Selective cytotoxicity of Clostridium perfringens delta toxin on rabbit leukocytes

Clostridium perfringens delta toxin was selectively cytotoxic for various rabbit leukocyte populations. The sensitivity of these populations to the toxin varied, depending on the tissue from which they were derived, from 28% (appendix) to 41% (bone marrow) and 32% (spleen). Macrophages were uniformly killed by delta toxin, whereas thymocytes were essentially resistant. Selective cytotoxicity was correlated to the specific binding of the radiolabeled toxin by target cells. The relationship between sensitivity to the toxin and the presence of GM2 ganglioside in the cell membrane of rabbit leukocytes is discussed. Delta toxin might prove a useful new tool for separating leukocyte subpopulations based on their differential sensitivity to the cytolethal effect of this protein.