title: Latent cytomegalovirus infection amplifies CD8 T-lymphocyte mobilisation and egress in response to exercise.
abstract: Exercise induces mobilisation of CD8(+) T lymphocytes (CD8TL) into the peripheral blood. This response is largely confined to effector-memory CD8TLs: antigen experienced cells which have a strong tissue-homing and effector potential. This study investigated whether effector-memory cells also account for the CD8TL egress from peripheral blood following exercise. As latent Cytomegalovirus (CMV) infection is associated with a robust expansion in the number and proportion of effector-memory CD8TLs, we also investigated if CMV serostatus was a determinant of the CD8TL responses to exercise. Fourteen males (Mean age 35, SD ± 14 yrs), half of whom were CMV seropositive (CMV(+)), ran on a treadmill for 60 min at 80% VO(2) max. Blood was collected at baseline, during the final minute of exercise, and 15 min and 60 min thereafter. CD8TL memory subsets were characterised by flow cytometry, using the cell-surface markers CD45RA, CD27, and CD28. The results confirmed that CD8TLs with an effector-memory phenotype (CD27(-)CD28(-)CD45RA(+/-)) exhibited the largest increase during exercise (+200% to +250%), and also showed the largest egress from blood 60 min post-exercise (down to 40% of baseline values). Strikingly, the mobilisation and subsequent egress of total CD8TLs was nearly twice as large in CMV(+) individuals. This effect appeared specific to CD8TLs, and was not seen for CD4(+) T lymphocytes or total lymphocytes. This effect of CMV serostatus was largely driven by the higher numbers of exercise-responsive effector-memory CD8TLs in the CMV(+) participants. This is the first study to demonstrate that infection history is a determinant of immune system responses to exercise.
authors.affiliation: School of Sport and Exercise Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
authors.forename: James E
authors.initials: JE
authors.lastname: Turner
authors.forename: Sarah
authors.initials: S
authors.lastname: Aldred
authors.forename: Oliver C
authors.initials: OC
authors.lastname: Witard
authors.forename: Mark T
authors.initials: MT
authors.lastname: Drayson
authors.forename: Paul M
authors.initials: PM
authors.lastname: Moss
authors.forename: Jos A
authors.initials: JA
authors.lastname: Bosch
mesh_terms: D000328:Adult; D015308:Anaerobic Threshold / Q000502:physiology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000502:physiology*; D003586:Cytomegalovirus Infections / Q000097:blood / Q000276:immunology* / Q000821:virology; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005434:Flow Cytometry; D006801:Humans; D007156:Immunologic Memory / Q000276:immunology; D007157:Immunologic Surveillance; D018655:Lymphocyte Count; D008297:Male; D017735:Virus Latency