Ingredient in Semen Dramatically Increases HIV Infection
December 17th, 2007 Posted by: Dr. Cox
(Ivanhoe Newswire) â An ingredient in semen could be to blame for most HIV infections.
New research from Germany shows the ingredient â prostatic acidic phosphatase (PAP) â dramatically increases the ability of the HIV virus to cause infection. Scientists found when fragments of PAP are isolated from semen they form tiny fibers called amyloid fibrils. The fibrils catch particles of HIV and help them to penetrate target cells which significantly enhances the infection rate.
âWe were not expecting to find an enhancer, and were even more surprised about the strength,â study author Frank Kirchhoff, University Clinic of Ulm, Germany, was quoted as saying. âMost enhancers have maybe a two- or three-fold effect, but here the effect was amazingâmore than 50-fold and, under certain conditions, more than 100,000-fold. At first, I didnât believe it, but we ran the experiment over and over, always with the same result.â
Results also show the effects of amyloid fibrils â called Semen-derived Enhancer of Virus Infection (SEVI) â are strongest when the levels of infectious virus are low, resembling the conditions of sexual transmission of HIV. Lab experiments find SEVI lowered the amount of virus required to infect tissue from human tonsils and drastically enhanced the viral infection in HIV-infected rats.
Researchers say the findings help explain the sexual transmission of HIV and could lead to new ways to prevent the spread of AIDS.
More than 90-percent of HIV infections are through sexual intercourse. HIV has infected about 60 million people and caused more than 20 million deaths worldwide.
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SOURCE: Cell, 2007