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Abstract
Numerous risk alleles for systemic lupus erythematosus (SLE) have now been identified. Analysis of the expression of genes with risk alleles in cells of hematopoietic origin demonstrates them to be most abundantly expressed in B cells and dendritic cells (DCs), suggesting that these cell types may be the drivers of the inflammatory changes seen in SLE. DCs are of particular interest as they act to connect the innate and the adaptive immune response. Thus, DCs can transform inflammation into autoimmunity, and autoantibodies are the hallmark of SLE. In this review, we focus on mechanisms of tolerance that maintain DCs in a non‐activated, non‐immunogenic state. We demonstrate, using examples from our own studies, how alterations in DC function stemming from either DC‐intrinsic abnormalities or DC‐extrinsic regulators of function can predispose to autoimmunity.
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Affiliation(s)
- Myoungsun Son
- The Feinstein Institute for Medical Research, Center for Autoimmune and Musculoskeletal Diseases, Manhasset, NY, USA
| | - Sun Jung Kim
- The Feinstein Institute for Medical Research, Center for Autoimmune and Musculoskeletal Diseases, Manhasset, NY, USA
| | - Betty Diamond
- The Feinstein Institute for Medical Research, Center for Autoimmune and Musculoskeletal Diseases, Manhasset, NY, USA
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Cohan S. Therapeutic efficacy of monthly subcutaneous injection of daclizumab in relapsing multiple sclerosis. Biologics 2016; 10:119-38. [PMID: 27672308 PMCID: PMC5026217 DOI: 10.2147/btt.s89218] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Despite the availability of multiple disease-modifying therapies for relapsing multiple sclerosis (MS), there remains a need for highly efficacious targeted therapy with a favorable benefit-risk profile and attributes that encourage a high level of treatment adherence. Daclizumab is a humanized monoclonal antibody directed against CD25, the α subunit of the high-affinity interleukin 2 (IL-2) receptor, that reversibly modulates IL-2 signaling. Daclizumab treatment leads to antagonism of proinflammatory, activated T lymphocyte function and expansion of immunoregulatory CD56(bright) natural killer cells, and has the potential to, at least in part, rectify the imbalance between immune tolerance and autoimmunity in relapsing MS. The clinical pharmacology, efficacy, and safety of subcutaneous daclizumab have been evaluated extensively in a large clinical study program. In pivotal studies, daclizumab demonstrated superior efficacy in reducing clinical and radiologic measures of MS disease activity compared with placebo or intramuscular interferon beta-1a, a standard-of-care therapy for relapsing MS. The risk of hepatic disorders, cutaneous events, and infections was modestly increased. The monthly subcutaneous self-injection dosing regimen of daclizumab may be advantageous in maintaining patient adherence to treatment, which is important for optimal outcomes with MS disease-modifying therapy. Daclizumab has been approved in the US and in the European Union and represents an effective new treatment option for patients with relapsing forms of MS, and is currently under review by other regulatory agencies.
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Affiliation(s)
- Stanley Cohan
- Providence Multiple Sclerosis Center
- Providence Brain and Spine Institute
- Providence Health & Services, Portland, OR, USA
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53
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Abstract
Previous studies have identified the immunological functions of transcription factor B lymphocyte-induced maturation protein-1 (Blimp-1) in various adaptive immune cell types such as T and B lymphocytes. More recently, it has been shown that Blimp-1 extends its functional roles to dendritic cells (DCs) and macrophages, two cell types belonging to the innate immune system. The protein acts as a direct and indirect regulator of target genes by recruiting chromatin modification factors and by regulating microRNA expression, respectively. In DCs, Blimp-1 has been identified as one of the components involved in antigen presentation. Genome-wide association studies identified polymorphisms associated with multiple autoimmune diseases such as system lupus erythematosus, rheumatoid arthritis, and inflammatory bowel disease in PRDM1, the gene encoding Blimp-1 protein. In this review, we will discuss the immune regulatory functions of Blimp-1 in DCs with a main focus on the tolerogenic mechanisms of Blimp-1 required to protect against the development of autoimmune diseases.
