The Acute Response of Cytotoxic T Cells Following Work-Matched Continuous Moderate Intensity and High Intensity Interval Exercise in Metastatic Cancer Patients Undergoing Chemotherapy : a Pilot Study

Tumor-bearing animal studies have suggested that aerobic exercise may acutely enhance anti-tumor immunity, partly by mobilizing effector cytotoxic T-cells (CTLs) in the bloodstream during exercise. This acute immune response being strongly driven by intensity, high-intensity interval exercise (HIIE) might thus be a promising strategy to stimulate anti-cancer immunity in cancer patients. Yet, so far, the acute effects of moderate continuous (MOD) and HIIE on circulating T-cells remain unknown in patients receiving chemotherapy. The objective of this study was to characterise the acute CTLs response following a MOD and a HIIE trial in metastatic cancer patients (all solid cancer types) undergoing chemotherapy. Eleven participants (45-65 years old) underwent a block-randomized crossover trial with a MOD and a duration and work-matched HIIE trial. Blood draws were performed before, after and 1h after each trial. Isolated peripheral blood mononuclear cells (PBMC) were stained to identify naive, central memory, effector memory (EM) and TEMRA CTLs. EM and TEMRA were evaluated for their expression of CD28, PD-1, CD95, CXCR3 and CXCR4. Total, CD28-, CD95+ and CXCR3+ TEMRA blood levels increased immediately following both trials and decreased back to baseline levels 1h after exercise cessation (all p < 0.01). In metastatic cancer patients, a MOD and a work-matched HIIE session both induced the preferential blood mobilization and egress of CXCR3+ TEMRA cells. This is consistent with the hypothesis that exercise might be able to acutely stimulate tumoricidal cytotoxic immunity.