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Reiter L, Greffrath J, Zidel B, Ostrowski M, Gommerman J, Madhi SA, Tran R, Martin-Orozco N, Panicker RKG, Cooper C, Pastrak A. Comparable safety and non-inferior immunogenicity of the SARS-CoV-2 mRNA vaccine candidate PTX-COVID19-B and BNT162b2 in a phase 2 randomized, observer-blinded study. Sci Rep 2024; 14:5365. [PMID: 38438427 PMCID: PMC10912344 DOI: 10.1038/s41598-024-55320-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 02/22/2024] [Indexed: 03/06/2024] Open
Abstract
In the aftermath of the COVID-19 pandemic, the evolution of the SARS-CoV-2 into a seasonal pathogen along with the emergence of new variants, underscores the need for dynamic and adaptable responses, emphasizing the importance of sustained vaccination strategies. This observer-blind, double-dummy, randomized immunobridging phase 2 study (NCT05175742) aimed to compare the immunogenicity induced by two doses of 40 μg PTX-COVID19-B vaccine candidate administered 28 days apart, with the response induced by two doses of 30 µg Pfizer-BioNTech COVID-19 vaccine (BNT162b2), administered 21 days apart, in Nucleocapsid-protein seronegative adults 18-64 years of age. Both vaccines were administrated via intramuscular injection in the deltoid muscle. Two weeks after the second dose, the neutralizing antibody (NAb) geometric mean titer ratio and seroconversion rate met the non-inferiority criteria, successfully achieving the primary immunogenicity endpoints of the study. PTX-COVID19-B demonstrated similar safety and tolerability profile to BNT162b2 vaccine. The lowest NAb response was observed in subjects with low-to-undetectable NAb at baseline or no reported breakthrough infection. Conversely, participants who experienced breakthrough infections during the study exhibited higher NAb titers. This study also shows induction of cell-mediated immune (CMI) responses by PTX-COVID19-B. In conclusion, the vaccine candidate PTX-COVID19-B demonstrated favourable safety profile along with immunogenicity similar to the active comparator BNT162b2 vaccine.
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Affiliation(s)
- Lawrence Reiter
- Providence Therapeutics Holdings Inc., 120-8832 Blackfoot Trail SE, Calgary, AB, T2J 3J1, Canada
| | - Johann Greffrath
- South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Bian Zidel
- Malton Medical Center, 6870 Goreway Dr., Mississauga, ON, L4V 1P1, Canada
| | - Mario Ostrowski
- Department of Medicine, Immunology, University of Toronto, Medical Sciences Building, Rm 6271. 1 King's College Circle, Toronto, ON, M5S 1A8, Canada
| | - Jennifer Gommerman
- Department of Immunology, Temerty Faculty of Medicine, 1 King's College Circle, Rm. 7233, Toronto, ON, M5S 1A8, Canada
| | - Shabir A Madhi
- South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Richard Tran
- Providence Therapeutics Holdings Inc., 120-8832 Blackfoot Trail SE, Calgary, AB, T2J 3J1, Canada
| | - Natalia Martin-Orozco
- Providence Therapeutics Holdings Inc., 120-8832 Blackfoot Trail SE, Calgary, AB, T2J 3J1, Canada
| | | | - Curtis Cooper
- The Ottawa Hospital Viral Hepatitis Program, Division of Infectious Diseases, Department of Medicine, The Ottawa Hospital, University of Ottawa, 75 Laurier Ave. East, Ottawa, ON, K1N 6N5, Canada
| | - Aleksandra Pastrak
- Providence Therapeutics Holdings Inc., 120-8832 Blackfoot Trail SE, Calgary, AB, T2J 3J1, Canada.
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Martin-Orozco N, Vale N, Mihic A, Amor T, Reiter L, Arita Y, Samson R, Hu Q, Gingras AC, Sorenson BT, Marcusson EG, Patel P. Phase I randomized, observer-blinded, placebo-controlled study of a SARS-CoV-2 mRNA vaccine PTX-COVID19-B. Sci Rep 2023; 13:8557. [PMID: 37236995 DOI: 10.1038/s41598-023-35662-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 05/22/2023] [Indexed: 05/28/2023] Open
Abstract
Access to vaccines against SARS-CoV-2 virus was limited in poor countries during the COVID-19 pandemic. Therefore, a low-cost mRNA vaccine, PTX-COVID19-B, was produced and evaluated in a Phase 1 trial. PTX-COVID19-B encodes Spike protein D614G variant without the proline-proline (986-987) mutation present in other COVID-19 vaccines. The aim of the study was to evaluate safety, tolerability, and immunogenicity of PTX-COVID19-B vaccine in healthy seronegative adults 18-64 years old. The trial design was observer-blinded, randomized, placebo-controlled, and tested ascending doses of 16-µg, 40-µg, or 100-µg in a total of 60 subjects who received two intramuscular doses, 4 weeks apart. Participants were monitored for solicited and unsolicited adverse events after vaccination and were provided with a Diary Card and thermometer to report any reactogenicity during the trial. Blood samples were collected on baseline, days 8, 28, 42, 90, and 180 for serum analysis of total IgG anti-receptor binding domain (RBD)/Spike titers by ELISA, and neutralizing antibody titers by pseudovirus assay. Titers in BAU/mL were reported as geometric mean and 95% CI per cohort. After vaccination, few solicited adverse events were observed and were mild to moderate and self-resolved within 48 h. The most common solicited local and systemic adverse event was pain at the injection site, and headache, respectively. Seroconversion was observed in all vaccinated participants, who showed high antibody titers against RBD, Spike, and neutralizing activity against the Wuhan strain. Neutralizing antibody titers were also detected against Alpha, Beta, and Delta variants of concerns in a dose dependent manner. All tested doses of PTX-COVID19-B were safe, well-tolerated, and provided a strong immunogenicity response. The 40-µg dose showed fewer adverse reactions than the 100-µg dose, and therefore was selected for a Phase 2 trial, which is currently ongoing.Clinical Trial Registration number: NCT04765436 (21/02/2021). ( https://clinicaltrials.gov/ct2/show/NCT04765436 ).
