January 30, 2013
Scientists Find T-Cell Protein That Helps Ward Off Influenza
Brett Smith for redOrbit.com - Your Universe Online
Ever wonder why some people don´t get the flu even though everyone around them is getting sick? A group of Australian researchers believe they have found an important clue for solving this mystery.According to new research in the journal Nature Immunology, some T-cells found on exposed body surfaces help to ward off infection better than others due to the selective expression of a certain protein, IFITM3.
When the body is exposed to the influenza virus, it results in the production of anti-influenza resident memory T-cells; these memory T-cells become ℠experienced´ through their initial encounter with the flu virus. Subsequent infections typically result in a much faster and more aggressive response when detecting the same antigen.
Unfortunately, many of these memory T-cells, like those on exposed mucosal surfaces of the lung, come in contact with other pathogens over the course of time, potentially becoming infected and killed by other infectious agents.
In the study, researchers from University of Melbourne and The Walter and Eliza Hall Institute in nearby Parkville, Australia found that T-cells that produce the protein IFITM3 are less susceptible to other infections. Those cells that did not express the protein didn´t survive a secondary wave of infection.
When the scientists were successfully able to increase the amount of IFITM3-producing memory T-cells, the overall survival rates greatly increased during subsequent infections.
“If we learn how to increase the number and longevity of T-cells expressing IFITM3, this could lead to improved vaccines that promote the generation of more resistant T-cells able to provide the greatest protection, for longer,” study co-author Jose Villadangos, a biologist from the University of Melbourne, said in a statement.
The scientists speculated that future studies might focus on uncovering the mechanisms, genetic or otherwise, that select for the expression of the crucial protein.
“We are currently trying to understand why some T-cells and not others express this protective molecule,” added Linda Wakim, also from the University of Melbourne. “Probably they encounter some form of chemical signal (a cytokine, or a surface molecule) in the tissues where they lodge, which induces the expression of IFITM3. If we identify these chemical cues, we may be able to include them in future vaccines.”
IFITM3 is a product of the IFITM3 gene in humans and previous research has identified it as a key protein in the defense against many diseases, including the H1N1 Swine Flu.
A study published last year showed that a single nucleotide alteration to the IFITM3 gene resulted in increased susceptibility to H1N1 and was overrepresented in those hospital patients who had been admitted with the disease.
Some of the research on this latest study was performed at the Walter and Eliza Hall Institute of Medical Research, Australia´s oldest medical research institute. Founded in 1915 by philanthropist Eliza Hall, the institute was initially hosted at the Melbourne hospital. The institute currently focuses heavily on cancer research, autoimmune diseases, and infectious diseases such as influenza and malaria.
In January, the researchers at the institute announced they had uncovered groundbreaking detail on the structure on functionality of the insulin molecule.