Authors

V Ezenwa¹;  ¹ Yale University, United States

Discussion

Many organisms show age-related declines in immune function (i.e., immunosenescence). In humans and some animals, immune aging has been linked to inadequate responses to infection and higher mortality risk. Interestingly, infection can also shape immunosenescence. For example, chronic viral infections (e.g., HIV, cytomegalovirus) in humans can accelerate immune system senescence. Thus, patterns of natural infection may play a non-negligible role in determining immunosenescence trajectories, and variation in individual infection history may help explain both the rate and survival consequences of immune aging. To understand whether common parasite infections contribute to immunosenescence and its potential survival costs, we examined the impact of long-term anthelmintic treatment on age-related changes in immunity in a wild mammal (African buffalo). We found that treatment slowed the rate of senescence for 6 out of 11 focal immune traits and buffered the mortality costs of age-related immune dysregulation. Our findings reveal a potential role for chronic helminth infection in driving patterns of immune aging and its fitness consequences in wild populations.