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Dakal TC, Dhabhai B, Pant A, Moar K, Chaudhary K, Yadav V, Ranga V, Sharma NK, Kumar A, Maurya PK, Maciaczyk J, Schmidt‐Wolf IGH, Sharma A. Oncogenes and tumor suppressor genes: functions and roles in cancers. MedComm (Beijing) 2024; 5:e582. [PMID: 38827026 PMCID: PMC11141506 DOI: 10.1002/mco2.582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 04/21/2024] [Accepted: 04/26/2024] [Indexed: 06/04/2024] Open
Abstract
Cancer, being the most formidable ailment, has had a profound impact on the human health. The disease is primarily associated with genetic mutations that impact oncogenes and tumor suppressor genes (TSGs). Recently, growing evidence have shown that X-linked TSGs have specific role in cancer progression and metastasis as well. Interestingly, our genome harbors around substantial portion of genes that function as tumor suppressors, and the X chromosome alone harbors a considerable number of TSGs. The scenario becomes even more compelling as X-linked TSGs are adaptive to key epigenetic processes such as X chromosome inactivation. Therefore, delineating the new paradigm related to X-linked TSGs, for instance, their crosstalk with autosome and involvement in cancer initiation, progression, and metastasis becomes utmost importance. Considering this, herein, we present a comprehensive discussion of X-linked TSG dysregulation in various cancers as a consequence of genetic variations and epigenetic alterations. In addition, the dynamic role of X-linked TSGs in sex chromosome-autosome crosstalk in cancer genome remodeling is being explored thoroughly. Besides, the functional roles of ncRNAs, role of X-linked TSG in immunomodulation and in gender-based cancer disparities has also been highlighted. Overall, the focal idea of the present article is to recapitulate the findings on X-linked TSG regulation in the cancer landscape and to redefine their role toward improving cancer treatment strategies.
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Affiliation(s)
- Tikam Chand Dakal
- Department of BiotechnologyGenome and Computational Biology LabMohanlal Sukhadia UniversityUdaipurRajasthanIndia
| | - Bhanupriya Dhabhai
- Department of BiotechnologyGenome and Computational Biology LabMohanlal Sukhadia UniversityUdaipurRajasthanIndia
| | - Anuja Pant
- Department of BiochemistryCentral University of HaryanaMahendergarhHaryanaIndia
| | - Kareena Moar
- Department of BiochemistryCentral University of HaryanaMahendergarhHaryanaIndia
| | - Kanika Chaudhary
- School of Life Sciences. Jawaharlal Nehru UniversityNew DelhiIndia
| | - Vikas Yadav
- School of Life Sciences. Jawaharlal Nehru UniversityNew DelhiIndia
| | - Vipin Ranga
- Dearptment of Agricultural BiotechnologyDBT‐NECAB, Assam Agricultural UniversityJorhatAssamIndia
| | | | - Abhishek Kumar
- Manipal Academy of Higher EducationManipalKarnatakaIndia
- Institute of Bioinformatics, International Technology ParkBangaloreIndia
| | - Pawan Kumar Maurya
- Department of BiochemistryCentral University of HaryanaMahendergarhHaryanaIndia
| | - Jarek Maciaczyk
- Department of Stereotactic and Functional NeurosurgeryUniversity Hospital of BonnBonnGermany
| | - Ingo G. H. Schmidt‐Wolf
- Department of Integrated OncologyCenter for Integrated Oncology (CIO)University Hospital BonnBonnGermany
| | - Amit Sharma
- Department of Stereotactic and Functional NeurosurgeryUniversity Hospital of BonnBonnGermany
- Department of Integrated OncologyCenter for Integrated Oncology (CIO)University Hospital BonnBonnGermany
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2
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Deng G, Song X, Greene MI. FoxP3 in T reg cell biology: a molecular and structural perspective. Clin Exp Immunol 2019; 199:255-262. [PMID: 31386175 PMCID: PMC7008219 DOI: 10.1111/cei.13357] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/30/2019] [Indexed: 12/27/2022] Open
Abstract
Regulatory T cells (Tregs) are specialized in immune suppression and play a dominant role in peripheral immune tolerance. Treg cell lineage development and function maintenance is determined by the forkhead box protein 3 (FoxP3) transcriptional factor, whose activity is fine‐tuned by its post‐translational modifications (PTMs) and interaction partners. In this review, we summarize current studies in the crystal structures, the PTMs and interaction partners of FoxP3 protein, and discuss how these insights may provide a roadmap for new approaches to modulate Treg suppression, and new therapies to enhance immune tolerance in autoimmune diseases.
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Affiliation(s)
- G Deng
- Department of Immunology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - X Song
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, China
| | - M I Greene
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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3
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Nagai Y, Ji MQ, Zhu F, Xiao Y, Tanaka Y, Kambayashi T, Fujimoto S, Goldberg MM, Zhang H, Li B, Ohtani T, Greene MI. PRMT5 Associates With the FOXP3 Homomer and When Disabled Enhances Targeted p185 erbB2/neu Tumor Immunotherapy. Front Immunol 2019; 10:174. [PMID: 30800128 PMCID: PMC6375878 DOI: 10.3389/fimmu.2019.00174] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 01/21/2019] [Indexed: 12/12/2022] Open
Abstract
Regulatory T cells (Tregs) are a subpopulation of T cells that are specialized in suppressing immune responses. Here we show that the arginine methyl transferase protein PRMT5 can complex with FOXP3 transcription factors in Tregs. Mice with conditional knock out (cKO) of PRMT5 expression in Tregs develop severe scurfy-like autoimmunity. In these PRMT5 cKO mice, the spleen has reduced numbers of Tregs, but normal numbers of Tregs are found in the peripheral lymph nodes. These peripheral Tregs that lack PRMT5, however, display a limited suppressive function. Mass spectrometric analysis showed that FOXP3 can be di-methylated at positions R27, R51, and R146. A point mutation of Arginine (R) 51 to Lysine (K) led to defective suppressive functions in human CD4 T cells. Pharmacological inhibition of PRMT5 by DS-437 also reduced human Treg functions and inhibited the methylation of FOXP3. In addition, DS-437 significantly enhanced the anti-tumor effects of anti-erbB2/neu monoclonal antibody targeted therapy in Balb/c mice bearing CT26Her2 tumors by inhibiting Treg function and induction of tumor immunity. Controlling PRMT5 activity is a promising strategy for cancer therapy in situations where host immunity against tumors is attenuated in a FOXP3 dependent manner.
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Affiliation(s)
- Yasuhiro Nagai
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Mei Q Ji
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Fuxiang Zhu
- Unit of Molecular Immunology, Key Laboratory of Molecular Virology & Immunology, CAS Center for Excellence in Molecular Cell Science, Institute Pasteur of Shanghai, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Yan Xiao
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Yukinori Tanaka
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Taku Kambayashi
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | | | | | - Hongtao Zhang
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Bin Li
- The Department of Immunology and Microbiology & Shanghai, Institute of Immunology, Shanghai JiaoTong University School of Medicine, Shanghai, China
| | - Takuya Ohtani
- Penn Institute for Immunology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Mark I Greene
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
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4
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Herrero MJ, Gitton Y. The untold stories of the speech gene, the FOXP2 cancer gene. Genes Cancer 2018; 9:11-38. [PMID: 29725501 PMCID: PMC5931254 DOI: 10.18632/genesandcancer.169] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 04/02/2018] [Indexed: 12/11/2022] Open
Abstract
FOXP2 encodes a transcription factor involved in speech and language acquisition. Growing evidence now suggests that dysregulated FOXP2 activity may also be instrumental in human oncogenesis, along the lines of other cardinal developmental transcription factors such as DLX5 and DLX6 [1-4]. Several FOXP familymembers are directly involved during cancer initiation, maintenance and progression in the adult [5-8]. This may comprise either a pro-oncogenic activity or a deficient tumor-suppressor role, depending upon cell types and associated signaling pathways. While FOXP2 is expressed in numerous cell types, its expression has been found to be down-regulated in breast cancer [9], hepatocellular carcinoma [8] and gastric cancer biopsies [10]. Conversely, overexpressed FOXP2 has been reported in multiple myelomas, MGUS (Monoclonal Gammopathy of Undetermined Significance), several subtypes of lymphomas [5,11], as well as in neuroblastomas [12] and ERG fusion-negative prostate cancers [13]. According to functional evidences reported in breast cancer [9] and survey of recent transcriptomic and proteomic analyses of different tumor biopsies, we postulate that FOXP2 dysregulation may play a main role throughout cancer initiation and progression. In some cancer conditions, FOXP2 levels are now considered as a critical diagnostic marker of neoplastic cells, and in many situations, they even bear strong prognostic value [5]. Whether FOXP2 may further become a therapeutic target is an actively explored lead. Knowledge reviewed here may help improve our understanding of FOXP2 roles during oncogenesis and provide cues for diagnostic, prognostic and therapeutic analyses.
