Journal: Retrovirology

Article Title: Live-virus exposure of vaccine-protected macaques alters the anti-HIV-1 antibody repertoire in the absence of viremia

doi: 10.1186/1742-4690-10-63

Figure Lengend Snippet: Mapping of anti-V3 binding Abs. A. Sequences of recombinant phages were assigned to V3 crown of HIV1084i or SHIV-1157ipEL-p. Gray shading, linear homologies; blue shading/white letters, amino acid difference between the two HIV-C envelopes (M307I). V3 mimotopes isolated using week 7 plasma (wk7-V3 mimotopes) were tested for plasma Ab binding using 14 time points of RRi-11 and RTr-11. Negative control, pre-immune plasma; weeks −1 and 0, vaccine-induced Ab responses; weeks 1–7, also include Ab responses induced during low-dose virus challenges; weeks 8–30, Ab responses after all challenges. Data illustrate results from two independent assays. Binding patterns are shown in form of a heat-map. OD signals 3x higher than signals detected with the wildtype phage control were considered positive. B. V3 amino-acid sequences of HIV1084i, SHIV-1157ipEL-p and SHIV SF162P4 . The two HIV clade C envelopes of SHIV-1157ipEL-p and HIV1084i differ in only one residue in the V3 crown (M307I; HXB2 numbering scheme ; highlighted in blue). SHIV SF162P4 shares the same gp120-sequence as HIV SF162 and has three mutations compared with the 1084i immunogen (M307I (blue), and R308P and Q315K (gray)). C. Sequences of synthetic peptide sets used for plasma Ab titration and peptide absorption analysis. Peptides corresponding to consensus clade C sequence differed in two amino-acid residues compared with immunogen-related peptides (HIV1084i): M307I (blue) and A316T (gray). D. Plasma samples of five vaccinees were assessed for binding Ab specificities at weeks 0 and 7 using two different V3 peptide sets (red bars, 1084i; blue bars, consensus clade C). Height of each bar, average titer calculated from three independent assays; error bars, standard error of the mean (SEM). Statistically significant differences between weeks 0 and 7 are indicated (if P < 0.05).

Article Snippet: As expected, the three other vaccinees that had detectable viral loads (RGe-11, RBr-11 and RDo-11) also showed a statistically significant boosting using the immunogen-related 1084i V3 peptides (red bars, P = 0.04, P = 0.008 and P = 0.012, respectively).

Techniques: Binding Assay, Recombinant, Isolation, Clinical Proteomics, Negative Control, Virus, Control, Residue, Sequencing, Titration, IF-P

Journal: Retrovirology

Article Title: Live-virus exposure of vaccine-protected macaques alters the anti-HIV-1 antibody repertoire in the absence of viremia

doi: 10.1186/1742-4690-10-63

Figure Lengend Snippet: Induction and boosting of cross-neutralizing anti-V3 Abs in the absence of viremia. Plasma samples (weeks 0 and 7) were tested for neutralizing activity against the challenge virus, SHIV-1157ipEL-p ( A ) and the heterologous clade B SHIV SF162P4 ( B ) by TZM-bl assay . Neutralization titers are expressed as the reciprocal plasma dilution inhibiting 50% of virus infection (IC 50 ). Each bar represents the average titer of at least two independent assays using triplicates of each sample and error bars show the SEM. Plasma nAb titers were compared between weeks 0 (before live-virus challenges) and 7 (after 5x multiple low-dose challenges). Plasma samples were incubated with either medium (plasma only, white bars) or one of the two peptide sets (red bars, 1084i V3; blue bars, consensus clade C V3) and IC 50 values were calculated. In case of a decreased IC 50 (depletion of neutralizing activity), percentages illustrate the degree of inhibition reached with each peptide set. P -values are shown (significance after Bonferroni correction, P < 0.025). Gray box and asterisks indicate neoantigen reactivity.

Article Snippet: As expected, the three other vaccinees that had detectable viral loads (RGe-11, RBr-11 and RDo-11) also showed a statistically significant boosting using the immunogen-related 1084i V3 peptides (red bars, P = 0.04, P = 0.008 and P = 0.012, respectively).

Techniques: Clinical Proteomics, Activity Assay, Virus, Neutralization, Infection, Incubation, Inhibition