Abstract: | The formation of nonspecific suppressor cells inhibiting the development of the graft versus host (GvH) reaction is shown to occur in the spleen of CBA mice after the injection of pertussis vaccine. 2 splenocyte populations have been found to possess suppressing activity: one of them comprises the splenocytes sensitive to anti-theta serum, carrying no receptors to IgG and IgM on their surface and incapable of adherence to the plastic surface; the splenocytes in the other population adhere to the plastic surface. During incubation and in vitro contact with the allogenic cells of intact donors the suppressor splenocytes release soluble mediators capable of suppressing the GvH reaction. |