title: The effects of passive anti-viral immunotherapy in AKR mice: II. Susceptibility to B cell lymphomagenesis.
abstract: Prevention of high frequency spontaneous T cell lymphoma development in AKR mice by mAb 18-5 treatment was shown to involve inhibition of the recombinant Class I MCF virus formation and elimination of the early occurring potential lymphoma cells (PLCs). A low B cell lymphoma incidence (16% at a mean latency of 540 days) and a low level of PLCs (yielding 12% B cell lymphoma development following lymphoid cell transfer) was observed in mAb 18-5 treated mice (in contrast to a high PLC level in thymectomized AKR mice that could be experimentally triggered to progress to overt CD5+ B cell lymphomas). Administration of anti CD8 mAb or IL-4 to 12-month-old mAb 18-5 pre-treated mice only slightly increased B cell lymphoma incidence (up to 30-40%). Exposure to split-dose irradiation resulted in 26% B cell lymphomas at a 250 day mean latency. The phenotypes of the B lymphomas developing in mAb 18-5 treated mice were: B220+ (14.8+, 6B2+), 6C3+, Mac2+, CD5-. Most lymphomas expressed l-a and surface IgM, pointing to their mature B cell characteristics. Moreover, in some of the lymphomas, high levels of IgM production and secretion were determined. A comparison of the morphological characteristics (based on light and ultrastructure microscopy) of CD5+ and CD5- B cell lymphomas developing in AKR mice indicated marked differences. Analysis of the IgH locus of representative CD5- B lymphomas showed an identical pattern of IgH rearrangement in some tumors (similar to previous findings among CD5+ lymphomas). The virological analysis of the CD5- B cell lymphomas (similar to those observed in the CD5+ B cell lymphomas of AKR origin) showed that their development did not require formation of the pathogenic MCF recombinant viruses. The differences observed between the CD5+ and CD5- B cell lymphomas developing in AKR mice (following prevention of spontaneous T cell lymphomagenesis) may be due to their origin of different B cell precursors or from B cells at different levels of differentiation.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000914:Antibodies, Viral / Q000276:immunology; D018956:CD5 Antigens / Q000032:analysis; D004279:DNA, Viral / Q000032:analysis; D015326:Gene Rearrangement, B-Lymphocyte, Heavy Chain; D005803:Genes, Immunoglobulin; D007116:Immunization, Passive; D007136:Immunoglobulins / Q000096:biosynthesis; D016130:Immunophenotyping; D016393:Lymphoma, B-Cell / Q000209:etiology* / Q000276:immunology; D051379:Mice; D008806:Mice, Inbred AKR / Q000276:immunology*; D008908:Mink Cell Focus-Inducing Viruses / Q000276:immunology; D014412:Tumor Virus Infections / Q000517:prevention & control
chemical_list: D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D018956:CD5 Antigens; D004279:DNA, Viral; D007136:Immunoglobulins