Figure 4.

After repeated injections with either Env or the subunit gp120, serum was harvested from mice and assessed for binding to Env. (A) Shown is IgG or IgM in serum pre-normalized for Env binding, as assessed by ELISA. (B) Mice (N = 5–6/group) were injected with Env and anti-Env or anti-gp120 serum was infused at the indicated time point. The mice were terminated on days 11–13 after start of the experiment. Control mice (N = 4–5/group) did not receive a serum infusion. (C) Assessment of Env-specific IgG by ELISA in serum from respective groups 13 days after injection with Env. (D) Detection of gp120 and gp41-specific germinal center (GC) B cells in groups of mice that had received Env-specific or gp120-specific serum, or no serum on day 4 after the Env injection. Shown is the accumulated data from two separate experiments.