Deakin University
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Immunosenescence in wild animals: meta-analysis and outlook

journal contribution
posted on 2024-08-22, 06:15 authored by A Peters, K Delhey, S Nakagawa, Anne AulsebrookAnne Aulsebrook, S Verhulst
AbstractImmunosenescence, the decline in immune defense with age, is an important mortality source in elderly humans but little is known of immunosenescence in wild animals. We systematically reviewed and meta‐analysed evidence for age‐related changes in immunity in captive and free‐living populations of wild species (321 effect sizes in 62 studies across 44 species of mammals, birds and reptiles). As in humans, senescence was more evident in adaptive (acquired) than innate immune functions. Declines were evident for cell function (antibody response), the relative abundance of naïve immune cells and an in vivo measure of overall immune responsiveness (local response to phytohaemagglutinin injection). Inflammatory markers increased with age, similar to chronic inflammation associated with human immunosenescence. Comparisons across taxa and captive vs free‐living animals were difficult due to lack of overlap in parameters and species measured. Most studies are cross‐sectional, which yields biased estimates of age‐effects when immune function co‐varies with survival. We therefore suggest longitudinal sampling approaches, and highlight techniques from human cohort studies that can be incorporated into ecological research. We also identify avenues to address predictions from evolutionary theory and the contribution of immunosenescence to age‐related increases in disease susceptibility and mortality.

History

Journal

Ecology Letters

Volume

22

Pagination

1709-1722

Location

England

ISSN

1461-023X

eISSN

1461-0248

Language

en

Publication classification

C1.1 Refereed article in a scholarly journal

Editor/Contributor(s)

Gaillard J

Issue

10

Publisher

Wiley