For all that is known about human immunodeficiency virus (HIV), some remarkably fundamental questions remain. One of the most notable, perhaps, is just how HIV manages to infect its primary target, CD4+-T cells, when so few of those cells can be found at the virus' typical entry points: the vagina, uterus, cervix, and rectum. It is conceivable that the virus may happen upon a stray macrophage or T cell, but for the most part, these cells are hard to come by.
Two years ago, Yvette van Kooyk, professor of molecular cell biology at Vrije University Medical Center, Amsterdam, and postdoc Teunis Geijtenbeek published back-to-back reports in Cell about a dendritic cell (DC)-specific receptor that appears to help DCs engage naïve T cells.1-3 But HIV's envelope protein can also bind this receptor, giving the virus a beachhead within the body. Together, these reports suggest a simple, elegant model for both T ...
