Rare Antibody Can Recognize, Prompt Immune System Response to HIV, May Be Used To Develop Vaccine
Scientists have discovered how 2G12 -- an antibody isolated nearly a decade ago in an HIV-positive person whose body seemed to resist the virus -- recognizes HIV and prompts the immune system to attack it, a finding that could help scientists develop an HIV vaccine, according to a study published in today's issue of Science, Reuters reports (Fox, Reuters, 6/26). In the past, scientists have struggled to find a vaccine that can recognize HIV and bind to it, which is difficult because the virus is coated in the same carbohydrates as regular body cells and is therefore not recognized as foreign material (BBC News, 6/26). Scientists from the Scripps Research Institute, Florida State University, the University of Oxford and the University of Agriculture in Vienna, Austria, analyzed the structure of 2G12 by diffracting X-rays from crystals of the antibody (NIH release, 6/26). The scientists discovered that because of the antibody's structure, it has a unique way of attaching itself to tiny proteins on the virus, which allows it to properly target HIV and prevent it from replicating (Dunn, Tallahassee Democrat, 6/27).
The researchers hope to use the structure of 2G12 as a template to design a vaccine-like antigen that would stimulate the body to make 2G12 or a similar antibody capable of neutralizing HIV. Such a vaccine would prevent HIV infection by allowing the body to attack the virus before it enters and infects the cells (Scripps Research Institute release, 6/26). The researchers think that 2G12 could be particularly successful as a vaccine candidate because the antibody seems to work despite HIV's frequent mutations, which allow the virus to avoid detection by the body. Kenneth Roux, an FSU professor involved in the study, said, "There have been 250 antibodies studied at the atomic level [but] [n]othing like this has ever been seen ... or speculated upon." According to Roux, a vaccine trial involving the antibody might not happen for years (Tallahassee Democrat, 6/27).