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Affiliation(s)
- Natalia Martin-Orozco
- Providence Therapeutics Holdings, 8832 Blackfoot Trail SE, Ste 120, Calgary, AB, T2J 3J1, Canada.
| | - Noah Vale
- Centricity Research, 2291 Kipling Avenue, Unit 117B, Toronto, ON, M9W 4L6, Canada
| | - Alan Mihic
- Centricity Research, 2291 Kipling Avenue, Unit 117B, Toronto, ON, M9W 4L6, Canada
| | - Talya Amor
- Centricity Research, 2291 Kipling Avenue, Unit 117B, Toronto, ON, M9W 4L6, Canada
| | - Lawrence Reiter
- Providence Therapeutics Holdings, 8832 Blackfoot Trail SE, Ste 120, Calgary, AB, T2J 3J1, Canada
| | - Yuko Arita
- Providence Therapeutics Holdings, 8832 Blackfoot Trail SE, Ste 120, Calgary, AB, T2J 3J1, Canada
| | - Reuben Samson
- Department of Molecular Genetics, University of Toronto, 1 King's College Cir, Rm 4396, Toronto, ON, M5S 1A8, Canada
- Lunenfeld-Tanenbaum Research Institute at Mount Sinai Hospital, Sinai Health System, 600 University Ave, Toronto, ON, M5G 1X5, Canada
| | - Queenie Hu
- Lunenfeld-Tanenbaum Research Institute at Mount Sinai Hospital, Sinai Health System, 600 University Ave, Toronto, ON, M5G 1X5, Canada
| | - Anne-Claude Gingras
- Department of Molecular Genetics, University of Toronto, 1 King's College Cir, Rm 4396, Toronto, ON, M5S 1A8, Canada
- Lunenfeld-Tanenbaum Research Institute at Mount Sinai Hospital, Sinai Health System, 600 University Ave, Toronto, ON, M5G 1X5, Canada
| | - Bradley Thomas Sorenson
- Providence Therapeutics Holdings, 8832 Blackfoot Trail SE, Ste 120, Calgary, AB, T2J 3J1, Canada
| | - Eric Gates Marcusson
- Providence Therapeutics Holdings, 8832 Blackfoot Trail SE, Ste 120, Calgary, AB, T2J 3J1, Canada
| | - Piyush Patel
- Providence Therapeutics Holdings, 8832 Blackfoot Trail SE, Ste 120, Calgary, AB, T2J 3J1, Canada
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Yasutomi M, Christiaansen AF, Imai N, Martin-Orozco N, Forst CV, Chen G, Ueno H. CD226 and TIGIT Cooperate in the Differentiation and Maturation of Human Tfh Cells. Front Immunol 2022; 13:840457. [PMID: 35273617 PMCID: PMC8902812 DOI: 10.3389/fimmu.2022.840457] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 01/28/2022] [Indexed: 11/29/2022] Open
Abstract
Costimulation pathways play an essential role in T cell activation, differentiation, and regulation. CD155 expressed on antigen-presenting cells (APCs) interacts with TIGIT, an inhibitory costimulatory molecule, and CD226, an activating costimulatory molecule, on T cells. TIGIT and CD226 are expressed at varying levels depending on the T cell subset and activation state. T follicular helper cells in germinal centers (GC-Tfh) in human tonsils express high TIGIT and low CD226. However, the biological role of the CD155/TIGIT/CD226 axis in human Tfh cell biology has not been elucidated. To address this, we analyzed tonsillar CD4+ T cell subsets cultured with artificial APCs constitutively expressing CD155. Here we show that CD226 signals promote the early phase of Tfh cell differentiation in humans. CD155 signals promoted the proliferation of naïve CD4+ T cells and Tfh precursors (pre-Tfh) isolated from human tonsils and upregulated multiple Tfh molecules and decreased IL-2, a cytokine detrimental for Tfh cell differentiation. Blocking CD226 potently inhibited their proliferation and expression of Tfh markers. By contrast, while CD155 signals promoted the proliferation of tonsillar GC-Tfh cells, their proliferation required only weak CD226 signals. Furthermore, attenuating CD226 signals rather increased the expression of CXCR5, ICOS, and IL-21 by CD155-stimulated GC-Tfh cells. Thus, the importance of CD226 signals changes according to the differentiation stage of human Tfh cells and wanes in mature GC-Tfh cells. High TIGIT expression on GC-Tfh may play a role in attenuating the detrimental CD226 signals post GC-Tfh cell maturation.
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Affiliation(s)
- Motoko Yasutomi
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Allison F Christiaansen
- EMD Serono Research and Development Institute Inc. (The Healthcare Business of Merck KGaA, Darmstadt, Germany), Billerica, MA, United States
| | - Naoko Imai
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Natalia Martin-Orozco
- EMD Serono Research and Development Institute Inc. (The Healthcare Business of Merck KGaA, Darmstadt, Germany), Billerica, MA, United States
| | - Christian V Forst
- Department of Genetics and Genomic Sciences, Department of Microbiology, The Icahn Institute for Data Science and Genomic Technology, New York, NY, United States
| | - Gang Chen
- EMD Serono Research and Development Institute Inc. (The Healthcare Business of Merck KGaA, Darmstadt, Germany), Billerica, MA, United States
| | - Hideki Ueno
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, United States.,Department of Immunology, Graduate School of Medicine, Kyoto University, Kyoto, Japan.,ASHBi Institute for the Advanced Study of Human Biology, Kyoto University, Kyoto, Japan
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Sim G, Martin-Orozco N, Jin L, Yang Y, Wu S, Washington E, Sanders D, Lacey C, Vence L, Hwu P, Radvanyi L. T145. European Journal of Cancer Supplements 2015. [DOI: 10.1016/j.ejcsup.2015.08.098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Zhang Y, Nguyen T, Tang P, Kennedy NJ, Jiao H, Zhang M, Reynolds JM, Jaeschke A, Martin-Orozco N, Chung Y, He WM, Wang C, Jia W, Ge B, Davis RJ, Flavell RA, Dong C. Regulation of Adipose Tissue Inflammation and Insulin Resistance by MAPK Phosphatase 5. J Biol Chem 2015; 290:14875-83. [PMID: 25922079 DOI: 10.1074/jbc.m115.660969] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Indexed: 11/06/2022] Open
Abstract
Obesity and metabolic disorders such as insulin resistance and type 2 diabetes have become a major threat to public health globally. The mechanisms that lead to insulin resistance in type 2 diabetes have not been well understood. In this study, we show that mice deficient in MAPK phosphatase 5 (MKP5) develop insulin resistance spontaneously at an early stage of life and glucose intolerance at a later age. Increased macrophage infiltration in white adipose tissue of young MKP5-deficient mice correlates with the development of insulin resistance. Glucose intolerance in MKP5-deficient mice is accompanied by significantly increased visceral adipose weight, reduced AKT activation, enhanced p38 activity, and increased inflammation in visceral adipose tissue when compared with wild-type (WT) mice. Deficiency of MKP5 resulted in increased inflammatory activation in macrophages. These findings thus demonstrate that MKP5 critically controls inflammation in white adipose tissue and the development of metabolic disorders.
