An ingredient in human semen boosts the ability of HIV (human immunodeficiency virus) to infect cells. Every day over 6800 persons become infected with HIV and over 5700 persons die from AIDS. More than 90 per cent of these infections are acquired through sexual intercourse. German and American researchers looked for factors in semen that might block infection with HIV-1, the most common strain of the virus that causes AIDS. Instead, a factor was found that enhanced transmission, in some experiments, as much as 50-fold. It was found that the naturally occurring prostatic acidic phosphatase (PAP), an enzyme produced by the prostate, can form tiny fibres called amyloid fibrils that can capture bits of the HIV and help it to infect cells. Amyloid fibrils formed from different proteins are associated with many diseases, including Alzheimer's and prion disease. Further studies are warranted on the role of amyloid in the transmission and pathogenesis of enveloped viruses, and compounds that might block this process to slow transmission of the disease may help in preventing HIV/AIDS.
Cell,
December 2007