Introduction:
Previous studies have shown that exercise has been related with strengthened vaccine-induced immune responses and chronic stress decreases immune function. This study aims to determine whether exercise can alleviate chronic stress-induced attenuation of vaccination responses in mice.
Methods:
C57BL/6 mice, aged 7 weeks old, were randomly assigned: control (CTRL, n=9), sedentary (SED, n=7), eccentric exercise (ECC, n=9), or voluntary wheel running (VWR, n=10) group. SED, ECC, and VWR mice received restraint stress for 6 hours/day, 5 days/week for 3 weeks. CTRL mice did not receive restraint stress. ECC mice exercised running downhill at -20% grade at 17m/min for 45 min. VWR mice voluntarily ran on a telemetered wheel. All groups received an OVA vaccination in two phases: first a sensitization phase with an intramuscular vaccination post 1-week of stress in the gastrocnemius muscle, a second intradermal vaccination in the ear post 3-weeks of stress. Swelling in the ear was measured to determine the proportional delayed-type hypersensitivity (DTH) reaction as part of the cell-mediated immune response (recruitment of memory T cells and effector cells) to the vaccine. Blood from the retro-orbital vein was collected pre-vaccination, 1wk, 2wk and 4wk post-vaccination for antibody responses.
Results:
In this study, there was a trend in increased humoral immunity, in regards to IgM and IgG antibody titers in the exercised groups. This study did not show any significant differences in cell-mediated immunity (indicated with delayed-type hypersensitivity (DTH)), with respect to the effect of exercise on chronic stress.
Conclusion:
Both acute eccentric exercise and voluntary wheel exercise training had a tendency to attenuate stress-induced reductions in antibody responses, but not cell-mediated responses. Further experiments are required to determine the precise significance of exercise’s effects, as well as the determination of the underlying mechanisms.Ope
