Experimental Salmonellosis VII. In Vitro Transfer of Cellular Immunity by Ribosomal Fraction of Mouse Mononuclear Phagocytes

Abstract

The mononuclear phagocytes (termed monocytes) of mice hyperim-munized with live vaccine of Salmonella enteritidis inhibited the intra-cellular growth of virulent strain 116-54 of S. enteritidis. Also, the monocytes withstood the degeneration of cells caused by the phagocytosis of bacteria in the absence of immune serum in the tissue culture medium, termed cellular immunity. When the nonimmune monocytes were incubated with the ribosomal fraction of immune monocytes, obtained from the abdominal cavity of mice hyperim-munized with live vaccine of S. enteritidis, they acquired cellular immunity, but the monocytes did not acquire immunity when ribosomal fractions from normal mouse monocytes or from the monocytes of mice immunized with killed vaccine of S. enteritidis were used. The transfer agent present in the ribosomal fraction of immune monocytes was inactivated by treatment with ribonuclease but not with deoxyribo-nuclease or with trypsin.