免疫衰老

免疫衰老（英語：immunosenescence）是一種隨著年歲的增長，免疫系統逐漸退化的過程。在2020年的一項研究指出，後天免疫系統比先天免疫系統更受老化影響。^[1]免疫系統包括生物對感染及免疫的長期記憶。由年齡引起的免疫缺陷在長壽及不長壽的物種也存在。^[2]

免疫衰老現象，已在猴子及老鼠等動物研究過 ^[3][4][5]。免疫衰老是一個導致老年死亡重大的原因。免疫老化，與株落失能和T-細胞滅絕, 是造成免疫系統失靈的重大原因。不過，T-細胞減少及株落失能仍有機會逆轉，但截止2020年，沒有任何方法及技術，可以逆轉免疫衰老。^[6][7]

免疫衰老，並不是一種隨機的退化現象。相反，它似乎概括了一種逆向的演化模式。大多數受免疫老化影響的因素，似乎都受到遺傳與基因的控制。^[8]

參考文獻

1. Pangrazzi L, Weinberger B. T cells, aging and senescence. Experimental Gerontology. February 2020, 134: 110887. PMID 32092501. S2CID 211237913. doi:10.1016/j.exger.2020.110887.
2. Ginaldi L, Loreto MF, Corsi MP, Modesti M, De Martinis M. Immunosenescence and infectious diseases. Microbes and Infection. August 2001, 3 (10): 851–857. PMID 11580980. doi:10.1016/S1286-4579(01)01443-5.
3. Letendre C, Sawyer E, Young LJ, Old JM. Immunosenescence in a captive semelparous marsupial, the red-tailed phascogale (Phascogale calura). BMC Zoology. 2018, 3: 10. S2CID 53496572. doi:10.1186/s40850-018-0036-3 .
4. Letendre C, Young LJ, Old JM. Limitations in the isolation and stimulation of splenic mononuclear cells in a dasyurid marsupial, Phascogale calura. BMC Research Notes. October 2018, 11 (1): 712. PMC 6180634 . PMID 30305168. doi:10.1186/s13104-018-3824-5 .
5. Nikolich-Zugich J, Rudd BD. Immune memory and aging: an infinite or finite resource?. Current Opinion in Immunology. August 2010, 22 (4): 535–540. PMC 2925022 . PMID 20674320. doi:10.1016/j.coi.2010.06.011.
6. Crespo J, Sun H, Welling TH, Tian Z, Zou W. T cell anergy, exhaustion, senescence, and stemness in the tumor microenvironment. Current Opinion in Immunology. April 2013, 25 (2): 214–221. PMC 3636159 . PMID 23298609. doi:10.1016/j.coi.2012.12.003.
7. Zhang Z, Liu S, Zhang B, Qiao L, Zhang Y, Zhang Y. T Cell Dysfunction and Exhaustion in Cancer. Frontiers in Cell and Developmental Biology. 2020, 8: 17. PMC 7027373 . PMID 32117960. doi:10.3389/fcell.2020.00017  （英语）.
8. Franceschi C, Valensin S, Fagnoni F, Barbi C, Bonafè M. Biomarkers of immunosenescence within an evolutionary perspective: the challenge of heterogeneity and the role of antigenic load. Experimental Gerontology. December 1999, 34 (8): 911–921. PMID 10673145. S2CID 32614875. doi:10.1016/S0531-5565(99)00068-6.

參考

• 老化
• 海佛烈克極限
• 細胞程序性死亡