Fig. 3.

Neutralizer ICs drive higher-avidity Abs and expanded GC B cell responses. (A to C) BALB/c mice were immunized twice, 3 weeks apart, with alum-adjuvanted gp120 ICs (ICs-alum) generated with serum Abs from four neutralizers (N) or four non-neutralizers (NN) (n = 5 to 8 mice per group, two experiments). Control groups received alum-adjuvanted gp120 or adjuvant alone. Ten days after the last immunization, we measured the titers of gp120-specific IgG Abs (A), the titers of high-avidity gp120-specific IgG Abs (B) in sera, and the percentage of GC B cells (C), defined as live CD3⁻CD19⁺CD38⁻CD95⁺ cells, in draining lymph nodes of immune mice. All assays were run in duplicate, and a Mann-Whitney test was used to compare responses induced by neutralizer (N) or non-neutralizer (NN) immunized animals. *P < 0.05 and **P < 0.01. The horizontal bars in all panels indicate mean, and error bars in all panels represent SEM.