Just when you thought you understood how HIV is transmitted, think again. Researchers have identified a new protein molecule, or receptor, called DC-SIGN that sits on the surface of dendritic cells in the mucosa.
Dendritic cells are part of the immune system.
These cells, not T-cells, now appear to be the first to encounter HIV when it's transmitted sexually. In the new model, immature dendritic cells called Langerhans cells snag the virus, and carry it to underlying tissue. Along comes a more mature dendritic cell with the DC-SIGN receptor. This cell ferries the virus through the mucosa over to T-cells in the lymph nodes. To the average person, what's also hot news is that DC-SIGN not only offers a new target for blocking HIV, but potentially, new treatments and prevention tools.