Immune cell function differs greatly among men and women and changes based on age, according to a study published Monday by USC researchers.
The study of a common type of white blood cell revealed that immune cell response to pathogens depends on a person’s gender and age, meaning precision medicine could better address such disparities, the USC-led research team reported in Nature Aging.
“A big take-home message is that with the push for personalized medicine, people focus on minute genetic differences, but we find that biological sex — the biggest genetic difference of all — is actually a great predictor for immune response seldom taken into account,” said Bérénice Benayoun, assistant professor at the USC Leonard Davis School of Gerontology and principal investigator of the study.
The mouse study has important implications for curing human diseases, especially sepsis, a condition in which the body’s defense system turns harmful to itself, the scientists said.
“With sepsis, what kills you is not actually the bacteria; it’s your response to the bacteria,” she said.
In the mouse study, males proved much more susceptible to sepsis than females, however, the scientists also found that the female disease-defense system changes with age and women become more susceptible over time.
Benayoun and her team focused the study on cells called neutrophils, which make up about 50% to 70% of white blood cells and are critical to fighting off infections. Understanding sex- and age-based differences in how neutrophils function could help uncover similar disparities in various human illnesses, such as why older people — and men in particular — are more likely to get severe symptoms with COVID-19 or why women are more likely to have autoimmune disorders, she said.
Benayoun and colleagues discovered differences in neutrophil activity between young and old mice, as well as between male and female mice, and their findings suggest that the differences between the two sexes become more amplified with age.
In addition to Benayoun, study co-authors include Ryan J. Lu, Minhoo Kim and Juan Bravo of the USC Leonard Davis School; Shalina Taylor, Kévin Contrepois, and Mathew Ellenberger of Stanford University; and Nirmal K. Sampathkumar of King’s College London, U.K.