The conundrum of human immune system "senescence".

Department of Immunology, University of Tübingen, Tübingen, Germany; Health Sciences North Research Institute, Sudbury, ON, Canada. Electronic address: graham.pawelec@uni-tuebingen.de. Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, 50011, United States. Department of Medicine and Research Center on Aging, Université de Sherbrooke, Sherbrooke, Québec, Canada. National Institute on Aging, 241 Bay View Boulevard, Baltimore, MD, 21225, United States. Mater Studiorum University of Bologna, Italy; Laboratory of Systems Biology of Healthy Aging, Department of Applied Mathematics, Lobachevsky State University, Nizhny Novgorod, Russia. Department of Medicine, Geriatric Division, University of Sherbrooke, 3001 12 Ave N, Sherbrooke, QC, J1H 5N4, Canada; Research Center on Aging, 1036 Rue Belvédère S, Sherbrooke, QC, J1H 4C4, Canada. Department of Medicine, University of Montreal, Montreal, Quebec, Canada; Centre Hospitalier de l'Université de Montréal Research Centre, Montreal, Quebec, Canada. Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, 02115, United States. National Hellenic Research Foundation, Institute of Chemical Biology, Athens, Greece. Departments of Biology and Medicine, University of Rochester, Rochester, NY, 14627, United States. Healthy Longevity Programme, Yong Loo Lin School of Medicine, National University of Singapore, 10 Medical Dr., 117597, Singapore; Centre for Healthy Longevity, National University Health System, Singapore, 1E Kent Ridge Rd., 119228, Singapore; Singapore Institute of Clinical Sciences, A⁎STAR, Singapore, 117609, Singapore; Buck Institute for Research on Aging, 8001 Redwood Blvd., Novato, CA, 94945, United States. A⁎STAR, 8 Biomedical Grove, #07, Neuros, Singapore, 138665, Singapore. Université de Lyon, F-69000, Lyon, France; Université Lyon 1, CNRS, UMR5558, Laboratoire de Biométrie et Biologie Évolutive, F-69622, Villeurbanne, France. State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China. Department of Medicine and Aged Care, @AgeMelbourne, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Victoria, Australia; Department of Human Movement Sciences, @AgeAmsterdam, Faculty of Behavioral and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam Movement Sciences, Amsterdam, the Netherlands. Division of Geriatric Medicine, Faculty of Medicine, McGill University and Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada. Medical Centre for the Elderly, University Hospital, University of Brasília (UnB), 70910-900, Brasília, DF, Brazil; McGill University Health Center (MUHC), Glen site, 1001 Boul. Décarie, H4A 3J1, Montreal, QC, Canada. Laboratory of Geroprotective and Radioprotective Technologies, Institute of Biology, Komi Science Center of RAS, Kommunisticheskaya St.28, 167982, Syktyvkar, Russia. Dept Geriatric Medicine, Radboud University Medical Center, Nijmegen, the Netherlands. Charles Perkins Centre, Faculty of Science School of Life and Environmental Sciences and School of Mathematics and Statistics, The University of Sydney, Australia. Biodemography of Aging Research Unit (BARU), Social Science Research Institute, Duke University, PO Box 90420, 2024 W. Main St. Durham, NC, 27705, United States. Insilico Medicine Hong Kong Ltd. 307A, Core Building 1, 1 Science Park East Avenue, Hong Kong Science Park, Pak Shek Kok, Hong Kong. Department of Pathophysiology, Medical University of Gdansk, M. Skłodowskiej-Curie 3a street, 80-210, Gdańsk, Poland. Cohen Groupe de recherche PRIMUS, Department of Family Medicine, University of Sherbrooke, 3001 12e Ave N, Sherbrooke, QC, J1H 5N4, Canada.

Mechanisms of ageing and development. 2020;:111357

Abstract

There is a great deal of debate on the question of whether or not we know what ageing is (Ref. Cohen et al., 2020). Here, we consider what we believe to be the especially confused and confusing case of the ageing of the human immune system, commonly referred to as "immunosenescence". But what exactly is meant by this term? It has been used loosely in the literature, resulting in a certain degree of confusion as to its definition and implications. Here, we argue that only those differences in immune parameters between younger and older adults that are associated in some definitive manner with detrimental health outcomes and/or impaired survival prospects should be classed as indicators of immunosenescence in the strictest sense of the word, and that in humans we know remarkably little about their identity. Such biomarkers of immunosenescence may nonetheless indicate beneficial effects in other contexts, consistent with the notion of antagonistic pleiotropy. Identifying what could be true immunosenescence in this respect requires examining: (1) what appears to correlate with age, though generality across human populations is not yet confirmed; (2) what clearly is part of a suite of canonical changes in the immune system that happen with age; (3) which subset of those changes accelerates rather than slows aging; and (4) all changes, potentially population-specific, that accelerate agig. This remains an immense challenge. These questions acquire an added urgency in the current SARS-CoV-2 pandemic, given the clearly greater susceptibility of older adults to COVID-19.

Methodological quality

Publication Type : Review

Metadata

MeSH terms : SARS-CoV-2