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Affiliation(s)
- Yongliang Zhang
- From the Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore, the Immunology Programme, Life Science Institute, National University of Singapore, Singapore 117597, Singapore
| | - Thang Nguyen
- the Department of Immunology, University of Washington, Seattle, Washington 98195
| | - Peng Tang
- From the Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore, the Immunology Programme, Life Science Institute, National University of Singapore, Singapore 117597, Singapore
| | - Norman J Kennedy
- the Howard Hughes Medical Institute, University of Massachusetts, Worcester, Massachusetts 01606
| | - Huipeng Jiao
- From the Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore, the Immunology Programme, Life Science Institute, National University of Singapore, Singapore 117597, Singapore
| | - Mingliang Zhang
- the Department of Endocrinology and Metabolism, Shanghai Jiaotong University Affiliated Sixth People's Hospital, Shanghai Diabetes Institute, Shanghai Clinical Center of Diabetes, Shanghai 200233, China
| | - Joseph M Reynolds
- the Department of Immunology, MD Anderson Cancer Center, Houston, Texas 77054
| | - Anja Jaeschke
- the Pathobiology and Molecular Medicine Graduate Program, University of Cincinnati, Ohio 45215
| | | | - Yeonseok Chung
- the Department of Immunology, MD Anderson Cancer Center, Houston, Texas 77054
| | - Wei-min He
- the Center for Environmental and Genetic Medicine, Institute of Biosciences and Technology, Texas A&M University System Health Sciences Center, Houston, Texas 77030
| | - Chen Wang
- the Department of Endocrinology and Metabolism, Shanghai Jiaotong University Affiliated Sixth People's Hospital, Shanghai Diabetes Institute, Shanghai Clinical Center of Diabetes, Shanghai 200233, China
| | - Weiping Jia
- the Department of Endocrinology and Metabolism, Shanghai Jiaotong University Affiliated Sixth People's Hospital, Shanghai Diabetes Institute, Shanghai Clinical Center of Diabetes, Shanghai 200233, China
| | - Baoxue Ge
- the Laboratory of Signal Transduction, Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences and Shanghai Jiao-Tong University School of Medicine, Shanghai 200025, China
| | - Roger J Davis
- the Howard Hughes Medical Institute, University of Massachusetts, Worcester, Massachusetts 01606
| | - Richard A Flavell
- the Department of Immunology, Howard Hughes Medical Institute, Yale University, New Haven, Connecticut 06520, and
| | - Chen Dong
- the Institute for Immunology, Tsinghua University, Beijing 100084, China
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6
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Sim GC, Martin-Orozco N, Jin L, Yang Y, Wu S, Washington E, Sanders D, Lacey C, Wang Y, Vence L, Hwu P, Radvanyi L. IL-2 therapy promotes suppressive ICOS+ Treg expansion in melanoma patients. J Clin Invest 2014; 124:99-110. [PMID: 24292706 DOI: 10.1172/jci46266] [Citation(s) in RCA: 171] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 09/26/2013] [Indexed: 12/11/2022] Open
Abstract
High-dose (HD) IL-2 therapy in patients with cancer increases the general population of Tregs, which are positive for CD4, CD25, and the Treg-specific marker Foxp3. It is unknown whether specific subsets of Tregs are activated and expanded during HD IL-2 therapy or whether activation of any particular Treg subset correlates with clinical outcome. Here, we evaluated Treg population subsets that were induced in patients with melanoma following HD IL-2 therapy. We identified a Treg population that was positive for CD4, CD25, Foxp3, and the inducible T cell costimulator (ICOS). This Treg population increased more than any other lymphocyte subset during HD IL-2 therapy and had an activated Treg phenotype, as indicated by high levels of CD39, CD73, and TGF-β. ICOS(+) Tregs were the most proliferative lymphocyte population in the blood after IL-2 therapy. Patients with melanoma with enhanced expansion of ICOS(+) Tregs in blood following the first cycle of HD IL-2 therapy had worse clinical outcomes than patients with fewer ICOS(+) Tregs. However, there was no difference in total Treg expansion between HD IL-2 responders and nonresponders. These data suggest that increased expansion of the ICOS(+) Treg population following the first cycle of HD IL-2 therapy may be predictive of clinical outcome.
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Liu X, Yan X, Zhong B, Nurieva RI, Wang A, Wang X, Martin-Orozco N, Wang Y, Chang SH, Esplugues E, Flavell RA, Tian Q, Dong C. Bcl6 expression specifies the T follicular helper cell program in vivo. ACTA ACUST UNITED AC 2012; 209:1841-52, S1-24. [PMID: 22987803 PMCID: PMC3457730 DOI: 10.1084/jem.20120219] [Citation(s) in RCA: 192] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
A novel Bcl6 reporter mouse is used to dissect the developmental requirements, plasticity, and genetic profile of Tfh cells. T follicular helper cells (Tfh cells) play a pivotal role in germinal center reactions, which require B cell lymphoma 6 (Bcl6) transcription factor. To analyze their relationships with other effector T cell lineages and their stability in vivo, we developed and analyzed a new Bcl6 reporter mouse alone or together with other lineage reporter systems. Assisted with genome-wide transcriptome analysis, we show substantial plasticity of T cell differentiation in the early phase of immune response. At this stage, CXCR5 appears to be expressed in a Bcl6-independent manner. Once Bcl6 is highly expressed, Tfh cells can persist in vivo and some of them develop into memory cells. Together, our results indicate Bcl6 as a bona fide marker for Tfh polarized program.
