An ultra-endurance event leads to changes in circulating regulatory T-cells, CD4+ naïve and CD8+ effector memory T-cells in the 48 h post-race recovery period

Hannah Lithgow; Laura Gibson; Russell Wilson; Neil Guthrie; Lesley Ingram-Sills; Tom Clifford; Mark Ross

doi:10.1007/s00421-024-05677-y

An ultra-endurance event leads to changes in circulating regulatory T-cells, CD4+ naïve and CD8+ effector memory T-cells in the 48 h post-race recovery period

Eur J Appl Physiol. 2024 Nov 27. doi: 10.1007/s00421-024-05677-y. Online ahead of print.

Authors

Hannah Lithgow^{1

2}, Laura Gibson², Russell Wilson^{1

2}, Neil Guthrie², Lesley Ingram-Sills², Tom Clifford^{3

4}, Mark Ross^{5

6}

Affiliations

¹ School of Energy, Geoscience, Infrastructure and Society, Institute of Life and Earth Sciences, Heriot-Watt University, JMF7, Edinburgh, EH14 4AS, UK.
² School of Applied Sciences, Edinburgh Napier University, Edinburgh, UK.
³ Institute of Cellular Medicine, Newcastle University, Newcastle, UK.
⁴ School of Sport, Exercise, and Health Sciences, Loughborough University, Loughborough, UK.
⁵ School of Energy, Geoscience, Infrastructure and Society, Institute of Life and Earth Sciences, Heriot-Watt University, JMF7, Edinburgh, EH14 4AS, UK. [email protected].
⁶ School of Applied Sciences, Edinburgh Napier University, Edinburgh, UK. [email protected].

PMID: 39604770
DOI: 10.1007/s00421-024-05677-y

Abstract

Purpose: Exercise is known to acutely affect T-lymphocyte populations in the peripheral blood, which is intensity- and duration-dependent. However, effects of longer duration endurance exercise (>5 h) on T-cells in the days following are unknown. The aim of this study was to investigate the circulating T-cell changes that occur in response to an ultra-endurance event, which may provide insight into the inflammatory response to ultra-endurance exercise.

Methods: Ten individuals (m = 7, f = 3) completing an Ironman 70.3 event volunteered for the study. Peripheral blood samples were taken 1-2 days pre-race (PRE-RACE), and 1 day (RACE + 1) and 2 days (RACE + 2) post-race, with circulating T-cells enumerated by flow cytometry (total CD3+, CD4+ and CD8+ T-cells, regulatory T-cells [CD4+CD25+CD127-; T_REG], naïve [CD27+CD45RA+; NA], central memory [CD27+CD45RA-; CM], effector memory [CD27-CD45RA-; EM], and effector memory CD45RA+ [CD27-CD45RA+; EMRA]).

Results: There were no changes in total CD3+, CD4+ and CD8+ T-cells. T_REG RACE + 1 was significantly higher compared to PRE-RACE, as were the proportion of CD4+ NA cells and CD8+ CM cells at RACE + 2; CD8+ EM cells fell at RACE + 2 (absolute counts and proportion).

Conclusion: In conclusion, the ultra-endurance event evoked T-cell changes over the 48 h recovery period, with an increase in T-cells that regulate the immune response, and a reduction in circulating EM T-cells, most likely trafficked to sites of tissue damage and inflammation.

Keywords: Adaptive immunity; Endurance; Exercise; Lymphocytes; T-cells.