Spleen cell proliferation in response to homologous antigens studied in congenic resistant strains of mice.

The proliferative responses obtained when spleen cell suspensions from two different inbred strains of mice were mixed were investigated further using congenic resistant strain pairs. Strong responses were obtained in 9 cases out of 12 where the two strains differed at a single gene locus controlling an H-2 histocompatibility antigen. No responses were obtained where the difference occurred at loci controlling weak histocompatibility antigens. These findings have been taken to provide additional circumstantial evidence that the response represents an in vitro homograft reaction to homologous tissue antigens.