title: Increased frequency of regulatory T cells in peripheral blood and tumour infiltrating lymphocytes in colorectal cancer patients.
abstract: Recent results have shown a correlation between survival and frequency of tumour infiltrating T lymphocytes in colorectal cancer patients. However, it remains unclear whether the frequency of regulatory T cells is higher in colorectal cancer as compared to normal colon. To address this question we analysed the frequency and function of regulatory T cells in the peripheral blood and tumour infiltrating lymphocytes of colorectal cancer patients. The proportion of regulatory T cells in the peripheral blood of colorectal cancer patients (mean 8%) was significantly higher than that in normal controls (mean 2.2%). There were significantly more regulatory T cells in tumour infiltrating lymphocytes (mean 19.2%) compared to lymphocytes from an autologous non-malignant portion of the colon (mean 9%). Regulatory T cells from colorectal cancer patients were FOXP3 positive and suppressed the proliferation of autologous CD4+ CD25- cells. A higher density of tumour infiltrating regulatory T cells was found in patients with advanced as compared to early disease. These results support the hypothesis that increased numbers of regulatory T cells in the blood and tumours of colorectal cancer patients may influence the immune response against cancer and suggest that strategies to overcome regulatory T cell activity may be beneficial in the treatment of human colorectal cancer.
authors: Tumor Immunology Group, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Oxford, United Kingdom.
authors: Khoon Lin
authors: KL
authors: Ling
authors: Sarah E
authors: SE
authors: Pratap
authors: Gaynor J
authors: GJ
authors: Bates
authors: Baljit
authors: B
authors: Singh
authors: Neil J
authors: NJ
authors: Mortensen
authors: Bruce D
authors: BD
authors: George
authors: Bryan F
authors: BF
authors: Warren
authors: Juan
authors: J
authors: Piris
authors: Giovanna
authors: G
authors: Roncador
authors: Stephen B
authors: SB
authors: Fox
authors: Alison H
authors: AH
authors: Banham
authors: Vincenzo
authors: V
authors: Cerundolo
mesh_terms: D016022:Case-Control Studies; D003106:Colon / Q000276:immunology; D015179:Colorectal Neoplasms / Q000097:blood / Q000276:immunology*; D051858:Forkhead Transcription Factors / Q000378:metabolism; D006801:Humans; D050378:T-Lymphocytes, Regulatory / Q000502:physiology*
chemical_list: C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors