls, as well as the anti-respiratory syncytial virus antibody palivizumab. The black dotted line indicates the positivity cutoff, determined using the mean +3 standard deviations of values of the negative controls used in the assay.

Article Snippet: To test IgA binding to TZM-bl/FcαRI-expressing cells, human IgA1(κ), IgA2(κ) (Athens Research and Technology, Athens GA), purified human secretory IgA (MP Biomedicals, LLC, Solon, Ohio), and FITC-conjugated goat anti-human IgA (Sigma) were used.

Techniques:

Journal: Journal of Virology

Article Title: Rare Detection of Antiviral Functions of Polyclonal IgA Isolated from Plasma and Breast Milk Compartments in Women Chronically Infected with HIV-1

doi: 10.1128/JVI.02084-18

Figure Lengend Snippet: IgA-mediated tier 1 HIV-1 neutralization is not enhanced in FcαRI-expressing cells or peripheral blood mononuclear cells. (A) To gain insight into the role of CD89 in HIV infectivity and neutralization, the cDNAs for the human FcαRI and the γ chain of the FcεR were transduced into TZM-bl cells using lentiviral constructs. Specific monoclonal antibodies and flow cytometry detected surface expression of FcαRI on this new TZM-bl cell line. (B) Flow cytometry diagrams show the capability of the TZM-bl/FcαRI cell line to bind to human monomeric IgA1 and monomeric IgA2, human colostrum secretory IgA, and monoclonal 2F5 IgA. (C) To determine whether neutralization activity is enhanced in the presence of Fc alpha receptor 1 (FcαRI), we examined the neutralization IC 50 using TZM-bl cells transduced with FcαRI and also in human peripheral blood mononuclear cells (PBMCs). Milk and plasma IgAs were tested for six participants with a variety of neutralization phenotypes in TZM-bl cells. The positive controls HIVIG (clade C) and b12 IgA MAb and the negative-control 2F5 MAb (broadly neutralizing, but does not neutralize MW965) were also tested. ND, not done for the indicated sample. Neutralization was not enhanced in either FcαRI-transduced TZM-bl cells or in peripheral blood mononuclear cells.

Article Snippet: To test IgA binding to TZM-bl/FcαRI-expressing cells, human IgA1(κ), IgA2(κ) (Athens Research and Technology, Athens GA), purified human secretory IgA (MP Biomedicals, LLC, Solon, Ohio), and FITC-conjugated goat anti-human IgA (Sigma) were used.

Techniques: Neutralization, Expressing, Infection, Construct, Flow Cytometry, Cytometry, Activity Assay, Transduction, Negative Control