Patrolling
immune system cells that may begin the HIV disease process by carrying the
virus from the site of the
infection to the
lymph nodes, where other immune cells become infected. Dendritic cells travel through the body and bind to foreign invaders-such as HIV-especially in external tissues, such as the skin and the membranes of the gut, lungs and reproductive tract. They then ferry the foreign substance to the
lymph nodes to stimulate
T cells and initiate an
immune response. In laboratory experiments, the dendritic cells that carry HIV also bind to CD4+
T cells, thereby allowing HIV to infect the CD4+
T cells. CD4+
T cells are the critical
immune system cells targeted by HIV and depleted during HIV
infection. See also
CD4 (
T4) or CD4+ Cells;
Lymph Nodes;
T Cells.