Immunization with idiotypic immunoglobulin protects against development of B lymphocytic leukemia, but emerging tumor cells can evade antibody attack by modulation.
Immunization of strain 2 guinea pigs with idiotypic IgM obtained from serum of animals in the terminal phase of the L2C leukemia produced high levels of circulating anti-idiotypic antibody that was cytotoxic for the tumor cells in the presence of syngeneic C. Such animals showed good protection against injected tumor cells, but after a long delay, leukemia did develop. As tumor cells appeared in the blood, anti-idiotype was consumed, but the cells displayed little or no surface Ig and could not be killed in vitro by anti-idiotype and C. However, as serum antibody levels fell, the cells displayed increasing amounts of surface IgM lambda of the same idiotype and regained their susceptibility to the antibody and C in vitro. It appears, therefore, that the ability of tumor cells to modulate their target idiotype can present a considerable problem for antibody-mediated attack.
D000818:Animals; D000920:Antibody-Dependent Cell Cytotoxicity; D001402:B-Lymphocytes / Q000276:immunology; D002471:Cell Transformation, Neoplastic / Q000276:immunology; D006168:Guinea Pigs; D007116:Immunization, Passive; D007130:Immunoglobulin Idiotypes / Q000276:immunology*; D007075:Immunoglobulin M / Q000008:administration & dosage* / Q000032:analysis; D007167:Immunotherapy; D007945:Leukemia, Lymphoid / Q000276:immunology / Q000628:therapy*; D011947:Receptors, Antigen, B-Cell / Q000032:analysis
D007130:Immunoglobulin Idiotypes; D007075:Immunoglobulin M; D011947:Receptors, Antigen, B-Cell