Immunity to tumor antigens: potential implications in human neuroblastoma

Immune reactions to tumor-specific and tumor-associated antigens have been demonstrated in animals with neoplasms with in vitro and in vovo techniques. Some of the antigens detected in vitro induce transplantation resistance in vivo, while others do not. Human neuroblastoma cells cultivated in vitro have been shown to possess common antigens to which lymphocytes from neuroblastoma patients react. Whether it is possible to augment the immune reactivity of patients with neuroblastoma to these common antigens and, if so, whether this heightened immune reactivity would have clinically beneficial effects are as yet unknown. These reactions are complex, involving both cellular and humoral mechanisms. The fact that one type of immune response can be detected to one type of antigen present in a tumor in vitro does not necessarily mean that the immune response is effective in vivo. Responses to other tumor antigens may be deficient, or the immune response may be depressed. This may be due to active suppression of and/or selective deficiencies in critical cell populations required for an augmented immune response; this possibility may be evaluated with techniques allowing for in vitro sensitization to tumor antigens.