model of HIV disease

Abstract: Microglia, alveolar macrophages, and Lan-gerhans cells are representatives of cells of macrophage lineage that are susceptible to infection with W.V-i and they play important roles in the pathogenesis of AIDS dementia, lymphoid interstitial pneumonia, and systemic viral invasion from mucosal surfaces, respec-tively. In contrast, elimination of CD4 T cells with resultant development of immunosuppression and AIDS is thought to be reflective of the exclusive tro-pism of the virus for CD4 T cells. Examination of these concepts in macaques infected with molecularly cloned strains of SWmac suggested that all strains of the virus are both macrophage- and lymphocyte-tropic and that all aspects of pathogenesis including loss of CD4 T cells are dependent on infection in both cell types. However, viral clones that caused productive lylic infection in macrophages were less virulent than those which caused persistent nonproductive infection. The former caused subclinical and even immunizing infections, whereas the latter caused activation and productive infection in CD4 T cells, AIDS, and sys-temic infection, even after inoculation of the virus on mucosal surfaces. If these findings on SIV are rele-vant to HIV-i disease, then demonstration that lilY-i isolates are macrophage-tropic probably does not nec-essarily correlate with their pathogenic potential. J