TY - JOUR
T1 - No evidence for constitutive innate immune senescence in a longitudinal study of a wild bird
AU - Roast, Michael J.
AU - Aranzamendi, Nataly Hidalgo
AU - Teunissen, Niki
AU - Fan, Marie
AU - Verhulst, Simon
AU - Peters, Anne
N1 - Funding Information:
Funding was provided by BirdLife Australia and the Holsworth Wildlife Research Endowment (to M.J.R.), the Australian Research Council (FT10100505 and DP150103595 to A.P.), and the Max Planck Society (to A.P.). Project approvals were obtained from the Australian Bird and Bat Banding Scheme (license 2230), Western Australia Department of Parks and Wildlife, Australian Wildlife Conservancy, and the Monash University School of Biological Sciences Animal Ethics Committee. Special thanks to Mornington Wildlife Sanctuary staff and to all volunteers and research assistants who made data collection possible. M.J.R., A.P., and S.V. conceived and designed the study. M.J.R., N.H.A., M.F., and N.T. collected data and samples. M.J.R. conducted laboratory analyses. M.J.R., A.P., and S.V. analyzed the data. M.J.R. and A.P. wrote the manuscript, with all authors contributing comments.
Funding Information:
was provided by BirdLife Australia and the Holsworth Wildlife Research Endowment (to M.J.R.), the Australian Research Council (FT10100505 and DP150103595 to A.P.), and the Max Planck Society (to A.P.). Project approvals were obtained from the Australian Bird and Bat Banding Scheme (license 2230), Western Australia Department of Parks and Wildlife, Australian Wildlife Conservancy, and the Monash University School of Biological Sciences Animal Ethics Committee. Special thanks to Mornington Wildlife Sanctuary staff and to all volunteers and research assistants who made data collection possible. M.J.R., A.P., and S.V. conceived and designed the study. M.J.R., N.H.A., M.F., and N.T. collected data and samples. M.J.R. conducted laboratory analyses. M.J.R., A.P., and S.V. analyzed the data. M.J.R. and A.P. wrote the manuscript, with all authors contributing comments.
Publisher Copyright:
© 2021 The University of Chicago. All rights reserved.
PY - 2022/1
Y1 - 2022/1
N2 - Aging is associated with declines in physiological performance; declining immune defenses particularly could have consequences for age-related fitness and survival. In aging vertebrates, adaptive (memory-based) immune responses typically become impaired, innate (nonspecific) responses undergo lesser declines, and inflammation increases. Longitudinal studies of immune functions in wild animals are rare, yet they are needed to understand immunosenescence under evolutionarily relevant conditions. Using longitudinal data from a tropical passerine (Malurus coronatus) population, we investigate how population trends emerge from within-individual changes and between-individual heterogeneity (e.g., selective disappearance) in immune status. We quantified constitutive immune indexes (haptoglobin [inflammation associated], natural antibodies, complement [lytic] activity, and heterophil-lymphocyte ratio; n p 505–631) in individuals sampled one to seven times over 5 yr. Unexpectedly, longitudinal analyses showed no age-related change within individuals in any immune index, despite sufficient power to detect within-individual change. Between individuals, we found age-related declines in natural antibodies and increases in heterophil-lymphocyte ratios. However, selective disappearance could not adequately explain between-individual age effects, and longitudinal models could not explain our data better than cross-sectional analyses. The lack of clear within-individual immunosenescence is itself notable. Persistent levels of haptoglobin, complement activity, and natural anti- bodies into old age suggests that these immune components are maintained, potentially with adaptive significance.
AB - Aging is associated with declines in physiological performance; declining immune defenses particularly could have consequences for age-related fitness and survival. In aging vertebrates, adaptive (memory-based) immune responses typically become impaired, innate (nonspecific) responses undergo lesser declines, and inflammation increases. Longitudinal studies of immune functions in wild animals are rare, yet they are needed to understand immunosenescence under evolutionarily relevant conditions. Using longitudinal data from a tropical passerine (Malurus coronatus) population, we investigate how population trends emerge from within-individual changes and between-individual heterogeneity (e.g., selective disappearance) in immune status. We quantified constitutive immune indexes (haptoglobin [inflammation associated], natural antibodies, complement [lytic] activity, and heterophil-lymphocyte ratio; n p 505–631) in individuals sampled one to seven times over 5 yr. Unexpectedly, longitudinal analyses showed no age-related change within individuals in any immune index, despite sufficient power to detect within-individual change. Between individuals, we found age-related declines in natural antibodies and increases in heterophil-lymphocyte ratios. However, selective disappearance could not adequately explain between-individual age effects, and longitudinal models could not explain our data better than cross-sectional analyses. The lack of clear within-individual immunosenescence is itself notable. Persistent levels of haptoglobin, complement activity, and natural anti- bodies into old age suggests that these immune components are maintained, potentially with adaptive significance.
KW - Aging
KW - Ecoimmunology
KW - Gerontology
KW - Immunosenescence
KW - Inflammaging
UR - http://www.scopus.com/inward/record.url?scp=85121673713&partnerID=8YFLogxK
U2 - 10.1086/717937
DO - 10.1086/717937
M3 - Article
C2 - 34870562
AN - SCOPUS:85121673713
SN - 1522-2152
VL - 95
SP - 54
EP - 65
JO - Physiological and Biochemical Zoology
JF - Physiological and Biochemical Zoology
IS - 1
ER -