Fig. (2).

Two major mechanisms that might be involved in HIV infection of astrocytes in vivo are shown. One occurs via the cell-to-cell contact with HIV-infected lymphocytes, by which immature HIV particles are transmitted to astrocytes. The second may require inflammatory factors (e.g., cytokines, chemokines, etc.) produced from HIV-infected perivascular macrophages and/or microglia that up-regulate expression of HIV receptor and co-receptors in astrocytes making the cell (highlighted) permissive to HIV infection. Mø - macrophage