Figure 3. PD-L2 deficiency results in increased PC-specific ASC numbers in the spleen and bone marrow.

A) ELISPOT analysis of PC-specific IgM⁺ ASC number in the BM and spleen of naïve WT, PD-1^−/−, PD-L2^−/−, and PD-L1^−/− mice. B) ELISA analysis of PC-specific IgM in supernatant from unstimulated, naïve 7-day splenocyte cultures. C) ELISPOT analysis of splenic PC-specific IgM⁺ ASC size in WT and PD-L2^−/− mice. D) Frequency and number of splenic PC-specific total plasmablasts and PC-specific B-1a plasmablasts (CD5⁺19⁺138⁺) in WT and PD-L2^−/− mice. E) Frequencies of peritoneal B cells (CD19⁺CD11b^+/−) that bind PC in WT and PD-L2^−/− mice, with distribution among B-1a, B-1b, and B-2 cells indicated. F) PD-L2 expression on PC-specific peritoneal B cells in WT mice relative to total B-1 cell PD-L2 expression and isotype control staining. G) Blimp1, total IgM (intracellular + extracellular), and Pax5 levels in peritoneal B cells (CD5⁺19⁺ vs CD5^neg19⁺) in WT and PD-L2^−/− mice. N ≥ 4 mice/group; for A, analyzed by ANOVA with Dunnett Post Test; B-G analyzed by Student’s t test (* p<0.05, ** p<0.005, *** p<0.001).