S100A9 protein is a novel ligand for the receptor CD85j and their interaction is implicated in the NK cell-mediated control of HIV-1 replication

Background CD85j is a receptor expressed by different cells of the human immune system including Natural Killer (NK) cells. Previous reports have shown that CD85j interacts with several MHC-I molecules, as well as with some viral proteins (Cosman D et al., 1997). We have also demonstrated that CD85j NK cells efficiently control HIV-1 replication in monocyte-derived dendritic cells (MDDC) in vitro (Scott-Algara D et al., 2008). We hypothesize that the CD85j NK cell-mediated anti-HIV activity in MDDC is specifically dependent on the interaction between CD85j receptor and unknown non-HLA class I ligand(s). Therefore we focused on the identification CD85j ligand(s) and its(their) implication in the control of HIV-1 infection.