Abstract:

STUDIES on the cytotoxic action of antibodies, plasmin and streptococcal haemolysins on Ehrlich ascites tumour cells (E-cells) have been recently described (GCinsburg, 1959; Ginsburg and Grossowicz, 1960; Ginsburg and Ram, 1960). It was found that the cytopathogenic changes induced in the tumour cells by streptococcal haemolysins were morphologically very similar to those caused by anti-Ehrlich ascites tumour rabbit serum (AE), the action of the latter is known to be complement dependent (Flax, 1956; Goldberg and Green, 1959). It is known that both the haemolytic as well as the cytopathogenic effect caused by streptococcal haemolysins can be inhibited by antihaemolytic agents such as cholesterol, lecithin, congo red and trypan blue (Van Heyningen, 1950; Bernheimer, 1954; Ginsburg, 1959; Ginsburg and Grossowicz, 1960). On the other hand, the cytotoxic and haemolytic effect of antibodies can be inhibited by agents known to destroy or inhibit complement action, chelating agents, plasmin, heparin etc. (Gorrill and Hobson, 1952; Pillemer, Ratnoff, Blum and Lepow, 1953; Mayer, 1 958; Ginsburg and Ram, 1960). The present study shows that the cytotoxic action of antibodies produced in the rabbit against Ehrlich ascites tumour cells can be inhibited by various phospholipids and some of their constituents as well as by agents known to inhibit streptococcal haemolysins. In addition the inhibition of immune haemolysis by phospholipids will be described.