IDIOTYPE VACCINATION STRATEGIES AGAINST A MURINE B-CELL LYMPHOMA - DENDRITIC CELLS LOADED WITH IDIOTYPE AND BISPECIFIC IDIOTYPE-X ANTICLASS-II ANTIBODIES CAN PROTECT AGAINST TUMOR-GROWTH

Three strategies were used to evaluate 38C13 B-cell lymphoma-specific idiotype immunization to protect against subsequent lymphoma challenge in C3H/He mice. It was observed that tumor-specific immunity could be induced by immunization with (i) KLH-conjugated 38C13 B-cell lymphoma idiotype in complete Freund's adjuvants (survival rate 80%), (ii) den dritic cells pulsed in vitro with native idiotype protein (survival ra te 80%), and (iii) bispecific antibodies composed of B-lymphoma-relate d idiotype and an MHC class II binding moiety (survival rate 40%). Pre sentation of idiotype determinants by dendritic cells or bispecific an tibody resulted in lymphoma-specific immunity and obviated the require ment for carrier protein or adjuvant. Moreover, primed dendritic cells induced predominant development of a tumor-specific T-cell response. Each of these immunization strategies resulted in long-term survival w ithout the emergence of idiotype variants or the induction of tumor do rmancy.