Immunoglobulin idiotypes (Id) of malignant B cells are tumor-specific antigens that may be targeted for immunotherapy. Id-directed immunotherapy by immunization with autologous Id has been initiated in clinical trials to control residual disease in B-cell lymphoma and multiple myeloma. The effector mechanisms responsible for destruction of B-cell tumors are a controversial issue. The authors show that vaccination with Id-pulsed dendritic cells (DCs) or with soluble Id-KLH in adjuvant induced immune responses that eliminated both B-cell lymphoma and myeloma in tumor-bearing mice; however, the two vaccination regimens resulted in distinct immune responses. Whereas soluble Id plus adjuvant induced high levels of anti-Id antibodies, the Id-pulsed DCs did not induce anti-Id or any antitumor antibodies. Immunization with Id-pulsed DCs induced a significant increase in the frequency of Id-reactive T cells. Depletion studies in DC-vaccinated mice showed that the predominant effector cells responsible for tumor rejection were of the CD8+ subset. The finding that DC-based Id vaccines elicit tumor protection, which is entirely based on cell-mediated effector mechanisms, is of particular importance for plasma cell tumors because these tumors do not express Id on the surface and hence do not bind anti-Id antibodies.
|Number of pages||6|
|Journal||Journal of Immunotherapy|
|State||Published - 2005|
- B-cell lymphoma
- Cell-mediated immune responses
- Idiotype vaccines
- Plasma cell tumors