Objective To explore the effect of exercise on the celluar immune function of mice induced by PM_2.5.

Methods Twenty-four male C57BL/6 mice were randomly assigned into four groups, filtered air, concentrated PM_2.5, exercise and filtered air, and exercise and concentrated PM_2.5, with six mice in each group.The mice in the exercise group ran on the treadmill for 1 h every day, and then the mice in the four groups were respectively exposed to concentrated PM_2.5 or filtered air after 1 h of rest.After twenty-four weeks, flow cytometric assay was used to detect the quantity of CD3⁺CD4⁺CD8a⁺ T cells, CD18⁺ T cells and CD154⁺ T cells in spleen in mice of the four groups.

Results The median concentration of PM_2.5 in the exposure chamber, filtered chamber and ambient air were 49.24, 12.18, 32.25 μg/m³, respectively.PM_2.5 exposure led to increase in CD3⁺CD4⁺CD8a⁺ T cells (P < 0.05) and decrease in CD154⁺ T cells (P < 0.05), whereas running was beneficial for decreasing CD3⁺CD4⁺CD8a⁺ T cells (P < 0.05) and increasing CD154⁺ T cells (P < 0.05).

Conclusions PM_2.5 exposure induces perturbation of the immune system.Regular running proves to be helpful for maintaining the balance of the immune system and improving the body′s resistance to PM_2.5.