MEXICO CITY -- A Claflin University professor is trying to turn the search for an HIV vaccine inside-out.
Unlike traditional vaccine approaches that try to stop the HIV virus from entering a human cell, Dr. Omar Bagasra has started developing a vaccine that stops HIV after it's already inside.
"It's a new way of looking at vaccines," he said.
Bagasra presented his idea this week at the XVII International Conference on AIDS. He is a biology professor at Claflin and director of the Orangeburg school's S.C. Center for Biotechnology.
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Globally, $933 million was invested in HIV vaccine research in 2006, most of which relied on manipulating the body's immune system, but so far, there is no successful product.
The premature closing last year of a clinical trial because of a failed vaccine has strengthened the call for new ways to block replication of the HIV virus.
HIV infects a human cell by releasing its genetic material, called mRNA, into it. MRNA is quickly converted to DNA, which is easily incorporated into the body's own DNA inside the cell nucleus. That makes it hard for the immune system to detect and destroy the invading virus.
But Bagasra's vaccine would flush HIV-susceptible cells in advance with another type of genetic material, called MicroRNA, to prevent such incorporation. It would bind up parts of the virus's genetic material into a three-stranded protein and so prevent it from entering the nucleus of the human cell.
"It's a novel direction in which to develop anti-HIV approaches, and that's something we continue to need," said Dr. Eric Hunter, a renowned HIV researcher at Emory University.
Bagasra's vaccine contains genetic material from human cells, coated with fat and fitted with a protein that recognizes the immune cells HIV targets.
His team injected immune cells with an early version of the vaccine and found that even after being exposed to high concentrations of HIV, they did not become infected.
Bagasra's work has potential, but there are hurdles to scale before the vaccine could be used in humans.
First, he will have to figure out a way to efficiently deliver the genetic material in the vaccine to HIV-susceptible cells while avoiding other cells. It's not clear how the vaccine material would affect non-immune system cells. But Bagasra believes it will not be harmful, because the body naturally produces similar types of protein.
A major concern is that since the vaccine can disable DNA formed when HIV enters a human cell, it might also damage the DNA and hinder normal gene function of the person who receives the vaccine.
In addition, for the vaccine to work, human cells would need to be inoculated before being exposed to HIV.
Bagasra anticipates that it can be given to babies soon after birth, since it does not need a mature immune system in order to work.
But even before birth, it might be possible to inoculate stem cells that eventually become the HIV-targeted immune cells, Bagasra said.
His team now is testing its vaccine model using human blood, rather than just individual cells.
He hopes to address the major laboratory issues and begin clinical trials in the next several years.