HIV-1 traffic: cell-free, cell-associated and other CNS activating stories

ssues of HIV-1 trafficking into the central nervous system (CNS) are closely linked with entry of cells from the periphery into the CNS, their immune status, and the resultant immune activation of neural cells. In addition, molecular evolution of HIV-1 in different tissue compartments and the changes of acquired immune responses to virus influence these phenomena. Although the mode of HIV-1 penetration of the CNS may be diverse, there is general consensus that monocyte-associated virus is the predominant route of HIV-1 traffic in the brain. Mononuclear phagocytes (MPs) deliver the virus to the brain acting as a "Trojan horse. " Neuro-immune events in late stage HIV-1-associated dementia (HAD) mainly revolve around MP secretory products (cellular and viral toxins) produced during HIV-1 encephalitis. Thus, indirect mechanisms initiated by activated MPs play a major role in neuronal dysfunction, resulting in HAD