Australia: New Immune Treatment May Control AIDS Virus

Building upon successful outcomes with monkeys, scientists are already planning human trials of a new approach to fighting HIV infection.

In findings reported Friday online, researchers described the potential treatment known as OPAL, for Overlapping Peptide-pulsed Autologous Cells. The process involves mixing a patient’s own blood cells with tiny bits of protein from HIV. The approach would be categorized as an immunotherapy technique or a therapeutic vaccine, said Stephen Kent of the University of Melbourne and colleagues.

The researchers worked with macaque monkeys infected with the related simian immunodeficiency virus (SIV). The team took peptides from the virus and placed them in laboratory dishes with both whole blood and isolated immune system cells. This helped train the cells to recognize the virus and mount a more effective defense against it.

"Virus-specific CD4 cells are typically very weak in HIV-infected humans or SIV-infected macaques; dramatic enhancement of these cells were induced by OPAL immunotherapy and this may underlie its efficacy," the team wrote.

The researchers noted that the best results were attained when the treatment was introduced soon after infection. "Although it may be challenging to identify humans within three weeks of infection, this is when HIV-1 subjects typically present with acute infection," they wrote.

"Levels of virus in vaccinated monkeys were 10-fold lower than in controls, and this was durable for over one year after the initial vaccinations," the team wrote. "The immunotherapy resulted in fewer deaths from AIDS. We conclude this is a promising immunotherapy technique. Trials in HIV-infected humans of OPAL therapy are planned."

The full report, "Control of Viremia and Prevention of AIDS Following Immunotherapy of SIV-Infected Macaques with Peptide-Pulsed Blood," was published in Public Library of Science Pathogens (2008;4(5):e1000055).

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