CD8+ T Cell Senescence: Lights and Shadows in Viral Infections, Autoimmune Disorders and Cancer.
Int J Mol Sci
; 23(6)2022 Mar 21.
Article
in English
| MEDLINE | ID: covidwho-1753507
ABSTRACT
CD8+ T lymphocytes are a heterogeneous class of cells that play a crucial role in the adaptive immune response against pathogens and cancer. During their lifetime, they acquire cytotoxic functions to ensure the clearance of infected or transformed cells and, in addition, they turn into memory lymphocytes, thus providing a long-term protection. During ageing, the thymic involution causes a reduction of circulating T cells and an enrichment of memory cells, partially explaining the lowering of the response towards novel antigens with implications in vaccine efficacy. Moreover, the persistent stimulation by several antigens throughout life favors the switching of CD8+ T cells towards a senescent phenotype contributing to a low-grade inflammation that is a major component of several ageing-related diseases. In genetically predisposed young people, an immunological stress caused by viral infections (e.g., HIV, CMV, SARS-CoV-2), autoimmune disorders or tumor microenvironment (TME) could mimic the ageing status with the consequent acceleration of T cell senescence. This, in turn, exacerbates the inflamed conditions with dramatic effects on the clinical progression of the disease. A better characterization of the phenotype as well as the functions of senescent CD8+ T cells can be pivotal to prevent age-related diseases, to improve vaccine strategies and, possibly, immunotherapies in autoimmune diseases and cancer.
Keywords
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
Autoimmune Diseases
/
Virus Diseases
/
HIV Infections
/
COVID-19
/
Neoplasms
Type of study:
Prognostic study
Topics:
Vaccines
Limits:
Humans
Language:
English
Year:
2022
Document Type:
Article
Affiliation country:
Ijms23063374
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