ABSTRACT
The humoral and cellular immune responses to a growing tumor have been studied extensively in cancer patients; however, the immunoregulatory functions of these responses are not well characterized. One can speculate that cancer patients are capable of producing cancer antibodies, but that the antibodies "disappear" from the circulation through binding to anti-idiotypic antibodies. The ultimate aim of Ab2 immunizations is to induce protective immunity against tumors. Since human tumors can only be grown in immunodeficient animals, the possible immu-notherapeutic effects of Ab2 immunizations must ultimately be evaluated directly in patients. G. T. Nepom et al. have produced Ab2 in rabbits to murine MAb against melanoma-associated antigen p97 (Ab,). Mice immunized with the Ab2 demonstrated delayed-type hypersensitivity (DTH) reactions when challenged with melanoma cells expressing 380,000 p97 molecules per cell, but not when challenged with melanoma cells expressing only 2600 such molecules.
