Human immunodeficiency virus infection of the brain: Pitfalls in evaluating infected/affected cell populations

Monocyte/macrophages and CD4 T-cells are the primary hematopoietic targets of productive HIV infection. In the brain, potential cellular targets for HIV infection include perivascular and parenchymal macrophages/microglia, oligodendrocytes, endothelia, neurons, and astrocytes. We examine evidence of productive and non-productive infection for each cell type in the brains of HIV-infected patients with and without HIV encephalitis. Despite the voluminous literature and substantial experimental effort over the past two decades, evidence for productive infection of any brain cell other than macrophages is left wanting.