Friday, August 27, 2010
Potential HIV Drug Keeps Virus out of Cells
This new protocol will actually block the virus from infecting new cells. Add that to the progress made to date, we are seeing the day in the future in which this particular horror will be seen off the stage.
What is most impressive regarding the HIV fight is the impact that it has had on medical thinking itself. No longer do we discount a drug because it is not a magic bullet. We now think instead of biological cocktails that erode the ability of the disease to progress.
This is showing up in many other places with some success.
I would say today that transmittable diseases are becoming more and more susceptible to our therapies and while the risk of a pandemic is real, even more real is the complete decline of susceptible populations because of massive travel.
There are no desert islands in which a population is susceptible to the common cold.
Potential HIV Drug Keeps Virus out of Cells
ScienceDaily (Aug. 24, 2010) — Following up a pioneering 2007 proof-of-concept study, a University of Utah biochemist and colleagues have developed a promising new anti-HIV drug candidate, PIE12-trimer, that prevents HIV from attacking human cells.
D-peptide inhibitors (PIE12, yellow) binding to the HIV "pocket" region (orange). PIE12 binds to the pocket, preventing interaction of other HIV components required to mediate HIV's entry into target cells. (Credit: Michael S. Kay, M.D., Ph.D.,
University of Utah ) School of Medicine
Michael S. Kay, M.D., Ph.D., associate professor of biochemistry in the University of Utah School of Medicine and senior author of the study published on Aug. 18, 2010, online by the Journal of Virology, is raising funds to begin animal safety studies, followed by human clinical trials in two to three years. Kay believes PIE12-trimer is ideally suited for use as a vaginal microbicide (topically applied drug) to prevent HIV infection. His research group is particularly focused on preventing the spread of HIV in
Africa, which has an estimated two-thirds of the world's 33 million HIV patients according to the World Health Organization.
"We believe that PIE12-trimer could provide a major new weapon in the arsenal against HIV/AIDS. Because of its ability to block the virus from infecting new cells, PIE12-trimer has the potential to work as a microbicide to prevent people from contracting HIV and as a treatment for HIV infected people. HIV can develop resistance rapidly to existing drugs, so there is a constant need to develop new drugs in hopes of staying ahead of the virus." Kay said.
PIE12-trimer was designed with a unique "resistance capacitor" that provides it with a strong defense against the emergence of drug-resistant viruses.
Peptide drugs have great therapeutic potential, but are often hampered by their rapid degradation in the body. D-peptides are mirror-image versions of natural peptides that cannot be broken down, potentially leading to higher potency and longevity in the body. Despite these potential advantages, no D-peptides have yet been developed.
PIE12-trimer consists of three D-peptides (PIE12) linked together that block a "pocket" on the surface of HIV critical for HIV's gaining entry into the cell. "Clinical trials will determine if PIE12-trimer is as effective in humans as it is in the lab," Kay said.
Across the world, HIV occurs in many different strains and has the ability to mutate to resist drugs aimed at stopping it. Due to the high conservation of the pocket region across strains, PIE12-trimer worked against all major HIV strains worldwide, from Southeast Asia and South America to the
United States and Africa.
To help advance toward human clinical trials, Kay and co-authors Brett D. Welch, Ph.D., and Debra M. Eckert, Ph.D., research assistant professor of biochemistry, formed a company, Kayak Biosciences, which is owned by the
. If PIE12-trimer proves to be an effective and safe drug against HIV, the same D-Peptide drug design principles can be applied against other viruses, according to Kay. Approval of the first D-peptide drug would also greatly stimulate development of other D-peptide drugs. University of Utah Research Foundation
The study's first authors are Welch, and U of U graduate student J. Nicholas Francis. Also contributing were U graduate students Joseph Redman and Matthew Weinstock, as well as Eckert. Images of how PIE12 binds to the HIV pocket were obtained using X-ray crystallography, a technology that provides high-resolution analysis of atomic structures, and were provided by Frank Whitby, Ph.D., research assistant professor of biochemistry, and Christopher P. Hill, Ph.D., professor and co-chair of the Department of Biochemistry. The study includes colleagues from
Thomas Jefferson University in Philadelphia and Monogram Biosciences, South San Francisco, Calif.
This research was funded by the National Institutes of Health and the
. University of Utah Research Foundation