Dissociation of biological activities of Corynebacterium parvum by chemical fractionation

Abstract

Fractionation of Corynebacterium parvum (C. parvum) by phenol-water extraction resulted in components which differentially affected the cell-mediated cytotoxic response to tumor alloantigens in mice. The residue of the extraction (Fraction C) and its light component (Fraction D) retained all of the activities of the whole micro-organism, i.e. inhibition of primary spleen cell cytotoxicity, inhibition of in vitro memory cell-mediated cytotoxicity (CMC) and generation of macrophage-like suppressor cells. Administration of the phenol phase extracted material (Fraction A) inhibited both the primary and memory cytotoxic responses, but did not elicit suppressor macrophages. Destruction of carbohydrate components of Fraction D significantly reduced its ability to inhibit the memory response and to elicit suppressor macrophages. In contrast, its ability to inhibit the primary cytotoxic reponse was unaffected. This study clearly demonstrates that the several effects of C. parvum administration on the cell-mediated cytotoxic response to tumor alloantigens can be associated with different components of the organism. Furthermore, the dissociation of the effects indicate that the generation of primary cytotoxic lymphocytes, the priming of memory cytotoxic lymphocytes, and the induction of regulatory macrophages are not necessarily linked during the generation of a normal cytotoxic response.