Powerful Anti-AIDS Agent Found In Tears And In Urine Of Preg...( bility to invade immunecells. The ribo...)

The new study, published in the March 16 issue of The Proceedings of the National Academy of Sciences, caps an intensive five-year search for the powerful anti-AIDS and anti-cancer agent present in a most unusual source-the urine of pregnant women. Researchers had suspected that human chorionic gonadotropin (hCG), a pregnancy hormone produced by the placenta, was the agent because it inhibited HIV-infected immune cells in the laboratory and in small clinical studies shrank Kaposi's sarcoma tumors in AIDS patients. Moreover, AIDS transmission rarely occurs during the first trimester of pregnancy when hCG levels are high. The main function of hCG is to stabilize pregnancy and protect the embryo from rejection by the mother's body.

However proof of hCG's effects wasn't straightforward. Although crude preparations of hCG inhibited the growth of Kaposi's sarcoma cells and HIV-infected cells in the laboratory, Dr. Lee-Huang and many other scientists showed that highly purified extracts of hCG failed to have any affect on these cells. So it wasn't clear whether hCG itself or some other protein in the urine from which it was prepared was responsible. Dr. Lee-Huang's laboratory narrowed the search to a portion of the hormone called the beta subunit; but to her surprise, the culprits turned out to be other proteins that are also present in the urine and stick to the beta subunit.

In the new study, Dr. Lee-Huang and co-workers isolated the beta subunit from commercial preparations of hCG prepared from the urine of pregnant women. Then, using techniques such as electrophoresis, liquid chromatography and amino acid sequencing, they painstakingly separated and purified the proteins present in the subunit and tested each against HIV-infected cells, as well as analyzed their amino acid sequences. The entire process took about two years.

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Contact: Marjorie Shaffer
Marjorie.Shaffer@med.nyu.edu
212-263-5488
New York University Medical Center and School of Medicine
16-Mar-1999