Contribution of Endotoxin to Antibody Formation against T2 Phage

Abstract

INDUCTION of a primary immune response in vitro remains one of the most ambitious aims of the experimental immunologist. Fishman suggested that the initial step in antibody formation is the processing of the antigen by macrophages; in these cells “reactive RNA” is formed which is assumed to transmit information for the synthesis of antibody to lymphoid cells¹. To prove this experimentally, Fishman and other investigators used T2 phage as the test antigen. They reported that RNA extracted from macrophages, which had phagocytosed T2 phage, induced synthesis of antiphage antibodies in untreated lymph node cells. But stocks of T2 phage contain soluble cellular substances from the E. coli hosts on which they were grown, including bacterial somatic antigen. This antigen is an effective non-specific stimulant of immune reactions and we therefore investigated the possible effects of the somatic antigen on the immune response to T2 phage. Endotoxin has been shown to have adjuvant properties² and also to cause release of preformed antibodies from antibody forming cells^3,4.