1
|
Zhu S, Lalani AI, Jin J, Sant’Angelo D, Covey LR, Liu K, Young HA, Ostrand-Rosenberg S, Xie P. The adaptor protein TRAF3 is an immune checkpoint that inhibits myeloid-derived suppressor cell expansion. Front Immunol 2023; 14:1167924. [PMID: 37207205 PMCID: PMC10189059 DOI: 10.3389/fimmu.2023.1167924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 04/20/2023] [Indexed: 05/21/2023] Open
Abstract
Myeloid-derived suppressor cells (MDSCs) are aberrantly expanded in cancer patients and under other pathological conditions. These cells orchestrate the immunosuppressive and inflammatory network to facilitate cancer metastasis and mediate patient resistance to therapies, and thus are recognized as a prime therapeutic target of human cancers. Here we report the identification of the adaptor protein TRAF3 as a novel immune checkpoint that critically restrains MDSC expansion. We found that myeloid cell-specific Traf3-deficient (M-Traf3 -/-) mice exhibited MDSC hyperexpansion during chronic inflammation. Interestingly, MDSC hyperexpansion in M-Traf3 -/- mice led to accelerated growth and metastasis of transplanted tumors associated with an altered phenotype of T cells and NK cells. Using mixed bone marrow chimeras, we demonstrated that TRAF3 inhibited MDSC expansion via both cell-intrinsic and cell-extrinsic mechanisms. Furthermore, we elucidated a GM-CSF-STAT3-TRAF3-PTP1B signaling axis in MDSCs and a novel TLR4-TRAF3-CCL22-CCR4-G-CSF axis acting in inflammatory macrophages and monocytes that coordinately control MDSC expansion during chronic inflammation. Taken together, our findings provide novel insights into the complex regulatory mechanisms of MDSC expansion and open up unique perspectives for the design of new therapeutic strategies that aim to target MDSCs in cancer patients.
Collapse
Affiliation(s)
- Sining Zhu
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, United States
- Graduate Program in Cellular and Molecular Pharmacology, Rutgers University, Piscataway, NJ, United States
| | - Almin I. Lalani
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, United States
- Graduate Program in Cellular and Molecular Pharmacology, Rutgers University, Piscataway, NJ, United States
| | - Juan Jin
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, United States
- Department of Pharmacology, Anhui Medical University, Hefei, Anhui, China
| | - Derek Sant’Angelo
- Child Health Institute of New Jersey, Rutgers University, New Brunswick, NJ, United States
- Department of Pediatrics, Rutgers Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ, United States
- Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, United States
| | - Lori R. Covey
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, United States
- Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, United States
| | - Kebin Liu
- Department of Biochemistry and Molecular Biology, Medical College of Georgia, Augusta, GA, United States
| | - Howard A. Young
- Laboratory of Cancer Immunometabolism, Center for Cancer Research, National Cancer Institute at Frederick, National Institutes of Health, Frederick, MD, United States
| | - Suzanne Ostrand-Rosenberg
- Department of Biological Sciences, The University of Maryland, Baltimore County, Baltimore, MD, United States
| | - Ping Xie
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, United States
- Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, United States
- *Correspondence: Ping Xie,
| |
Collapse
|
2
|
Hornick EL, Bishop GA. TRAF3: Guardian of T lymphocyte functions. Front Immunol 2023; 14:1129251. [PMID: 36814922 PMCID: PMC9940752 DOI: 10.3389/fimmu.2023.1129251] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 01/27/2023] [Indexed: 02/08/2023] Open
Abstract
Tumor necrosis factor receptor (TNFR)-associated factor 3 (TRAF3) is an adapter protein with many context-specific functions. Early studies of lymphocyte TRAF3 hinted at TRAF3's importance for T cell function, but elucidation of specific mechanisms was delayed by early lethality of globally TRAF3-/- mice. Development of a conditional TRAF3-deficient mouse enabled important descriptive and mechanistic insights into how TRAF3 promotes optimal T cell function. Signaling through the T cell antigen receptor (TCR) fails to induce normal proliferation and survival in TRAF3 -/- T cells, and TCR-activated cells in vitro and in vivo have deficient cytokine production. These defects can be traced to incorrect localization and function of negative regulatory phosphatases acting at different parts of the signaling cascade, as can dysregulated effector responses and memory T cell homeostasis in vivo and an enlarged regulatory T cell (Treg) compartment. The important regulatory activity of TRAF3 is also evident at members of the TNFR superfamily and cytokine receptors. Here, we review significant advances in mechanistic understanding of how TRAF3 regulates T cell differentiation and function, through modulation of signaling through the TCR, costimulatory receptors, and cytokine receptors. Finally, we briefly discuss the recent identification of families carrying single allele loss-of-function mutations in TRAF3, and compare the findings in their T cells with the T cell defects identified in mice whose T cells completely lack T cell TRAF3. Together, the body of work describing TRAF3-mediated regulation of T cell effector function and differentiation frame TRAF3 as an important modulator of T cell signal integration.
