Major histocompatibility complex restriction of maternally induced suppression in young adult mice.

This study focused on the mode in which maternal T cells induce suppression of plaque-forming cell (PFC) response in offspring. The maternal T cells of C57BL/6J pregnant mice, which had been intraperitoneally injected with 2 x 10(8) of sheep red blood cells (SRBC) on day 12 of gestation, were transferred, 5 days after immunization, into (C3H/HeJ x C57BL/6J)F1 normal pregnant mice on day 12 of gestation. The (C3H/HeJ x C57BL/6J)F1 x C3H/HeJ offspring of (C3H/HeJ x C57BL/6J)F1 recipient pregnant mice were reared to more than 6 weeks of age, and their anti-SRBC PFC responses were examined. Suppression of anti-SRBC PFC response was observed in H-2bxk but not H-2k offspring. Thus, maternal T cells of SRBC-immunized pregnant mice induce suppression of anti-SRBC PFC in offspring with restriction to major histocompatibility complex (MHC) haplotype utilized in maternal T-cell responses during pregnancy. Maternal CD4+ T cells are responsible for the MHC-restricted induction of PFC suppression in offspring. Furthermore we demonstrated, in this report, using adoptive transfer of maternal T cells from SRBC-immunized pregnant mice and in vitro secondary PFC assay in the offspring, that maternal T-cell-mediated suppression results from the development of CD4+ suppressor T cells in offspring. Moreover, the activation of suppressor T cells in offspring depends on the recognition of SRBC antigens presented in association with the same MHC haplotype as that utilized in the maternal T-cell response during pregnancy. Thus, the maternal T cells of SRBC-immunized pregnant mice generate a repertoire of suppressor T cells in their offspring.