HIV vaccine comes closer to reality

A research team from the University of Texas, including an Indian origin scientist, has come closer to creating a vaccine for human immunodeficiency virus (HIV) by creating an antigen that induces protective antibodies capable of neutralizing genetically diverse HIV strains.

"The complexity of HIV has for long thwarted development of an effective HIV vaccine. Our findings open a new path toward an effective preventative and therapeutic vaccine," said Dr Sudhir Paul, the study's senior author and a professor in the Department of Pathology and Laboratory Medicine at The University of Texas Medical School at Houston.

"The new antigen is a prototype vaccine. This prototype successfully eliminates nature's restrictions on the production of broadly-neutralizing antibodies to HIV by the immune system," he added.

The vaccines work by introducing an antigen into the body, which spurs the immune system to produce antibodies that guard against infection.

Previously-tested HIV vaccine candidates stimulated vigorous production of antibodies to the mutable segments of the virus envelope. But, these vaccine candidates did not stimulate the production of antibodies to the regions essential for virus attachment to host T cells, the process that initiates infection.

In the new study, the researchers used a chemically-activated form of the HIV envelope protein gp120 to stimulate the production of mouse monoclonal antibodies that block infection of cultured human cells by genetically-diverse HIV strains from around the world.

Paul said these same antibodies could be found in humans who remain free of AIDS despite long-term HIV infection.

"Dr Paul's team has developed a revolutionary antibody technology and used it to overcome major obstacles to a vaccine for HIV," said Dr Robert L Hunter, professor and chairman of the Department of Pathology and Laboratory Medicine at the UT Medical School at Houston.

"They identified antibodies that neutralized 100 per cent of strains drawn from the major viral subtypes.

"Furthermore, they have developed ways to immunize animals to produce them. No previous vaccine candidate has even approached these objectives," he added.

The study appears in the Journal of Biological Chemistry.