Collapse
Affiliation(s)
- Emma L Hornick
- Department of Microbiology and Immunology, The University of Iowa, Iowa City, IA, United States
| | - Gail A Bishop
- Department of Microbiology and Immunology, The University of Iowa, Iowa City, IA, United States.,Department of Internal Medicine, The University of Iowa, Iowa City, IA, United States.,Research, Iowa City Veterans Affairs Medical Center, Iowa City, IA, United States
| |
Collapse
|
3
|
Arkee T, Hostager BS, Houtman JCD, Bishop GA. TRAF3 in T Cells Restrains Negative Regulators of LAT to Promote TCR/CD28 Signaling. THE JOURNAL OF IMMUNOLOGY 2021; 207:322-332. [PMID: 34145060 DOI: 10.4049/jimmunol.2001220] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 04/29/2021] [Indexed: 12/11/2022]
Abstract
The adaptor protein TNFR-associated factor 3 (TRAF3) is required for in vivo T cell effector functions and for normal TCR/CD28 signaling. TRAF3-mediated enhancement of TCR function requires engagement of both CD3 and CD28, but the molecular mechanisms underlying how TRAF3 interacts with and impacts TCR/CD28-mediated complexes to enhance their signaling remains an important knowledge gap. We investigated how TRAF3 is recruited to, and regulates, CD28 as a TCR costimulator. Direct association with known signaling motifs in CD28 was dispensable for TRAF3 recruitment; rather, TRAF3 associated with the CD28-interacting protein linker of activated T cells (LAT) in human and mouse T cells. TRAF3-LAT association required the TRAF3 TRAF-C domain and a newly identified TRAF2/3 binding motif in LAT. TRAF3 inhibited function of the LAT-associated negative regulatory protein Dok1, which is phosphorylated at an inhibitory tyrosine residue by the tyrosine kinase breast tumor kinase (Brk/PTK6). TRAF3 regulated Brk activation in T cells, limiting the association of protein tyrosine phosphatase 1B (PTP1B) with the LAT complex. In TRAF3-deficient cells, LAT complex-associated PTP1B was associated with dephosphorylation of Brk at an activating tyrosine residue, potentially reducing its ability to inhibit Dok1. Consistent with these findings, inhibiting PTP1B activity in TRAF3-deficient T cells rescued basal and TCR/CD28-mediated activation of Src family kinases. These results reveal a new mechanism for promotion of TCR/CD28-mediated signaling through restraint of negative regulation of LAT by TRAF3, enhancing the understanding of regulation of the TCR complex.
Collapse
Affiliation(s)
- Tina Arkee
- Department of Microbiology and Immunology, The University of Iowa, Iowa City, IA.,Graduate Program in Immunology, The University of Iowa, Iowa City, IA.,Medical Scientist Training Program, The University of Iowa, Iowa City, IA
| | - Bruce S Hostager
- Department of Microbiology and Immunology, The University of Iowa, Iowa City, IA
| | - Jon C D Houtman
- Department of Microbiology and Immunology, The University of Iowa, Iowa City, IA.,Graduate Program in Immunology, The University of Iowa, Iowa City, IA.,Medical Scientist Training Program, The University of Iowa, Iowa City, IA
| | - Gail A Bishop
- Department of Microbiology and Immunology, The University of Iowa, Iowa City, IA; .,Graduate Program in Immunology, The University of Iowa, Iowa City, IA.,Medical Scientist Training Program, The University of Iowa, Iowa City, IA.,Department of Internal Medicine, The University of Iowa, Iowa City, IA; and.,Iowa City VA Medical Center, Iowa City, IA
| |
Collapse
|
4
|
Arkee T, Bishop GA. TRAF family molecules in T cells: Multiple receptors and functions. J Leukoc Biol 2019; 107:907-915. [PMID: 31749173 DOI: 10.1002/jlb.2mr1119-397r] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 11/05/2019] [Accepted: 11/07/2019] [Indexed: 12/13/2022] Open
Abstract
The TNFR superfamily of receptors, the major focus of the recent TNFR Superfamily Conference held in June 2019, employ the TNFR-associated factor (TRAF) family of adaptor proteins in key aspects of their signaling pathways. Although many early studies investigated TRAF functions via exogenous overexpression in nonhematopoietic cell lines, it has subsequently become clear that whereas TRAFs share some overlap in function, each also plays unique biologic roles, that can be highly context dependent. This brief review summarizes the current state of knowledge of functions of each of the TRAF molecules that mediate important functions in T lymphocytes: TRAFs 1, 2, 3, 5, and 6. Due to our current appreciation of the contextual nature of TRAF function, our focus is upon findings made specifically in T lymphocytes. Key T cell functions for each TRAF are detailed, as well as future knowledge gaps of interest and importance.
Collapse
Affiliation(s)
- Tina Arkee
- Graduate Program in Immunology, The University of Iowa, Iowa City, Iowa, USA.,Medical Scientist Training Program, The University of Iowa, Iowa City, Iowa, USA
| | - Gail A Bishop
- Graduate Program in Immunology, The University of Iowa, Iowa City, Iowa, USA.,Medical Scientist Training Program, The University of Iowa, Iowa City, Iowa, USA.,Depts. of Microbiology & Immunology and Internal Medicine, The University of Iowa, Iowa City, Iowa, USA.,Iowa City VA Medical Center, Iowa City, Iowa, USA
| |
Collapse
|
5
|
Zhu S, Jin J, Gokhale S, Lu AM, Shan H, Feng J, Xie P. Genetic Alterations of TRAF Proteins in Human Cancers. Front Immunol 2018; 9:2111. [PMID: 30294322 PMCID: PMC6158389 DOI: 10.3389/fimmu.2018.02111] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Accepted: 08/28/2018] [Indexed: 12/25/2022] Open
Abstract
The tumor necrosis factor receptor (TNF-R)-associated factor (TRAF) family of cytoplasmic adaptor proteins regulate the signal transduction pathways of a variety of receptors, including the TNF-R superfamily, Toll-like receptors (TLRs), NOD-like receptors (NLRs), RIG-I-like receptors (RLRs), and cytokine receptors. TRAF-dependent signaling pathways participate in a diverse array of important cellular processes, including the survival, proliferation, differentiation, and activation of different cell types. Many of these TRAF-dependent signaling pathways have been implicated in cancer pathogenesis. Here we analyze the current evidence of genetic alterations of TRAF molecules available from The Cancer Genome Atlas (TCGA) and the Catalog of Somatic Mutations in Cancer (COSMIC) as well as the published literature, including copy number variations and mutation landscape of TRAFs in various human cancers. Such analyses reveal that both gain- and loss-of-function genetic alterations of different TRAF proteins are commonly present in a number of human cancers. These include pancreatic cancer, meningioma, breast cancer, prostate cancer, lung cancer, liver cancer, head and neck cancer, stomach cancer, colon cancer, bladder cancer, uterine cancer, melanoma, sarcoma, and B cell malignancies, among others. Furthermore, we summarize the key in vivo and in vitro evidence that demonstrates the causal roles of genetic alterations of TRAF proteins in tumorigenesis within different cell types and organs. Taken together, the information presented in this review provides a rationale for the development of therapeutic strategies to manipulate TRAF proteins or TRAF-dependent signaling pathways in different human cancers by precision medicine.