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Affiliation(s)
- Xindong Liu
- Department of Immunology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
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Chung Y, Lee YH, Zhang Y, Martin-Orozco N, Yamazaki T, Zhou D, Kang CY, Hwu P, Kwak LW, Dong C. T cells and T cell tumors efficiently generate antigen-specific cytotoxic T cell immunity when modified with an NKT ligand. Oncoimmunology 2012; 1:141-151. [PMID: 22720235 PMCID: PMC3376985 DOI: 10.4161/onci.1.2.18479] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Various Invariant NKT (iNKT) cell ligands have been shown as potent adjuvants in boosting T cell reactivates to antigens on professional APC. Non-professional APC, such as T cells, also co-expressing MHC class I and CD1d, have been unattractive cell vaccine carriers due to their poor immunogenicity. Here, we report that T cells as well as T cell lymphoma can efficiently generate antigen-specific cytotoxic T lymphocytes (CTL) responses in mice in vivo, when formulated to present iNKT ligand α-galactosylceramide (αGC) on their surface CD1d. Vaccination with αGC-pulsed EG-7 T-cell lymphoma induced tumor-specific CTL response and suppressed the growth of EG-7 in a CD8 T cell-dependent manner. Injection of αGC-loaded CD4 T cells in mice efficiently activated iNKT cells in vivo. While T cells loaded with a class I-restricted peptide induced proliferation but not effector differentiation of antigen-specific CD8 T cells, injection of T cells co-pulsed with αGC strongly induced IFNγ and Granzyme B expression in T cells and complete lysis of target cells in vivo. Presentation of αGC and peptide on the same cells was required for optimal CTL response and vaccinating T cells appeared to directly stimulate both iNKT and cytotoxic CD8 T cells. Of note, the generation of this cytotoxic T cell response was independent of IL-4, IFNγ, IL-12, IL-21 and costimulation. Our data indicate that iNKT cell can license a non-professional APC to directly trigger antigen-specific cytotoxic T cell responses, which provides an alternative cellular vaccine strategy against tumors.
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Affiliation(s)
- Yeonseok Chung
- Department of Immunology; Center for Cancer Immunology Research; University of Texas MD Anderson Cancer Center; Houston, TX USA ; Institute of Molecular Medicine; University of Texas Medical School; Houston, TX USA
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9
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Martin-Orozco N, Li Y, Wang Y, Liu S, Hwu P, Liu YJ, Dong C, Radvanyi L. Melanoma cells express ICOS ligand to promote the activation and expansion of T-regulatory cells. Cancer Res 2010; 70:9581-90. [PMID: 21098714 DOI: 10.1158/0008-5472.can-10-1379] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
CD4(+)CD25(+)Foxp3(+) T-regulatory cells (Tregs) accumulate in tumors; however, little is known about how the tumor environment influences this process. Here we show that human melanomas express inducible T-cell costimulator ligand (ICOS-L/B7H) that can provide costimulation through ICOS for the expansion of activated Tregs maintaining high Foxp3 and CD25 expression as well as a suppressive function. Thus, ICOS-L expression by melanoma tumor cells may directly drive Treg activation and expansion in the tumor microenvironment as another mechanism of immune evasion.
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Affiliation(s)
- Natalia Martin-Orozco
- Department of Immunology, The University of Texas, M. D. Anderson Cancer Center, Houston, Texas, USA
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Yamazaki T, Goya I, Graf D, Craig S, Martin-Orozco N, Dong C. A butyrophilin family member critically inhibits T cell activation. J Immunol 2010; 185:5907-14. [PMID: 20944003 DOI: 10.4049/jimmunol.1000835] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The costimulatory molecules in the B7-CD28 families are important in the regulation of T cell activation and tolerance. The butyrophilin family of proteins shares sequence and structure homology with B7 family molecules; however, the function of the butyrophilin family in the immune system has not been defined. In this study, we performed an analysis on multiple butyrophilin molecules and found that butyrophilin-like (BTNL)1 molecule functions to dampen T cell activation. BTNL1 mRNA was broadly expressed, but its protein was only found in APCs and not T cells. The putative receptor for BTNL1 was found on activated T cells and APCs. Also, recombinant BTNL1 molecule inhibited T cell proliferation by arresting cell cycle progression. The administration of neutralizing Abs against BTNL1 provoked enhanced T cell activation and exacerbated disease in autoimmune and asthma mouse models. Therefore, BTNL1 is a critical inhibitory molecule for T cell activation and immune diseases.
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Affiliation(s)
- Tomohide Yamazaki
- Department of Immunology, MD Anderson Cancer Center, Houston, TX 77030, USA
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Martin-Orozco N, Muranski P, Chung Y, Yang XO, Yamazaki T, Lu S, Hwu P, Restifo NP, Overwijk WW, Dong C. T helper 17 cells promote cytotoxic T cell activation in tumor immunity. Immunity 2009; 31:787-98. [PMID: 19879162 DOI: 10.1016/j.immuni.2009.09.014] [Citation(s) in RCA: 579] [Impact Index Per Article: 38.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2008] [Revised: 06/11/2009] [Accepted: 09/04/2009] [Indexed: 12/16/2022]
Abstract
Although T helper 17 (Th17) cells have been found in tumor tissues, their function in cancer immunity is unclear. We found that interleukin-17A (IL-17A)-deficient mice were more susceptible to developing lung melanoma. Conversely, adoptive T cell therapy with tumor-specific Th17 cells prevented tumor development. Importantly, the Th17 cells retained their cytokine signature and exhibited stronger therapeutic efficacy than Th1 cells. Unexpectedly, therapy using Th17 cells elicited a remarkable activation of tumor-specific CD8(+) T cells, which were necessary for the antitumor effect. Th17 cells promoted dendritic cell recruitment into the tumor tissues and in draining lymph nodes increased CD8 alpha(+) dendritic cells containing tumor material. Moreover, Th17 cells promoted CCL20 chemokine production by tumor tissues, and tumor-bearing CCR6-deficient mice did not respond to Th17 cell therapy. Thus, Th17 cells elicited a protective inflammation that promotes the activation of tumor-specific CD8(+) T cells. These findings have important implications in antitumor immunotherapies.
