6 variants/binding site, P = NS by t-test), even though the vaccine elicited significantly lower magnitude of V4 binding (1955 vs. 10,468 MFI, P = 0.0031 by t-test). In addition, the depth of V2 binding among vaccinated guinea pigs could not be predicted by magnitude alone. For example, while HIV-1-infected humans and HIV-1-vaccinated
guinea pigs had the same magnitude of V2-specific responses (5998 vs. 7770 MFI, P = NS by t-test), the vaccinated guinea pigs had significantly greater depth of V2-specific binding (7 vs. 20 variants/binding site, P = 0.0161 by t-test). Despite substantial differences in the human and guinea pig studies, this example demonstrates how the microarray can discriminate between magnitude and depth of selleck antibody responses. This information may be highly relevant
to HIV-1 vaccine researchers who aim to design a global HIV-1 vaccine capable of blocking acquisition of diverse HIV-1 strains. We also calculated the relative clade- or CRF-specific binding present for the three most frequent clades (A, B, and C). Fig. 7 demonstrates the percent of each clade- or CRF-specific peptide set that was positive for the four groups within the variable regions V1V2 and V3. In Fig. 7A, we can see that among vaccinated monkeys and guinea pigs, V1V2-specific responses were increased compared to the other cohorts, CAL-101 cell line and that binding to clades A and C V1V2 peptides predominated, whereas clade B-specific binding was relatively low. This finding likely reflects the fact that both monkeys and guinea Methisazone pigs received clade C Env immunogens. In contrast, in Fig. 7B, we can see that among HIV-1-infected subjects, who had increased
V3-specific responses, binding to clade B peptides predominated. This finding presumably reflects the fact that these subjects were from North America and were infected with clade B HIV-1. These data suggest that the microarray may not only be useful for measuring cross-clade immune responses following vaccination, but also may have an application in serotyping HIV-1-infected subjects. Further studies with larger numbers of HIV-1-infected subjects from different regions could test this hypothesis. Finally, we also designed the microarray to assess HIV-1-specific binding across the HIV-1 proteome. In Fig. 8A, we demonstrate the magnitude, breadth, and depth of HIV-1-specific binding to gp120, gp41, Gag, Nef, Pol, Rev, Tat, and Vif proteins among 5 HIV-1-infected human subjects. We observed that gp41 (which includes regions from the cytoplasmic tail) has the highest binding magnitude, followed by Gag. Fig. 8B shows the antibody binding pattern for Gag among 5 HIV-1-infected subjects; peak values are noted within the p17 region, with very little Gag-specific binding among naïve controls (Fig. 8C). Antibody binding to non-Env proteins may be relevant to evaluate vaccine potency and for certain non-neutralizing antibodies (Lewis, 2014).