Dissociation between tumour resistance and delayed-type hypersensitivity to tumour-associated antigens in the mouse.

A comparison was made in mice between resistance to growth of a syngeneic methylcholanthrene-induced fibrosarcoma (Meth A) and specific delayed-type hypersensitivity to this tumour. Resistance could be induced in 90% of mice following a single injection of 10(4) Meth A cells. This resistance could be transferred by spleen cells but not serum. Delayed skin reactivity to ultrasonicated Meth A cells was found in both tumour-resistant and tumour-bearing mice and could be passively transferred by spleen cells and serum. These findings suggest a dissociation between tumour resistance and specific delayed-type hypersensitivity. It would appear that, in this system, delayed skin reactivity to Meth A tumour cells is mediated by humoral antibody despite a mononuclear cell infiltrate at 24 and 48 h and that this could be the reason for its lack of correlation with host resistance to tumour growth which is cell-mediated and not transferable by serum.