Journals of Gerontology Series A: Biological Sciences and Medical Sciences, Vol 53, Issue 5 B347-B353, Copyright © 1998 by The Gerontological Society of America
Stress exacerbates age-related decrements in the immune response to an experimental influenza viral infection
DA Padgett, RC MacCallum and JF Sheridan
Department of Oral Biology, College of Dentistry, Ohio State University, USA.
To test the hypothesis that stress exacerbates immune decrements associated
with aging, the impact of restraint stress on immunosenescence was assessed
using an experimental model of influenza A/Puerto Rico/8/34 viral
infection. Beginning one day prior to infection, male C57BL/6 mice, 3 and
22 months of age, were subjected nightly to 12 hours of restraint stress.
In both age groups, restraint induced a comparable increase in serum
corticosterone levels. However, in contrast to the 3-month-old controls,
serum corticosterone levels in 22-month-old mice returned to baseline
slower after removal of the stressor. The characteristic influenza-driven
increase in cellularity of the lung and draining lymph node was decreased
by age and further suppressed by stress. Natural killer cell activity and
virus-specific T helper cell function were also blunted by age and almost
completely abrogated by stress. Furthermore, due to the weak immune
response to viral infection, aged animals subjected to stress had a lower
survival rate than age-matched controls.
