AUTOLOGOUS CELLULAR IMMUNE-RESPONSE IN CANCER TODAY

The study of autologous immune reactions has represented a turning point in the effort to understand the immunological relationship between host and tumor. By this approach it was shown that most patients bearing primary lesions have lymphocytes able to react against their own neoplastic cells. Such as reactivity tends to fade away during tumor progression. However, a number of recent studies has provided evidence that, although with a low frequency, even metastatic patients may possess T lymphocyte clones which recognize autologous tumor cells in MHC-restricted fashion. Clonal analysis of the lymphocyte response has documented the presence of different individually unique tumor-specific antigens in melanoma cells. However, tumor antigens shared among different melanomas were also described. Evidence for the existence of specific tumor antigens on other human neoplasms is less convincing. It has also been demonstrated that, in addition to TCR/CD3 complex and MHC/tumor antigen interactions, adhesion molecules play an important role in cell recognition of autologous tumor. The clinical relevance of such observations appears to emerge both from a diagnostic and therapeutic point of view. In fact, autologous lymphocyte killing of tumor cells may predict prognosis in previously untreated patients with a primary cancer. Adoptive immunotherapy with autologous tuinor-specific T cells in combination with IL-2 remains a promising therapeutic approach at least with melanoma, although further studies are necessary to improve the yield and in vitro expansion of tumor-specific T cells from sucn patients.