Immunosenescence

Original Editor - Lucinda hampton

Top Contributors - Lucinda hampton  

Introduction[edit | edit source]

Immunosenescence refers to the changes in immune function that contributes to the increased sensitivity to disease in older people. It includes remodelling of lymphoid organs (those responsible for producing lymphocytes and antibodies) which lead to changes in the immune function of the elderly, which is closely connected to the development of infections, autoimmune diseases, and malignant tumors[1].

New research suggests that immunosenescence may be the result of secondary changes caused by environmental and lifestyle factors, with nutrition, exercise, and medications taken over ones life influencing the immune function as we age.

Immunosenesence changes:

  1. With time, the epithelial barriers of the skin, lungs, and digestive tract break down, making us more susceptible to microorganisms.
  2. The immune cells eg T cells and B cells behave differently in the aging body. The capability of these cells to counter the threat of foreign bodies is decreased, increasing the risk of acquiring infections eg influenza, COVID 19 and pneumonia[2]
Process of Immunosenescence

Infectious Disease[edit | edit source]

Immunosenesence leads to an increased susceptibility to infectious disease, caused essentially by a decreased ability of the immune system to respond effectively to new pathogens or vaccines. This age-associated, intrinsic failure of the immune system (ie “immunosenescence”) leads to an increased morbidity and mortality from infectious disease in the older persons and in the poor immune response to vaccines designed to protect against these diseases[3].

Drug/Supplement Use?[edit | edit source]

Genetic and dietary manipulation and use of drugs have been selected to attempt to increase lifespan and health span in numerous models. e.g. 1. Metformin, which has demonstrated protective effects against several age-related diseases in humans. Metformin positively influences metabolic and cellular processes strongly resembling those associated with the development of age-related conditions, such as inflammation, autophagy, and cellular senescence.[4] 2. NAD levels naturally decline with age. NAD+ support cellular function in a variety of significant ways, eg keep our DNA healthy, converting food into usable energy and regulating the sleep/wake cycles. Low levels of NAD are associated with increased risk of heart disease, type 2 diabetes, Alzheimer’s disease and accelerated aging. Treatment of AD mice with NAD+ reduced neuroinflammation, attenuated DNA damage, and prevented cellular senescence. However taking NAD-boosting supplements is a leap of faith, not a scientifically proven way to reduce disease risk or increase longevity.[5] [6]

Inflammaging[edit | edit source]

Inflammaging

Age-related changes in the immune system also include chronic inflammation. The upregulation of the inflammatory immune response in the body associated with age is called inflammaging. Since many chronic diseases are linked to inflammation, this also contributes to aging and illness.

Inflammaging is a specific type of chronic inflammation, characterized as a sterile inflammation (meaning it persists even if the when the body isn’t battling any infections). Differing from infection-driven inflammation, inflammaging is low-grade. Inflammation is chronic, sustained by these types of stimuli:

  • Self (cell debris and molecules)
  • Quasi-self (gut microbiota)
  • Non-self (pathogens)

A small number of damaged receptors triggers this type of inflammation, which sense the stimuli and activate the innate immune response[7].

Physiotherapy Implications[edit | edit source]

Older persons exercising

Scientific data firmly supports the idea that regular exercise ( low-cost and a non-pharmacological treatment), specifically tailored in the older person, induce many restorative mechanisms such as:a “telo-protective” effect; triggers the anti-inflammatory phenotype; boosts the adaptive immune system and subsequently inhibits the accelerated immunosenescence process; increases post-vaccination immune responses; and may extend a healthy lifespan[8].

Taking in the above information, promoting and educating clients of importance of lifelong good exercise habits should be encouraged.

References[edit | edit source]

  1. Lian J, Yue Y, Yu W, Zhang Y. Immunosenescence: a key player in cancer development. Journal of Hematology & Oncology. 2020 Dec;13(1):1-8. Available: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7653700/(accessed 22.7.2022)
  2. Lohman H, Padilla R, Byers-Connon S. Occupational Therapy with elders. St. Louis, MO: Mosby. 2019 Available:https://www.sciencedirect.com/book/9780323498463/occupational-therapy-with-elders (accessed 21.7.2022)
  3. Crooke SN, Ovsyannikova IG, Poland GA, Kennedy RB. Immunosenescence: a systems-level overview of immune cell biology and strategies for improving vaccine responses. Experimental gerontology. 2019 Sep 1;124:110632. Available: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6849399/(accessed 22.7.2022)
  4. Barzilai N, Crandall JP, Kritchevsky SB, Espeland MA. Metformin as a tool to target aging. Cell metabolism. 2016 Jun 14;23(6):1060-5. Available:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5943638/ (accessed 22.7.2022)
  5. Hou, Y., Wei, Y., Lautrup, S., Yang, B., Wang, Y., Cordonnier, S., Mattson, M.P., Croteau, D.L. and Bohr, V.A., 2021. NAD+ supplementation reduces neuroinflammation and cell senescence in a transgenic mouse model of Alzheimer’s disease via cGAS–STING. Proceedings of the National Academy of Sciences, 118(37), p.e2011226118. Available:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8449423/ (accessed 22.7.2022)
  6. Washington Paste Do NAD-boosting supplements fight aging? Not according to current research. Available:https://www.washingtonpost.com/lifestyle/wellness/do-nad-boosting-supplements-fight-aging-not-according-to-current-research/2019/11/26/ffc95704-07c4-11ea-818c-fcc65139e8c2_story.html (accessed 22.7.2022)
  7. Liv health Inflammaging: How Aging And Inflammation Can Cause Age-Related Diseases Available:https://livhealth.com/inflammaging/ (accessed 22.7.2022)
  8. Domaszewska K, Boraczyński M, Tang YY, Gronek J, Wochna K, Boraczyński T, Wieliński D, Gronek P. Protective Effects of Exercise Become Especially Important for the Aging Immune System in The Covid-19 Era. Aging and Disease. 2022 Feb;13(1):129. Available:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8782560/ (accessed 22.7.2022)