Different Sensitivities to Hydrocortisone of Natural Killer Cell Activity and Hybrid Resistance to Parental Marrow Grafts

Abstract

Natural killer cells and cells mediating F₁ anti-parent responses in vivo and in vitro differ in their sensitivity to hydrocortisone acetate. NK cell activity is sharply decreased after in vivo drug administration whereas induction of specific F₁ anti-parent or anti-allogeneic cytotoxicity and hybrid resistance to parental marrow grafts are not impaired. Because of several other properties shared by the NK and anti-Hh host reactivities, it is still suggested that the effector cells are generated from a single differentiation pathway, but that they differ with respect to specificity and sensitivity to hydrocortisone.