Medications called combination antiretroviral therapy (ART) disrupt the viral replication process and can delay the onset of AIDS by decades.
However, even without taking ART, a small percentage of people infected with HIV do not have the persistent loss of T cells and increase in levels of HIV after initial infection. They can sometimes go many years, even more than a decade, without the virus seriously compromising the immune system or leading to AIDS.
Through the Pitt Men's Study/MACS, eight such "nonprogressors" were assessed twice a year for an average of 11 years and compared to eight typically progressing HIV-positive counterparts.
Dr. Rappocciolo and her colleagues found that in nonprogressors, the dendritic cells were not transferring the virus to T cells at detectible levels. When taking a closer look at these dendritic cells, the researchers discovered that the cells had low levels of cholesterol, even though the nonprogressors had regular levels of cholesterol in their blood. A similar finding was shown for B lymphocytes, which also pass HIV to T cells, leading to high rates of HIV replication.
Cholesterol is an essential component of the outer membranes of cells. It is required for HIV to replicate efficiently in different types of cells. None of the study participants were taking statins, which are cholesterol-lowering medications that some people take to prevent vascular problems when cholesterol in their blood is too high.
When HIV was directly mixed with the nonprogressors' T cells in the laboratory, thos
|Contact: Allison Hydzik|
University of Pittsburgh Schools of the Health Sciences