Collapse
Affiliation(s)
- Sining Zhu
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, United States
- Graduate Program in Cellular and Molecular Pharmacology, Rutgers University, Piscataway, NJ, United States
| | - Juan Jin
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, United States
- Department of Pharmacology, Anhui Medical University, Hefei, China
| | - Samantha Gokhale
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, United States
- Graduate Program in Cellular and Molecular Pharmacology, Rutgers University, Piscataway, NJ, United States
| | - Angeli M. Lu
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, United States
| | - Haiyan Shan
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, United States
- Department of Obstetrics and Gynecology, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, China
| | - Jianjun Feng
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, United States
- Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education of the People's Republic of China, Fisheries College of Jimei University, Xiamen, China
| | - Ping Xie
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, United States
- Member, Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, United States
| |
Collapse
|
6
|
Zhu S, Jin J, Gokhale S, Lu AM, Shan H, Feng J, Xie P. Genetic Alterations of TRAF Proteins in Human Cancers. Front Immunol 2018. [PMID: 30294322 DOI: 10.3389/fimmu.2018.02111/bibtex] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023] Open
Abstract
The tumor necrosis factor receptor (TNF-R)-associated factor (TRAF) family of cytoplasmic adaptor proteins regulate the signal transduction pathways of a variety of receptors, including the TNF-R superfamily, Toll-like receptors (TLRs), NOD-like receptors (NLRs), RIG-I-like receptors (RLRs), and cytokine receptors. TRAF-dependent signaling pathways participate in a diverse array of important cellular processes, including the survival, proliferation, differentiation, and activation of different cell types. Many of these TRAF-dependent signaling pathways have been implicated in cancer pathogenesis. Here we analyze the current evidence of genetic alterations of TRAF molecules available from The Cancer Genome Atlas (TCGA) and the Catalog of Somatic Mutations in Cancer (COSMIC) as well as the published literature, including copy number variations and mutation landscape of TRAFs in various human cancers. Such analyses reveal that both gain- and loss-of-function genetic alterations of different TRAF proteins are commonly present in a number of human cancers. These include pancreatic cancer, meningioma, breast cancer, prostate cancer, lung cancer, liver cancer, head and neck cancer, stomach cancer, colon cancer, bladder cancer, uterine cancer, melanoma, sarcoma, and B cell malignancies, among others. Furthermore, we summarize the key in vivo and in vitro evidence that demonstrates the causal roles of genetic alterations of TRAF proteins in tumorigenesis within different cell types and organs. Taken together, the information presented in this review provides a rationale for the development of therapeutic strategies to manipulate TRAF proteins or TRAF-dependent signaling pathways in different human cancers by precision medicine.
Collapse
Affiliation(s)
- Sining Zhu
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, United States
- Graduate Program in Cellular and Molecular Pharmacology, Rutgers University, Piscataway, NJ, United States
| | - Juan Jin
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, United States
- Department of Pharmacology, Anhui Medical University, Hefei, China
| | - Samantha Gokhale
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, United States
- Graduate Program in Cellular and Molecular Pharmacology, Rutgers University, Piscataway, NJ, United States
| | - Angeli M Lu
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, United States
| | - Haiyan Shan
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, United States
- Department of Obstetrics and Gynecology, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, China
| | - Jianjun Feng
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, United States
- Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education of the People's Republic of China, Fisheries College of Jimei University, Xiamen, China
| | - Ping Xie
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, United States
- Member, Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, United States
| |
Collapse
|
7
|
Ebner P, Versteeg GA, Ikeda F. Ubiquitin enzymes in the regulation of immune responses. Crit Rev Biochem Mol Biol 2017; 52:425-460. [PMID: 28524749 PMCID: PMC5490640 DOI: 10.1080/10409238.2017.1325829] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 04/06/2017] [Accepted: 04/28/2017] [Indexed: 12/25/2022]
Abstract
Ubiquitination plays a central role in the regulation of various biological functions including immune responses. Ubiquitination is induced by a cascade of enzymatic reactions by E1 ubiquitin activating enzyme, E2 ubiquitin conjugating enzyme, and E3 ubiquitin ligase, and reversed by deubiquitinases. Depending on the enzymes, specific linkage types of ubiquitin chains are generated or hydrolyzed. Because different linkage types of ubiquitin chains control the fate of the substrate, understanding the regulatory mechanisms of ubiquitin enzymes is central. In this review, we highlight the most recent knowledge of ubiquitination in the immune signaling cascades including the T cell and B cell signaling cascades as well as the TNF signaling cascade regulated by various ubiquitin enzymes. Furthermore, we highlight the TRIM ubiquitin ligase family as one of the examples of critical E3 ubiquitin ligases in the regulation of immune responses.
