"Male Semen Makes HIV More Potent"
Friday, December 14, 2007
An article in American Scientific describes the fascinating results on components of male sperm that enhances the transmission of HIV.
German scientists found a component of human semen may facilitate the spread of the virus by targeting immune system cells, in some cases making the pathogen up to 100,000 times more virulent. The co-author Frank Kirchhoff, a virologist at the University of Ulm Clinic in Germany explained that they had in initially set out to determine if semen contained factors that inhibit the HIV infection.
Most enhancers have maybe a two- or three-fold effect, but here the effect was amazing—more than 50-fold and, under certain conditions, more than 100,000-fold.
Kirchhoff and his team screened through many of the 900 proteins found in seminal fluid in their hunt for potential inhibitors and enhancers of HIV transmission. Among the enhancing factors uncovered were fragments of a protein called prostatic acid phosphatase that is secreted by the prostate gland. An analysis of the peptide's structure in semen indicated that it hooked up with similar fragments to create amyloid fibers (clusters of protein fragments that have also been implicated in diseases such as Alzheimer's). The scientists refer to the amyloid fibers as "semen-derived enhancer of virus infection" (SEVI). If they do not link to become fibers, the researchers report, the peptide segments remain inactive and do not enhance viral transmission. The HIV with the semen component was five times more effective at transmitting the virus. In situations where low levels of virus are transferred—as during intercourse—Kirchhoff says, SEVI can make HIV up to 100,000 times more likely to spread when compared with the virus alone.
Postdoctoral fellow Nadia Roan, along with Warner Greene, a senior investigator at the University of California, San Francisco's Gladstone Institute of Virology and Immunology, wrote: "If SEVI truly increases the real world heterosexual spread of HIV by several orders of magnitude, then negating the activity of this factor could conceivably diminish these frequencies to levels that might virtually eliminate semen-driven HIV transmission."
As many know, HIV infection is increasing with each passing moment. Although this article promises no easy answers, it is however research that could be a stepping stone into saving lives.
Labels: Science
posted by Sonya @ 12/14/2007 06:46:00 PM,
