Mitochondrial Dysfunction in CD4+ T Effector Memory RA+ Cells
by
, , ,
Marie Strickland
1,2,
Salanne Lee
1,
Shi Yong Neo
1,
Akhila Balachander
1,
Ivy Low
1,
Seri Mustafah
1,
Wah Ing Goh
3,
Graham D. Wright
3,
Anis Larbi
1,3 and
Sylvia L. F. Pender
2,* 1
Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (A*STAR), 8A Biomedical Grove, Immunos, Singapore 138648, Singapore
2
School of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO17 1BJ, UK
3
Research Support Centre (RSC), Agency for Science, Technology and Research (A*STAR), 30 Biopolis Street, Matrix Building, Singapore 138671, Singapore
*
Author to whom correspondence should be addressed.
Biology 2023, 12(4), 597; https://doi.org/10.3390/biology12040597
Submission received: 31 December 2022
/
Revised: 28 March 2023
/
Accepted: 6 April 2023
/
Published: 14 April 2023
(This article belongs to the Special Issue Mitochondrial Dynamics and Function)
Simple Summary
The mitochondria is the powerhouse of the cell. This powerhouse becomes somehow dysfunctional as we get older; hence, our immune responses to infection become poor, resulting in poor vaccine efficiency. This factor is essential when designing vaccines for the elderly. In this study, we aim to study the biology of specific immune cells and understand why and how they exhibit different mitochondrial phenomena and dynamics when confronted with stimulation following infection.
Abstract
Human ageing is accompanied by poor responses to infection and decreased vaccine efficacy. While the causes of this can be attributed to defects in the immune system that increase with age, it is unknown whether mitochondrial dysfunction may also contribute to these phenomena. This study aims to assess mitochondrial dysfunction in CD4+ terminal effector memory T cells re-expressing CD45RA (TEMRA) cells and other CD4+ memory T cell subtypes, which are increased in number in the elderly population, with respect to how their metabolic responses to stimulation are altered compared to CD4+ naïve T cells. In this study, we show that CD4+ TEMRA cells exhibit altered mitochondrial dynamics compared to CD4+ naïve cells and CD4+ central and effector memory cells, with a 25% reduction in OPA1 expression. CD4+ TEMRA and memory cells show increased upregulation of Glucose transporter 1 following stimulation and higher levels of mitochondrial mass compared to CD4+ naïve T cells. Additionally, TEMRA cells exhibit a decrease in mitochondrial membrane potential compared to other CD4+ memory cell subsets by up to 50%. By comparing young to aged individuals, more significant mitochondria mass and lower membrane potential were observed in CD4+ TEMRA of young individuals. In conclusion, we suggest that CD4+ TEMRA cells may be impaired with respect to their metabolic response to stimulation, possibly contributing to impaired responses to infection and vaccination.
