Age‐associated Epstein–Barr virus‐specific T cell responses in seropositive healthy adults |
| |
Authors: | A Orfao de Matos S Fiorentino Gómez S M Quijano Gómez |
| |
Institution: | 1. Servicio General de Citometría y Departamento de Medicina, Centro de Investigación del Cáncer (Instituto de Biología Molecular y Celular del Cáncer and IBSAL;2. CSIC‐USAL), Universidad de Salamanca, , Salamanca, Spain;3. Grupo de Inmunobiología y Biología Celular, Departamento de Microbiología, Facultad de Ciencias, Pontificia Universidad Javeriana, , Bogotá, Colombia |
| |
Abstract: | Epstein–Barr virus (EBV) is present in 95% of the world's adult population. The immune response participates in immune vigilance and persistent infection control, and this condition is maintained by both a good quality (functionality) and quantity of specific T cells throughout life. In the present study, we evaluated EBV‐specific CD4+ and CD8+ T lymphocyte responses in seropositive healthy individuals younger and older than 50 years of age. The assessment comprised the frequency, phenotype, functionality and clonotypic distribution of T lymphocytes. We found that in both age groups a similar EBV‐specific T cell response was found, with overlapping numbers of tumour necrosis factor (TNF)‐α+ T lymphocytes (CD4+ and CD8+) within the memory and effector cell compartments, in addition to monofunctional and multi‐functional T cells producing interleukin (IL)‐2 and/or interferon (IFN)‐γ. However, individuals aged more than 50 years showed significantly higher frequencies of IL‐2‐producing CD4+ T lymphocytes in association with greater production of soluble IFN‐γ, TNF‐α and IL‐6 than subjects younger than 50 years. A polyclonal T cell receptor (TCR)‐variable beta region (Vβ) repertoire exists in both age groups under basal conditions and in response to EBV; the major TCR families found in TNF‐α+/CD4+ T lymphocytes were Vβ1, Vβ2, Vβ17 and Vβ22 in both age groups, and the major TCR family in TNF‐α+/CD8+ T cells was Vβ13·1 for individuals younger than 50 years and Vβ9 for individuals aged more than 50 years. Our findings suggest that the EBV‐specific T cell response (using a polyclonal stimulation model) is distributed throughout several T cell differentiation compartments in an age‐independent manner and includes both monofunctional and multi‐functional T lymphocytes. |
| |
Keywords: | EBV‐specific memory and effector T lymphocytes flow cytometry multi‐functional T lymphocytes soluble cytokines TCR‐Vβ repertoire |
|
|