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Affiliation(s)
- Maria Jesus Herrero
- Center for Neuroscience Research, Children's National Medical Center, NW, Washington, DC, USA
| | - Yorick Gitton
- Sorbonne University, INSERM, CNRS, Vision Institute Research Center, Paris, France
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5
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Serena G, Yan S, Camhi S, Patel S, Lima RS, Sapone A, Leonard MM, Mukherjee R, Nath BJ, Lammers KM, Fasano A. Proinflammatory cytokine interferon-γ and microbiome-derived metabolites dictate epigenetic switch between forkhead box protein 3 isoforms in coeliac disease. Clin Exp Immunol 2017; 187:490-506. [PMID: 27936497 DOI: 10.1111/cei.12911] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 11/16/2016] [Accepted: 11/17/2016] [Indexed: 12/21/2022] Open
Abstract
Coeliac disease (CD) is an autoimmune enteropathy triggered by gluten and characterized by a strong T helper type 1 (Th1)/Th17 immune response in the small intestine. Regulatory T cells (Treg ) are CD4+ CD25++ forkhead box protein 3 (FoxP3+ ) cells that regulate the immune response. Conversely to its counterpart, FoxP3 full length (FL), the alternatively spliced isoform FoxP3 Δ2, cannot properly down-regulate the Th17-driven immune response. As the active state of CD has been associated with impairments in Treg cell function, we aimed at determining whether imbalances between FoxP3 isoforms may be associated with the disease. Intestinal biopsies from patients with active CD showed increased expression of FOXP3 Δ2 isoform over FL, while both isoforms were expressed similarly in non-coeliac control subjects (HC). Conversely to what we saw in the intestine, peripheral blood mononuclear cells (PBMC) from HC subjects did not show the same balance between isoforms. We therefore hypothesized that the intestinal microenvironment may play a role in modulating alternative splicing. The proinflammatory intestinal microenvironment of active patients has been reported to be enriched in butyrate-producing bacteria, while high concentrations of lactate have been shown to characterize the preclinical stage of the disease. We show that the combination of interferon (IFN)-γ and butyrate triggers the balance between FoxP3 isoforms in HC subjects, while the same does not occur in CD patients. Furthermore, we report that lactate increases both isoforms in CD patients. Collectively, these findings highlight the importance of the ratio between FoxP3 isoforms in CD and, for the first time, associate the alternative splicing process mechanistically with microbial-derived metabolites.
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Affiliation(s)
- G Serena
- Massachusetts General Hospital and Division of Pediatric Gastroenterology and Nutrition, Center for Celiac Research, Mucosal Immunology and Biology Research Center, Boston, MA, USA.,Graduate Program in Life Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - S Yan
- Massachusetts General Hospital and Division of Pediatric Gastroenterology and Nutrition, Center for Celiac Research, Mucosal Immunology and Biology Research Center, Boston, MA, USA
| | - S Camhi
- Massachusetts General Hospital and Division of Pediatric Gastroenterology and Nutrition, Center for Celiac Research, Mucosal Immunology and Biology Research Center, Boston, MA, USA
| | - S Patel
- Massachusetts General Hospital and Division of Pediatric Gastroenterology and Nutrition, Center for Celiac Research, Mucosal Immunology and Biology Research Center, Boston, MA, USA
| | - R S Lima
- Massachusetts General Hospital and Division of Pediatric Gastroenterology and Nutrition, Center for Celiac Research, Mucosal Immunology and Biology Research Center, Boston, MA, USA
| | - A Sapone
- Massachusetts General Hospital and Division of Pediatric Gastroenterology and Nutrition, Center for Celiac Research, Mucosal Immunology and Biology Research Center, Boston, MA, USA.,Celiac Center, Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - M M Leonard
- Massachusetts General Hospital and Division of Pediatric Gastroenterology and Nutrition, Center for Celiac Research, Mucosal Immunology and Biology Research Center, Boston, MA, USA
| | - R Mukherjee
- Celiac Center, Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - B J Nath
- Department of Gastroenterology, Massachusetts General Hospital, Boston, MA, USA
| | - K M Lammers
- Massachusetts General Hospital and Division of Pediatric Gastroenterology and Nutrition, Center for Celiac Research, Mucosal Immunology and Biology Research Center, Boston, MA, USA
| | - A Fasano
- Massachusetts General Hospital and Division of Pediatric Gastroenterology and Nutrition, Center for Celiac Research, Mucosal Immunology and Biology Research Center, Boston, MA, USA.,European Biomedical Research Institute of Salerno (EBRIS), Salerno, Italy
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6
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Recouvreux MS, Grasso EN, Echeverria PC, Rocha-Viegas L, Castilla LH, Schere-Levy C, Tocci JM, Kordon EC, Rubinstein N. RUNX1 and FOXP3 interplay regulates expression of breast cancer related genes. Oncotarget 2016; 7:6552-65. [PMID: 26735887 PMCID: PMC4872732 DOI: 10.18632/oncotarget.6771] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 11/28/2015] [Indexed: 12/21/2022] Open
Abstract
Runx1 participation in epithelial mammary cells is still under review. Emerging data indicates that Runx1 could be relevant for breast tumor promotion. However, to date no studies have specifically evaluated the functional contribution of Runx1 to control gene expression in mammary epithelial tumor cells. It has been described that Runx1 activity is defined by protein context interaction. Interestingly, Foxp3 is a breast tumor suppressor gene. Here we show that endogenous Runx1 and Foxp3 physically interact in normal mammary cells and this interaction blocks Runx1 transcriptional activity. Furthermore we demonstrate that Runx1 is able to bind to R-spondin 3 (RSPO3) and Gap Junction protein Alpha 1 (GJA1) promoters. This binding upregulates Rspo3 oncogene expression and downregulates GJA1 tumor suppressor gene expression in a Foxp3-dependent manner. Moreover, reduced Runx1 transcriptional activity decreases tumor cell migration properties. Collectively, these data provide evidence of a new mechanism for breast tumor gene expression regulation, in which Runx1 and Foxp3 physically interact to control mammary epithelial cell gene expression fate. Our work suggests for the first time that Runx1 could be involved in breast tumor progression depending on Foxp3 availability.
