Aids 17 Antibodies to HI viruses discovered

AIDS: Researchers have discovered 17 antibodies against the HIV virus

18/08/2011

For almost 30 years scientists worldwide have been seeking effective therapies for the immune deficiency disease AIDS. Again and again, researchers announced first successes, which allegedly push back the HI virus. So far, however, without a resounding therapeutic success. Californian researchers now report discovering 17 new antibodies that could be effective against AIDS viruses.

Resistant immunoglobulins determined
Are US scientists a step ahead in the fight against AIDS? A research team led by Laura Walker of the Scripps Research Institute in La Jolla, California reported discovering 17 antibodies that appear to be effective in fighting HIV viruses. In one study, they took four HIV-infected immunoglobulins from the blood. The special feature, all four subjects were so far resistant to the HI virus, so that the actual immune deficiency disease has not yet erupted. In more than 10 percent of those infected with HIV, the human defense system develops its own antibodies, which work against many types of AIDS viruses. This knowledge has been used intensively in research for several years.

In a cross test on 162 different HI viruses it was found that the newly discovered antibodies acted ten to one hundred times more potent than previously measured antibodies. Even if the antibodies were only present in a very low concentration, they could still kill up to 50 percent of the AIDS-causing viruses. It turned out that a large number of immunoglobulins were highly potent against a large number of pathogens.

Abwehrkörper could make widespread Aids virus type C harmless
The antibodies were able to harm even Type A AIDS viruses, which are particularly prevalent on the African sub-Saharan continent. About half of all AIDS patients worldwide are infected with this virus strain. Very adaptable viruses such as hepatitis C, HIV, and influenza viruses have so far made every attempt to develop an active ingredient, as the researchers in the journal „Nature“ to report. The globally circulating and widely mutated virus variants have failed all previous attempts to find a potential antibody. However, according to the study leader, a mix of different and potent immunoglobulins could help them make their first breakthrough in the search for a vaccine. The first step was laid by successfully isolating the various and broadly neutralizing antibodies from several people. Here's hope that „an antibody-based vaccine is achievable“, explained Laura Walker.

Immunoglobulins are proteins which form antigens on viral or bacterial invaders. From this develop antibodies that support the immune system. For the study blood was taken from about 1800 HIV patients. Using the isolated antibodies of the four donors, the researchers investigated whether and in what form AIDS viruses are inhibited or neutralized. Four blood sera were found to be particularly effective and successfully drove back a variety of pathogens successfully. These were then used for further research. From this, the scientists isolated the B memory cells, that is, cells that produce antibodies. With the help of a gene analysis genes were determined in the cells, which programmed particularly immunoglobulins. This resulted in 17 monoclonal antibodies in which efficiency was investigated.

Back in 2010, researchers at the National Institutes of Health's Bethesda (NIH) National Institute of Allergy and Infectious Diseases (NIAID) discovered naturally occurring antibodies called VRC01 and VRC02 in the blood of an AIDS patient. These prevented the penetration of HI viruses so that the disease could not break out. Since then, this approach has been followed closely in AIDS research. Nonetheless, research has continued to grow and few results have led to Phase III clinical trials, in which serum is also administered to human volunteers.

Conventional Approach of Antibody Vaccination
The most successful study projects to date have been performed by researchers as part of a research project conducted in Thailand. In the years 2003 to 2009, a study was carried out with more than 16,000 people. Participants were given a combination of two different vaccines. One part contained a bird's pox virus genetically infected with HI virus proteins and the other part an isolated viral protein. The method is used in the professional world as „active immunization“ referred to, in which the body's defenses are to be stimulated in order to produce suitable antibodies against the AIDS virus. However, the method was only moderately successful, as only a success rate of 31 percent was achieved. In addition, the results are repeatedly questioned critically, because the active immunization only worked against individual strains. Therefore, the conventional approach of antibody vaccination could take a new direction in research. However, it may take years, if not decades, for an effective product to develop. The obviously tricky Aids virus has managed over the past 30 years time and again to resist any approach. (Sb)

Read about AIDS:
30 years of AIDS: still no cure in sight?
Two million HIV infected teens worldwide
China: clinics deny Aids patients
UN warns against rapid spread of AIDS
AIDS: SI virus is considered a precursor to HIV
Why some people do not get AIDS despite HIV
AIDS: No fate with real antibodies?