Macrophages: do they impact AIDS progression more than CD4 T cells?

Destruction of CD4(+) T cells is considered to be the main cause of immunodeficiency manifested by opportunistic infections in HIV-1-infected humans, as well as in SIV-infected macaques. We propose that monocyte/macrophage lineage cells also play an important role in the pathogenesis of AIDS, based on our recent work with the SIV/rhesus macaque animal model. We propose that damage to CD4(+) T cells is important and readily apparent, but damage to monocyte/macrophage lineage cells, although less obvious, may provide the missing link to predict the onset of opportunistic infections and progression to AIDS.