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Affiliation(s)
- María Sol Recouvreux
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE-UBA-CONICET), Buenos Aires, Argentina.,Present Address: Oncology Institute "Angel H Roffo", Buenos Aires, Argentina
| | - Esteban Nicolás Grasso
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE-UBA-CONICET), Buenos Aires, Argentina.,Present Address: Immunopharmacology Laboratory, IQUIBICEN-CONICET, FCEN-UBA, Buenos Aires, Argentina
| | | | - Luciana Rocha-Viegas
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE-UBA-CONICET), Buenos Aires, Argentina.,Departamento de Fisiología y Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, UBA, Buenos Aires, Argentina
| | - Lucio Hernán Castilla
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Carolina Schere-Levy
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE-UBA-CONICET), Buenos Aires, Argentina
| | - Johanna Melisa Tocci
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE-UBA-CONICET), Buenos Aires, Argentina
| | - Edith Claudia Kordon
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE-UBA-CONICET), Buenos Aires, Argentina.,Departamento de Química Biológica, UBA, Buenos Aires, Argentina
| | - Natalia Rubinstein
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE-UBA-CONICET), Buenos Aires, Argentina.,Departamento de Fisiología y Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, UBA, Buenos Aires, Argentina
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7
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Sanmartín E, Ortiz-Martínez F, Pomares-Navarro E, García-Martínez A, Rodrigo-Baños M, García-Escolano M, Andrés L, Lerma E, Aranda FI, Martínez-Peinado P, Sempere-Ortells JM, Peiró G. CD44 induces FOXP3 expression and is related with favorable outcome in breast carcinoma. Virchows Arch 2016; 470:81-90. [DOI: 10.1007/s00428-016-2045-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2016] [Revised: 09/19/2016] [Accepted: 11/10/2016] [Indexed: 01/15/2023]
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8
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Guo G, He Z, Shi Z. Correlation between FOXP3 expression and gastric cancer. Oncol Lett 2016; 12:1554-1558. [PMID: 27446470 DOI: 10.3892/ol.2016.4752] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 05/03/2016] [Indexed: 12/21/2022] Open
Abstract
The aim of the present study was to investigate the expression and function of forkhead box protein 3 (FOXP3) in gastric cancer using a rat model. A total of 92 Wistar rats were divided into two groups: An experimental group (n=46) and a control group (n=46). In the experimental group, sarcosine ethyl ester hydrochloride and sodium nitrite carcinogens were administered for 6 months to induce gastric cancer, whereas the control group was administered saline. Reverse transcription-polymerase chain reaction, immunoblotting, immunohistochemistry and western blotting were applied to analyze FOXP3 expression in gastric cancer and normal gastric tissue in the experimental and control groups, respectively. The association between FOXP3 expression and gastric cancer pathogenesis was investigated. In the experimental group, 6/46 rats developed hyperplastic lesions (grade I), 8 rats developed precancerous lesions (grade II), 18 rats developed early stage gastric cancer (grade III) and 14 rats developed gastrointestinal invasive carcinoma (grade IV). FOXP3 transcription and expression was observed in all gastric tissues of the experimental group. FOXP3 transcription and expression levels were significantly higher in the experimental group than in the control group (P<0.05). Furthermore, in the experimental group, a higher lesion grade was associated with a higher level of FOXP3 transcription and expression (P<0.05). FOXP3 protein was predominantly distributed in the tumor nuclei of the gastric cancer tissues. In the 32 pathological slices of gastric cancer tissue obtained from the experimental group, 20 cases (62.50%) exhibited positive FOXP3 staining. In the hyperplastic (grade I) and precancerous gastric (grade II) tissues, 2 cases (33.33%) and 4 cases (50.00%) exhibited positive FOXP3 staining, respectively. However, no positive FOXP3 expression was identified in the 46 pathological gastric tissue slices obtained from the control group. In conclusion, the expression of FOXP3 exhibits a positive correlation with gastric lesion grade. Therefore, FOXP3 may exhibit an important function in the occurrence and development of gastric cancer.
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Affiliation(s)
- Guoxiao Guo
- Department of General Surgery, Henan University Huaihe Hospital, Kaifeng, Henan 475000, P.R. China
| | - Zhikuan He
- Department of General Surgery, Henan University Huaihe Hospital, Kaifeng, Henan 475000, P.R. China
| | - Zhaohui Shi
- Department of General Surgery, Henan University Huaihe Hospital, Kaifeng, Henan 475000, P.R. China
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10
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Kashima H, Momose F, Umehara H, Miyoshi N, Ogo N, Muraoka D, Shiku H, Harada N, Asai A. Epirubicin, Identified Using a Novel Luciferase Reporter Assay for Foxp3 Inhibitors, Inhibits Regulatory T Cell Activity. PLoS One 2016; 11:e0156643. [PMID: 27284967 PMCID: PMC4902191 DOI: 10.1371/journal.pone.0156643] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 05/17/2016] [Indexed: 12/21/2022] Open
Abstract
Forkhead box protein p3 (Foxp3) is crucial to the development and suppressor function of regulatory T cells (Tregs) that have a significant role in tumor-associated immune suppression. Development of small molecule inhibitors of Foxp3 function is therefore considered a promising strategy to enhance anti-tumor immunity. In this study, we developed a novel cell-based assay system in which the NF-κB luciferase reporter signal is suppressed by the co-expressed Foxp3 protein. Using this system, we screened our chemical library consisting of approximately 2,100 compounds and discovered that a cancer chemotherapeutic drug epirubicin restored the Foxp3-inhibited NF-κB activity in a concentration-dependent manner without influencing cell viability. Using immunoprecipitation assay in a Treg-like cell line Karpas-299, we found that epirubicin inhibited the interaction between Foxp3 and p65. In addition, epirubicin inhibited the suppressor function of murine Tregs and thereby improved effector T cell stimulation in vitro. Administration of low dose epirubicin into tumor-bearing mice modulated the function of immune cells at the tumor site and promoted their IFN-γ production without direct cytotoxicity. In summary, we identified the novel action of epirubicin as a Foxp3 inhibitor using a newly established luciferase-based cellular screen. Our work also demonstrated our screen system is useful in accelerating discovery of Foxp3 inhibitors.
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Affiliation(s)
- Hajime Kashima
- Center for Drug Discovery, Graduate School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
| | - Fumiyasu Momose
- Department of Immuno-Gene Therapy, Mie University Graduate School of Medicine, Mie 514-8507, Japan
| | - Hiroshi Umehara
- Center for Drug Discovery, Graduate School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
| | - Nao Miyoshi
- Center for Drug Discovery, Graduate School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
| | - Naohisa Ogo
- Center for Drug Discovery, Graduate School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
| | - Daisuke Muraoka
- Center for Drug Discovery, Graduate School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
| | - Hiroshi Shiku
- Mie University Center for Comprehensive Cancer Immunotherapy, Mie 514-8507, Japan
| | - Naozumi Harada
- Mie University Center for Comprehensive Cancer Immunotherapy, Mie 514-8507, Japan
- * E-mail: (AA); (NH)
| | - Akira Asai
- Center for Drug Discovery, Graduate School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
- * E-mail: (AA); (NH)
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11
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Bhaskaran N, Cohen S, Zhang Y, Weinberg A, Pandiyan P. TLR-2 Signaling Promotes IL-17A Production in CD4+CD25+Foxp3+ Regulatory Cells during Oropharyngeal Candidiasis. Pathogens 2015; 4:90-110. [PMID: 25790134 PMCID: PMC4384074 DOI: 10.3390/pathogens4010090] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Revised: 03/05/2015] [Accepted: 03/11/2015] [Indexed: 12/17/2022] Open
Abstract
Recent studies show that CD4+CD25+Foxp3+ regulatory cells (Tregs) produce effector cytokines under inflammatory conditions. However, the direct role of microbial agents that serve as toll-like receptor (TLR) ligands in the induction of effector cytokines in Tregs is less clear. Here we show that CD4+Foxp3+Tregs produce the effector cytokine IL-17A during oropharyngeal candidiasis (OPC) and inflammatory bowel disease in a TLR-2/Myd88 signaling dependent manner. TLR-2 ligands promote proliferation in Tregs in the presence and absence of TCR signals and inflammatory cytokines in vitro. The proliferation is directly dependent on TLR-2 expression in Tregs. Consistent with this, Tlr2−/− mice harbor fewer thymically derived Tregs and peripheral Tregs under homeostatic conditions in vivo. However, under Th17 inducing conditions, IL-6 and TLR-2 signaling both in Tregs as well as antigen presenting cells (APC) are critical for maximal ROR-γt and IL-17A up-regulation in Foxp3+ Tregs. The minimal and transient loss of Foxp3 expression and suppressive properties are due to the presence of IL-6 in the milieu, but not the direct effect of TLR-2 signaling in Tregs. Taken together, our data reveal that TLR-2 signaling promotes not only proliferation, but also IL-17A in Tregs, depending on the cytokine milieu. These IL-17A producing Tregs may be relevant in mucosal infections and inflammation.
