Latent Cytomegalovirus infection amplifies CD8 T-lymphocyte mobilisation and egress in response to exercise.
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Colleges, School and Institutes
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 60min at 80% V O(2) max. Blood was collected at baseline, during the final minute of exercise, and 15min and 60min 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 60min 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.
|Number of pages||9|
|Journal||Brain, Behaviour, and Immunity|
|Publication status||Published - 16 Jul 2010|
- CD8(+) T lymphocytes, Lymphocytosis, Immune surveillance, Human, Stress, Memory lymphocytes, Lymphocytopenia, Exercise, Migration, Cytomegalovirus