ABSTRACT
The LP-BM5 murine leukemia virus causes acquired immunodeficiency syndrome in C57BL/6J mice (MAIDS), similar to that of AIDS in humans. The objective of this study was to determine the effect of LP-BM5 viral infection on cellular activation and membrane integrity of splenocytes. Oxidative burst in splenocytes in response to exposure to PMA (20 microg/ml) was significantly higher (p<.02) in infected than in control mice at two weeks post-infection using luminol-enhanced chemiluminescence. By 13 weeks post-infection superoxide anion production in infected mice was significantly lower when compared to controls coinciding with decreased proliferative response to mitogens. The extent of cell membrane damage as indicated by lactic dehydrogenase (LDH) activity in serum was significantly higher in infected than in control mice (p<.001). The results from this study suggests that LP-BM5 virus causes an initial stimulation of cellular activity followed by a decreased cell activation characterized by decreased proliferation of splenocytes and decreased oxygen radical production. Decreased cell membrane integrity indicated by increased LDH activity may partly be responsible for these changes.
Subject(s)
L-Lactate Dehydrogenase/biosynthesis , Leukemia Virus, Murine/physiology , Reactive Oxygen Species/metabolism , Spleen/enzymology , Spleen/metabolism , Animals , Concanavalin A/pharmacology , Enzyme Activation , Female , Lymphocyte Activation , Mice , Mice, Inbred C57BL , Spleen/cytology , Spleen/immunologyABSTRACT
We are currently using caprine arthritis encephalitis virus (CAEV) infection in goats as a model to understand changes in some clinical parameters and host response to infection with human immunodeficiency virus (HIV). The objective of this study was to measure changes in serum antioxidant activities in various age groups of goats infected with CAEV. Serum from CAEV-infected goats had significantly higher catalase activity (105.47 +/- 5.96 kU/l) than serum from healthy control goats (79.92 +/- 17.06 kU/l). Moreover, serum catalase activity increased with increase in the time after infection with CAEV. No change was observed in total superoxide dismutase (SOD) or glutathione peroxidase activity although CuZn SOD levels were elevated in infected goats. There was a positive correlation between serum catalase activity and hydrogen peroxide (H2O2) scavenging activity (r = 0.70, p < 0.05). In order to investigate cell membrane integrity, we determined lactate dehydrogenase (LDH) activity in infected goats. Although there was a transient increase in LDH no correlation was observed between increased serum catalase activity and LDH activity (r = 0.16, p > 0.05). We have earlier observed decreased oxyradical production in CAEV infected goats. This observed increase in serum catalase, a scavenger of endogenous free radicals such as H2O2 may be partly responsible for the observed decrease in oxygen radicals found in vivo.
Subject(s)
Antioxidants/analysis , Arthritis, Infectious/veterinary , Arthritis-Encephalitis Virus, Caprine , Catalase/blood , Disease Models, Animal , Glutathione Peroxidase/blood , Goat Diseases/blood , HIV Infections , Lentivirus Infections/veterinary , Superoxide Dismutase/blood , Age Factors , Animals , Arthritis, Infectious/enzymology , Arthritis, Infectious/virology , Cachexia/enzymology , Cachexia/veterinary , Cachexia/virology , Free Radical Scavengers , Goats/blood , Hydrogen Peroxide/blood , L-Lactate Dehydrogenase/blood , Lentivirus Infections/enzymologyABSTRACT
Goats infected with caprine arthritis-encephalitis virus (CAEV) show chronic arthritis and cachexia, which are progressive in nature. The immunopathogenic mechanisms responsible for these progressive clinical symptoms have not been fully elucidated. Various haematological and immunological parameters were evaluated in experimentally-infected goats showing typical signs of CAEV-induced disease. Infected goats showed recurrent lymphocytosis that may be due to constant presentation of antigen by infected cells of a monocyte/macrophage lineage. The serum alkaline phosphatase and gamma-glutamyl transferase concentrations were elevated in infected goats, a characteristic of hepatic and bone disorders. All other serum chemistry parameters were similar between infected and control goats. Importantly, the serum tumour necrosis factor-alpha (TNF-alpha) levels were higher in infected goats. The cachexia seen in infected goats may be at least partly due to altered metabolism as a result of prolonged elevation of serum TNF-alpha levels. Depressed natural killer cell activity was observed in infected goats and may contribute towards the establishment of a persistent infection with CAEV.
