title: Phenotypic heterogeneity of Gross virus-induced thymic lymphomas in the rat: cellular origins and migratory properties.
abstract: Neoplastic thymocytes from rat thymic lymphoma-leukemias induced by the rat-adapted Gross leukemia virus (RAGV) were analyzed for a variety of differentiation markers. The neoplasms from individual rats all expressed the antigenic phenotype MP+, W3/13+, Thy-1+, RT-1+, RT-7+, W3/25-. However, approximately two-thirds of the neoplasms were positive for the OX 8 antigen, and one-third were negative. The OX 8- neoplasms only involved the thymus, whereas approximately 40% of the OX 8+ neoplasms involved the spleen as well as the thymus. Virtually all OX 8+ and OX 8- neoplastic cells contained terminal deoxynucleotidyl transferase (TdT), and both OX 8+ and OX 8- lymphomas expressed the lactate dehydrogenase (LDH)-5' isozyme and the primary, but not the secondary, ADA isozyme. This enzymatic phenotype is characteristic of thymocyte precursors, but not thymocytes. Our results therefore indicate that RAGV-induced lymphomas arise from transformed prethymic TdT+ cells which contain the LDH-5' and the primary ADA isozymes. These preleukemic cells presumably migrate to the thymus where they express the RT-7 pan-T-cell antigen and, in some instances, the OX 8 antigen during the development of overt leukemia. The OX 8+ neoplasms, being more differentiated than their OX 8- counterparts, then migrate to peripheral lymphoid tissues.
mesh_terms: D000406:AKR murine leukemia virus / Q000472:pathogenicity*; D000818:Animals; D000954:Antigens, Surface / Q000032:analysis; D003593:Cytoplasm / Q000276:immunology; D004253:DNA Nucleotidylexotransferase / Q000378:metabolism; D005260:Female; D007075:Immunoglobulin M / Q000378:metabolism; D007527:Isoenzymes / Q000032:analysis; D007942:Leukemia, Experimental / Q000201:enzymology / Q000276:immunology / Q000473:pathology*; D008223:Lymphoma / Q000201:enzymology / Q000276:immunology / Q000473:pathology*; D008297:Male; D051381:Rats; D011917:Rats, Inbred Lew; D013953:Thymus Neoplasms / Q000201:enzymology / Q000276:immunology / Q000473:pathology*
chemical_list: D000954:Antigens, Surface; D007075:Immunoglobulin M; D007527:Isoenzymes; D004253:DNA Nucleotidylexotransferase