title: Role of LAP+CD4+T cells in the tumor microenvironment of colorectal cancer.
abstract: OBJECTIVE
  To investigate the abundance and potential functions of LAP+CD4+T cells in colorectal cancer (CRC).
  
  
  METHODS
  Proportions of LAP+CD4+T cells were examined in peripheral blood and tumor/paratumor tissues of CRC patients and healthy controls using flow cytometry. Expression of phenotypic markers such as forkhead box (Fox)p3, cytotoxic T-lymphocyte-associated protein (CTLA)-4, chemokine CC receptor (CCR)4 and CCR5 was measured using flow cytometry. LAP-CD4+and LAP+CD4+T cells were isolated using a magnetic cell-sorting system and cell purity was analyzed by flow cytometry. Real-time quantitative polymerase chain reaction was used to measure expression of cytokines interleukin (IL)-10 and transforming growth factor (TGF)-β.
  
  
  RESULTS
  The proportion of LAP+CD4+T cells was significantly higher in peripheral blood from patients (9.44% ± 3.18%) than healthy controls (1.49% ± 1.00%,P< 0.001). Among patients, the proportion of LAP+CD4+T cells was significantly higher in tumor tissues (11.76% ± 3.74%) compared with paratumor tissues (3.87% ± 1.64%,P< 0.001). We also observed positive correlations between the proportion of LAP+CD4+T cells and TNM stage (P< 0.001), distant metastasis (P< 0.001) and serum level of carcinoembryonic antigen (P< 0.05). Magnetic-activated cell sorting gave an overall enrichment of LAP+CD4+T cells (95.02% ± 2.87%), which was similar for LAP-CD4+T cells (94.75% ± 2.76%). In contrast to LAP-CD4+T cells, LAP+CD4+T cells showed lower Foxp3 expression but significantly higher levels of CTLA-4, CCR4 and CCR5 (P< 0.01). LAP+CD4+T cells expressed significantly larger amounts of IL-10 and TGF-β but lower levels of IL-2, IL-4, IL-17 and interferon-γ, compared with LAP-CD4+T cells.
  
  
  CONCLUSIONS
  LAP+CD4+T cells accumulated in the tumor microenvironment of CRC patients and were involved in immune evasion mediated by IL-10 and TGF-β.
authors.affiliation: Wu Zhong, Lei Zhang, Department of Gastrointestinal Surgery, Ganzhou Hospital of Nanchang University, Ganzhou 341000, Jiangxi Province, China.
authors.forename: Wu
authors.initials: W
authors.lastname: Zhong
authors.affiliation: Wu Zhong, Lei Zhang, Department of Gastrointestinal Surgery, Ganzhou Hospital of Nanchang University, Ganzhou 341000, Jiangxi Province, China.
authors.forename: Zhi-Yuan
authors.initials: ZY
authors.lastname: Jiang
authors.affiliation: Wu Zhong, Lei Zhang, Department of Gastrointestinal Surgery, Ganzhou Hospital of Nanchang University, Ganzhou 341000, Jiangxi Province, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Wu Zhong, Lei Zhang, Department of Gastrointestinal Surgery, Ganzhou Hospital of Nanchang University, Ganzhou 341000, Jiangxi Province, China.
authors.forename: Jia-Hao
authors.initials: JH
authors.lastname: Huang
authors.affiliation: Wu Zhong, Lei Zhang, Department of Gastrointestinal Surgery, Ganzhou Hospital of Nanchang University, Ganzhou 341000, Jiangxi Province, China.
authors.forename: Shi-Jun
authors.initials: SJ
authors.lastname: Wang
authors.affiliation: Wu Zhong, Lei Zhang, Department of Gastrointestinal Surgery, Ganzhou Hospital of Nanchang University, Ganzhou 341000, Jiangxi Province, China.
authors.forename: Cun
authors.initials: C
authors.lastname: Liao
authors.affiliation: Wu Zhong, Lei Zhang, Department of Gastrointestinal Surgery, Ganzhou Hospital of Nanchang University, Ganzhou 341000, Jiangxi Province, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Cai
authors.affiliation: Wu Zhong, Lei Zhang, Department of Gastrointestinal Surgery, Ganzhou Hospital of Nanchang University, Ganzhou 341000, Jiangxi Province, China.
authors.forename: Li-Sheng
authors.initials: LS
authors.lastname: Chen
authors.affiliation: Wu Zhong, Lei Zhang, Department of Gastrointestinal Surgery, Ganzhou Hospital of Nanchang University, Ganzhou 341000, Jiangxi Province, China.
authors.forename: Sen
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Wu Zhong, Lei Zhang, Department of Gastrointestinal Surgery, Ganzhou Hospital of Nanchang University, Ganzhou 341000, Jiangxi Province, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Guo
authors.affiliation: Wu Zhong, Lei Zhang, Department of Gastrointestinal Surgery, Ganzhou Hospital of Nanchang University, Ganzhou 341000, Jiangxi Province, China.
authors.forename: Yun-Fei
authors.initials: YF
authors.lastname: Cao
authors.affiliation: Wu Zhong, Lei Zhang, Department of Gastrointestinal Surgery, Ganzhou Hospital of Nanchang University, Ganzhou 341000, Jiangxi Province, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Gao
mesh_terms: D000328:Adult; D000368:Aged; D060908:CTLA-4 Antigen / Q000378:metabolism; D015179:Colorectal Neoplasms / Q000276:immunology* / Q000473:pathology; D005260:Female; D005434:Flow Cytometry; D051858:Forkhead Transcription Factors / Q000378:metabolism; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D016753:Interleukin-10 / Q000378:metabolism*; D020381:Interleukin-17 / Q000378:metabolism; D007376:Interleukin-2 / Q000378:metabolism; D015847:Interleukin-4 / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D060888:Real-Time Polymerase Chain Reaction; D054398:Receptors, CCR4 / Q000378:metabolism; D019713:Receptors, CCR5 / Q000378:metabolism; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000378:metabolism*; D053773:Transforming Growth Factor beta1 / Q000378:metabolism; D059016:Tumor Microenvironment / Q000276:immunology*
chemical_list: C515354:CCR4 protein, human; C584933:CCR5 protein, human; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; C508609:IL10 protein, human; C508717:IL17A protein, human; C508594:IL2 protein, human; C508598:IL4 protein, human; D020381:Interleukin-17; D007376:Interleukin-2; D054398:Receptors, CCR4; D019713:Receptors, CCR5; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D016753:Interleukin-10; D015847:Interleukin-4; D007371:Interferon-gamma
keywords: Colorectal cancer; Interleukin-10; LAP+CD4+ T cells; Transforming growth factor-β; Tumor microenvironment