Collapse
|
8
|
Marcial GE, Ford AL, Haller MJ, Gezan SA, Harrison NA, Cai D, Meyer JL, Perry DJ, Atkinson MA, Wasserfall CH, Garrett T, Gonzalez CF, Brusko TM, Dahl WJ, Lorca GL. Lactobacillus johnsonii N6.2 Modulates the Host Immune Responses: A Double-Blind, Randomized Trial in Healthy Adults. Front Immunol 2017; 8:655. [PMID: 28659913 PMCID: PMC5466969 DOI: 10.3389/fimmu.2017.00655] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 05/18/2017] [Indexed: 12/12/2022] Open
Abstract
Lactobacillus johnsonii N6.2 mitigates the onset of type 1 diabetes (T1D) in biobreeding diabetes-prone rats, in part, through changes in kynurenine:tryptophan (K:T) ratios. The goal of this pilot study was to determine the safety, tolerance, and general immunological response of L. johnsonii N6.2 in healthy subjects. A double-blind, randomized clinical trial in 42 healthy individuals with no known risk factors for T1D was undertaken to evaluate subject responses to the consumption of L. johnsonii N6.2. Participants received 1 capsule/day containing 108 colony-forming units of L. johnsonii N6.2 or placebo for 8 weeks. Comprehensive metabolic panel (CMP), leukocyte subpopulations by complete blood count (CBC) and flow cytometry, serum cytokines, and relevant metabolites in the indoleamine-2,3-dioxygenase pathway were assessed. L. johnsonii N6.2 survival and intestinal microbiota was analyzed. Daily and weekly questionnaires were assessed for potential effects of probiotic treatment on general wellness. The administration of L. johnsonii N6.2 did not modify the CMP or CBC of participants suggesting general safety. In fact, L. johnsonii N6.2 administration significantly decreased the occurrence of abdominal pain, indigestion, and cephalic syndromes. As predicted, increased serum tryptophan levels increased resulting in a decreased K:T ratio was observed in the L. johnsonii N6.2 group. Interestingly, immunophenotyping assays revealed that monocytes and natural killer cell numbers were increased significantly after washout (12 weeks). Moreover, an increase of circulating effector Th1 cells (CD45RO+CD183+CD196−) and cytotoxic CD8+ T cells subset was observed in the L. johnsonii N6.2 group. Consumption of L. johnsonii N6.2 is well tolerated in adult control subjects, demonstrates systemic impacts on innate and adaptive immune populations, and results in a decreased K:T ratio. These data provide support for the safety and feasibility of using L. johnsonii N6.2 in prevention trials in subjects at risk for T1D. Trial registration: This trial was registered at http://clinicaltrials.gov as NCT02349360.
Collapse
Affiliation(s)
- Guillermo E Marcial
- Department of Microbiology and Cell Science, Genetics Institute, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States
| | - Amanda L Ford
- Food Science and Human Nutrition Department, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States
| | - Michael J Haller
- Department of Pediatrics, College of Medicine, University of Florida, Gainesville, FL, United States
| | - Salvador A Gezan
- School of Forest Resources and Conservation, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States
| | - Natalie A Harrison
- Department of Microbiology and Cell Science, Genetics Institute, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States
| | - Dan Cai
- Department of Microbiology and Cell Science, Genetics Institute, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States
| | - Julie L Meyer
- Department of Soil and Water Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States
| | - Daniel J Perry
- Department of Pathology, Immunology, and Laboratory Medicine, College of Medicine, University of Florida, Gainesville, FL, United States
| | - Mark A Atkinson
- Department of Pathology, Immunology, and Laboratory Medicine, College of Medicine, University of Florida, Gainesville, FL, United States
| | - Clive H Wasserfall
- Department of Pathology, Immunology, and Laboratory Medicine, College of Medicine, University of Florida, Gainesville, FL, United States
| | - Timothy Garrett
- Department of Pathology, Immunology, and Laboratory Medicine, College of Medicine, University of Florida, Gainesville, FL, United States
| | - Claudio F Gonzalez
- Department of Microbiology and Cell Science, Genetics Institute, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States
| | - Todd M Brusko
- Department of Pathology, Immunology, and Laboratory Medicine, College of Medicine, University of Florida, Gainesville, FL, United States
| | - Wendy J Dahl
- Food Science and Human Nutrition Department, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States
| | - Graciela L Lorca
- Department of Microbiology and Cell Science, Genetics Institute, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States
| |
Collapse
|
9
|
Niu K, Xu J, Cao Y, Hou Y, Shan M, Wang Y, Xu Y, Sun M, Wang B. BAP31 is involved in T cell activation through TCR signal pathways. Sci Rep 2017; 7:44809. [PMID: 28333124 PMCID: PMC5363085 DOI: 10.1038/srep44809] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 02/15/2017] [Indexed: 12/15/2022] Open
Abstract
BAP31 is a ubiquitously expressed endoplasmic reticulum (ER) membrane protein. The functions of BAP31 in the immune system have not been investigated due to the lack of animal models. Therefore we created a BAP31 conditional knockdown mouse by performing a knockdown of BAP31 in the thymus. In doing so, we demonstrate that the maturation of T cells is normal but the number of T cells is less in the thymus of the knockout mouse. In addition, the spleen and lymph nodes of peripheral immune organs contained a lesser proportion of the mature T cells in the thymus specific BAP31 knockout mice. The BAP31 knockout T cells decreased the proliferation activated by TCR signal pathways. Further studies clarified that BAP31 affects the phosphorylation levels of both Zap70/Lck/Lat of the upstream members and Akt/GSK/Jnk/Erk of the downstream members of TCR signal pathways. Furthermore, BAP31 can regulate the expression of some markers such as CD3/TCRα/TCRβ and some cytokines like IL-2/IFN-γ/IL-6/TNF-α which are important for T cell activation. Taken together, these results demonstrate that BAP31 may play an important role in T cell activation by regulating TCR signaling.
