HIV infection impairs more than just T cells
Infection with HIV, the virus that causes AIDS, results in substantial CD4+ T cell loss, which impairs immune responses to bacterial and fungal infections. To uncover changes in other immune cell types, Arnold et al. compared the pathogen-induced responses of peripheral blood mononuclear cells (PBMCs) from HIV-infected patients with the responses of PBMCs from healthy donors. They also analyzed the responses of healthy donor PBMCs that were experimentally depleted of CD4+ T cells to mimic the HIV-infected state. Mathematical analysis predicted and experiments showed that, independently from the loss of CD4+ T cells, the defective response of the immune cell network in HIV-infected patients to pathogens was associated with decreased production of interferon-γ by natural killer cells. Similar analysis of immune cells populations, rather than of purified subsets, may help to identify network-level effects in other diseases.