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Zhang Y, Reynolds JM, Chang SH, Martin-Orozco N, Chung Y, Nurieva RI, Dong C. MKP-1 is necessary for T cell activation and function. J Biol Chem 2009; 284:30815-24. [PMID: 19748894 DOI: 10.1074/jbc.m109.052472] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
MAPKs are evolutionarily conserved immune regulators. MAPK phosphatases (MKPs) that negatively regulate MAPK activities have recently emerged as critical players in both innate and adaptive immune responses. MKP-1, also known as DUSP1, was previously shown to negatively regulate innate immunity by inhibiting pro-inflammatory cytokine production. Here, we found that MKP-1 is necessary in T cell activation and function. MKP-1 deficiency in T cells impaired the activation, proliferation, and function of T cells in vitro, associated with enhanced activation of JNK and reduced NFATc1 translocation into the nucleus. Consistently, MKP-1(-/-) mice were defective in anti-influenza immunity in vivo and resistant to experimental autoimmune encephalomyelitis. Our results thus demonstrate that MKP-1 is a critical positive regulator of T cell activation and function and may be targeted in treatment of autoimmune diseases.
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Affiliation(s)
- Yongliang Zhang
- Department of Immunology, M. D. Anderson Cancer Center, Houston, Texas 77030, USA
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Martin-Orozco N, Dong C. The IL-17/IL-23 axis of inflammation in cancer: friend or foe? Curr Opin Investig Drugs 2009; 10:543-549. [PMID: 19513943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
IL-17, a proinflammatory cytokine that is regulated by IL-23, is crucial for the development of a novel CD4+ T-cell subset called T-helper 17 (Th17) cells, which promotes tissue inflammation in host defense responses against infection, as well as in chronic autoimmune diseases. IL-17 and IL-23 expression, as well as the presence of Th17 cells, have been documented in several human carcinomas, but their function in tumors remains controversial. This review summarizes the current literature on IL-17, IL-23 and Th17 cells in human tumors and animal models of cancer, discussing their possible roles in cancer development and cancer immunity, and presenting a personal perspective of this research area.
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Affiliation(s)
- Natalia Martin-Orozco
- MD Anderson Cancer Center, Department of Immunology, 7455 Fannin Street, Houston, TX 77030, USA
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Liu X, Alexiou M, Martin-Orozco N, Chung Y, Nurieva RI, Ma L, Tian Q, Kollias G, Lu S, Graf D, Dong C. Cutting edge: A critical role of B and T lymphocyte attenuator in peripheral T cell tolerance induction. J Immunol 2009; 182:4516-20. [PMID: 19342624 DOI: 10.4049/jimmunol.0803161] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
T cell activation and tolerance are delicately regulated by costimulatory molecules. Although B and T lymphocyte attenuator (BTLA) has been shown as a negative regulator for T cell activation, its role in peripheral T cell tolerance induction in vivo has not been addressed. In this study, we generated a novel strain of BTLA-deficient mice and used three different models to characterize the function of BTLA in controlling T cell tolerance. In an oral tolerance model, BTLA-deficient mice were found resistant to the induction of T cell tolerance to an oral Ag. Moreover, compared with wild-type OT-II cells, BTLA(-/-) OT-II cells were less susceptible to tolerance induction by a high-dose OVA peptide administered i.v. Finally, BTLA(-/-) OT-I cells caused autoimmune diabetes in RIP-mOVA recipient mice. Our results thus demonstrate an important role for BTLA in the induction of peripheral tolerance of both CD4(+) and CD8(+) T cells in vivo.
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Affiliation(s)
- Xikui Liu
- Department of Immunology, MD Anderson Cancer Center, Houston, TX 77030, USA
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15
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Liu X, Alexiou M, Martin-Orozco N, Chung Y, Nurieva R, Tian Q, Lu S, Kollias G, Graf D, Dong C. A critical role of BTLA in peripheral T cell tolerance induction (48.18). The Journal of Immunology 2009. [DOI: 10.4049/jimmunol.182.supp.48.18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
T cell activation and tolerance are delicately regulated by costimulatory molecules. Although B and T lymphocyte attenuator (BTLA) has been shown as a negative regulator for T cells activation, its role in peripheral T cell tolerance induction in vivo has not been addressed. In this study, we generated a novel strain of BTLA-deficient mice, and employed three different models to characterize the function of BTLA in controlling T cell tolerance. In an oral tolerance model, BTLA-deficient mice were found resistant to the induction of T cell tolerance to an oral antigen. Moreover, compared with wild-type OT-II cells, BTLA-/- OT-II cells were less susceptible to tolerance induction by high-dose Ova peptide administered intravenously. Finally, BTLA-/- OT-I cells caused autoimmune diabetes in RIP-mOVA recipient mice. Our results thus demonstrate an important role of BTLA in the induction of peripheral tolerance of both CD4+ and CD8+ T cells in vivo.
