Both Cytomegalovirus and Epstein-Barr virus infections affect quantities of circulating T- cells and combined they result in an aging-related T-cell phenotype at younger age

Abstract Cytomegalovirus (CMV) is known to alter circulating effector memory CD45RA + (TemRA) or CD45RA - (TemRO) T-cell numbers, but whether Epstein-Barr virus (EBV) does the same or this is amplified during a CMV and EBV co-infection is unclear. Immune cell numbers in blood of children and young, middle-aged, and senior adults ( n = 336) were determined with flow cytometry, and additional multivariate linear regression, intra-group correlation, and cluster analyses were performed. CMV alone caused more immune cell variance for all age groups, and CMV + EBV - senior adults had more late-differentiated CD4 + and CD8 + TemRA and TemRO T-cells. EBV alone resulted in a more equal immune cell composition for children and young adults, and CMV - EBV + senior adults had more intermediate/late-differentiated CD4 + TemRA and TemRO T-cells. CMV and EBV together gave young and middle-aged adults with an elevated BMI and anti-CMV antibody levels a similar immune cell composition as senior adults, and CMV + EBV + middle-aged adults had more late-differentiated CD8 + TemRA, TemRO, and HLA-DR + CD38 - T-cells than CMV + EBV - controls. This study identified CMV- or EBV-induced changes in T-cell numbers and that some young and middle-aged adults were more negatively impacted by a CMV and EBV co-infection giving them an aging-related T-cell phenotype.