Background
HIV infection leads to a progressive depletion of uninfected CD4 cells. We showed that NKp44L, a cellular ligand for an activating NK receptor is over-expressed during HIV infection and is correlated with both CD4 depletion and increase in viral load. NKp44L+CD4+ cells are highly sensitive to the NK lysis activity. However, HIV-infected cells are resistant to NK killing, suggesting that HIV-1 develop escape mechanisms to counteract NK cytotoxicity.