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Affiliation(s)
- Xikui Liu
- 1Immunology, MD Anderson Cancer Center, Houston, TX
| | - Maria Alexiou
- 2Immunology, Biomedical Sciences Research Center 'Al. Fleming', Hellas, Greece
| | | | | | - Roza Nurieva
- 1Immunology, MD Anderson Cancer Center, Houston, TX
| | | | - Sijie Lu
- 4Stem Cell Transplantation & Cellular Therapy, MD Anderson Cancer Center, Houston, TX
| | - George Kollias
- 2Immunology, Biomedical Sciences Research Center 'Al. Fleming', Hellas, Greece
| | - Daniel Graf
- 2Immunology, Biomedical Sciences Research Center 'Al. Fleming', Hellas, Greece
| | - Chen Dong
- 1Immunology, MD Anderson Cancer Center, Houston, TX
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16
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Martin-Orozco N, Chung Y, Chang SH, Wang YH, Dong C. Th17 cells promote pancreatic inflammation but only induce diabetes efficiently in lymphopenic hosts after conversion into Th1 cells. Eur J Immunol 2009; 39:216-24. [PMID: 19130584 DOI: 10.1002/eji.200838475] [Citation(s) in RCA: 272] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
IDDM is characterized by leukocyte invasion to the pancreatic tissues followed by immune destruction of the islets. Despite the important function of Th17 cells in other autoimmune disease models, their function in IDDM is relatively unclear. In this study, we found association of elevated Th17 cytokine expression with diabetes in NOD mice. To understand the function of Th17 cells in IDDM, we differentiated islet-reactive BDC2.5 TcR transgenic CD4(+) cells in vitro into Th17 cells and transferred them into NOD.scid and neonate NOD mice. NOD.scid recipient mice developed rapid onset of diabetes with extensive insulitic lesions, whereas in newborn NOD mice, despite extensive insulitis, most recipient mice did not develop diabetes. Surprisingly, BDC2.5(+) cells recovered from diabetic NOD.scid mice, in comparison with those from neonate NOD mice, showed predominant IFN-gamma over IL-17 expression, indicating conversion of donor cells into Th1 cells. Moreover, diabetes progression in NOD.scid recipients was dependent on IFN-gamma while anti-IL-17 treatment reduced insulitic inflammation. These results indicate that islet-reactive Th17 cells promote pancreatic inflammation, but only induce IDDM upon conversion into IFN-gamma producers.
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17
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Yamazaki T, Yang XO, Chung Y, Fukunaga A, Nurieva R, Pappu B, Martin-Orozco N, Kang HS, Ma L, Panopoulos AD, Craig S, Watowich SS, Jetten AM, Tian Q, Dong C. CCR6 regulates the migration of inflammatory and regulatory T cells. J Immunol 2009; 181:8391-401. [PMID: 19050256 DOI: 10.4049/jimmunol.181.12.8391] [Citation(s) in RCA: 391] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Th17 and regulatory T (Treg) cells play opposite roles in autoimmune diseases. However, the mechanisms underlying their proper migration to inflammatory tissues are unclear. In this study, we report that these two T cell subsets both express CCR6. CCR6 expression in Th17 cells is regulated by TGF-beta and requires two nuclear receptors, RORalpha and RORgamma. Th17 cells also express the CCR6 ligand CCL20, which is induced synergistically by TGF-beta and IL-6, which requires STAT3, RORgamma and IL-21. Th17 cells, by producing CCL20, promote migration of Th17 and Treg cells in vitro in a CCR6-dependent manner. Lack of CCR6 in Th17 cells reduces the severity of experimental autoimmune encephalomyelitis and Th17 and Treg recruitment into inflammatory tissues. Similarly, CCR6 on Treg cells is also important for their recruitment into inflammatory tissues. Our data indicate an important role of CCR6 in Treg and Th17 cell migration.
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Affiliation(s)
- Tomohide Yamazaki
- Department of Immunology, M.D. Anderson Cancer Center, Houston, TX 77030, USA
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18
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Zou L, Mendez F, Martin-Orozco N, Peterson EJ. Defective positive selection results in T cell lymphopenia and increased autoimmune diabetes in ADAP-deficient BDC2.5-C57BL/6 mice. Eur J Immunol 2008; 38:986-94. [PMID: 18383041 DOI: 10.1002/eji.200737881] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Adhesion and degranulation promoting adapter protein (ADAP), a positive regulator of T cell receptor (TCR) signaling, is required for thymocyte development and T cell homeostasis. To investigate the role of ADAP in a T cell-driven autoimmune response, we generated ADAP-deficient, BDC2.5 TCR transgenic, diabetes-prone (C57BL/6) mice (BDC/B6). We observed a striking enhancement of diabetes incidence in ADAP-deficient mice, both in animals homozygous for I-Ag7, and in mice carrying one I-Ab allele (BDC/B6g7/b). Increased disease correlates with significantly reduced numbers of pathological CD4(+) T cells in the mice. Consistent with a state of functional lymphopenia in ADAP-deficient BDC/B6g7/b mice, T cells display increased homeostatic proliferation. Transfer of syngeneic lymphocytes or T cells both blocks ADAP-dependent diabetes and relieves exaggerated homeostatic T cell proliferation observed in ADAP-deficient mice. Marked attenuation in cellularity of the CD4+ single-positive thymocyte compartment in ADAP-deficient BDC/B6g7/b animals suggests a mechanism for induction of the lymphopenia. We conclude that inefficient positive selection in ADAP deficiency results in lymphopenia that leads to enhanced autoimmune diabetes in the BDC/B6g7/b model. Our findings support the notion that ineffective thymic T cell output can be a powerful causative factor in lymphopenia-driven autoimmune diabetes.
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Affiliation(s)
- Liangxing Zou
- Department of Internal Medicine and Center for Immunology, University of Minnesota, Minneapolis, MN 55455, USA
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19
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Abstract
Costimulation was originally shown to be important in T-cell activation and effector differentiation. Recent characterization of B7/butyrophilin and members of the CD28 superfamily has revealed a large number of negative costimulatory molecules that dampen T-cell activation and regulate immune tolerance. Some of these molecules have been shown to be upregulated in the tumor microenvironment and may serve as potential targets for augmenting anti-tumor immunity. In this article, we summarize recent developments in the field of inhibitory costimulation and discuss the future direction of therapeutic manipulation of inhibitory costimulation in tumor immunotherapy.
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Affiliation(s)
- Natalia Martin-Orozco
- Department of Immunology, The University of Texas M.D. Anderson Cancer Center, TX, USA.
