Sean R. Hosein Comments On the Future of HIV/AIDS Research
Sean R. Hosein: Science and Medicine Editor at CATIE (Canadian AIDS Treatment Information Exchange), Canada's national AIDS treatment information agency, and a science advisor to the Ontario Ministry of Health's AIDS Bureau
One finding that has puzzled researchers for the past two decades is that the immune systems of people living with HIV/AIDS (PHAs) are clearly quite active; indeed, in some cases, they are apparently hyperactive. Yet these PHAs still eventually develop serious infections. It may be that HIV tricks the immune system into suppressing the activity of useful antiviral defenses while allowing ineffective responses to continue. Ultimately, this type of situation works in favor of the virus. Despite all that HIV throws at the immune system, some PHAs survive for many years without taking anti-HIV therapy and without developing symptoms of AIDS or having their cell counts fall significantly. These people are called long-term nonprogressors (LTNPs). By studying how the immune systems of LTNPs adapt to and survive HIV infection, researchers could eventually invent therapies that are more effective and that, hopefully, cause fewer side effects.
An important chemical signal (or cytokine) used by cells is interleukin-10 (IL-10). When produced in large amounts by cells, IL-10 can weaken the immune response against viruses, bacteria and fungi. Some researchers think that HIV may trick the immune system into producing large amounts of IL-10, weakening the body's ability to fight the virus. Researchers at Mt. Sinai Hospital in Toronto have been studying the immune systems of PHAs, including some LTNPs, with a focus on production of IL-10.
The Mt. Sinai researchers found that T-cells taken from LTNPs and healthy HIV negative people produced relatively low levels of IL-10. T-cells taken from people with AIDS produced between two to five times more IL-10. Those PHAs who took highly active antiretroviral therapy (HAART) were able to significantly reduce their levels of IL-10. The work done in Toronto confirms that of another research team in Norway, which also found that HAART reduced IL-10 levels but was not able to return them to low, normal levels seen in HIV negative people. An immune booster that would be able to further reduce levels of IL-10 in PHAs taking HAART might enhance the immune system's ability to fight HIV. IL-10 also appears to play a role in regulating the CD4+ cell count. Reducing levels of IL-10 could help raise the CD4+ cell count in PHAs. Expect to see more research on therapies to reduce IL-10 levels in the future.
This article was provided by AIDS Community Research Initiative of America. It is a part of the publication CRIA Update. Visit ACRIA's website to find out more about their activities, publications and services.