Low-dose challenge of PGT121 treated rhesus monkeys
(A) Binding of PGT121 to 293T cells transfected with an empty vector control (Mock) or expression plasmids encoding SIV Env, HIV Env, or a membrane-anchored HIV gp120. One representative experiment out of two is shown.
(B) Infectivity of SIVdup pseudotyped with HIV-1 Env (HIV Env), SIV Env, or HIV-1 gp120 and SIV Env (gp120+SIV Env) on TZMbl cells in the presence of the indicated concentrations of PGT121. Mean and standard deviation of three replicates of one representative experiment out of two is shown.
(C) Viral RNA load after low dose challenge. Rhesus macaques were treated with 1 mg/kg body weight of control antibody (n = 4) or PGT121 (n = 5) 24 h prior to rectal inoculation with 2,800 infectious units of HIV Env pseudotyped SIVdup. The uninfected control monkey (2816) and two of the uninfected monkeys from the PGT121 treatment group (2701, 2782) were re-challenged 70 days after the first challenge. Plasma viral RNA levels at the indicated time points are shown. Four- and five-digit numbers are monkey designations. Animals that were re-challenged 70 days after the first challenge are given the suffix “RE.” See also Table S1 for PGT121 serum concentrations.