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54
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IL2Rβ-dependent signals drive terminal exhaustion and suppress memory development during chronic viral infection. Proc Natl Acad Sci U S A 2016; 113:E5444-53. [PMID: 27573835 DOI: 10.1073/pnas.1604256113] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Exhaustion of CD8(+) T cells severely impedes the adaptive immune response to chronic viral infections. Despite major advances in our understanding of the molecular regulation of exhaustion, the cytokines that directly control this process during chronicity remain unknown. We demonstrate a direct impact of IL-2 and IL-15, two common gamma-chain-dependent cytokines, on CD8(+) T-cell exhaustion. Common to both cytokine receptors, the IL-2 receptor β (IL2Rβ) chain is selectively maintained on CD8(+) T cells during chronic lymphocytic choriomeningitis virus and hepatitis C virus infections. Its expression correlates with exhaustion severity and identifies terminally exhausted CD8(+) T cells both in mice and humans. Genetic ablation of the IL2Rβ chain on CD8(+) T cells restrains inhibitory receptor induction, in particular 2B4 and Tim-3; precludes terminal differentiation of highly defective PD-1(hi) effectors; and rescues memory T-cell development and responsiveness to IL-7-dependent signals. Together, we ascribe a previously unexpected role to IL-2 and IL-15 as instigators of CD8(+) T-cell exhaustion during chronic viral infection.
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55
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Weiss JM, Chen W, Nyuydzefe MS, Trzeciak A, Flynn R, Tonra JR, Marusic S, Blazar BR, Waksal SD, Zanin-Zhorov A. ROCK2 signaling is required to induce a subset of T follicular helper cells through opposing effects on STATs in autoimmune settings. Sci Signal 2016; 9:ra73. [PMID: 27436361 DOI: 10.1126/scisignal.aad8953] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Rho-associated kinase 2 (ROCK2) determines the balance between human T helper 17 (TH17) cells and regulatory T (Treg) cells. We investigated its role in the generation of T follicular helper (TFH) cells, which help to generate antibody-producing B cells under normal and autoimmune conditions. Inhibiting ROCK2 in normal human T cells or peripheral blood mononuclear cells from patients with active systemic lupus erythematosus (SLE) decreased the number and function of TFH cells induced by activation ex vivo. Moreover, inhibition of ROCK2 activity decreased the abundance of the transcriptional regulator Bcl6 (B cell lymphoma 6) and increased that of Blimp1 by reducing the binding of signal transducer and activator of transcription 3 (STAT3) and increasing that of STAT5 to the promoters of the genes Bcl6 and PRDM1, respectively. In the MRL/lpr murine model of SLE, oral administration of the selective ROCK2 inhibitor KD025 resulted in a twofold reduction in the numbers of TFH cells and antibody-producing plasma cells in the spleen, as well as a decrease in the size of splenic germinal centers, which are the sites of interaction between TFH cells and B cells. KD025-treated mice showed a substantial improvement in both histological and clinical scores compared to those of untreated mice and had reduced amounts of Bcl6 and phosphorylated STAT3, as well as increased STAT5 phosphorylation. Together, these data suggest that ROCK2 signaling plays a critical role in controlling the development of TFH cells induced by autoimmune conditions through reciprocal regulation of STAT3 and STAT5 activation.
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Affiliation(s)
| | - Wei Chen
- Kadmon Research Institute, New York, NY 10016, USA
| | | | | | - Ryan Flynn
- Division of Blood and Marrow Transplantation, Department of Pediatrics and Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA
| | | | | | - Bruce R Blazar
- Division of Blood and Marrow Transplantation, Department of Pediatrics and Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA
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56
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Abstract
CD8+ T cells play a cardinal feature in response to alloantigens and are able to generate effector/memory T cells independently from CD4+ T cells. To investigate the impact of aging on CD8 T cells, we used a fully mismatched mouse skin transplant model. Our findings showed a prolonged allograft survival in older recipients associated with a significant increase of CD4+ and CD8+ CD44high CD62Llow effector/memory T cells and a reduced systemic IFNγ production. When reconstituting young CBA Rag-1 mice that lack mature T and B cells with old CD8+ T cells expressing clonal anti-H2K T cell receptor (TCR) alloreactive for MHC I, graft survival was significantly prolonged and comparable to those receiving young CD8+ T cells. Moreover, our data showed that reduced systemic IFNγ levels observed in old recipients had been linked to a compromised expression of the IL-2R β subunit (CD122) by old CD8+ T cells. In addition, we observed an impaired IFNγ production on IL-2 receptor activation. At the same time, gene profiling analysis of old CD8 T cells demonstrated reduced chemokine ligand-3 and CD40L expression that resulted in compromised CD8+ T cell/dendritic cell communication, leading to impaired migratory and phagocytic activity of CD11c cells.Collectively, our study demonstrated that aging delays allograft rejection. CD8 T cells play a critical role in this process linked to a compromised production of IFNγ, in addition to a defective IL-2 receptor signaling machinery and a defective communication between CD8 T cells and dendritic cells.
