Preliminary evidence of reductive stress in human cytotoxic T-cells following exercise

This study investigated immunophenotypic differences in intracellular thiol redox state of peripheral blood mononuclear cells (PBMCs) isolated from trained (TR, n=9, mean {plus minus} SD: age 28 {plus minus} 5 years; BMI 23.2 {plus minus} 2.6 kg·m ; VO 56.9 {plus minus} 6.1 ml·kg ·min ) and recreationally active (RA, n=11, mean {plus minus} SD: age 27 {plus minus} 6 years; BMI 24.2 {plus minus} 3.7 kg·m ; VO 45.1 {plus minus} 6.4 ml·kg ·min ) participants before and after a maximal aerobic exercise tolerance test. Blood samples were taken before (PRE), during (sample acquired at 70% HRmax), immediately (POST+0) and 15 minutes post-exercise (POST+15). PBMCs were isolated and reduced thiol analysis (fluorescein-5 maleimide (F5M)) by immunophenotype (CD3+, CD4+ and CD8 ) was performed using flow cytometry. A significant increase in cellular F5M fluorescence was observed in CD3+ T-cells at POST+0, with changes driven to a greater extent by CD8 T-cells (fold change in both groups CD4: +2.3, CD8: +2.8; p