DNA IMMUNIZATION INDUCES PROTECTIVE IMMUNITY AGAINST B-CELL LYMPHOMA

Idiotypic determinants of the immunoglobulin expressed on the surface of B-cell lymphomas are tumor-specific antigens (TSAs), which can be t argeted by immunotherapy. Immunization with DNA constructs encoding th e idiotype (Id) of a murine B-cell lymphoma induced specific anti-id a ntibody responses and protected mice against tumor challenge. Use of D NA encoding an Id/CM-CSF (idiotype/granuiocyte-macrophage colony-stimu lating factor) fusion protein improved vaccine efficacy, and xenogenei c immunoglobulin constant region determinants were required for immuno genicity. These results indicate that DNA may be a simple and efficaci ous means of inducing immune responses against a weak, otherwise unrec ognized tumor antigen, provided that additional stimuli are included w ith the DNA.