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20
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Martin-Orozco N, Wang YH, Yagita H, Dong C. Cutting Edge: Programmed death (PD) ligand-1/PD-1 interaction is required for CD8+ T cell tolerance to tissue antigens. J Immunol 2007; 177:8291-5. [PMID: 17142723 DOI: 10.4049/jimmunol.177.12.8291] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Constitutive presentation of tissue Ags by dendritic cells results in tolerance of autoreactive CD8+ T cells; however, the underlying molecular mechanisms are not well understood. In this study we show that programmed death (PD)-1, an inhibitory receptor of the CD28 family, is required for tolerance induction of autoreactive CD8+ T cells. An antagonistic Ab against PD-1 provoked destructive autoimmune diabetes in RIP-mOVA mice expressing chicken OVA in the pancreatic islet cells, which received naive OVA-specific CD8+ OT-I cells. This effect was mediated by the PD ligand (PD-L) PD-L1 but not by PD-L2. An increased number of effector OT-I cells recovered from the pancreatic lymph nodes of anti-PD-L1-treated mice showed down-regulation of PD-1. Furthermore, the blockade of PD-1/PD-L1 interaction during the priming phase did not significantly affect OT-I cell division but enhanced its granzyme B, IFN-gamma, and IL-2 production. Thus, during the presentation of tissue Ags to CD8+ T cells, PD-1/PD-L1 interaction crucially controls the effector differentiation of autoreactive T cells to maintain self-tolerance.
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Affiliation(s)
- Natalia Martin-Orozco
- University of Texas M.D. Anderson Cancer Center, 7455 Fannin, Houston, TX 77030, USA
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21
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Nurieva R, Thomas S, Nguyen T, Martin-Orozco N, Wang Y, Kaja MK, Yu XZ, Dong C. T-cell tolerance or function is determined by combinatorial costimulatory signals. EMBO J 2006; 25:2623-33. [PMID: 16724117 PMCID: PMC1478197 DOI: 10.1038/sj.emboj.7601146] [Citation(s) in RCA: 180] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2005] [Accepted: 04/24/2006] [Indexed: 12/13/2022] Open
Abstract
Activated in immune responses, T lymphocytes differentiate into effector cells with potent immune function. CD28 is the most prominent costimulatory receptor for T-cell activation. However, absence of CD28 costimulation did not completely impair effector function of CD4 or CD8 T cells. Moreover, increasing number of costimulatory molecules are recently found on antigen-presenting cells to regulate T-cell activation. To understand the molecular mechanisms that determine T-cell function or tolerance, we have collectively examined the roles of positive and negative costimulatory molecules. Antigen-specific naïve CD4 and CD8 T cells, only when activated in the absence of both CD28 and ICOS pathways, were completely impaired in effector function. These tolerant T cells not only were anergic with profound defects in TcR signal transduction but also completely lacked expression of effector-specific transcription factors. T-cell tolerance induction in this system requires the action by negative costimulatory molecules; T-cell proliferation and function was partially restored by inhibiting PD-1, B7-H3 or B7S1. This work demonstrates that T-cell function or tolerance is controlled by costimulatory signals.
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MESH Headings
- Animals
- Antigens, Differentiation, T-Lymphocyte/genetics
- Antigens, Differentiation, T-Lymphocyte/immunology
- B7-1 Antigen/genetics
- B7-1 Antigen/immunology
- CD28 Antigens/immunology
- Cells, Cultured
- Immune Tolerance
- Inducible T-Cell Co-Stimulator Protein
- Interleukin-2/immunology
- Lymphocyte Activation
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Receptors, Antigen, T-Cell/immunology
- Signal Transduction/physiology
- T-Lymphocyte Subsets/immunology
- T-Lymphocytes/immunology
- Transcription, Genetic
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Affiliation(s)
- Roza Nurieva
- Department of Immunology, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Sunil Thomas
- Department of Immunology, University of Washington, Seattle, WA, USA
| | - Thang Nguyen
- Department of Immunology, University of Washington, Seattle, WA, USA
| | - Natalia Martin-Orozco
- Department of Immunology, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Ying Wang
- Department of Immunology, University of Washington, Seattle, WA, USA
| | | | - Xue-Zhong Yu
- H Lee Moffitt Cancer Center & Research Institute, University of South Florida, Tampa, FL, USA
| | - Chen Dong
- Department of Immunology, University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Department of Immunology, University of Texas MD Anderson Cancer Center, 7455 Fannin, Unit 906, Houston, TX 77030, USA. Tel.: +1 713 563 3203; Fax: +1 713 563 0604; E-mail:
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22
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Abstract
Costimulation regulates the activation of naive T cells as they first encounter antigens in the secondary lymphoid organs. But recently characterized costimulatory molecules of the B7 family appear to have roles beyond initial T cell activation. New evidence shows that negative costimulators expressed by tumors and normal tissues afford local protection from T cell–mediated attack.
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23
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Jaeckel E, Furman MH, Martin-Orozco N, Ploegh HL, von Boehmer H, Manns MP. Ineffiziente Antigenpräsentation von GAD65 im Thymus verursacht eine defekte negative Selektion von GAD65-reaktiven T Zellen. DIABETOL STOFFWECHS 2006. [DOI: 10.1055/s-2006-944031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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24
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Martin-Orozco N, Touret N, Zaharik ML, Park E, Kopelman R, Miller S, Finlay BB, Gros P, Grinstein S. Visualization of vacuolar acidification-induced transcription of genes of pathogens inside macrophages. Mol Biol Cell 2005; 17:498-510. [PMID: 16251362 PMCID: PMC1345685 DOI: 10.1091/mbc.e04-12-1096] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The objective of these studies was to analyze the role of the ionic environment of phagosomal vacuoles in the control of pathogens by macrophages. Digital imaging and flow cytometry were used to follow the induction of the phoP promoter of Salmonella enterica Typhimurium within live macrophages. Manipulating the Mg2+ concentration within the Salmonella-containing vacuole (SCV) was without effect on the early induction of PhoPQ. Moreover, direct measurement of [Mg2+] within the SCV using nanosensor particles showed that, during this initial period of phoP activation, the concentration of the divalent cation is rapidly regulated and stabilizes around 1 mm. Extrusion of other divalent cations via the Nramp1 efflux pump was similarly ruled out as an important contributor to the activation of the regulon. By contrast, induction of PhoP was greatly attenuated when the pH gradient across the SCV membrane was dissipated. A second, more modest pH-independent component of PhoP induction was unmasked by inhibition of the vacuolar proton pump. This second component was eliminated by pretreatment of cells with IFNgamma, even though the cytokine augmented the overall PhoP response. These findings demonstrate the existence of at least three separate activators of phoP transcription: resting and IFNgamma-stimulated pH-sensitive components, plus a pH-independent component.
