Implication of the Thy-1 antigen on mouse thymus cells in the recognition of 'self' structures.

Thymus cells of mice form rosettes with autologous and allogeneic erythrocytes. The nature of the thymus cell receptors which mediate the binding of erythrocytes is not known. The aim of the present study was to determine the effect of various antisera to T-cell specific antigens on the formation of rosettes by mouse thymus cells. In all strains of mice tested, the exposure of thymus cells to rabbit anti-mouse brain serum (RABR) was found to inhibit autorosette formation. Similarly, monoclonal Thy-1 antibodies inhibited the formation of autorosettes by thymus cells in all strains tested. Monoclonal antibodies against Lyt-1, Lyt-2, and TL determinants had no such effect. Monoclonal Thy-1 antibodies inhibited the formation of rosettes with allogeneic erythrocytes only when the thymus contained the Lyt-2.2 allele (BALB/c, C57BL), but not when it contained the Lyt-2.1 allele (AKR/J, C3H, DBA/2). These results indicate that Thy-1 determinants on thymus cells are involved in the recognition of 'self' structures, shared by erythrocytes of all strains of mice. Lyt-2 determinants may play a role in the recognition of 'non-self', allogeneic determinants, but the thymus cell surface structures encoded by the two Lyt-2 alleles may differ in their affinity to allogeneic erythrocytes.