Health News: Having ancestors who were frequently exposed to stress can improve one’s own immune response to early-life stressors. Further consideration of historical stressor exposure may help understand how early-life stressors affect adult physiology.
Penn State researchers found that lizards whose ancestors lived in low-stress environments experienced suppressed immune function when they were exposed to prolonged stress. But, for lizards whose ancestors lived in high-stress environments experienced robust immune function when we exposed them to prolonged stress.
These results conclude that immunological response to stressors actually is dependent upon the environment experienced by ancestors. The researchers believe that the results may be similar in other animals and even in humans. However, various animals are subjected to different kinds of stressors.
For the lizards used in this research, the stress is often the result of attacks by fire ants that can break lizards’ skin, leaving them vulnerable to infection. So, it’s not safe to suppress immune function in response to fire ants. “It turns out that lizards whose ancestors are from areas with fire ants have an improved immune response to stress, which may help to ensure their survival,” said Gail McCormick, a graduate student in Langkilde’s lab at the time of the research.
The research team examined how stress alters immune responses on animals with different heritages. They captured pregnant females from the wild from two different kinds of environments — one that had been invaded by fire ants (60-to-70 years prior, or the equivalent of 30-to-40 lizard generations), and one that had not yet been invaded by fire ants.
The team raised the offspring of the captured females in high- and low-stress environments until they were adults. They created high-stress conditions by either exposing the lizards to fire ants or by dosing them every week with the stress-relevant hormone corticosterone dissolved in oil.
“We found that offspring of lizards from high-stress environments had suppressed immune function while offspring of lizards from low-stress environments had enhanced immune function when they were exposed to stress relevant hormones during their own lifetime,” said McCormick.
To Know More, You May Refer To:
Gail L. McCormick, Travis R. Robbins, Sonia A. Cavigelli, Tracy Langkilde. Population history with invasive predators predicts innate immune function response to early life glucocorticoid exposure. The Journal of Experimental Biology, 2019; jeb.188359 DOI: 10.1242/jeb.188359