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Affiliation(s)
- Natarajan Bhaskaran
- Department of Biological Sciences, School of Dental Medicine, Case Western Reserve University, Cleveland, OH 44106, USA.
| | - Samuel Cohen
- Department of Biological Sciences, School of Dental Medicine, Case Western Reserve University, Cleveland, OH 44106, USA.
| | - Yifan Zhang
- Department of Biological Sciences, School of Dental Medicine, Case Western Reserve University, Cleveland, OH 44106, USA.
| | - Aaron Weinberg
- Department of Biological Sciences, School of Dental Medicine, Case Western Reserve University, Cleveland, OH 44106, USA.
| | - Pushpa Pandiyan
- Department of Biological Sciences, School of Dental Medicine, Case Western Reserve University, Cleveland, OH 44106, USA.
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12
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Mu J, Tai X, Iyer SS, Weissman JD, Singer A, Singer DS. Regulation of MHC class I expression by Foxp3 and its effect on regulatory T cell function. THE JOURNAL OF IMMUNOLOGY 2014; 192:2892-903. [PMID: 24523508 DOI: 10.4049/jimmunol.1302847] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Expression of MHC class I molecules, which provide immune surveillance against intracellular pathogens, is higher on lymphoid cells than on any other cell types. In T cells, this is a result of activation of class I transcription by the T cell enhanceosome consisting of Runx1, CBFβ, and LEF1. We now report that MHC class I transcription in T cells also is enhanced by Foxp3, resulting in higher levels of class I in CD4(+)CD25(+) T regulatory cells than in conventional CD4(+)CD25(-) T cells. Interestingly, the effect of Foxp3 regulation of MHC class I transcription is cell type specific: Foxp3 increases MHC class I expression in T cells but represses it in epithelial tumor cells. In both cell types, Foxp3 targets the upstream IFN response element and downstream core promoter of the class I gene. Importantly, expression of MHC class I contributes to the function of CD4(+)CD25(+) T regulatory cells by enhancing immune suppression, both in in vitro and in vivo. These findings identify MHC class I genes as direct targets of Foxp3 whose expression augments regulatory T cell function.
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Affiliation(s)
- Jie Mu
- Experimental Immunology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
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Delacher M, Schreiber L, Richards DM, Farah C, Feuerer M, Huehn J. Transcriptional control of regulatory T cells. Curr Top Microbiol Immunol 2014; 381:83-124. [PMID: 24831347 DOI: 10.1007/82_2014_373] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Regulatory T cells (Tregs) constitute unique T cell lineage that plays a key role for immunological tolerance. Tregs are characterized by the expression of the forkhead box transcription factor Foxp3, which acts as a lineage-specifying factor by determining the unique suppression profile of these immune cells. Here, we summarize the recent progress in understanding how Foxp3 expression itself is epigenetically and transcriptionally controlled, how the Treg-specific signature is achieved and how unique properties of Treg subsets are defined by other transcription factors. Finally, we will discuss recent studies focusing on the molecular targeting of Tregs to utilize the specific properties of this unique cell type in therapeutic settings.
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Affiliation(s)
- Michael Delacher
- Immune Tolerance, Tumor Immunology Program, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
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14
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Lozano T, Casares N, Lasarte JJ. Searching for the Achilles Heel of FOXP3. Front Oncol 2013; 3:294. [PMID: 24350059 PMCID: PMC3847665 DOI: 10.3389/fonc.2013.00294] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Accepted: 11/18/2013] [Indexed: 01/01/2023] Open
Abstract
FOXP3 is a multifaceted transcription factor with a major role in the control of immune homeostasis mediated by T regulatory cells (Treg). The immunoregulatory function of FOXP3 may hinder the induction of immune responses against cancer and infectious agents, and thus, development of inhibitors of its functions might give new therapeutic opportunities for these diseases. But also, FOXP3 is an important tumor suppressor factor in some types of cancers, and therefore, understanding the structure and function of FOXP3 is crucial to gaining insights into the development of FOXP3-targeted therapeutic strategies. FOXP3 homodimerize and likely form supramolecular complexes which might include hundreds of proteins which constitute the FOXP3 interactome. Many of the functions of FOXP3 are clearly regulated by the interactions with these cofactors contributing importantly on the establishment of Treg-cell signature. We summarize here the structural/functional information on this FOXP3 complex, to identify potential opportunities for the development of new strategies to modulate FOXP3 activity.
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Affiliation(s)
- Teresa Lozano
- Gene Therapy and Hepatology Area, Center for Applied Medical Research (CIMA), University of Navarra , Pamplona , Spain
| | - Noelia Casares
- Gene Therapy and Hepatology Area, Center for Applied Medical Research (CIMA), University of Navarra , Pamplona , Spain
| | - Juan José Lasarte
- Gene Therapy and Hepatology Area, Center for Applied Medical Research (CIMA), University of Navarra , Pamplona , Spain
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15
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Takenaka M, Seki N, Toh U, Hattori S, Kawahara A, Yamaguchi T, Koura K, Takahashi R, Otsuka H, Takahashi H, Iwakuma N, Nakagawa S, Fujii T, Sasada T, Yamaguchi R, Yano H, Shirouzu K, Kage M. FOXP3 expression in tumor cells and tumor-infiltrating lymphocytes is associated with breast cancer prognosis. Mol Clin Oncol 2013; 1:625-632. [PMID: 24649219 PMCID: PMC3915667 DOI: 10.3892/mco.2013.107] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Accepted: 04/05/2013] [Indexed: 12/04/2022] Open
Abstract
The forkhead box protein 3 (FOXP3) transcription factor is highly expressed in tumor cells as well as in regulatory T cells (Tregs). It plays a tumor-enhancing role in Tregs and suppresses carcinogenesis as a potent repressor of several oncogenes. The clinical prognostic value of FOXP3 expression has not yet been elucidated. In this study, immunohistochemistry was used to investigate the prognostic significance of FOXP3 expression in tumor cells and tumor-infiltrating lymphocytes (TILs) in breast cancer patients. Of the 100 tumor specimens obtained from primary invasive breast carcinoma, 63 and 57% were evaluated as FOXP3+ tumor cells and as being highly infiltrated by FOXP3+ lymphocytes, respectively. Although FOXP3 expression in tumor cells was of no prognostic significance, FOXP3+ lymphocytes were significantly associated with poor overall survival (OS) (n=98, log-rank test P=0.008). FOXP3 exhibited a heterogeneous subcellular localization in tumor cells (cytoplasm, 31%; nucleus, 26%; both, 6%) and, although cytoplasmic FOXP3 was associated with poor OS (P= 0.058), nuclear FOXP3 demonstrated a significant association with improved OS (P=0.016). Furthermore, when patients were grouped according to their expression of tumor cytoplasmic FOXP3 and lymphocyte FOXP3, there were notable differences in the Kaplan-Meier curves for OS (P<0.001), with a high infiltration of FOXP3+ lymphocytes accompanied by a cytoplasmic FOXP3+ tumor being the most detrimental phenotype. These findings indicated that FOXP3 expression in lymphocytes as well as in tumor cells may be a prognostic marker for breast cancer. FOXP3 in tumor cells may have distinct biological activities and prognostic values according to its localization, which may help establish appropriate cancer treatments.
