Speaker
Description
Physical activity induces rapid, selective leukocyte mobilization, thereby modulating immune surveillance. Among the most responsive cell types to high-intensity exercise are NK and CD8+ T cells, key effectors of immune defense against infected and malignant cells. However, comprehensive characterization of acute high-intensity interval training (HIIT)-induced effects on leukocyte populations is limited. We collected peripheral blood from 23 healthy participants undergoing a supervised, group-based HIIT session at baseline, immediately post-exercise (ex02), and 1h post-exercise (ex60). Cell counts were quantified using clinical-grade flow cytometry. CD8+ T cells were analyzed for memory and differentiation status and virus peptide reactivity using DNA-barcoded peptide-MHC multimer staining targeting 250 peptides. Chemokine receptor expression (CX3CR1, CXCR2, CXCR4, CCR2, CCR5) and ligand regulation were evaluated via flow cytometry and Olink proteomics. Associations between individual characteristics – fitness, sex, body composition, and age – and CD8+ T cell mobilization were analyzed. Chemokine receptor expression on CD4⁺, γδ T cells, NK cells, and monocytes was profiled using flow cytometry and FlowSOM clustering. A single HIIT bout induced robust cell type-specific mobilization followed by substantial egress, consistent across fitness levels, body composition and age. NK, γδ and CD8+ T cells were the most HIIT-responsive cell types. Catecholamines NE and EPI peaked post-exercise, and NE was selectively associated with CD8+ T cell mobilization. Memory subsets were reorganized, reducing terminally differentiated and CD57⁺, PD-1⁺, and CD28neg cells at ex60 post exercise. Circulating virus-reactive T cells increased across 12 virus types. HIIT modulated chemokine receptor profiles in a cell type-specific manner – CD56dim CX3CR1⁺ CXCR2⁺ NK cells and two populations of CD8+ T cells with distinct chemokine receptor patterns were preferentially mobilized. Acute HIIT mobilizes functional, virus-reactive CD8+ T cells with features indicative of enhanced migratory and activation potential, supporting translational use from tumor immunology to infectious diseases.The study is registered at clinicaltrials.gov (NCT05826496).
Keywords
acute exercise; adaptive immunity; chemokine receptor; endurance exercise; exercise immunology; migration
| Abstract submitters declaration | yes |
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| Conflict of Interest & Ethical Approval | yes |