Collapse
Affiliation(s)
- Kunwei Niu
- Institute of Biochemistry and Molecular Biology, College of Life and Health Sciences, Northeastern University, Shenyang 110169, China
| | - Jialin Xu
- Institute of Biochemistry and Molecular Biology, College of Life and Health Sciences, Northeastern University, Shenyang 110169, China
| | - Yuhua Cao
- Institute of Biochemistry and Molecular Biology, College of Life and Health Sciences, Northeastern University, Shenyang 110169, China
| | - Yue Hou
- Institute of Biochemistry and Molecular Biology, College of Life and Health Sciences, Northeastern University, Shenyang 110169, China
| | - Mu Shan
- Institute of Biochemistry and Molecular Biology, College of Life and Health Sciences, Northeastern University, Shenyang 110169, China
| | - Yanqing Wang
- Institute of Biochemistry and Molecular Biology, College of Life and Health Sciences, Northeastern University, Shenyang 110169, China
| | - Yang Xu
- Institute of Biochemistry and Molecular Biology, College of Life and Health Sciences, Northeastern University, Shenyang 110169, China
| | - Mingyi Sun
- Institute of Biochemistry and Molecular Biology, College of Life and Health Sciences, Northeastern University, Shenyang 110169, China
| | - Bing Wang
- Institute of Biochemistry and Molecular Biology, College of Life and Health Sciences, Northeastern University, Shenyang 110169, China
| |
Collapse
|
10
|
Du G, Yang N, Gong W, Fang Y, He J, Zhou N, Lu X, Zhao Y. CD8 + effector memory T cells induce acute rejection of allogeneic heart retransplants in mice possibly through activating expression of inflammatory cytokines. Exp Cell Res 2017; 355:1-8. [PMID: 28232114 DOI: 10.1016/j.yexcr.2017.02.036] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 01/15/2017] [Accepted: 02/20/2017] [Indexed: 11/29/2022]
Abstract
BACKGROUND To investigate the effects of CD8+ memory T (Tm) cells and CD8+ effector memory T (Tem) cells on the results of allogeneic heart retransplantations performed in mice. METHODS A skin transplantation model was used to generate sensitized splenic CD8+ Tem cells for infusion into BALB/c mice. One week after infusion, the BALB/c mice underwent allogeneic heart transplantation in the abdominal cavity. Cyclosporin A was administered via intraperitoneal injection starting one day prior to transplantation to arrest immunological rejection of the transplanted heart. The effects of sensitized CD8+ Tem cells on allogeneic heart graft rejection were examined by monitoring survival of the transplanted hearts, the infiltration of effector memory CD8+ T cells into myocardium, and expressions of inflammatory cytokines in blood serum. RESULTS Adoptive transfer of sensitized CD8+ Tem cells prior to transplantation induced an acute rejection response which decreased the survival of transplanted hearts. The rejection response was accompanied by an infiltration of CD8+ Tem cells into the transplanted myocardial tissue. Additionally, infusion of sensitized CD8+ Tem cells induced markedly increased expressions of IL-2 and IFN-γ, and decreased expression of TGF-β in the transplanted hearts, as well as higher levels of IFN-γ and CXCL-9 in blood serum. CONCLUSIONS The infusion of sensitized CD8+ Tem cells induced an acute graft rejection response and decreased the survival of grafted hearts by regulating the expressions of inflammatory cytokines including CXCL-9, IL-2, and INF-γ. Cyclosporin A had no therapeutic effect on the graft rejection response induced by sensitized CD8+ Tem cells.
Collapse
Affiliation(s)
- Gang Du
- National Center for International Research of Biological Targeting Diagnosis and Therapy, Guangxi Key Laboratory of Biological Targeting Diagnosis and Therapy Research, Collaborative Innovation Center for Targeting Tumor Diagnosis and Therapy, Guangxi Medical University, Nanning, Guangxi 530021, China; Guangxi Key Laboratory of Biological Targeting Diagnosis and Therapy Research, Guangxi Medical University, Nanning 530021, China; The First Affiliated Hospital of Guangxi Medical University, Nanning 530021, China; The Department of Immunology, Guangxi Medical University, Nanning 530021, China
| | - Nuo Yang
- National Center for International Research of Biological Targeting Diagnosis and Therapy, Guangxi Key Laboratory of Biological Targeting Diagnosis and Therapy Research, Collaborative Innovation Center for Targeting Tumor Diagnosis and Therapy, Guangxi Medical University, Nanning, Guangxi 530021, China; Guangxi Key Laboratory of Biological Targeting Diagnosis and Therapy Research, Guangxi Medical University, Nanning 530021, China; The First Affiliated Hospital of Guangxi Medical University, Nanning 530021, China; The Department of Immunology, Guangxi Medical University, Nanning 530021, China
| | - Wenlin Gong
- National Center for International Research of Biological Targeting Diagnosis and Therapy, Guangxi Key Laboratory of Biological Targeting Diagnosis and Therapy Research, Collaborative Innovation Center for Targeting Tumor Diagnosis and Therapy, Guangxi Medical University, Nanning, Guangxi 530021, China; Guangxi Key Laboratory of Biological Targeting Diagnosis and Therapy Research, Guangxi Medical University, Nanning 530021, China
| | - Yuan Fang
- National Center for International Research of Biological Targeting Diagnosis and Therapy, Guangxi Key Laboratory of Biological Targeting Diagnosis and Therapy Research, Collaborative Innovation Center for Targeting Tumor Diagnosis and Therapy, Guangxi Medical University, Nanning, Guangxi 530021, China; Guangxi Key Laboratory of Biological Targeting Diagnosis and Therapy Research, Guangxi Medical University, Nanning 530021, China; The Department of Immunology, Guangxi Medical University, Nanning 530021, China
| | - Jian He
- National Center for International Research of Biological Targeting Diagnosis and Therapy, Guangxi Key Laboratory of Biological Targeting Diagnosis and Therapy Research, Collaborative Innovation Center for Targeting Tumor Diagnosis and Therapy, Guangxi Medical University, Nanning, Guangxi 530021, China; Guangxi Key Laboratory of Biological Targeting Diagnosis and Therapy Research, Guangxi Medical University, Nanning 530021, China; The Department of Immunology, Guangxi Medical University, Nanning 530021, China
| | - Nuo Zhou
- National Center for International Research of Biological Targeting Diagnosis and Therapy, Guangxi Key Laboratory of Biological Targeting Diagnosis and Therapy Research, Collaborative Innovation Center for Targeting Tumor Diagnosis and Therapy, Guangxi Medical University, Nanning, Guangxi 530021, China; Guangxi Key Laboratory of Biological Targeting Diagnosis and Therapy Research, Guangxi Medical University, Nanning 530021, China
| | - Xiaoling Lu
- National Center for International Research of Biological Targeting Diagnosis and Therapy, Guangxi Key Laboratory of Biological Targeting Diagnosis and Therapy Research, Collaborative Innovation Center for Targeting Tumor Diagnosis and Therapy, Guangxi Medical University, Nanning, Guangxi 530021, China; Guangxi Key Laboratory of Biological Targeting Diagnosis and Therapy Research, Guangxi Medical University, Nanning 530021, China; The Department of Immunology, Guangxi Medical University, Nanning 530021, China.
