FIG 3.

Boosting capacity and functional neutralization capacity of delayed antibody responses that develop following transient CD4⁺ T cell depletion. (A) C57BL/6 mice were depleted of CD4⁺ T cells or left untreated, immunized intramuscularly with 10¹⁰ vp of Ad26-SIV Env, and boosted 4 months postprime with 10¹⁰ vp of Ad5-SIV Env. (B) SIV Env-specific antibody titers prior to and following boosting immunization. (C) Fold change in SIV Env-specific antibody responses pre- to postboost. (D) Serum 50% neutralization capacity (IC₅₀) of tier 1A SIVmac251.TCLA.15 Env-expressing pseudoviruses or a MuLV negative-control pseudovirus. Each dot represents an individual mouse, and the line indicates the mean ± the standard error of the mean (C) or the median (D). The horizontal dotted line denotes the limit of detection for the assay (n = 6 to 8/group pooled from two experiments).