Specific and Nonspecific Immune Resistance Enhancing Activity of Staphage Lysate

The immunopotentiating activity of staphage lysage (SPL) was evaluated in terms of its imune protection against lethal bacterial infection and its antitumor activity. Mice were pretreated weekly with 108 viable, Staphylococcus aureus?, strain 18Z for 3 weeks (Induction), followed by intraperitoneal SPL injections (Elicitation) at various times in relation to infectious challenge or tumor implantation. Induction without elicitation, or elicitation alone failed to provide protection against Klebsiella pneumoniae? infection and resulted in only 30-40% survival against homologous infection with pathogenic S. aureus? type III, whereas combined induction and elicitation produced enhanced resistance to infection and reduced mortality. Survival following combined induction and elicitation regimens resulted in 50% and 80-100% survival in mice inoculated with K. pneumoniae and S. aureus, respectively. SPL had no antitumor effect in mice implanted with Sarcoma-180. However, there was a significant prolongation of median survival time resulting from induction and elicitation in animals implanted which Ehrlich's ascites. This enhancement of immune resistance may possibly be related to activation of thymus-modulated lymphocytes and macrophages by SPL.