Figure 5.

B cell intrinsic cGAS signaling is not required for autoreactive germinal center participation but marginally impacts PC output in the spleen. (A) Schematic overview of experimental setup with timeline. (B) B cell frequencies out of live, singlet lymphocytes, in lymphoid tissues of cGAS-KO (blue, n = 7) and WT (red, n = 7) chimeras. Each dot represents an individual mouse and bars indicate mean +/- SD, with statistical significance given for two-way ANOVA followed by Sidak’s post-test (α = 0.05), ns = not significant, ** = p<0.01. (C) As in (B), but for GCB cell frequencies instead. (D) Representative example from a cGAS-KO chimera showing gates used to define CD45.1 vs. PA-GFP within the B cell (left) and GCB cell (right) compartments, and the parent GCB cell gate (center). (E) As (B) but showing relative GCB to B cell ratios for the compartment of interest (COI, CD45.1^- PA-GFP^-). (F) Confocal micrographs of spleen sections from a representative cGAS-KO chimera stained for IgD (naïve B cells, blue), CD45.1 (green), CD45.2 (red) and the marginal zone (CD169, not shown). Left, lower magnification image, with indication of the marginal zone (broken white line, based on CD169 staining, Figure S5K ) and three GCs (numbered). Subsequent panels present higher magnification images of each of the three numbered GCs in the left panel. Channel assignments and brightness were adjusted to enhance visual clarity of micrographs. (G) As (E) but showing relative PC (plasma blast/cell, CD138^hi within live, singlet lymphocytes) to B cell ratios for the compartment of interest (COI, CD45.1^- PA-GFP^-). (H) As (B), but for 564Igi idiotype (9D11⁺) frequencies of PA-GFP positive B cells.