CMV amplifies T-cell redeployment to acute exercise independently of HSV-1 serostatus.

PURPOSE: Latent cytomegalovirus (CMV) infection has been shown to alter the lymphocyte response to acute aerobic exercise, likely due to the corresponding increase in exercise-responsive memory CD8(+) T cells. It is unknown if latent infection with another herpesvirus, herpes simplex virus 1 (HSV-1), also plays a role in shaping the lymphocyte response to exercise. METHODS: Thirty-two men (ages 39.3 ± 14.7 yr) counterbalanced by CMV and HSV-1 serostatus (positive/negative) cycled for 30 min at ∼80% peak power. Blood sampled before, immediately after, and 1 h after exercise was analyzed by flow cytometry for T-cell subset enumeration. RESULTS: In resting blood, HSV-1(+) had fewer lymphocytes, CD4(+) T cells, KLRG1(-) CD28(+) CD4(+) T cells, and CD45RA(-)CCR7(+)CD4(+) T cells than HSV-1(-), whereas CMV(+) had increased numbers of lymphocytes, CD8(+) T cells, KLRG1(+)CD28(-)CD4(+) and CD8(+) T cells, and CD45RA(+)CCR7(-)CD8(+) T cells and a lower CD4:CD8 T-cell ratio than CMV(-). After exercise, CMV(+) had a greater mobilization of CD8(+) T cells, KLRG1+CD28(-)CD4+ and CD8(+) T cells, and CD45RA+CCR7(-)CD8+ T cells independently of HSV-1 serostatus, as well as a greater egress of these subsets 1 h after exercise. HSV serostatus did not influence total CD8(+) T-cell response to exercise. CONCLUSIONS: The impact of latent CMV infection on the redeployment of T-cell subsets with exercise is independent of HSV-1 infection. This is most likely due to the unique ability of CMV to alter the composition of the memory T-cell pool in favor of exercise-responsive T-cell subsets.

The effects of age and viral serology on γδ T-cell numbers and exercise responsiveness in humans.

γδ T-cells are cytotoxic effector cells that preferentially migrate to peripheral tissues and recognize many types of antigen. We examined the effects of age and viral serology on the exercise responsiveness of γδ T-cells. Blood was collected from 17 younger (age: 23-35yrs) and 17 older (50-64yrs) healthy males matched for cytomegalovirus (CMV), Epstein-Barr virus, herpes simplex virus-1 and Parvovirus B19 serologic status before and after a single bout of cycling exercise. Older had lower numbers and proportions of γδ T-cells than younger, while CMV was associated with increased numbers and proportions of γδ T-cells in younger but not older. Exercise evoked a ∼2-fold increase in circulating γδ T-cell numbers. The magnitude of this response was 3-times greater in younger compared to older, and 1.6-times greater in younger CMV-infected compared to younger non CMV-infected. To conclude, γδ T-cell numbers and exercise responsiveness decreases with age and may contribute to impaired immunosurveillance after acute acute physical stress.