Genetic control of rheumatoid factor production in the mouse. Role of genes linked to the immunoglobulin heavy chain locus and to the major histocompatibility complex.

The influence of Igh-1 and H-2 linked genes on the production of IgG2a-specific rheumatoid factors (RF) by 129/Sv mice was examined. Heterozygous animals carrying the 129 alleles, H-2b and Igh-1a, and either H-2k, H-2a, or Igh-1b (but not Igh-1d or Igh-1e) had considerably reduced RF levels. In contrast, Igh-1b linked genes failed to suppress RF production by MRL/MpJ-lpr mice. This lack of suppression was linked to the lymphoproliferation trait characteristic of these animals.