HIV and chemokines: Ligands sharing cell-surface receptors

At the cell surface, chemokine receptors and CD4 act in concert to bind to human immunodeficiency virus (HIV) and trigger its entry into and infection of cells. Several different chemokine receptors can act as co-receptors for HIV entry, although either CCR5 or CXCR4 is used by all HIV-1 strains studied so far. The capacity of different HIV strains to exploit different chemokine receptors influences their cell tropism, cytopathicity and pathogenicity. Chemokines, the natural ligands for these receptors, can block HIV entry and are thus potential starting points for the design of novel therapeutic agents against HIV infection.