title: Psychological stress increases human T cell apoptosis in vitro.
abstract: OBJECTIVE
  Recent studies have shown that apoptosis is involved in stress responses. The present study examined if stressors increase in vitro apoptosis of peripheral blood T lymphocytes in a dose-dependent manner.
  
  
  METHODS
  Daily subjective stress was quantitatively analyzed in 40 nonsmoking men with a daily hassles questionnaire. Apoptosis of T lymphocytes was measured by flowcytometry using Annexin V/PI double staining method after 0, 12, and 24 h of culture in the presence or absence of dexamethasone (DEX). Using a cross-sectional design, the current study examined the relationship between stress and in vitro apoptosis of T cells.
  
  
  RESULTS
  Results showed that apoptosis of T lymphocytes in vitro has a significant correlation with stress and age. Stress was positively correlated with percentage of apoptosis in T cells after 12 h of culture, irrespective of DEX treatment. Age was positively correlated with the percentage of T cell apoptosis after 0 and 12 h of coculture with DEX.
  
  
  CONCLUSIONS
  These results indicate that age-related apoptosis and stress-related apoptosis of T cells are modulated through different mechanisms. This is the first study to show that in vitro lymphocyte apoptosis is influenced by daily stress in a dose-dependent manner.
authors.affiliation: Department of Immunology, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Japan.
authors.forename: Shotaro
authors.initials: S
authors.lastname: Sakami
authors.forename: Akinori
authors.initials: A
authors.lastname: Nakata
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamamura
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Kawamura
mesh_terms: D000203:Activities of Daily Living / Q000523:psychology; D000375:Aging / Q000276:immunology / Q000378:metabolism; D017304:Annexin A5 / Q000378:metabolism; D017209:Apoptosis / Q000276:immunology*; D002478:Cells, Cultured; D003907:Dexamethasone / Q000494:pharmacology; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D015213:Neuroimmunomodulation / Q000276:immunology*; D010718:Phosphatidylserines / Q000378:metabolism; D011930:Reaction Time / Q000187:drug effects / Q000276:immunology; D013315:Stress, Psychological / Q000097:blood* / Q000276:immunology*; D011795:Surveys and Questionnaires; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology*
chemical_list: D017304:Annexin A5; D010718:Phosphatidylserines; D003907:Dexamethasone