Immunological enhancement of primary tumor development and its prevention

While it has been known for decades that the growth of tumor transplants can be enhanced immunologically, the potential significance of these previous findings to the development of primary tumors and the mechanisms of tumor enhancement has remained obscure. This review will summarize recent experiments indicating that primary turner development, can De enhanced by active immunization. The evidence suggests that antibodies, B cells and CD4(+) T cells can play a critical role in enhancing the development of primary tumors, whereas endogenous interferon-gamma (IFN gamma) can counteract enhancement. Thus, we envision two possible functions of IFN gamma: (i) preventing B cell and antibody enhancement and (ii) counteracting tumor promotion independent of T and B cells.