| | - Yongxiang Zhao
- National Center for International Research of Biological Targeting Diagnosis and Therapy, Guangxi Key Laboratory of Biological Targeting Diagnosis and Therapy Research, Collaborative Innovation Center for Targeting Tumor Diagnosis and Therapy, Guangxi Medical University, Nanning, Guangxi 530021, China; Guangxi Key Laboratory of Biological Targeting Diagnosis and Therapy Research, Guangxi Medical University, Nanning 530021, China; The First Affiliated Hospital of Guangxi Medical University, Nanning 530021, China; The Department of Immunology, Guangxi Medical University, Nanning 530021, China.
| |
Collapse
|
11
|
Bishop GA. TRAF3 as a powerful and multitalented regulator of lymphocyte functions. J Leukoc Biol 2016; 100:919-926. [PMID: 27154354 PMCID: PMC6608063 DOI: 10.1189/jlb.2mr0216-063r] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 03/31/2016] [Accepted: 04/07/2016] [Indexed: 12/12/2022] Open
Abstract
This review summarizes the current state of knowledge regarding the roles of the signaling adapter protein tumor necrosis factor receptor (TNFR)-associated factor 3 in regulating the functions of B and T lymphocytes. In B lymphocytes, TNFR-associated factor 3 inhibits signaling by TNFR superfamily receptors, Toll-like receptors, and interleukin-6R. In contrast, signaling to B cells by the virally encoded oncogenic protein latent membrane protein 1 is promoted by TNFR-associated factor 3. An important B cell-specific role for TNFR-associated factor 3 is the inhibition of homeostatic survival, directly relevant to the common occurrence of TNFR-associated factor 3 mutations in human B cell malignancies. TNFR-associated factor 3 was recently found to be a resident nuclear protein in B cells, where it interacts with and inhibits gene expression mediated by the cAMP response element-binding protein transcription complex, including expression of the prosurvival protein myeloid leukemia cell differentiation protein 1. In T lymphocytes, TNFR-associated factor 3 is required for normal signaling by the T cell antigen receptor, while inhibiting signaling by the interleukin-2 receptor. Cytoplasmic TNFR -associated factor 3 restrains nuclear factor-κB2 activation in both T and B cells. Clinical implications and future directions for the study of this context-dependent signaling regulator are discussed.
Collapse
Affiliation(s)
- Gail A Bishop
- Department of Microbiology, The University of Iowa, Iowa City, Iowa, USA;
- Department of Internal Medicine, The University of Iowa, Iowa City, Iowa, USA; and
- Department of Veterans Affairs Medical Center, Iowa City, Iowa, USA
| |
Collapse
|
12
|
Abstract
Ubiquitination has emerged as a crucial mechanism that regulates signal transduction in diverse biological processes, including different aspects of immune functions. Ubiquitination regulates pattern-recognition receptor signaling that mediates both innate immune responses and dendritic cell maturation required for initiation of adaptive immune responses. Ubiquitination also regulates the development, activation, and differentiation of T cells, thereby maintaining efficient adaptive immune responses to pathogens and immunological tolerance to self-tissues. Like phosphorylation, ubiquitination is a reversible reaction tightly controlled by the opposing actions of ubiquitin ligases and deubiquitinases. Deregulated ubiquitination events are associated with immunological disorders, including autoimmune and inflammatory diseases.
Collapse
Affiliation(s)
- Hongbo Hu
- Department of Rheumatology and Immunology, State Key Laboratory of Biotherapy & Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Shao-Cong Sun
- Department of Immunology, The University of Texas MD Anderson Cancer Center, 7455 Fannin Street, Unit 902, Houston, TX 77030, USA.,The University of Texas Graduate School of Biomedical Sciences, Houston, TX 77030, USA
| |
Collapse
|
13
|
Abstract
Tumor necrosis factor receptor (TNFR)-associated factor 3 (TRAF3) is broadly involved in different receptor-mediated signaling pathways. Considerable progress was made recently in understanding the role of TRAF3 in T cell biology. Here we review these new findings about how TRAF3 participates in T cell development and function. The different roles of TRAF3 in distinct immune cells are also compared. That TRAF3 is required for T cell effector functions, and invariant Natural Killer T cell function and development, was unexpected. Another surprising finding is that TRAF3 normally restrains regulatory T cell development. It is now clear that TRAF3 regulates signaling to T cells not only through costimulatory members of the TNFR superfamily, but also through the T cell receptor complex, and cytokine receptors. The diverse roles it plays support the multifaceted nature of this molecule. How TRAF3 mediates integration of different signaling cascades is an important topic for future study.
