Anti-self receptors. II. Demonstration of H-2L region-restricted receptors on subpopulations of peripheral T and B lymphocytes.

Subpopulations of murine spleen, lymph node, and bone marrow cells can bind autologous erythrocytes. The specificity of this interaction was investigated and it was found that these lymphoid cells, like thymocytes, primarily recognize self-H-2L antigens on red cells. Three experimental approaches were used to reach this conclusion: i) The inhibition of autorosetting with erythrocyte sonicates from different H-2 congenic and recombinant mouse strains; ii) the specific blocking of autorosette-inhibition with anti-H-2L antibodies, and iii) the analysis of H-2L mutant mice. The inhibition studies also demonstrated that extrathymic lymphocytes, like thymocytes, carry receptors that can distinguish between b, q and s haplotypes but cannot differentiate between the H-2L molecules expressed by d and k haplotypes. It was found that subpopulations of both T and B lymphocytes autorosette via H-2L restricted receptors. In fact, the majority (80%) of autorosetting cells in spleen were B lymphocytes. Furthermore, the H-2L restricted receptors on B lymphocytes were distinct from surface Ig and could develop in athymic (nude) mice. These findings imply that H-2 restricted receptors on lymphocytes play a much more fundamental and comples role in the immune system than simply directing the interaction of cytotoxic T lymphocytes with target cells.