In the March 31, 2006 issue of Science, NIAID research fellow Johnan Kaleeba, Ph.D. and senior investigator Edward A. Berger; Ph.D., describe how the molecule xCT is a major gateway that KSHV uses to enter human cells. The molecule may also play a role in the development of Kaposi's sarcoma and other syndromes associated with the virus.
The natural function of xCT in the body is to transport molecules necessary for protecting against stress into cells. When cells are stressed, they express more xCT on their surfaces. Of note, this sort of stress can be caused by KSHV itself. This suggests that the virus may facilitate its own infectivity and dissemination in the body by inducing a physiological state that results in increased numbers of its own receptor.
"The advancement of knowledge achieved in this study highlights the outstanding intramural research that takes place here on the NIH campus," says Elias A. Zerhouni, M.D., NIH director.
"Understanding the mechanisms of cell entry of Kaposi's sarcoma herpesvirus is a landmark achievement in and of itself," says NIAID director Anthony S. Fauci, M.D. "But the connection between the virus and expression of its own receptor on a cell is even more provocative because it might change the way we think about KSHV-associated diseases and their treatment."
Although less common in the United States now than early in the AIDS pandemic, Kaposi's sarcoma is still the most common cancer associated with HIV infection. Prior to the AIDS pandemic, it was
Source:NIH/National Institute of Allergy and Infectious Diseases