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Affiliation(s)
- Natalia Martin-Orozco
- Cell Biology Program, Hospital for Sick Children and Department of Biochemistry, University of Toronto, Toronto, Ontario M5G 1X8, Canada
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25
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Touret N, Martin-Orozco N, Paroutis P, Furuya W, Lam-Yuk-Tseung S, Forbes J, Gros P, Grinstein S. Molecular and cellular mechanisms underlying iron transport deficiency in microcytic anemia. Blood 2004; 104:1526-33. [PMID: 15155465 DOI: 10.1182/blood-2004-02-0731] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
AbstractA mutation of the iron transporter Nramp2 (DMT1, Slc11a2) causes microcytic anemia in mk mice and in Belgrade rats by impairing iron absorption in the duodenum and in erythroid cells, causing severe iron deficiency. Both mk and Belgrade animals display a glycine-to-arginine substitution at position 185 (G185R) in the fourth predicted transmembrane domain of Nramp2. To study the molecular basis for the loss of function of Nramp2G185R, we established cell lines stably expressing extracellularly tagged versions of wild-type (WT) or mutated transporters. Like WT Nramp2, the G185R mutant was able to reach the plasmalemma and endosomal compartments, but with reduced efficiency. Instead, a large fraction of Nramp2G185R was detected in the endoplasmic reticulum, where it was unstable and was rapidly degraded by a proteasome-dependent mechanism. Moreover, the stability of the mutant protein that reached the plasma membrane was greatly reduced, further diminishing its surface density at steady state. Last, the specific metal transport activity of plasmalemmal Nramp2G185R was found to be significantly depressed, compared with its WT counterpart. Thus, a singlepoint mutation results in multiple biosynthetic and functional defects that combine to produce the impaired iron deficiency that results in microcytic anemia.
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Affiliation(s)
- Nicolas Touret
- Programme in Cell Biology, The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada M5G 1X8.
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26
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Abstract
We report the identification of two peptides from Salmonella OmpC porin that can bind to major histocompatibility complex class I K(b) molecules and are targets of cytotoxic T lymphocytes from Salmonella-infected mice. These peptides are conserved in gram-negative bacterial porins and are the first Salmonella porin-specific epitopes described for possible CD8(+)-T-cell elimination of infected cells.
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Affiliation(s)
- Alberto Diaz-Quiñonez
- Departamento de Biomedicina Molecular, Centro de Investigación y Estudios Avanzados (CINVESTAV), 07000 Mexico City, Mexico
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27
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Martin-Orozco N, Chen Z, Poirot L, Hyatt E, Chen A, Kanagawa O, Sharpe A, Mathis D, Benoist C. Paradoxical dampening of anti-islet self-reactivity but promotion of diabetes by OX40 ligand. J Immunol 2004; 171:6954-60. [PMID: 14662903 DOI: 10.4049/jimmunol.171.12.6954] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Costimulatory signals received by diabetogenic T cells during priming by or upon secondary encounter with autoantigen are decisive in determining the outcome of autoimmune attack. The OX40-OX40 ligand (OX40L) costimulatory pathway is known to influence T cell responses, prompting us to examine its role in autoimmune diabetes. A null allele at OX40L completely prevented diabetes development in nonobese diabetic mice and strongly reduced its incidence in a TCR transgenic model (BDC2.5). However, somewhat paradoxically, the initial activation of T cells responsive to islet beta cell Ag was slightly faster and more efficient in the absence of OX40L, with an increased degree of cell proliferation and survival in the deficient hosts. Activated T cell migration into and retention within the islets was also slightly accelerated. When challenged in vitro, splenocytes from BDC2.5.OX40L(o/o) mice showed no altered reactivity to exogenously added peptide, no bias to the Th1 or Th2 phenotype, and no alteration in T cell survival. Thus, the OX40/OX40L axis has the paradoxical effect of dampening the early activation and migration of autoimmune T cells, but sustains the long-term progression to autoimmune destruction.
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Affiliation(s)
- Natalia Martin-Orozco
- Section on Immunology and Immunogenetics, Joslin Diabetes Center, Department of Medicine, Brigham and Women's Hospital, and Harvard Medical School, Boston, MA 02215, USA
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28
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Stratmann T, Martin-Orozco N, Mallet-Designe V, Poirot L, McGavern D, Losyev G, Dobbs CM, Oldstone MBA, Yoshida K, Kikutani H, Mathis D, Benoist C, Haskins K, Teyton L. Susceptible MHC alleles, not background genes, select an autoimmune T cell reactivity. J Clin Invest 2003; 112:902-14. [PMID: 12975475 PMCID: PMC193666 DOI: 10.1172/jci18337] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2003] [Accepted: 07/08/2003] [Indexed: 12/31/2022] Open
Abstract
To detect and characterize autoreactive T cells in diabetes-prone NOD mice, we have developed a multimeric MHC reagent with high affinity for the BDC-2.5 T cell receptor, which is reactive against a pancreatic autoantigen. A distinct population of T cells is detected in NOD mice that recognizes the same MHC/peptide target. These T cells are positively selected in the thymus at a surprisingly high frequency and exported to the periphery. They are activated specifically in the pancreatic LNs, demonstrating an autoimmune specificity that recapitulates that of the BDC-2.5 cell. These phenomena are also observed in mouse lines that share with NOD the H-2g7 MHC haplotype but carry diabetes-resistance background genes. Thus, a susceptible haplotype at the MHC seems to be the only element required for the selection and emergence of autoreactive T cells, without requiring other diabetogenic loci from the NOD genome.
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Affiliation(s)
- Thomas Stratmann
- Department of Immunology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
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29
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Abstract
Experiments in nonobese diabetic (NOD) mice that lacked expression of glutamic acid decarboxylase (GAD) in beta cells have suggested that GAD represents an autoantigen essential for initiating and maintaining the diabetogenic immune response. Several attempts of inducing GAD-specific recessive tolerance to support this hypothesis have failed. Here we report on successful tolerance induction by expressing a modified form of GAD under control of the invariant chain promoter resulting in efficient epitope display. In spite of specific tolerance insulitis and diabetes occurred with normal kinetics indicating that GAD is not an essential autoantigen in the pathogenesis of diabetes.
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Affiliation(s)
- Elmar Jaeckel
- Dana Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
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