title: T lymphocyte activation in visceral adipose tissue of patients with oesophageal adenocarcinoma.
abstract: BACKGROUND
  Visceral adipose tissue may fuel obesity-associated chronic inflammation and tumorigenesis. T cells may be important in visceral adipose tissue in driving inflammation, but they have not yet been characterized in patients with cancer. This study aimed to characterize T lymphocytes in visceral adipose tissue and peripheral blood from patients with oesophageal adenocarcinoma.
  
  
  METHODS
  Omental fat was taken from 35 patients with oesophageal adenocarcinoma at the start of surgery. Flow cytometry was performed to assess T cell activation status and cytokine production in omentum and peripheral blood.
  
  
  RESULTS
  A large population of lymphocytes was present in the omentum. Omental CD4(+) and CD8(+) T cells displayed significantly enhanced expression of the T cell activation markers CD69 (P < 0·001) and CD107a (CD8(+) T cells: P < 0·01), and significantly decreased CD62L expression (P < 0·05), compared with blood. Significantly higher proportions of CD45RO(+) T cells compared with CD45RA(+) T cells were present in omentum (P < 0·001 and P = 0·012 for CD4(+) and CD8(+) cells respectively). Interferon γ was the most abundant cytokine expressed by omental T cells, with a significantly higher level than in blood and subcutaneous adipose tissue (P < 0·01).
  
  
  CONCLUSIONS
  Visceral adipose tissue is a rich source of activated proinflammatory CD4(+) and CD8(+) T cells. It may fuel chronic inflammation via T cell-mediated pathways.
authors.affiliation: Department of Surgery, Institute of Molecular Medicine, Trinity Centre for Health Sciences, St James's Hospital and Trinity College Dublin, Ireland.
authors.forename: J
authors.initials: J
authors.lastname: Lysaght
authors.forename: E H
authors.initials: EH
authors.lastname: Allott
authors.forename: C L
authors.initials: CL
authors.lastname: Donohoe
authors.forename: J M
authors.initials: JM
authors.lastname: Howard
authors.forename: G P
authors.initials: GP
authors.lastname: Pidgeon
authors.forename: J V
authors.initials: JV
authors.lastname: Reynolds
mesh_terms: D000230:Adenocarcinoma / Q000276:immunology*; D000368:Aged; D000369:Aged, 80 and over; D016516:CD4-CD8 Ratio; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes; D016207:Cytokines / Q000096:biosynthesis; D004938:Esophageal Neoplasms / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D050152:Intra-Abdominal Fat / Q000276:immunology*; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D009852:Omentum / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D016207:Cytokines; D007371:Interferon-gamma