CM-reactive immunity and anti-H-2b immunity do not cross react. A. Spleen cells from naïve BALB/c mice (black), from BALB/c mice 2 weeks after immunization with CM/CFA (white), or from BALB/c mice 2 weeks after i.p. injection of 15×106 B6 spleen cells (grey) were tested in IFNγ ELISPOT assays against CM (10 μg/mL), B6 spleens cells or equimolar, control, ovalbumin (OVA). n=4/group, *p<0.05. B–C. Sera was obtained from BALB/c mice that were immunized with CM/CFA or OVA/CFA and 2 weeks later transplanted with syngeneic BALB/c hearts (sera obtained 2 weeks after transplant) or from mice 2 weeks after i.p. injection of 15×106 B6 (H-2b) spleen cells. The sera were tested for binding to B6 thymocytes by flow cytometry (B) or for reactivity to CM by ELISA, serum diluted at the dilutions shown (C). n=4 per group, *p<0.05 versus same dilution in other groups. No reactivity was detected using sera from naïve mice (data not shown).