Lymphocyte mitogen reactivity and enumeration of circulating B- and T-cells during feline leukemia virus infection in the cat.
Mitogen-induced blast transformation of peripheral blood lymphocytes and quantitative changes in circulating T- and B-cells were studied serially in cats inoculated with feline leukemia virus (FeLV). Concanavalin A-induced blast transformation sharply declined beginning at 5 weeks post inoculation (Pl) in FeLV-infected cats when compared to age-matched uninfected control cats. Similar but less consistent changes were seen in responses to pokeweed mitogen-induced stimulation. In most infected kittens this defect persisted until they died from thymic lymphosarcoma, 15-24 weeks Pl. An early lymphopenia, due primarily to a decrease in circulating B-cells, occurred in infected cats 5-8 weeks Pl. Following a return of total and B-lymphocytes to control values, infected cats developed increased numbers of T-cells at 16 or more weeks Pl, which correlated with circulating lymphoblastic lymphocytes bearing T-cell markers. These results correlated neoplasia arising in a thymus-derived lymphocyte population with mitogenic hyporeactivity in the preneoplastic period and suggested that FeLV-induced immune alterations may be a necessary antecedent of leukemogenesis in the cat.
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D002415:Cats; D003208:Concanavalin A / Q000494:pharmacology; D004912:Erythrocytes / Q000276:immunology; D007165:Immunosuppression Therapy; D005256:Leukemia Virus, Feline; D007942:Leukemia, Experimental / Q000209:etiology / Q000276:immunology*; D007958:Leukocyte Count; D008213:Lymphocyte Activation; D008228:Lymphoma, Non-Hodgkin / Q000209:etiology / Q000276:immunology*; D008934:Mitogens / Q000494:pharmacology; D009374:Neoplasms, Experimental / Q000209:etiology / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D013953:Thymus Neoplasms / Q000209:etiology / Q000276:immunology*
D008934:Mitogens; D003208:Concanavalin A