HIV affects characteristically -

As already stated, HIV affects cells having CD4 receptors. The CD4 receptors appear to be involved in T-cell death. Monocytes and macrophages, which possess CD4 receptor in lesser concentration are not destroyed as extensively as are T cells. This is clinically significant in two ways :- Monocytes and macrophages serve as reservoirs for HIV as it replicates protected within these cells from the immune system. These cells migrate across the blood brain barrier carrying HIV to the central nervous system. HIV causes brain disease, and the predominant cell type harboring HIV in the central nervous system is the monocyte macrophage line.