Alastair J. Cunningham

Ontogeny of spontaneous rosette forming cells in mice against syngeneic, allogeneic and xenogeneic erythrocytes

Abstract Thymocytes and spleen cells from normal mice will bind to syngeneic or foreign erythrocytes in vitro , forming rosettes. Under our conditions, the proportion of lymphocytes forming autorosettes is extremely high, typically about 20–40%. In adult mice a hierarchy of rosette frequencies is evident in the order auto- ≥ allo- ≥ xeno-RFC, i.e., numbers of rosettes decrease as the phylogenetic difference between erythrocyte type and the mouse increases. Furthermore lymphocytes able to form rosettes against self and some closely related red cells seem to be present earliest in ontogeny, being already high in late foetal tissues. These patterns suggest some kind of dynamic developmental process generating rosette-forming cells, rather than simple “non-specific” sticking. The autorosette forming cells in spleen comprise approximately equal numbers of B and T cells. Whilst autorosette-forming cells in thymus are not affected by anti-Ig treatment those in spleen can be inhibited by capping their Ig. A possible role for self antigens in actively priming immunocompetent cells is discussed.