Tolerance of Cell Mediated Immune Responses after in vitro Treatment of Competent Cells with Mitomycin c

Abstract

THE graft-versus-host (g-vs-h) reaction produced by the injection of parental strain spleen cells (using inbred mice) into young F₁ hybrids is often chosen as a model of cellular type immunity in which the reactivity of the injected cells can be followed and in which the action of immunosuppressive agents can be evaluated. In earlier studies it was demonstrated that the onset of g-vs-h reactions in the parental–F₁ hybrid system is prevented if small amounts of drugs like cyclophosphamid, actinomycin c or SP–I Sandoz are administered within 24 h of injection of the lymphoid cells¹. Similar results were obtained by Meuwissen and one of us (R. A. G.)² when the cell inoculum was treated in vitro with mitomycin c, according to the procedure introduced by Bach and Voynow for the one way stimulation of lymphoid cells in vitro³. In these studies it was not, however, determined whether the injected cells were killed by the treatment, or were surviving in the recipient animals in an inactive or specific tolerant state.