Fig. 2

Distinct pattern of SIV Env linear peptide-specific plasma IgG responses in AGMs and RMs. Plasma samples from SIVsab92018ivTF-infected AGMs and SIVmac251-infected RMs during acute and chronic infection were tested against species-specific overlapping linear peptides spanning SIV envelope (Env) gp160 by ELISA. a Each peak represents the median plasma binding levels of all monkeys against each peptide across Env gp160. Each block represents the plasma binding level of b AGMs and RMs at week 15 and 1 year against each peptide within the V1, V2, and gp41 regions, or c AGMs at week 3 and week 6. Linear V2-specific plasma IgG response emerged at week 6 in AGMs. At week 15, AGM plasma showed a unique binding to a cluster of peptides in the V2 and V3 loops that increased in magnitude through chronic infection in addition to binding clusters nearby the gp120/gp41 fusion domain and immunodominant region of Env gp41