Fig. 3: Adoptively transferred engineered B cells can undergo antigen-induced activation in-vivo.

a Experimental scheme of the in vivo assays. Splenic B cells, from C57BL/6 CD45.1 mice, were engineered as in Fig. 1 and infused to otherwise syngeneic CD45.2 recipient mice. Different mice groups were immunized on the following day with gp120 antigens from either the THRO4156.18 (THRO) or the YU2.DG (YU2) HIV strains. When boosted by an additional injection, the mice received the same antigen as in the prime injection. Different mice groups were sacrificed 8 days following injections for spleen collection or terminally bled 14 days after injection for serum collection. b Representative analysis by flow cytometry of the accumulation of engineered cells in the GCs of mice immunized with either the YU2.DG or the THRO4156.18 gp120 antigens, 8 days following a prime antigen injection. Gating on live, singlets, B220⁺, GL-7⁺. c Quantification of b. Each dot represents a different mouse. Error bars represent SD (n = 3, represents amouse, data represented as mean values +/− SD). d Representative analysis by flow cytometry of CD45.1 expression among gp120 binding GC cells. Pre-gating on singlets, live, B220⁺, GL-7⁺. e Quantification of d. Each dot represents a different mouse. Error bars represent SD (n = 3, each dot represents a mouse, data represented as mean values +/− SD). For gating strategy see Supplementary Fig. 12.