Abstract

Lentiviruses are widespread pathogens of the Felidae, infecting both domestic cats and non-domestic felids. Within the domestic cat population, feline immunodeficiency virus (FIV) is a significant cause of disease, with infection resulting in an immunodeficiency syndrome characterised by recurrent gingivitis-stomatitis, cachexia, wasting, neuropathology and an increased risk of tumour development. The association between lentiviral infection and disease development in non-domestic felids is less clear, however lentivirus-infected African lions show a marked decline in CD4 T lymphocytes and the expansion of an activated CD8a/b lymphocyte sub-population, analogous to observations in FIV and HIV infections. Moreover, captive lions have succumbed to lentivirus-associated diseases after prolonged infection and specific pathological changes including lymphadenopathy, gingivitis, tongue papillomas and cachexia have been described recently in free-ranging lions. In this presentation, I explore the role of the virus-receptor interaction in the pathogenesis of feline AIDS , examining the link between the expression of the viral receptors CD134 and CXCR4 , cell tropism and pathogenesis, and comparing the lentiviruses of the domestic cat and the African lion. Moreover, our recent data suggest that the nature of the virus-receptor interaction alters with disease progression, suggesting that the virus we isolate from a cat displaying clinical signs may differ significantly from the virus that is transmitted between cats.