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Affiliation(s)
- Miki Takenaka
- Departments of Pathology, School of Medicine, Kurume University, Kurume, Fukuoka 830-0011, Japan ; ; Surgery, School of Medicine, Kurume University, Kurume, Fukuoka 830-0011, Japan
| | - Naoko Seki
- Research Center for Innovative Cancer Therapy, School of Medicine, Kurume University, Kurume, Fukuoka 830-0011, Japan
| | - Uhi Toh
- Surgery, School of Medicine, Kurume University, Kurume, Fukuoka 830-0011, Japan
| | - Satoshi Hattori
- Biostatistical Center, Kurume University, Kurume, Fukuoka 830-0011, Japan
| | - Akihiko Kawahara
- Department of Diagnostic Pathology, Kurume University Hospital, Kurume, Fukuoka 830-0011, Japan
| | - Tomohiko Yamaguchi
- Department of Diagnostic Pathology, Kurume University Hospital, Kurume, Fukuoka 830-0011, Japan
| | - Keiko Koura
- Departments of Pathology, School of Medicine, Kurume University, Kurume, Fukuoka 830-0011, Japan ; ; Surgery, School of Medicine, Kurume University, Kurume, Fukuoka 830-0011, Japan
| | - Ryuji Takahashi
- Surgery, School of Medicine, Kurume University, Kurume, Fukuoka 830-0011, Japan
| | - Hiroko Otsuka
- Surgery, School of Medicine, Kurume University, Kurume, Fukuoka 830-0011, Japan
| | - Hiroki Takahashi
- Surgery, School of Medicine, Kurume University, Kurume, Fukuoka 830-0011, Japan
| | - Nobutaka Iwakuma
- Surgery, School of Medicine, Kurume University, Kurume, Fukuoka 830-0011, Japan
| | - Shino Nakagawa
- Surgery, School of Medicine, Kurume University, Kurume, Fukuoka 830-0011, Japan
| | - Teruhiko Fujii
- Surgery, School of Medicine, Kurume University, Kurume, Fukuoka 830-0011, Japan ; ; Multidisciplinary Treatment Center, Kurume University Hospital, Kurume, Fukuoka 830-0011, Japan
| | - Tetsuro Sasada
- Department of Immunology, School of Medicine, Kurume University, Kurume, Fukuoka 830-0011, Japan
| | - Rin Yamaguchi
- Departments of Pathology, School of Medicine, Kurume University, Kurume, Fukuoka 830-0011, Japan
| | - Hirohisa Yano
- Departments of Pathology, School of Medicine, Kurume University, Kurume, Fukuoka 830-0011, Japan
| | - Kazuo Shirouzu
- Surgery, School of Medicine, Kurume University, Kurume, Fukuoka 830-0011, Japan
| | - Masayoshi Kage
- Research Center for Innovative Cancer Therapy, School of Medicine, Kurume University, Kurume, Fukuoka 830-0011, Japan ; ; Department of Diagnostic Pathology, Kurume University Hospital, Kurume, Fukuoka 830-0011, Japan
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16
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Clocchiatti A, Di Giorgio E, Demarchi F, Brancolini C. Beside the MEF2 axis: unconventional functions of HDAC4. Cell Signal 2012; 25:269-76. [PMID: 23063464 DOI: 10.1016/j.cellsig.2012.10.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Accepted: 10/07/2012] [Indexed: 12/17/2022]
Abstract
The class IIa deacetylase HDAC4 is unequivocally known as a negative regulator of MEF2-dependent transcription. In the past years several works have allowed us to understand how different signals, mirroring specific environmental circumstances keep in check the repressive action of HDAC4 against MEF2s. At the same time, pieces of evidence have gradually accumulated about HDAC4 activities emancipated from MEF2s. The aim of this review is to discuss about these "unconventional functions" of HDAC4.
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Affiliation(s)
- Andrea Clocchiatti
- Dipartimento di Scienze Mediche e Biologiche and MATI Center of Excellence, Università degli Studi di Udine, P.le Kolbe 4-33100 Udine, Italy
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17
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Deng G, Xiao Y, Zhou Z, Nagai Y, Zhang H, Li B, Greene MI. Molecular and biological role of the FOXP3 N-terminal domain in immune regulation by T regulatory/suppressor cells. Exp Mol Pathol 2012; 93:334-8. [PMID: 23041265 DOI: 10.1016/j.yexmp.2012.09.013] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Accepted: 09/17/2012] [Indexed: 12/26/2022]
Abstract
Regulatory T (Treg) cells are essential in preventing the host from developing certain autoimmune diseases and limiting excessive immune responses against pathogens. The normal function of most Treg cells requires sustained expression of functional FOXP3, a member of the FOXP family transcription factors. FOXP3 is distinct from other subfamily members because of its unique proline rich amino (N)-terminal domain. Mutations in this region are occasionally identified in certain patients with X-linked autoimmunity-allergic dysregulation syndrome (XLAAD) and similar mutations also increase susceptibility of autoimmune diseases in rodent models. Previous analyses of the FOXP3 N-terminal domain revealed a role in nuclear import, interaction with other transcription factors, and as sites of specific post-translational modifications of FOXP3 that contribute to FOXP3 stability.
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Affiliation(s)
- Guoping Deng
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, 19104-6082, USA
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18
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Yang M, Wei H, Zhao T, Wang X, Zhang A, Zhou H. Characterization of Foxp3 gene from grass carp (Ctenopharyngodon idellus): a rapamycin-inducible transcription factor in teleost immune system. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2012; 38:98-107. [PMID: 22613483 DOI: 10.1016/j.dci.2012.04.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Revised: 04/20/2012] [Accepted: 04/24/2012] [Indexed: 06/01/2023]
Abstract
In this study, we cloned grass carp foxp3 (gcfoxp3) gene including 5' flanking region and determined its expression profiles in vivo under immunosuppressive conditions. Sequence analysis revealed that the promoter of gcfoxp3 contains AP-1, AML-1/Runx1, NF-κb and GATA-3 binding sites, which positively or negatively regulate mammalian foxp3 expression. In addition, the intron II of gcfoxp3 contains some putative binding sites including AP-1, NFAT, Smad3, RAR, CREB/ATF and FOXO1, which are corresponding to their locations in the proximal intronic enhancers of human foxp3. In an in vivo model of grass carp, an immunosuppressive agent rapamycin was showed to stimulate gcfoxp3 mRNA expression in thymus, gill, head kidney and spleen after bacterial challenge. Moreover, rapamycin increased gcFoxp3 protein levels with an additive manner in the infected fish. These findings support the involvement of fish Foxp3 in immune response and highlight a possible signaling pathway that regulates teleost Foxp3 expression.
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Affiliation(s)
- Mu Yang
- School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, People's Republic of China
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19
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Transcription factor Foxp3 and its protein partners form a complex regulatory network. Nat Immunol 2012; 13:1010-9. [PMID: 22922362 PMCID: PMC3448012 DOI: 10.1038/ni.2402] [Citation(s) in RCA: 335] [Impact Index Per Article: 27.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Accepted: 07/19/2012] [Indexed: 02/07/2023]
Abstract
The transcription factor Foxp3 is indispensible for the differentiation and function of regulatory T cells (Treg cells). To gain insights into the molecular mechanisms of Foxp-mediated gene expression we purified Foxp3 complexes and explored their composition. Biochemical and mass-spectrometric analyses revealed that Foxp3 forms multi-protein complexes of 400–800 kDa or larger and identified 361 associated proteins, ~30% of which are transcription-related. Foxp3 directly regulated expression of a large proportion of the genes encoding its co-factors. Reciprocally, some transcription factor partners of Foxp3 facilitated its expression. Functional analysis of Foxp3 cooperation with one such partner, GATA-3, provided further evidence for a network of transcriptional regulation afforded by Foxp3 and its associates to control distinct aspects of Treg cell biology.
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20
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Lindqvist CA, Loskog ASI. T regulatory cells in B-cell malignancy - tumour support or kiss of death? Immunology 2012; 135:255-60. [PMID: 22112044 DOI: 10.1111/j.1365-2567.2011.03539.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
It is well established that T regulatory (Treg) cells counteract tumour immunity. However, conflicting results describing the role of Treg cells in haematological tumours warrant further investigations to clarify the interactions between Treg cells and the tumour. B-cell malignancy derives from different stages of B-cell development and differentiation in which T cells play a profound role. The transformed B cell may still be in need of T-cell help to thrive but simultaneously they may be recognized and destroyed by cytotoxic lymphocytes. Recent reports demonstrate that Treg cells can suppress and even kill B cells as part of their normal function to rescue the body from autoimmunity. An emerging body of evidence points out that Treg cells not only inhibit tumour-specific T cells but may also have a role in suppressing the progression of the B-cell tumour. In this review, we discuss the origin and function of Treg cells and their role in patients with B-cell tumours.
