Fig. 1. Detection of BG18-like responses in rhesus macaques.

(A) The definition of a BG18 type I HC precursor that was used for searching naïve B cells plotted in (B) for humans (HuPre1) and macaques (RmPre1 and RmPre2), where pre1 and pre2 refer to different alleles. The position of the FG(V/L) was allowed to start at position 7, 8, or 9 of the HCDR3. The alignment shows the FG(V/L) starting at position 8. The BG18-inferred germline (BG18_GL₀) HCDR3 sequence is shown for comparison. Black indicates templated regions of the HCDR3; blue and red indicate junction regions. (B) Frequency of BG18 type I HC sequences in 14 human donors and 60 rhesus macaques. (C) Immunization schedule of NHPs (n=8) with N332-GT5 + SMNP and sampling time points for which sorting and BCR sequencing were carried out. ED, escalating dose; LN FNA, lymph node fine needle aspirate; PBMC, peripheral blood mononuclear cells. (D) Frequency of Env⁺ GC B cells as a percentage of total CD20⁺ B cells. The gray area is set from 0.001% to the median frequency of Env⁺ GC B cells observed in the pre-immunization samples. Lines indicate the median +/− interquartile range. The dotted vertical line indicates that a bolus boost occurred at week 10. (E and H) Number of BG18 type I sequences identified in (E) GC or (H) memory B cells at different time points, with each circle representing a different animal. (F and I) Frequency of BG18-like sequences among Env⁺ B cells from (F) GC or (I) memory B cells. (G and J) Frequency of BG18-like sequences among (G) GC or (J) memory B cells. (E – J) Bars indicate the median +/− interquartile range for the responders. For (E and F) "All" indicates the result of combining all sequences from weeks 3 to 13. In (G) "All" indicates the median frequency among the responders from weeks 3 to 13 at the time points for which responses were detected. In E-G, MD39 group (n=4) indicates Env+ sequences isolated from GC B cells at weeks 3, 4, 7 and 10 after priming with BG505 SOSIP MD39 trimer. ND, not detected.