Immunological mechanisms in the pathogenesis of virus-induced murine leukemia. II. Characterization of autoreactive thymocytes.

The nature of the reaction and the type of effector cells involved in the reactivity of thymocytes from Moloney murine leukemia virus (MuLV-M)-carrier mice against normal syngeneic target cells has been further characterized. The reaction is mediated by viable MuLV-infected thymocytes. Lysates of carrier thymocytes are not more effective in causing target cell reduction than are lysates of normal thymus cells. Soluble mediators do not appear to be involved in the reaction. The thymocytes mediating the reaction are non-adherent cells positive for the theta-C3H and H-2-k alloantigens, but are negative for detectable murine IgG determinants. Their resistance to corticosteroid treatment further identifies them as functionally mature immunocytes.