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Affiliation(s)
- Camilla A Lindqvist
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
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21
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Lalmansingh AS, Karmakar S, Jin Y, Nagaich AK. Multiple modes of chromatin remodeling by Forkhead box proteins. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2012; 1819:707-15. [PMID: 22406422 DOI: 10.1016/j.bbagrm.2012.02.018] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2011] [Revised: 02/08/2012] [Accepted: 02/14/2012] [Indexed: 10/28/2022]
Abstract
Forkhead box (FOX) proteins represent a large family of transcriptional regulators unified by their DNA binding domain (DBD) known as a 'forkhead' or 'winged helix' domain. Over 40 FOX genes have been identified in the mammalian genome. FOX proteins share significant sequence similarities in the DBD which allow them to bind to a consensus DNA response element. However, their modes of action are quite diverse as they regulate gene expression by acting as pioneer factors, transcription factors, or both. This review focuses on the mechanisms of chromatin remodeling with an emphasis on three sub-classes-FOXA, FOXO, and FOXP members. FOXA proteins serve as pioneer factors to open up local chromatin structure and thereby increase accessibility of chromatin to factors regulating transcription. FOXP proteins, in contrast, function as classic transcription factors to recruit a variety of chromatin modifying enzymes to regulate gene expression. FOXO proteins represent a hybrid subclass having dual roles as pioneering factors and transcription factors. A subset of FOX proteins interacts with condensed mitotic chromatin and may function as 'bookmarking' agents to maintain transcriptional competence at specific genomic sites. The overall diversity in chromatin remodeling function by FOX proteins is related to unique structural motifs present within the DBD flanking regions that govern selective interactions with core histones and/or chromatin coregulatory proteins. This article is part of a Special Issue entitled: Chromatin in time and space.
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Affiliation(s)
- Avin S Lalmansingh
- Division of Therapeutic Proteins, Office of Biotechnology Products, Office of Pharmaceutical Sciences, Center for Drug Evaluation and Research, Food and Drug administration, Bethesda, MD 20892, USA
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22
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Goodman WA, Cooper KD, McCormick TS. Regulation generation: the suppressive functions of human regulatory T cells. Crit Rev Immunol 2012; 32:65-79. [PMID: 22428855 PMCID: PMC3413266 DOI: 10.1615/critrevimmunol.v32.i1.40] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Proper regulation of immune homeostasis is necessary to limit inflammation and prevent autoimmune and chronic inflammatory diseases. Many autoimmune diseases, such as psoriasis, are driven by vicious cycles of activated T cells that are unable to be suppressed by regulatory T cells. Effective suppression of auto-reactive T cells by regulatory T cells (Treg) is critical for the prevention of spontaneous autoimmune disease. Psoriatic Treg cells have been observed to a defect in their capacity to regulate, which clearly contributes to psoriasis pathogenesis. A challenge for translational research is the development of novel therapeutic interventions for autoimmune diseases that will result in durable remissions. Understanding the mechanism(s) of dysregulated T cell responses in autoimmune disease will allow for the development of future therapeutic strategies that may be employed to specifically target pathogenic, proinflammatory cells. Several reports have demonstrated a pathogenic role for Thl and Thl7 cells in psoriasis as well as other autoimmune diseases. Similarly, several laboratories have independently demonstrated functional defects in regulatory T cells isolated from patients with numerous divergent autoimmune diseases. One primary challenge of research in autoimmune diseases is therefore to restore the balance between chronic T cell activation and impairment of Treg suppressor mechanisms. To this end, it is critical to develop an understanding of the many suppressive mechanisms employed by Treg cells in hopes of developing more targeted therapeutic strategies for Treg-mediated autoimmune diseases.
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Affiliation(s)
- Wendy A Goodman
- Department of Medicine, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio 44106, USA.
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23
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Pandiyan P, Zheng L, Lenardo MJ. The molecular mechanisms of regulatory T cell immunosuppression. Front Immunol 2011; 2:60. [PMID: 22566849 PMCID: PMC3342245 DOI: 10.3389/fimmu.2011.00060] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Accepted: 10/19/2011] [Indexed: 12/22/2022] Open
Abstract
CD4⁺CD25⁺Foxp3⁺ T lymphocytes, known as regulatory T cells or T(regs), have been proposed to be a lineage of professional immune suppressive cells that exclusively counteract the effects of the immunoprotective "helper" and "cytotoxic" lineages of T lymphocytes. Here we discuss new concepts on the mechanisms and functions of T(regs). There are several key points we emphasize: 1. Tregs exert suppressive effects both directly on effector T cells and indirectly through antigen-presenting cells; 2. Regulation can occur through a novel mechanism of cytokine consumption to regulate as opposed to the usual mechanism of cytokine/chemokine production; 3. In cases where CD4⁺ effector T cells are directly inhibited by T(regs), it is chiefly through a mechanism of lymphokine withdrawal apoptosis leading to polyclonal deletion; and 4. Contrary to the current view, we discuss new evidence that T(regs), similar to other T-cells lineages, can promote protective immune responses in certain infectious contexts (Chen et al., 2011; Pandiyan et al., 2011). Although these points are at variance to varying degrees with the standard model of T(reg) behavior, we will recount developing findings that support these new concepts.
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Affiliation(s)
- Pushpa Pandiyan
- Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health Bethesda, MD, USA.
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24
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Molecular mechanisms underlying the regulation and functional plasticity of FOXP3(+) regulatory T cells. Genes Immun 2011; 13:1-13. [PMID: 22048454 DOI: 10.1038/gene.2011.77] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
CD4(+) CD25(+) regulatory T (Treg) cells engage in the maintenance of immunological self-tolerance and homeostasis by limiting aberrant or excessive inflammation. The transcription factor forkhead box P3 (FOXP3) is critical for the development and function of Treg cells. The differentiation of the Treg cell lineage is not terminal, as developmental and functional plasticity occur through the sensing of inflammatory signals in the periphery. Here, we review the recent progress in our understanding of the molecular mechanisms underlying the regulation and functional plasticity of CD4(+) CD25(+) FOXP3(+) Treg cells, through the perturbation of FOXP3 and its complex at a transcriptional, translational and post-translational level.
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25
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Regulation of IL-2 gene expression by Siva and FOXP3 in human T cells. BMC Immunol 2011; 12:54. [PMID: 21955384 PMCID: PMC3208582 DOI: 10.1186/1471-2172-12-54] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Accepted: 09/28/2011] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Severe autoinflammatory diseases are associated with mutations in the Foxp3 locus in both mice and humans. Foxp3 is required for the development, function, and maintenance of regulatory T cells (Tregs), a subset of CD4 cells that suppress T cell activation and inflammatory processes. Siva is a pro-apoptotic gene that is expressed across a range of tissues, including CD4 T cells. Siva interacts with three tumor necrosis factor receptor (TNFR) family members that are constitutively expressed on Treg cells: CD27, GITR, and OX40. RESULTS Here we report a biophysical interaction between FOXP3 and Siva. We mapped the interaction domains to Siva's C-terminus and to a central region of FOXP3. We showed that Siva repressed IL-2 induction by suppressing IL-2 promoter activity during T cell activation. Siva-1's repressive effect on IL-2 gene expression appears to be mediated by inhibition of NFkappaB, whereas FOXP3 repressed both NFkappaB and NFAT activity. CONCLUSIONS In summary, our data suggest that both FOXP3 and Siva function as negative regulators of IL-2 gene expression in Treg cells, via suppression of NFAT by FOXP3 and of NFkappaB by both FOXP3 and Siva. Our work contributes evidence for Siva's role as a T cell signalling mediator in addition to its known pro-apoptotic function. Though further investigations are needed, evidence for the biophysical interaction between FOXP3 and Siva invites the possibility that Siva may be important for proper Treg cell function.
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26
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Nonsegmental vitiligo and autoimmune mechanism. Dermatol Res Pract 2011; 2011:518090. [PMID: 21804820 PMCID: PMC3144695 DOI: 10.1155/2011/518090] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Revised: 05/30/2011] [Accepted: 06/01/2011] [Indexed: 11/18/2022] Open
Abstract
Nonsegmental vitiligo is a depigmented skin disorder showing acquired, progressive, and depigmented lesions of the skin, mucosa, and hair. It is believed to be caused mainly by the autoimmune loss of melanocytes from the involved areas. It is frequently associated with other autoimmune diseases, particularly autoimmune thyroid diseases including Hashimoto's thyroiditis and Graves' disease, rheumatoid arthritis, type 1 diabetes, psoriasis, pernicious anemia, systemic lupus erythematosus, Addison's disease, and alopecia areata. This indicates the presence of genetically determined susceptibility to not only vitiligo but also to other autoimmune disorders. Here, we summarize current understanding of autoimmune pathogenesis in non-segmental vitiligo.