Collapse
Key Words
- DC, dendritic cell
- IBD, inflammatory bowel disease
- ICOS, inducible co-stimulator
- IKK, IκB kinase
- IL-2 receptor
- IL-2, interleukin-2
- Jak1, Janus kinase 1
- LMC, litter mate control
- LMP1, latent membrane protein-1
- MAPK, mitogen-activated protein kinase
- MΦ, macrophage
- NIK, NF-κB inducing kinase
- NLR, nucleotide binding-oligomerization domain (NOD)-like receptor
- RLR, retinoic acid-inducible gene (RIG)-I-like receptor
- SLAM, signaling lymphocyte activation molecule
- SOCS1, Suppressor of cytokine signaling 1
- T cell
- T cell receptor
- T-TRAF3−/−, CD4CreTRAF3flox/flox
- TCPTP, T cell protein tyrosine phosphatase
- TCR, T cell receptor
- TFH, follicular helper T cell
- TFR, follicular Treg cell
- TLR, Toll-like receptor
- TNFR, Tumor necrosis factor receptor
- TRAF3
- TRAF3, TNFR-associated factor 3
- Tcm cell, central memory T cell
- Tem cell, effector memory T cell
- Treg cell, regulatory T cell
- adaptor molecule
- iNKT cell, invariant Natural Killer T cell
- invariant Natural Killer T cell
- regulatory T cell
- signaling pathway
Collapse
Affiliation(s)
- Zuoan Yi
- a Departments of Microbiology ; University of Iowa ; Iowa City , IA USA
| | | | | |
Collapse
|
14
|
O'Leary CE, Lewis EL, Oliver PM. Ubiquitylation as a Rheostat for TCR Signaling: From Targeted Approaches Toward Global Profiling. Front Immunol 2015; 6:618. [PMID: 26732666 PMCID: PMC4679856 DOI: 10.3389/fimmu.2015.00618] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 11/26/2015] [Indexed: 12/24/2022] Open
Abstract
T cell receptor (TCR) signaling must be precisely tuned to limit collateral damage and prevent reactivity to self, while still allowing robust protective immune responses that control pathogen invasion. One process that can be used to promote, modify, or terminate TCR signaling is ubiquitylation. During ubiquitylation, ubiquitin is covalently attached to target proteins through a multistep process, in which E3 ubiquitin ligases promote the formation of ubiquitin chains on selected substrates. Ubiquitylation can facilitate protein–protein interactions, direct a protein to a specific subcellular location, or initiate protein destruction. Like phosphorylation, ubiquitylation is a reversible process – deubiquitylating enzymes counteract ligase function by removing ubiquitin chains. This reversibility also allows for ubiquitin chain “editing.” Based on an emerging wealth of information from genetic loss-of-function studies showing that deregulation of ubiquitylation pathways leads to immune dysfunction, it has become increasingly apparent that the dynamic process of ubiquitylation is critical for normal immune cell function. In this review, we will describe how ubiquitylation acts as a key modulator and integrator of signaling downstream of TCR engagement. Specifically, we highlight the known roles of the substrate-specific E3 ligases and deubiquitylating enzymes in TCR signaling and T cell activation. While it is clear that ubiquitin enzymes tune T cell signaling and T cell function, elucidating the molecular mechanisms by which these proteins modulate T cells has met with significant challenges. Identifying substrates of these enzymes has been a particular challenge, and thus substrates of many E3 ligases and deubiquitylating enzymes remain largely unknown. To that end, we discuss the promise, and some practical considerations, of using proteomics-based techniques for unbiased identification of putative substrates of ubiquitin cascade proteins within primary T cells. These methods provide an exciting opportunity for further defining how TCR signals are regulated and for identifying new targets for therapeutic modulation.
Collapse
Affiliation(s)
- Claire E O'Leary
- Perelman School of Medicine, University of Pennsylvania , Philadelphia, PA , USA
| | - Emma L Lewis
- Perelman School of Medicine, University of Pennsylvania , Philadelphia, PA , USA
| | - Paula M Oliver
- Perelman School of Medicine, University of Pennsylvania , Philadelphia, PA , USA
| |
Collapse
|
15
|
Lalani AI, Luo C, Han Y, Xie P. TRAF3: a novel tumor suppressor gene in macrophages. ACTA ACUST UNITED AC 2015; 2:e1009. [PMID: 26661944 DOI: 10.14800/macrophage.1009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Tumor necrosis factor receptor-associated factor 3 (TRAF3), a member of the TRAF family of cytoplasmic adaptor proteins with E3 ligase activity, is ubiquitously expressed in various cell types of the immune system. It is shared for signaling by a variety of adaptive and innate immune receptors as well as cytokine receptors. Previous studies examining conditional TRAF3-deficient mouse models that have the Traf3 gene specifically deleted in B lymphocytes or T lymphocytes have revealed the diverse and critical in vivo functions of TRAF3 in adaptive immunity. Although in vitro evidence points to a pivotal and indispensable role for TRAF3 in type I interferon production induced by pattern recognition receptors in macrophages and dendritic cells, the in vivo functions of TRAF3 in the innate immune system had long remained unclear. Three laboratories have recently addressed this gap in knowledge by investigating myeloid cell-specific TRAF3-deficient (genotype: TRAF3flox/floxLysM+/Cre) mice. The new evidence together demonstrates that specific ablation of TRAF3 in myeloid cells leads to inflammatory diseases, altered progression of diabetes, and spontaneous development of different types of tumors and infections in mice. These new findings indicate that TRAF3 acts as an anti-inflammatory factor and is required for optimal innate immunity in myeloid cells. Strikingly, the new evidence also identifies TRAF3 as a novel tumor suppressor gene in macrophages and other myeloid cells. In this review, we discuss and summarize the new findings and current knowledge about the multi-faceted regulatory roles and complex signaling mechanisms of myeloid cell TRAF3 in inflammation, innate immunity, and tumor development.
