The ability to induce and expand the immune response across most or all parts of the virus is highly advantageous. Our results, which consistently demonstrated sharply enhanced immunity in vaccinated animals, suggest that this therapy could also work in humans.

The findings hold great promise for the treatment of HIV, other chronic viral infections, and drug resistant infections -- which are becoming a major problem, says Associate Professor Stephen Kent from the University of Melbourne’s Department of Microbiology and Immunology.

“We have invented a simple new technology to boost the ability of the immune system to fight chronic infections, such as AIDS and Hepatitis C, Associate Professor Kent says. "This involves using a patient’s own blood treated with small overlapping proteins of the virus [called peptides].”

The research will be published today in the Journal of Virology.

Huge Immune Response

The National Health and Medical Research Council (NHMRC) has awarded funding of almost $500,000 to refine the technique, called "Overlapping Peptide Pulsed Autologous Cells" (OPAL), so that it can be studied in humans.

“The ability to induce and expand the immune response across most or all parts of the virus is highly advantageous. Our results, which consistently demonstrated sharply enhanced immunity in vaccinated animals, suggest that this therapy could also work in humans,” the researchers report.

The team initially set out to develop a technique for measuring the effectiveness of an HIV vaccine. They first extracted blood from previously vaccinated animals and then coated the cells with HIV peptide markers (a technique which only takes an hour to complete).

In a normal situation, when HIV or any virus infects a cell, it leaves behind tell-tale markers, or peptides, on the cell surfaces that tell the immune system the cell is infected. In this study, the researchers did not infect the animals with HIV, but rather created the illusion to the body that these cells were infected because they had the tell-tale markers (peptides) on their surface.

When they injected this peptide-coated blood back into the vaccinated animals, they found that it triggered a huge immune response.

Human Testing Planned

“When we analysed HIV-specific immunity in the weeks following the assays (peptide-coating), a marked enhancement of virus-specific immunity was induced,” Associate Professor Kent says.

“The technique was also effective for boosting the immune response to Hepatitis C peptides, and we believe that it could be refined for many different viral infections and cancers. We have also shown it can be used to induce immune responses against drug resistant forms of HIV. The OPAL technique is simpler than current cell-based vaccine techniques, which usually require isolation of rare specialised cells from blood,”he adds.

The researchers plan to embark on a series of experiments to refine the technique to make it more practical and to generate bigger responses. They plan to begin human testing of the OPAL therapy in the next one to two years.