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27
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Tao H, Mimura Y, Aoe K, Kobayashi S, Yamamoto H, Matsuda E, Okabe K, Matsumoto T, Sugi K, Ueoka H. Prognostic potential of FOXP3 expression in non-small cell lung cancer cells combined with tumor-infiltrating regulatory T cells. Lung Cancer 2011; 75:95-101. [PMID: 21719142 DOI: 10.1016/j.lungcan.2011.06.002] [Citation(s) in RCA: 174] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Revised: 05/10/2011] [Accepted: 06/03/2011] [Indexed: 12/23/2022]
Abstract
Expression of the transcription factor FOXP3 characterizes regulatory T cells (Tregs) that engage in the maintenance of immunological self-tolerance and immune homeostasis. Intra-tumoral accumulation of Tregs is associated with unfavorable prognosis in several kinds of cancers. Recently, expression of FOXP3 and its association with prognosis have also been shown in some cancer cells in clinical studies. For non-small cell lung cancer (NSCLC), however, prognostic significance of tumor FOXP3 expression and its relationship with Tregs remain unknown. FOXP3 expression in cancer cells and tumor-infiltrating lymphocytes was examined by immunohistochemical staining of surgical specimens from 87 patients with NSCLC. Prognostic values of the tumor-infiltrating Treg count and tumor FOXP3 expression status were evaluated retrospectively. FOXP3-positive cancer cells were observed in 27 of 87 (31.0%) patients. There was no significant relationship between Treg count and tumor FOXP3 status. Increased Treg counts were associated with worse overall and relapse-free survival whereas the influence of tumor FOXP3 status on survival was not significant. However, when FOXP3-positive cancer cells were present, the relationship between Treg accumulation and worse prognosis was attenuated. In contrast, patients without tumor FOXP3 expression and high Treg count had significantly worse overall and relapse-free survival (hazard ratio: 3.118 and 3.325, p=0.028 and 0.024, respectively) than other groups. These results suggest that tumor FOXP3 expression has a better prognostic potential in NSCLC and that in combination with tumor-infiltrating Treg count the absence of tumor FOXP3 allows the selection of high-risk patients.
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Affiliation(s)
- Hiroyuki Tao
- Department of Thoracic Surgery, NHO Yamaguchi-Ube Medical Center, 685 Higashi-kiwa, Ube, 755-0241, Japan.
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28
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Heinze E, Chan G, Mory R, Khavari R, Alavi A, Chung SY, Nishimura RN, Weisbart RH. Tumor suppressor and T-regulatory functions of Foxp3 are mediated through separate signaling pathways. Oncol Lett 2011; 2:665-668. [PMID: 22848246 DOI: 10.3892/ol.2011.307] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2010] [Accepted: 05/11/2011] [Indexed: 11/05/2022] Open
Abstract
Foxp3 is a nuclear transcription factor that is both a tumor suppressor factor and regulator of T-regulatory cell (Treg) function, and is a potential therapeutic target in both autoimmunity and cancer. In order to distinguish molecular pathways responsible for these separate Foxp3 functions, deletion mutants of Foxp3 proteins were transduced and analyzed for cytotoxic activity in human cancer cell lines Skov3, MDA-MB-231, MCF-7 and Jurkat. Human Foxp3 cDNA mutants were amplified and ligated to produce plasmids for direct cell transfection. Constructs were produced and confirmed by DNA sequencing. Lipofectamine 2000 was used for plasmid transfection. Foxp3 cells were then examined. The results of our experiments reveal retention of tumor suppressor function in the absence of NFAT binding and transcriptional activation required for Treg function. Our results have significant implications for the design of autoimmune and cancer therapies that target Foxp3 and Treg cells.
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Affiliation(s)
- Emil Heinze
- Department of Medicine, Olive View-UCLA Medical Center, Sylmar, CA 91342
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29
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Lindqvist CA, Christiansson LH, Thörn I, Mangsbo S, Paul-Wetterberg G, Sundström C, Tötterman TH, Simonsson B, Enblad G, Frisk P, Olsson-Strömberg U, Loskog ASI. Both CD4+ FoxP3+ and CD4+ FoxP3- T cells from patients with B-cell malignancy express cytolytic markers and kill autologous leukaemic B cells in vitro. Immunology 2011; 133:296-306. [PMID: 21463298 DOI: 10.1111/j.1365-2567.2011.03439.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Cytotoxic CD4(+) T cells have been found in patients with chronic lymphocytic leukaemia (CLL) and seem to be involved in the regulation of malignant B cells. The CD4(+) T regulatory cells (Tregs) can regulate various immune cells, including B cells, by inducing their apoptosis. Hence, different subgroups of CD4(+) T cells may be involved in the regulation of malignant B cells. In this study, the cytotoxic phenotype and function of various CD4(+) T-cell subgroups were investigated in patients with B-cell malignancies. Peripheral blood was collected from patients with CLL, various B-cell lymphomas, healthy adult donors, children with precursor B-cell acute lymphoblastic leukaemia (pre-B ALL) and from healthy children. CD4(+) T cells (CD3(+) CD4(+) FoxP3(-)), Tregs (CD3(+) CD4(+) CD127(low) FoxP3(+)) and CD127(high) FoxP3(+) T cells (CD3(+) CD4(+) CD127(high) FoxP3(+)) were analysed for their expression of the cytolytic markers CD107a and Fas ligand. Patients with CLL had increased CD107a expression on all tested T-cell subgroups compared with healthy donors. Similar results were found in patients with B-cell lymphomas whereas the CD107a expression in children with pre-B ALL was no different from that in healthy controls. Fas ligand expression was similar between patient cells and cells of healthy donors. CD4(+) T cells and Tregs from patients with CLL and healthy donors were subsequently purified and cultured in vitro with autologous B cells. Both subgroups lysed B cells and killing was confirmed by granzyme ELISAs. In conclusion, cytotoxic populations of CD4(+) T cells, including Tregs, are present in patients with B-cell malignancy and may be an important factor in immune-related disease control.
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Affiliation(s)
- Camilla A Lindqvist
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Sweden
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Redpath M, Xu B, van Kempen LC, Spatz A. The dual role of the X-linked FoxP3 gene in human cancers. Mol Oncol 2011; 5:156-63. [PMID: 21489891 DOI: 10.1016/j.molonc.2011.03.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2011] [Accepted: 03/11/2011] [Indexed: 01/18/2023] Open
Abstract
The FoxP3 (forkhead box P3) gene is an X-linked gene that is submitted to inactivation. It is an essential transcription factor in CD4(+)CD25(+)FoxP3 regulatory T cells, which are therapeutic targets in disseminated cutaneous melanoma. Moreover, FoxP3 is an important tumor suppressor gene in carcinomas and has putative cancer suppressor gene function in cutaneous melanoma as well. Therefore understanding the structure and function of the FoxP3 gene is crucial to gaining insight into the biology of melanoma to better develop immunotherapeutics and future therapeutic strategies.
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Affiliation(s)
- Margaret Redpath
- Department of Pathology, McGill University, Montreal, QC, Canada
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31
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Xiao Y, Li B, Zhou Z, Hancock WW, Zhang H, Greene MI. Histone acetyltransferase mediated regulation of FOXP3 acetylation and Treg function. Curr Opin Immunol 2010; 22:583-91. [PMID: 20869864 PMCID: PMC2967626 DOI: 10.1016/j.coi.2010.08.013] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Accepted: 08/19/2010] [Indexed: 01/12/2023]
Abstract
Regulatory T cells (Tregs) are required for the maintenance of immune homeostasis as first clearly described by Herman Waldmann's laboratory. Dysfunction of Treg cells also leads to fatal autoimmunity in humans and mice. Conversely, the activation of different classes of Tregs operative systemically and within the cancer microenvironment can suppress host anti-tumor immune responses and promote tumor progression. Therefore, the development of new therapeutic approaches to regulate the activity of Treg cells may have considerable clinical potential. FOXP3 is the key transcriptional regulator of Treg development and function. The activity of FOXP3 is regulated by acetylation, a process catalyzed by distinct types of histone/protein acetyltransferases (HATs) that regulate the functions of many transcription factors, independently of FOXP3, as well as non-histone proteins, in addition to their effects on chromatin accessibility. Interactions between FOXP3 and these enzymes determine the suppressive function of FOXP3. Clearly, small molecules targeting these enzymes are candidates for the regulation of Treg function in vaccines and tumor therapies.
