XXXX autologous rosette-forming cells. III. Binding of erythrocytes from different species to the T-cell receptors for autologous red blood cells.

@entity1 @entity1707 @entity742 @entity19 @entity95 @entity2823
Spontaneous rosette formation in @entity1 is restricted to a subpopulation of the circulating T cells. We have previously shown that the interaction between lymphocytes and autologous red blood cells (auto-RBC) is not mediated by a self-recognition mechanism, since allogeneic (allo-) RBC bind to T cells through the same receptors. In this work, we have extended these observations to thymocytes. Using a mixed-rosette assay in which one type of erythrocyte was identified by @entity2823 labeling, we have shown that almost all the thymocytes which attached auto-RBC could also fix allo-RBC. However, as for the peripheral blood lymphocytes (PBL), binding of @entity1 RBC to thymocytes occurred with varying affinities according to the erythrocyte's origin. In order to further study the specificity of the erythrocyte to lymphocyte binding in rosette formation, PBL were mixed with auto-RBC and erythrocytes of xenogeneic (xeno-) origin. Although very disparate incidences of rosettes were found according to the species from which the RBC were derived, most of the autorosetting lymphocytes also had receptors for xeno-RBC. In addition, preincubation of PBL with monoclonal antibody OKT11A (directed against the @entity742 RBC receptors on T cells) completely abrogated rosette formation with all the erythrocytes tested ( @entity1 auto- and allo-, @entity742 , @entity1707 , and @entity95 ) except @entity19 RBC. Taken together these data strongly suggest that @entity1 auto- or allo-, as well as @entity742 or some other xeno-RBC, bind to T lymphocytes by a single receptor and that the combining sites are expressed with different densities or varying affinities depending upon the RBC's origin. Therefore, spontaneous autorosettes may represent T lymphocytes having high-affinity receptors for @entity742 RBC.
