title: Preferential expansion of pro-inflammatory Tregs in human non-small cell lung cancer.
abstract: OBJECTIVE
  Lung cancer is the leading cause of cancer-related death in the USA. Regulatory T cells (Tregs) normally function to temper immune responses and decrease inflammation. Previous research has demonstrated different subsets of Tregs with contrasting anti- or pro-inflammatory properties. This study aimed to determine Treg subset distributions and characteristics present in non-small cell lung cancer (NSCLC) patients.
  
  
  METHODS
  Peripheral blood was collected from healthy controls (HC) and NSCLC patients preceding surgical resection, and mononuclear cells were isolated, stained, and analyzed by flow cytometry. Tregs were defined by expression of CD4 and CD25 and classified into CD45RA(+)Foxp3(int) (naïve, Fr. I) or CD45RA(-)Foxp3(hi) (activated Fr. II). Activated conventional T cells were CD4(+)CD45RA(-)Foxp3(int) (Fr. III).
  
  
  RESULTS
  Samples from 23 HC and 26 NSCLC patients were collected. Tregs isolated from patients with NSCLC were found to have enhanced suppressive function on naive T cells. Cancer patients had significantly increased frequencies of activated Tregs (fraction II: FrII), 17.5 versus 3.2% (P < 0.001). FrII Tregs demonstrated increased RORγt and IL17 expression and decreased IL10 expression compared to Tregs from HC, indicating pro-inflammatory characteristics.
  
  
  CONCLUSIONS
  This study demonstrates that a novel subset of Tregs with pro-inflammatory characteristics preferentially expand in NSCLC patients. This Treg subset appears identical to previously reported pro-inflammatory Tregs in human colon cancer patients and in mouse models of polyposis. We expect the pro-inflammatory Tregs in lung cancer to contribute to the immune pathogenesis of disease and propose that targeting this Treg subset may have protective benefits in NSCLC.
authors.affiliation: Department of Surgery, Feinberg School of Medicine, Northwestern University, Suite 650, 676 N St. Clair, Chicago, IL, 60611, USA.
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Phillips
authors.forename: Lawrence M
authors.initials: LM
authors.lastname: Knab
authors.forename: Nichole R
authors.initials: NR
authors.lastname: Blatner
authors.forename: Leila
authors.initials: L
authors.lastname: Haghi
authors.forename: Malcolm M
authors.initials: MM
authors.lastname: DeCamp
authors.forename: Shari L
authors.initials: SL
authors.lastname: Meyerson
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Heiferman
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Heiferman
authors.forename: Fotini
authors.initials: F
authors.lastname: Gounari
authors.forename: David J
authors.initials: DJ
authors.lastname: Bentrem
authors.forename: Khashayarsha
authors.initials: K
authors.lastname: Khazaie
mesh_terms: D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000276:immunology*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000276:immunology*; D008213:Lymphocyte Activation; D008297:Male; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*