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Affiliation(s)
- Yan Xiao
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA 19104
| | - Bin Li
- Key Laboratory of Molecular Virology & Immunology, Unit of Molecular Immunology, Institute Pasteur of Shanghai, China 200031
| | - Zhaocai Zhou
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China 200031
| | - Wayne W. Hancock
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA 19104
| | - Hongtao Zhang
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA 19104
| | - Mark I. Greene
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA 19104
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32
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Chaplin DD. Overview of the immune response. J Allergy Clin Immunol 2010; 125:S3-23. [PMID: 20176265 DOI: 10.1016/j.jaci.2009.12.980] [Citation(s) in RCA: 1005] [Impact Index Per Article: 71.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2009] [Revised: 12/18/2009] [Accepted: 12/21/2009] [Indexed: 12/12/2022]
Abstract
The immune system has evolved to protect the host from a universe of pathogenic microbes that are themselves constantly evolving. The immune system also helps the host eliminate toxic or allergenic substances that enter through mucosal surfaces. Central to the immune system's ability to mobilize a response to an invading pathogen, toxin, or allergen is its ability to distinguish self from nonself. The host uses both innate and adaptive mechanisms to detect and eliminate pathogenic microbes, and both of these mechanisms include self-nonself discrimination. This overview identifies key mechanisms used by the immune system to respond to invading microbes and other exogenous threats and identifies settings in which disturbed immune function exacerbates tissue injury.
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Affiliation(s)
- David D Chaplin
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294-2170, USA.
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Koh KP, Sundrud MS, Rao A. Domain requirements and sequence specificity of DNA binding for the forkhead transcription factor FOXP3. PLoS One 2009; 4:e8109. [PMID: 19956618 PMCID: PMC2779587 DOI: 10.1371/journal.pone.0008109] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2009] [Accepted: 11/03/2009] [Indexed: 11/26/2022] Open
Abstract
The forkhead, winged-helix transcription factor FOXP3 is preferentially expressed in T regulatory (Treg) cells and is critical for their immunosuppressive function. Mutations that abolish FOXP3 function lead to systemic autoimmunity in mice and humans. However, the manner by which FOXP3 recognizes cognate DNA elements is unclear. Here we identify an in vitro optimized DNA sequence to assess FOXP3 DNA binding by electrophoretic mobility shift assay (EMSA). The optimized sequence contains two tandem copies of a core DNA element resembling, but not identical to, the canonical forkhead (FKH) binding element. The tandem nature of this optimized FOXP3-binding oligonucleotide suggests a requirement for multimerization, and EMSA experiments confirm that both the DNA-binding FKH domain and an intact leucine-zipper domain, which mediates homo-multimerization of FOXP3, are required for DNA binding. These results establish a practical framework for understanding the molecular basis by which FOXP3 regulates gene transcription and programs Treg suppressive function.
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Affiliation(s)
- Kian Peng Koh
- Department of Pathology, Harvard Medical School and Immune Disease Institute, Boston, Massachusetts, United States of America
| | - Mark S. Sundrud
- Department of Pathology, Harvard Medical School and Immune Disease Institute, Boston, Massachusetts, United States of America
| | - Anjana Rao
- Department of Pathology, Harvard Medical School and Immune Disease Institute, Boston, Massachusetts, United States of America
- * E-mail:
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Wang L, de Zoeten EF, Greene MI, Hancock WW. Immunomodulatory effects of deacetylase inhibitors: therapeutic targeting of FOXP3+ regulatory T cells. Nat Rev Drug Discov 2009; 8:969-81. [PMID: 19855427 PMCID: PMC2884987 DOI: 10.1038/nrd3031] [Citation(s) in RCA: 147] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Classical zinc-dependent histone deacetylases (HDACs) catalyse the removal of acetyl groups from histone tails and also from many non-histone proteins, including the transcription factor FOXP3, a key regulator of the development and function of regulatory T cells. Many HDAC inhibitors are in cancer clinical trials, but a subset of HDAC inhibitors has important anti-inflammatory or immunosuppressive effects that might be of therapeutic benefit in immuno-inflammatory disorders or post-transplantation. At least some of these effects result from the ability of HDAC inhibitors to enhance the production and suppressive functions of FOXP3(+) regulatory T cells. Understanding which HDACs contribute to the regulation of the functions of regulatory T cells may further stimulate the development of new class- or subclass-specific HDAC inhibitors with applications beyond oncology.
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Affiliation(s)
- Liqing Wang
- Division of Transplant Immunology, Children's Hospital of Philadelphia, Philadelphia 19104, USA
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Hancock WW, Özkaynak E. Three distinct domains contribute to nuclear transport of murine Foxp3. PLoS One 2009; 4:e7890. [PMID: 19924293 PMCID: PMC2774276 DOI: 10.1371/journal.pone.0007890] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Accepted: 10/23/2009] [Indexed: 01/19/2023] Open
Abstract
Foxp3, a 47-kDa transcription factor, is necessary for the function of CD4+CD25+ regulatory T cells (Tregs), with an essential role in the control of self-reactive T cells and in preventing autoimmunity. Activation of Tregs by TCR engagement results in upregulation of Foxp3 expression, followed by its rapid nuclear transport and binding to chromatin. Here, we identify three distinct Foxp3 domains that contribute to nuclear transport. The first domain (Domain 1) comprises the C-terminal 12 amino acids. The second domain (Domain 2) is located immediately N-terminal to the forkhead domain (FHD), recently reported to be a binding site for the runt-related transcription factor 1/acute myeloid leukemia 1 (Runx1/AML1). The third domain (Domain 3) is located within the N-terminal first 51 amino acids. Unlike the known nuclear localization signals (NLSs), none of these three regions are rich in basic residues and do not bear any similarity to known monopartite or bipartite NLSs that have one or more clusters of basic amino acids. The basic arginine-lysine-lysine-arginine (RKKR) sequence, located 12-aa from the C-terminal end of Foxp3 was previously reported to be a nuclear localization signal (NLS) for several proteins, including for a GFP-Foxp3 hybrid. Evidence is provided here that in the full-length native Foxp3 RKKR does not function as an NLS. The data reported in this study indicates that Foxp3 achieves nuclear transport by binding to other nuclear factors and co-transporting with them to the nucleus.
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Affiliation(s)
- Wayne W. Hancock
- Division of Transplant Immunology, Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia and the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Engin Özkaynak
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia and the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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Zhou Z, Song X, Berezov A, Li B, Greene MI. Structural aspects of the FOXP3 regulatory complex as an immunopharmacological target. Int Immunopharmacol 2009; 9:518-20. [PMID: 19539569 DOI: 10.1016/j.intimp.2009.01.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2009] [Accepted: 01/22/2009] [Indexed: 02/07/2023]
Abstract
The forkhead family transcription factor FOXP3 plays a fundamental role in immune homeostasis. FOXP3 dysfunction in regulatory T cells (Tregs) contributes to multiple disease processes such as autoimmunity, tumor development, and viral infection. FOXP3 cooperates and associates with a group of other transcriptional factors, co-repressors and co-activators in Tregs to form one or more dynamic regulatory complexes. These ensembles communicate with multiple key signaling pathways to either upregulate or downregulate the expression of downstream target genes such as cytokines and cell surface receptors, which are critical for the control of normal immune responses. Although the details of the underlying mechanism by which FOXP3 operates as a transcriptional repressor or an activator is largely undefined, FOXP3(+) Tregs based cellular therapies have been studied in animal models. Our recent studies concerning the FOXP3 complex ensemble provide structural and biochemical insights into FOXP3 function of Tregs, which are essential to the development of novel immunopharmacological agents for treating human immunological disease.
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Affiliation(s)
- Zhaocai Zhou
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104-6082, USA
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