NEW YORK, N.Y., February 28, 1997 -- Laboratory research by Memorial Sloan-Kettering Cancer Center scientists shows that HIV-infected immune cells take in more vitamin C and glucose than their healthy counterparts, which may aid replication of the AIDS virus. At the same time, however, extremely high levels of the vitamin are more toxic to the HIV-infected cells than to healthy immune cells, the investigators report in the Feb. 28 issue of the Journal of Biological Chemistry.
HIV-infected cells grown in the laboratory appear to be more sensitive to the toxic effects of vitamin C, explained Dr. David W. Golde, Physician-in-Chief of Memorial Hospital and senior author of the paper. At the same levels of exposure, the HIV-infected cells took in more vitamin C than uninfected immune cells.
The laboratory research provides the foundation to begin to understand the relationship among vitamin C, HIV infection, and cell metabolism, and may lead to new therapeutic targets to counter the AIDS virus, he added. Vitamin C is essential to the human body and is necessary for normal function of the immune system.
The researchers studied vitamin C uptake and its effects on AIDS-virus production in HIV-infected and healthy immune cells, after finding in previous studies that cancer cells also take in more glucose and vitamin C than normal cells. In addition, Dr. Golde and his colleagues were the first to prove, in 1993, that the same molecule that allows glucose into cells also serves as a route for vitamin C to enter. Although vitamin C is used by cells in one chemical form (ascorbic acid), it enters cells in another form (dehydroascorbic acid). Once inside the cell, this vital nutrient is reconverted to its original form, whose different shape and size prevent it from leaving the cell.
This series of studies prompted Dr. Golde and his colleagues to ask whether HIV-infected cells
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Memorial Sloan-Kettering Cancer Center