title: Functional heterogeneity of in vitro selected variants from an IgM-secreting rat immunocytoma.
abstract: A long-term tissue culture line of highly metastatic IR202 immunocytoma of LOU rats, and five of its clones (B4, C2, C4, C5, and D3) were established and studied comparatively. All such cells were similar in terms of: (i) light microscopic morphology, (ii) growth rate, (iii) saturation density, (iv) cell cycle progression, and (v) cell surface IgM, major histocompatibility complex (MHC) class I and class II antigen expression, but (vi) showed a non-homogeneous pattern of chromosomal constitution, with both numerical and structural abnormalities detected in variable proportions of the different cell variants. Moreover, IR202 variants exhibited a marked difference in the production of soluble factors which was closely associated with the ability of their supernatants to inhibit mitogen (affinity-purified goat F(ab')2 fragments specific for rat mu-chains (anti-mu antibody), lipopoly saccharide (LPS), or concanavalin A (ConA))-induced proliferation of normal splenic B and/or T lymphocytes. These results are consistent with the concept of intratumor heterogeneity and the ability of immunoglobulin-secreting tumors to induce severe immune dysfunction in host animals and humans.
authors.affiliation: Department of Immunopathology, National Institute of Haematology, Blood Transfusion, and Immunology, Budapest, Hungary.
authors.forename: E
authors.initials: E
authors.lastname: Puskás
authors.forename: R
authors.initials: R
authors.lastname: Mihalik
authors.forename: M R
authors.initials: MR
authors.lastname: Avalos
authors.forename: F
authors.initials: F
authors.lastname: Uher
mesh_terms: D000818:Animals; D000912:Antibodies, Neoplasm / Q000032:analysis*; D002453:Cell Cycle; D002455:Cell Division; D002999:Clone Cells / Q000276:immunology / Q000473:pathology*; D017077:Culture Media, Conditioned / Q000494:pharmacology; D016207:Cytokines / Q000378:metabolism; D004273:DNA, Neoplasm / Q000032:analysis; D003864:Depression, Chemical; D007075:Immunoglobulin M / Q000032:analysis*; D007153:Immunologic Deficiency Syndromes / Q000209:etiology; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000150:complications / Q000276:immunology / Q000473:pathology*; D008213:Lymphocyte Activation / Q000187:drug effects; D008297:Male; D051379:Mice; D008811:Mice, Inbred DBA; D009368:Neoplasm Transplantation; D051381:Rats; D011919:Rats, Inbred Strains; D011947:Receptors, Antigen, B-Cell / Q000032:analysis*; D014407:Tumor Cells, Cultured
chemical_list: D000912:Antibodies, Neoplasm; D017077:Culture Media, Conditioned; D016207:Cytokines; D004273:DNA, Neoplasm; D007075:Immunoglobulin M; D011947:Receptors, Antigen, B-Cell