ACTIVE SPECIFIC IMMUNOTHERAPY OF ADENOCARCINOMAS PRODUCING IMMUNOSUPPRESSIVE MUCINS

摘要

Adenocarcinomas display and circulate immunosuppresive mucins such as epiglycanin. Pretreatment with cyclophosphamide or other suppressor T cell-inhibitory agents enhances the specific immune response to a synthetic glycoconjugate presenting the T-alpha hapten. Tumor-bearing mice received this tumor vaccine formulation were able to achieve approximately 90 % long-term survival (> 90 days). When mice were treated with the same vaccine formulation without cyclophosphamide, 25 % survival for the same length of time was observed. Many surviving mice had good delayed-type hypersensitivity responsiveness to the synthetic conjugate and among them a few also had good IgG antibody titer against the same conjugate. Upon further intraperitoneal challenge with 1 x 10<4> live Ta3-Ha tumor cells, approximately 30 % of the surviving animals which had been pretreated with the complete vaccine formulation were still able to sustain long-term survival or complete care. Circulating immunosuppressive mucins may also be removed by pheresis.