Immunogenic changes of murine lymphoma cells following in vitro treatment with aryl-triazene derivatives.

A series of dimethyl aryl-triazene derivatives and related monomethyl compounds were studied for their efficacy in mediating a strong increase in immunogenicity (i.e., chemical xenogenization, CX) of murine leukemic cells following in vitro treatment. It was found that all compounds under investigation were able to induce CX. The dimethyl derivatives were able to induce CX only after metabolic activation, whereas related monomethyl compounds were active per se. The antigenicity acquired by triazene-treated leukemic cells was very marked; intact hosts histocompatible with the parental line were able to reject up to 10(7) cells. Antigenic tumor cells retained their immunogenic properties even after a large number of transplant generations in the absence of the drug. This means that marked immunogenicity of triazene-treated cells is a stable and heritable characteristic.