H-2 control of expression of an idiotype shared by normal B cells and a B-cell lymphoma

The spleens of normal B10,H-2^aH-44^bp/Wts (2^a4^b) mice; contain cells which, in response to mitogen stimulation, secrete hemolytic antibody specific for a determinant present on both sheep and bromelain-treated mouse erythrocytes. These cells were found to be Ly-1 positive. Approximately 50% of these cells bear surface immunoglobulin (sIg) with the same idiotype as the sIg of a 2^a4^b-derived B-cell lymphoma, CH12. Backcross analysis revealed H-2 control of the frequency of the idiotype-positive B cell. The regulatory gene did not correlate with the Igh-1 allotype, and analysis of 22 inbred mouse strains mapped the gene to the I-E subregion. Surprisingly, only strains homozygous for E^kexpressed the idiotype, and expression was a recessive trait. Possible mechanisms for this control of idiotype expression and its relation to lymphomagenesis are discussed.Abbreviations used in this paper 2^a4^b B10.H-2^aH-4^bp/Wts - Br-MRBC bromelain-treated mouse erythrocytes - C complement - LPS lipopolysaccharide W - pfc plaque-forming cells - sIg surface immunoglobulin - SRBC sheep erythrocytes - Ts T suppressor.