Why many of the human antibodies produced against HIV-1 are ineffective is revealed in two independent studies published online this week in Nature Structural & Molecular Biology. These findings may have implications for future vaccine design.
Our immune system produces antibodies that can protect us against many diseases; however HIV-1 seems impervious to such defenses. The viral protein gp41 plays a crucial role for viral fusion with and entry into cells. Though antibodies against gp41 are formed in HIV-1 patients, those that can effectively block cell infection are exceedingly rare. Nathan Nicely and Barton Haynes in one study and Bing Chen in another study show that the most common, yet ineffective antibodies recognize gp41 in a form that it adopts after the virus has already entered the cell, explaining why they cannot protect cells against HIV-1.