Cytomegalovirus Seropositivity Differences In T Cell Response To An Acute Cardiorespiratory Or Resistance Exercise Bout

The PURPOSE of this study was to determine if participants who are cytomegalovirus (CMV) seropositive (POS) had a different response to acute exercise than those who are seronegative (NEG), and if the responses were different for two types of exercise, cardiorespiratory (CRE) and resistance (RE). We hypothesized that there would be differences related to seropositivity status for the more highly differentiated T cell subsets than less differentiated subsets. METHODS Twenty-four participants between the ages of 56-75 years and from a variety of fitness backgrounds who were in good health completed the study. On two separate visits, the participants performed a single ~30 mins session of CRE (70% heart rate reserve) or RE (70% 1 repetition maximum). Blood was collected before (PRE), immediately after (POST), and recovery 1 hour after (RECOV) each exercise session. Fresh whole blood was stained and a flow cytometer (Miltenyi MACS Quant 10) used to determine T cell type and subtype. Serum was frozen and stored at -80C for batch analyses of CMV seropositivity using a commercially available kit. All data is presented as mean difference ± SE between the two variables of interest. RESULTS There were no differences in age, MVPA, BMI, fat free mass, or VO2max between CMV groups. CRE increased CD3+ T cell count from PRE at POST (120 ± 47.3 x103 cells/μL; p = 0.0023) in POS but not in NEG (39.5 ± 51.4 x103 cells/μL; p > 0.05) participants. In response to RE, POST CD3+ T cells were higher in both POS (249 ± 61 x103 cells/μL; p = 0.0007) and NEG (174 ± 66.3 x103 cells/μL; p = 0.0070). RE modestly increased (15.3 ± 4.85 cells/μL; p = 0.0067) CD3 + CD8+ naïve T cells POS participants, but not in NEG and not in response to CRE. There were no differences (p > 0.05) between POS and NEG for CD4+ or CD8+ naïve T cells in response to CRE or RE. NEG CD4+ EMRA CD57+ T cells at post were higher than POS for CRE (6.74 ± 2.76 cells/μL; p = 0.0025) and RE (5.09 ± 2.57 cells/μL; p = 0.0278), and NEG was lower than POS CD8+ EMRA CD57+ at POST CRE (27.9 ± 6.44 cells/μL; p < 0.0001) and RE (27.6 ± 7.89 cells/μL; p = 0.00425). In CONCLUSION, there are differences in post-exercise T cell responses due to CMV seropositivity and type of exercise, and more differences in highly differentiated T cells. CMV seropositivity and exercise type may need to be considered when interpreting exercise immunology research.