Pathogenesis of ovine lentivirus-induced arthritis: phenotypic evaluation of T lymphocytes in synovial fluid, synovium, and peripheral circulation.
Sheep and goats develop a chronic, progressive arthritis reminiscent of rheumatoid arthritis, but caused by lentiviruses related to human immunodeficiency virus. The distribution of T lymphocytes in peripheral circulation of two infected sheep with arthritis, one infected sheep with interstitial pneumonia, three asymptomatic sheep, and three uninfected sheep was evaluated. Sheep with clinical disease have depressed ratios of CD4/CD8 lymphocytes in peripheral circulation compared to asymptomatic and uninfected animals. In one sheep, the depressed ratio was due to an absolute increase in CD8-positive lymphocytes. The predominant lymphocyte populations in both synovial fluid and synovium from this animal were also CD8 positive. Macrophages were the other predominant cell population in synovial fluid and were infected with lentivirus. Little cell-free virus was detected in the synovial fluid, although 1 in 400 cells was infected as determined by infectious center assays. Infected cells in the synovial fluid had a reduction in virus gene expression compared to infected cells in peripheral circulation. This reduction in virus gene expression may be due to the presence of interferon-like activity in the synovial fluid.
Kennedy-Stoskopf
S
S
Division of Comparative Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland 21205.
Zink
C
C
Narayan
O
O
D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D001168:Arthritis / Q000209:etiology / Q000276:immunology*; D016827:CD8 Antigens; D007372:Interferons / Q000032:analysis; D008264:Macrophages / Q000276:immunology; D009000:Monocytes / Q000276:immunology; D010641:Phenotype; D012190:Retroviridae / Q000302:isolation & purification; D012192:Retroviridae Infections / Q000150:complications / Q000276:immunology*; D012756:Sheep; D013582:Synovial Fluid / Q000276:immunology* / Q000382:microbiology; D013583:Synovial Membrane / Q000276:immunology*; D013601:T-Lymphocytes / Q000145:classification* / Q000276:immunology
D000945:Antigens, Differentiation, T-Lymphocyte; D016827:CD8 Antigens; D007372:Interferons