Figure 4.

High-affinity mAbs restrict BG18^gH responses in an epitope-dependent manner

(A) Schematic of experiment to evaluate the effects of i.v. administration of monoclonal antibodies on naive BH18^gH B cell responses in WT recipients.

(B and C) (B) GC cells as the percentage of total B cells and (C) CD45.2⁺ BG18^gH cells as the percentage of total GC B cells at 10 dpi in BG18^gH recipients receiving 30 μg of either high-affinity murine IgG1 BG18 mAb (BG18_d42.10, green) or high-affinity human IgG1 BG18 mAb (BG18_iGL0, red).

(D) CD45.2⁺ BG18^gH cells as the percentage of total GC B cells at 10 dpi of BG18^gH recipients receiving escalating concentrations of the high-affinity BG18_iGL0 mAb.

(E) CD45.2⁺ BG18^gH cells as the percentage of total GC B cells at 10 dpi of BG18^gH recipients receiving 10 μg of BG18 mAbs with increasing affinity for the N332_GT2 immunogen (BG18_Pre5 with K_D 1.3μM, BG18_Pre14 with K_D 93 nM, and BG18_iGL0 with K_D 4 nM).

(F) Schematic of the HIV Env trimer and binding sites of the bnAbs used in (G)–(J).

(G and H) (G) GC cells as the percentage of total B cells and (H) CD45.2⁺ BG18^gH cells as the percentage of total GC B cells at 10 dpi in BG18^gH recipients receiving 10 μg of the BG18-epitope binding mAbs BG18_iGL0 and PGT128.

(I and J) (I) GC cells as the percentage of total B cells and (J) CD45.2⁺ BG18^gH cells as the percentage of total GC B cells at 10 dpi in BG18^gH recipients receiving 10 μg of antibodies binding other epitopes on the N332-GT2 immunogen.

p values were calculated by ordinary one-way ANOVA with Dunnett’s multiple comparisons (^∗p < 0.05; ^∗∗p < 0.01; ^∗∗∗p < 0.001; ^∗∗∗∗p < 0.0001; ns, not significant). Figures represent data from one of at least two experiments with 3–5 mice per condition, with data presented as mean ± SD.