Fig 2. IgG-mediated suppression of primary IgM-responses in Cr2 KO mice.
Cr2 KO and BALB/c mice were immunized with 50 μg IgGb anti-SRBC and 5x107 SRBC, SRBC alone, or IgG alone. Five days after immunization, the number of spleen cells producing IgM anti-SRBC was assayed. Responses are shown as percentage of the direct PFC response/spleen in mice given SRBC alone (100%, open bars); black bars show responses in mice given IgG together with SRBC. Direct PFC/spleen in the respective control groups (receiving antigen alone) were: BALB/c, 76,208; Cr2 KO, 11,015. Data are pooled from three experiments; (n = 4/group in each experiment). p-values denote comparisons between mice immunized with IgG anti-SRBC together with SRBC and mice immunized with SRBC alone. ***, p < 0.001.