CAPRISA Discovers Antibodies Capable of Neutralizing HIV

• On 3 March 2014, Center for the AIDS Program of Research in South Africa (CAPRISA) discovers antibodies capable of neutralizing HIV strains. 
• It is a remarkable discovery of potent antibodies that could neutralize and kill multiple strains of HIV. 

• The achievement announced by South African Health Minister Aaron Motsoaledi studied how a South African woman's body responded to her HIV infection by making potent antibodies, broadly called neutralizing antibodies. 
• These potent antibodies are also called as neutralizing antibodies because of their ability to kill multiple strains of antibodies.
• The study, published in the scientific journal, Nature, describes how the team found and identified the antibodies in her blood and then duplicated them by cloning the antibodies in the laboratory. 
• The cloned antibodies were then used in a series of experiments in the laboratory to elucidate the pathway followed by her immune system to make these potent antibodies. 
• Experts from the Vaccine Research Center of the National Institute of Allergy and Infectious Diseases and Columbia University in New York were also involved in the project.

Structure of HIV


“Broadly neutralizing antibodies are considered to be the key to making an AIDS vaccine. This discovery provides new clues on how vaccines could be designed to elicit broadly neutralizing antibodies. The world needs an effective AIDS vaccine to overcome the global scourge of AIDS,” said Professor Salim Abdool Karim, Director of CAPRISA and President of the Medical Research Council, in his comments on the significance of the finding.

What is “Broadly neutralizing antibodies are considered to be the key to making an AIDS vaccine. This discovery provides new clues on how vaccines could be designed to elicit broadly neutralizing antibodies. The world needs an effective AIDS vaccine to overcome the global scourge of AIDS,” said Professor Salim Abdool Karim, Director of CAPRISA and President of the Medical Research Council, in his comments on the significance of the finding.


What are neutralizing antibodies ?

• All HIV infected people respond to HIV by making antibodies. 
• In most patients, these antibodies are not able to kill a wide range of HIV -- this is described as a lack of neutralization breadth. 
• However, in a few infected people, they naturally make antibodies that kill (neutralize) many different kinds of HIV (i.e. they are broadly neutralizing antibodies). 
• These antibodies have previously been shown to be effective in preventing and treating HIV infection in animals, but this has never before been shown in humans."

How the potent antibodies were developed

• The potent antibodies were made by the  researchers by first identifying the antibodies present in the blood of the CAP256 and then duplicating these antibodies by cloning it in the lab. 
• The cloned antibodies were then used to elucidate the pathway followed by the immune system to make these potent antibodies.

Findings of the Research

• In their earlier research in 2013, researchers at CAPRISA discovered that a shift in the position of one sugar molecule on the surface of the HIV virus led to the development of broadly neutralising antibodies against HIV.
• However, in the research conducted on CAP256, the researchers were also able to isolate a broadly neutralizing antibody and trace its origins to understand exactly how it rose. This could lead to new HIV vaccine strategies that are able to stimulate the rare precursors of these protective antibodies.
• The study conducted on CAP256 also showed that broadly neutralising antibodies have some unusual features. These antibodies generally have long arms which enabled them to reach through the sugar coat that protects HIV. Moreover these antibodies had long arms right at the outset requiring less time and fewer changes to become effective in killing HIV.
• All HIV infected people respond to HIV by making antibodies. In most patients, these antibodies are not able to kill a wide range of HIV  which is described as a lack of neutralization breadth. However, in a few infected people, they naturally make antibodies that neutralize many different kinds of HIV, with their broadly neutralizing antibodies.
• South African Department of Health (SADH) has more interest in this development than anyone else in the world since South Africa has the largest burden (30 percent) HIV infection globally.

Funding for the research

• The research was primarily funded by the US National Institutes of Health’s Vaccine Research Center and the South African Department of Science and Technology. 
• The South African researchers also have fellowships from the Wellcome Trust, the Fogarty International Center, the National Research Foundation and the Poliomyelitis Research Foundation.

What is CAPRISA ?

• CAPRISA ("Centre for the AIDS Programme of Research in South Africa") is the name of an AIDS research center based in Durban, South Africa. 
• It was established in 2002 under the National Institutes of Health program called Comprehensive International Program of Research on AIDS (CIPRA). 
• CAPRISA's mission is to promote HIV prevention and research its epidemiology.