A new study suggests the immune system is able to fight off some viruses but not others that lead to infections like HIV and hepatitis C because of a protein called interleukin-21 (IL-21). Interleukin-21 is a powerful molecule that is released by the immune cells during chronic infection. Researchers looked at two types of T-cells- CD4 T-cells and CD8 T-cells that play an important role in the body's response to infection including production of IL-21 and ability to fight off the virus. The researches found by infecting two groups of mice, one group was normal and the other without IL-21 recpetors, with a two strains of a virus. It was found that when the mice that lacked IL-21 were infected with the chronic strain the CD8 T-cells disappeared, this preventing the immune system from stopping the spread. However when infected with just the normal strain of the virus the mice that lack IL-21 were still able to fight the virus. The chief researcher, David Brooks sums up the findings as “IL-21 fuels CD8 T-cells' ability to function. After the immune system loses CD8 T-cells, it's unable to clear the virus. This tells us that IL-21 is a critical player in the body's fight against chronic infection.” This research can help us better understand chronic infections like HIV and hopefully find a cure for them.
References:
Article:
University of California - Los Angeles (2009, May). Key Protein Keeps Chronic Infection In Check. ScienceDaily. Accessed May 10, 2009, http://www.sciencedaily.com /releases/2009/05/090508103842.htm
Image:
AIDS information Switzerland. Accessed May 10, 2009, http://www.avert.org/aids-photo-gallery.php?photo_id=512&gallery_id=4
References:
Article:
University of California - Los Angeles (2009, May). Key Protein Keeps Chronic Infection In Check. ScienceDaily. Accessed May 10, 2009, http://www.sciencedaily.com /releases/2009/05/090508103842.htm
Image:
AIDS information Switzerland. Accessed May 10, 2009, http://www.avert.org/aids-photo-gallery.php?photo_id=512&gallery_id=4
