Effect of the graft-versus-host reaction on the immunological responsiveness of the mouse

Abstract

Graft-versus-host reaction has been induced in unirradiated adult ( C 57 BL x CBA ) F 1 hybrid mice by intravenous injection of parent-line spleen cells, and the capacity of the injected animals to react to first-set and second-set grafts of A -line skin, and to Salm. typhi H antigen, has been investigated. Injection of CBA cells resulted in little or no loss of weight, a low mortality, little or no impairment of the recipient’s capacity to react to A skin or to the bacterial antigen when encountered for the first time, and no loss of pre-existing immunity to A skin. Injection of (40 to 100) x 10 6 C 57 BL cells on the other hand resulted in severe loss of weight and diarrhoea, often culminating in death. Surviving non-immunized animals reacted feebly to the bacterial antigen and some were slower than normal in rejecting first-set grafts of A skin. Pre-existing immunity to A skin was lost except in the special case when the spleen cell donor had itself been immunized against A skin. It is concluded that severe graft-versus-host reaction depresses the host’s immunological reactivity, but that the foreign cells may enable the host to muster a variety of immunological reactions by proxy.