The role of liver in SIV pathogenesis
Description
The macrophage is a common target cell for lentiviral infections, including HIV/ SIV. The kupffer cells of the liver are the largest population of resident macrophages in the body and efficiently filter microbial and other harmful products originate from the gut. An emerging feature of HIV/SIV pathogenesis is the increased levels of microbial translocation that leads to chronic immune activation, occur primarily in the later stages of infection. We used Rhesus macaques for our study as it the premier non-human primate model for the study of human immunodeficiency virus (HIV). We found that there is marked turnover of monocytes/macrophages in the liver consisting of increased rates of apoptosis balanced and surpassed by increased macrophage turn over, resulting in a net increase in Kupffer cells throughout SIV infection. Interestingly, SIV RNA In-situ hybridization in liver, detected only one positive animal. Furthermore, we detected large amount of LPS in the liver in acute SIVmac251 infection. We observed that the liver contain large numbers of T cells predominantly effector CD8+ T cells, both in uninfected and SIV-infected macaques. Furthermore, these data suggests that; (i) Kupffer cells in the liver are not supportive of high levels of viral replication in vivo; (ii) the liver effectively filters elevated levels of microbial products that enter the liver via the portal circulation during early SIV infection