The decline in immune function with age is viewed as the most important factor contributing to older adults' increased infections and decreased response to vaccination. Aging brings about a selective decline in the number and function of T cells ‑ a type of white blood cell critical in the immune system's response to infection. But the few T cells that survive the longest may better protect against infections such as the flu, according to a study led by researchers from the University of Arizona College of Medicine ‑ Tucson. The researchers now are looking for ways to increase the number of these surviving T cells to improve protection against disease in older adults.
The study results are reported in the Aug. 1 Early Edition issue of the Proceedings of the National Academy of Sciences. The article, "Non-random attrition of the naïve CD8+ T-cell pool with aging governed by TCR:pMHC interactions," is available at www.pnas.org/papbyrecent.shtml
"We have discovered that aging brings about selective attrition of those T cells that defend us against new infections that we have not encountered before. Not all T cells age the same and the ones that will survive the longest have special features that may allow them to best protect against infections such as flu," says study senior author Janko Nikolich-Žugich, MD, PhD, chairman of the Department of Immunobiology, co-director of the Arizona Center on Aging, and Elizabeth Bowman Professor in Medical Research at the UA College of Medicine, and a member of the UA BIO5 Institute. "We now know that there are a few good cells that can be targeted by vaccination to expand their numbers and achieve protection.
Finding ways to expand them is our next and final challenge, and our team at the Arizona Center on Aging should be able to achieve that in the next few years."
Researchers who contributed to the study include Dr. Nikolich-Žugich; lead author Brian Rudd, PhD, research associate, UA Department of Immunobiology and member, Arizona Center on Aging and UA BIO5 Institute; Vanessa Venturi, PhD, Computational Biology Unit, Centre for Vascular Research, University of New South Wales, Kensington, New South Wales 2052, Australia; Gang Li, PhD, assistant research scientist, UA Department of Immunobiology, and member, Arizona Center on Aging and UA BIO5 Institute; Partha Samadder, PhD, associate research scientist, UA Department of Immunobiology and member, Arizona Center on Aging and UA BIO5 Institute; James Ertelt, PhD, Department of Pediatrics, Center for Infectious Disease and Microbiology Translational Research, University of Minnesota School of Medicine, Minneapolis, Minn.; Sing Sing Way, PhD, Department of Pediatrics, Center for Infectious Disease and Microbiology Translational Research, University of Minnesota School of Medicine, Minneapolis, Minn.; and Miles P. Davenport, PhD, Complex Systems in Biology Group, Centre for Vascular Research, University of New South Wales, Kensington, New South Wales 2052, Australia.
About the Arizona Center on Aging
The mission of the Arizona Center on Aging (ACOA) at the University of Arizona College of Medicine – Tucson is to promote long and healthy lives of older adults through coordinated programs in research, education, outreach and patient care. Established in 1980 as one of a network of Long Term Care Gerontology Centers authorized by the Older Americans Act, the ACOA was approved by the Arizona Board of Regents as a Center of Excellence at the Arizona Health Sciences Center in 1991. For more information, visit the center's website, www.aging.arizona.edu
About the UA College of Medicine Department of Immunobiology
The Department of Immunobiology, one of the five basic science departments at the University of Arizona College of Medicine – Tucson, conducts cutting-edge research in the development, function and regulation of the immune system in health and disease. Areas of study include the biology of microorganisms and their interaction with the immune system over the lifespan of the individual. Department faculty seek to improve and regulate the function of the immune system to reduce and prevent illness and death from infectious and autoimmune diseases and cancer. The department educates medical and other health sciences students, physicians and scientists in all areas of immunobiology and microbiology. For more information, visit the website http://immunobiology.arizona.edu/index.html
Journal
Proceedings of the National Academy of Sciences