Collapse
Affiliation(s)
- Almin I Lalani
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, New Jersey 08854, USA ; Graduate Program in Cellular and Molecular Pharmacology, Rutgers University, Piscataway, New Jersey 08854, USA
| | - Chang Luo
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, New Jersey 08854, USA
| | - Yeming Han
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, New Jersey 08854, USA
| | - Ping Xie
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, New Jersey 08854, USA ; Member, Rutgers Cancer Institute of New Jersey
| |
Collapse
|
16
|
Yang XD, Sun SC. Targeting signaling factors for degradation, an emerging mechanism for TRAF functions. Immunol Rev 2015; 266:56-71. [PMID: 26085207 PMCID: PMC4473799 DOI: 10.1111/imr.12311] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Tumor necrosis factor receptor (TNFR)-associated factors (TRAFs) form a family of proteins that are best known as signaling adapters of TNFRs. However, emerging evidence suggests that TRAF proteins, particularly TRAF2 and TRAF3, also regulate signal transduction by controlling the fate of intracellular signaling factors. A well-recognized function of TRAF2 and TRAF3 in this aspect is to mediate ubiquitin-dependent degradation of nuclear factor-κB (NF-κB)-inducing kinase (NIK), an action required for the control of NIK-regulated non-canonical NF-κB signaling pathway. TRAF2 and TRAF3 form a complex with the E3 ubiquitin ligase cIAP (cIAP1 or cIAP2), in which TRAF3 serves as the NIK-binding adapter. Recent evidence suggests that the cIAP-TRAF2-TRAF3 E3 complex also targets additional signaling factors for ubiquitin-dependent degradation, thereby regulating important aspects of immune and inflammatory responses. This review provides both historical aspects and new insights into the signaling functions of this ubiquitination system.
Collapse
Affiliation(s)
- Xiao-Dong Yang
- Shanghai Institute of Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shao-Cong Sun
- Department of Immunology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas, USA
| |
Collapse
|
17
|
Villanueva JE, Malle EK, Gardam S, Silveira PA, Zammit NW, Walters SN, Brink R, Grey ST. TRAF2 regulates peripheral CD8(+) T-cell and NKT-cell homeostasis by modulating sensitivity to IL-15. Eur J Immunol 2015; 45:1820-31. [PMID: 25931426 DOI: 10.1002/eji.201445416] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 02/18/2015] [Accepted: 04/28/2015] [Indexed: 11/07/2022]
Abstract
In this study, a critical and novel role for TNF receptor (TNFR) associated factor 2 (TRAF2) is elucidated for peripheral CD8(+) T-cell and NKT-cell homeostasis. Mice deficient in TRAF2 only in their T cells (TRAF2TKO) show ∼40% reduction in effector memory and ∼50% reduction in naïve CD8(+) T-cell subsets. IL-15-dependent populations were reduced further, as TRAF2TKO mice displayed a marked ∼70% reduction in central memory CD8(+) CD44(hi) CD122(+) T cells and ∼80% decrease in NKT cells. TRAF2TKO CD8(+) CD44(hi) T cells exhibited impaired dose-dependent proliferation to exogenous IL-15. In contrast, TRAF2TKO CD8(+) T cells proliferated normally to anti-CD3 and TRAF2TKO CD8(+) CD44(hi) T cells exhibited normal proliferation to exogenous IL-2. TRAF2TKO CD8(+) T cells expressed normal levels of IL-15-associated receptors and possessed functional IL-15-mediated STAT5 phosphorylation, however TRAF2 deletion caused increased AKT activation. Loss of CD8(+) CD44(hi) CD122(+) and NKT cells was mechanistically linked to an inability to respond to IL-15. The reduced CD8(+) CD44(hi) CD122(+) T-cell and NKT-cell populations in TRAF2TKO mice were rescued in the presence of high dose IL-15 by IL-15/IL-15Rα complex administration. These studies demonstrate a critical role for TRAF2 in the maintenance of peripheral CD8(+) CD44(hi) CD122(+) T-cell and NKT-cell homeostasis by modulating sensitivity to T-cell intrinsic growth factors such as IL-15.
Collapse
Affiliation(s)
| | | | - Sandra Gardam
- B cell Biology Group, Immunology Division, Garvan Institute of Medical Research, Darlinghurst, Australia
| | | | | | | | - Robert Brink
- B cell Biology Group, Immunology Division, Garvan Institute of Medical Research, Darlinghurst, Australia
| | | |
Collapse
|
18
|
So T, Nagashima H, Ishii N. TNF Receptor-Associated Factor (TRAF) Signaling Network in CD4 + T-Lymphocytes. TOHOKU J EXP MED 2015; 236:139-54. [DOI: 10.1620/tjem.236.139] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Takanori So
- Department of Microbiology and Immunology, Tohoku University Graduate School of Medicine
| | - Hiroyuki Nagashima
- Department of Microbiology and Immunology, Tohoku University Graduate School of Medicine
| | - Naoto Ishii
- Department of Microbiology and Immunology, Tohoku University Graduate School of Medicine
| |
Collapse
|