Cytomegalovirus Infection Impairs the Mobilization of Tissue-Resident Innate Lymphoid Cells into the Peripheral Blood Compartment in Response to Acute Exercise.

Eunhan Cho,Bailey Theall,Brian A Irving,Joshua Granger,Neil M Johannsen,James Stampley,Guillaume Spielmann

doi:10.3390/v13081535

Eunhan Cho, Bailey Theall + Show 5 more

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https://doi.org/10.3390/v13081535

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Abstract

Circulating immune cell numbers and phenotypes are impacted by high-intensity acute bouts of exercise and infection history with the latent herpesviruses cytomegalovirus (CMV). In particular, CMV infection history impairs the exercise-induced mobilization of cytotoxic innate lymphoid cells 1 (ILC1) cells, also known as NK cells, in the blood. However, it remains unknown whether exercise and CMV infection modulate the mobilization of traditionally tissue-resident non-cytotoxic ILCs into the peripheral blood compartment. To address this question, 22 healthy individuals with or without CMV (20–35 years—45% CMVpos) completed 30 min of cycling at 70% VO2 max, and detailed phenotypic analysis of circulating ILCs was performed at rest and immediately post-exercise. We show for the first time that a bout of high-intensity exercise is associated with an influx of ILCs that are traditionally regarded as tissue-resident. In addition, this is the first study to highlight that latent CMV infection blunts the exercise-response of total ILCs and progenitor ILCs (ILCPs). These promising data suggest that acute exercise facilitates the circulation of certain ILC subsets, further advocating for the improvements in health seen with exercise by enhancing cellular mobilization and immunosurveillance, while also highlighting the indirect deleterious effects of CMV infection in healthy adults.

Highlights

Published: 3 August 2021Acute exercise is a robust physiological stressor that promotes lymphocyte mobilization into the circulation [1,2]
We showed that helper innate lymphoid cells 1 (ILC1) and ILC3 cells were mobilized in the blood in response to acute exercise, no differences in mobilization were observed between CMVpos and CMVneg participants (p > 0.05)
Other confounding factors have been shown to affect cellular mobilization in response to acute exercise, including psychological well-being and sex [29], along with CMV infection status [30,31]. This is the first study to examine the effects of acute exercise on the mobilization of innate lymphoid cells (ILC) subsets, which are traditionally regarded as being tissue-resident and unlikely to respond to an acute stressor

Summary

Introduction

Published: 3 August 2021Acute exercise is a robust physiological stressor that promotes lymphocyte mobilization into the circulation [1,2]. This transient increase in the lymphocyte number in peripheral blood post-exercise is due to the exercise-induced stimulation of the sympathetic nervous system [1,3] and the associated increase in cardiac output [1,3], hemodynamic shear stress [1,3], and catecholamine concentration [1,3], all of which are factors leading to tissue-resident lymphocyte mobilization and lymphocyte demargination [4] This highly conserved response amongst individuals affects various circulating immune cells, including. ILCs are a highly heterogeneous population of innate immune cells, found across lymphoid and non-lymphoid tissues, including the liver, spleen, lymph nodes, and skin [9,10]

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