Unique Feature of HIV Helps Create Antibodies, Researchers Discover

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http://www.sciencedaily.com/releases/2012/10/121022081141.htm

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A unique change in the outer covering of the virus found in two HIV infected South African women enabled them to make potent antibodies which are able to kill up to 88 percent of HIV types from around the world. (Credit: © Jezper / Fotolia)

ScienceDaily (Oct. 22, 2012) — A new AIDS study, published Oct. 22 in the journal, Nature Medicine, describes how a unique change in the outer covering of the virus found in two HIV infected South African women enabled them to make potent antibodies which are able to kill up to 88% of HIV types from around the world. The ground-breaking discovery suggests an important new approach that could be useful in making an AIDS vaccine.

The study, performed by members of the Centre for the Aids Programme of Research in South Africa (CAPRISA) consortium, involves scientists from Wits University, the National Institute for Communicable Diseases (NICD) in Johannesburg, the University of KwaZulu-Natal and the University of Cape Town, who has been studying, over the last five years, how certain HIV-infected people develop very powerful antibody responses.

These antibodies are referred to as broadly neutralising antibodies because they kill a wide range of HIV types from different parts of the world. This CAPRISA team initially discovered that two KwaZulu-Natal women, one of whom participated in the CAPRISA 004 tenofovir gel study, could make these rare antibodies.

Through long-term follow-up laboratory studies on these two women, the team led by Wits researchers and Centre for HIV and STI at the National Institute for Communicable Diseases of the National Health Laboratory Service based scientists Dr Penny Moore and Professor Lynn Morris, discovered that a sugar (known as a glycan) on the surface protein coat of the virus at a specific position (referred to as position 332) forms a site of vulnerability in the virus and enables the body to mount a broadly neutralizing antibody response.