Research Brings Effective HIV Vaccine Closer to Reality
A research team from The University of Texas Medical School at Houston has come closer in 2009 to creating a new HIV vaccine. The scientist report the creation of the first antigen that induces protective antibodies capable of blocking infection of human cells by genetically-diverse strains of HIV.
The work comes out of the laboratory of Sudhir Paul, PhD. The report of their findings is available online in the the Journal of Biological Chemistry.
The new antigen differs from previously-tested HIV vaccines by virtue of its chemically-activated property that enables close sharing of electrons and produces strong covalent bonding. Researchers used a mouse model to generate the antibodies.
Dr Paul stated, "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. 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."
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 did not stimulate the production of antibodies to the regions essential for virus attachment to host T cells, the process that initiates infection.
Dr Paul and colleagues 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. These same antibodies can be found in humans who remain free of AIDS despite long-term HIV infection.
“While the prototype vaccine induces antibodies that neutralize infection of isolated human cells, we must also show that the antibodies prevent the natural process of infection within the body," said Stephanie Planque, Ph.D., co-author and researcher in Paul's laboratory.
According to the World Health Organization, thirty-three million people were living with HIV at the end of 2007. That same year, nearly 3 million people became newly infected, and 2 million died of acquired immunodeficiency syndrome or AIDS, which occurs at the most advanced stages of HIV infection. These scientists bring hope that an effective HIV vaccination may be possible.
"The induction of antibodies that neutralize infection of human blood cells by diverse strains of HIV from various parts of the world is an important milestone. This is an entirely new vaccination approach that might bypass the natural constraints on developing effective immunity against HIV," said Carl Hanson, Ph.D., study co-author and head of the Retrovirus Diagnostic Section of the Viral and Rickettsial Disease Laboratory of the California Department of Public Health.
University of Texas Health Science Center at Houston
Towards effective HIV vaccination. Induction of Binary Epitope Reactive Antibodies with Broad HIV Neutralizing Activity J. Biol. Chem. jbc.M109.032185 First Published on September 2, 2009, doi:10.1074/jbc.M109.032185
Written by Ramona Bates MD
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