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Liu C, Liu W, Fan L, Liu J, Li P, Zhang W, Gao J, Li Z, Zhang Q, Wang X. Sequences analyses and expression profiles in tissues and embryos of Japanese flounder (Paralichthys olivaceus) PRDM1. FISH PHYSIOLOGY AND BIOCHEMISTRY 2016; 42:467-482. [PMID: 26508172 DOI: 10.1007/s10695-015-0152-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 10/20/2015] [Indexed: 06/05/2023]
Abstract
PRDM1 (PRDI-BF1-RIZ1 homologous domain containing 1) appears to be a pleiotropic regulatory factor in various processes. It contains a PR (PRDI-BF1-RIZ1 homologous) domain protein and five zinc fingers. In the present study, a gene coding the homolog of prdm1 and the 5' regulatory region of prdm1 was identified from the Paralichthys olivaceus (denoted Po-prdm1). Results of real-time quantitative polymerase chain reaction amplification (RT-qPCR) and in situ hybridization (ISH) in embryos revealed that Po-prdm1 was highly expressed between the early gastrula and tail bud stages, with its expression peaking in the mid-gastrula stage, whereas the results of RT-qPCR and ISH in tissues demonstrated that Po-prdm1 transcripts were ubiquitously detected in all tissues, which indicates its pleiotropic function in multiple processes. ISH of gonadal tissues revealed that the transcripts were located in the nucleus and cytoplasm of the oocytes in the ovaries but only in the spermatogonia and not in the spermatocytes in the testes. The Po-prdm1 transcription factor binding sites and their conserved binding region among vertebrates were analyzed in this study. The combined results suggest that Po-PRDM1 has a conserved function in teleosts and mammals.
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Affiliation(s)
- Conghui Liu
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003, China
| | - Wei Liu
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003, China
| | - Lin Fan
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003, China
| | - Jinxiang Liu
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003, China
| | - Peizhen Li
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003, China
| | - Wei Zhang
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003, China
| | - Jinning Gao
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003, China
| | - Zan Li
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003, China
| | - Quanqi Zhang
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003, China
| | - Xubo Wang
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003, China.
- College of Marine Life Science, Ocean University of China, No. 5 Yushan Road, Qingdao, 266003, China.
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58
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A molecular threshold for effector CD8(+) T cell differentiation controlled by transcription factors Blimp-1 and T-bet. Nat Immunol 2016; 17:422-32. [PMID: 26950239 DOI: 10.1038/ni.3410] [Citation(s) in RCA: 124] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 02/01/2016] [Indexed: 12/11/2022]
Abstract
T cell responses are guided by cytokines that induce transcriptional regulators, which ultimately control differentiation of effector and memory T cells. However, it is unknown how the activities of these molecular regulators are coordinated and integrated during the differentiation process. Using genetic approaches and transcriptional profiling of antigen-specific CD8(+) T cells, we reveal a common program of effector differentiation that is regulated by IL-2 and IL-12 signaling and the combined activities of the transcriptional regulators Blimp-1 and T-bet. The loss of both T-bet and Blimp-1 leads to abrogated cytotoxic function and ectopic IL-17 production in CD8(+) T cells. Overall, our data reveal two major overlapping pathways of effector differentiation governed by the availability of Blimp-1 and T-bet and suggest a model for cytokine-induced transcriptional changes that combine, quantitatively and qualitatively, to promote robust effector CD8(+) T cell differentiation.
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59
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Pérol L, Piaggio E. New Molecular and Cellular Mechanisms of Tolerance: Tolerogenic Actions of IL-2. Methods Mol Biol 2016; 1371:11-28. [PMID: 26530792 DOI: 10.1007/978-1-4939-3139-2_2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Interleukin-2 (IL-2) is an old molecule with brand new functions. Indeed, IL-2 has been first described as a T-cell growth factor but recent data pointed out that its main function in vivo is the maintenance of immune tolerance. Mechanistically, IL-2 is essential for the development and function of CD4(+) Foxp3(+) regulatory T cells (Treg cells) that are essential players in the control of immune responded to self, tumors, microbes and grafts. Treg cells are exquisitely sensitive to IL-2 due to their constitutive expression of the high affinity IL-2 receptor (IL-2R) and the new paradigm suggests that low-doses of IL-2 could selectively boost Treg cells in vivo. Consequently, a growing body of clinical research is aiming at using IL-2 at low doses as a tolerogenic drug to boost endogenous Treg cells in patients suffering from autoimmune or inflammatory conditions. In this manuscript, we briefly review IL-2/IL-2R biology and the role of IL-2 in the development, maintenance, and function of Treg cells; and also its effects on other immune cell populations such as CD4(+) T helper cells and CD8(+) memory T cells. Then, focusing on type 1 diabetes, we review the preclinical studies and clinical trials supporting the use of low-doses IL-2 as a tolerogenic immunotherapy. Finally, we discuss the limitations and future directions for IL-2 based immunotherapy.
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Affiliation(s)
- Louis Pérol
- INSERM U932, 26 rue d'Ulm, 75005, Paris, France.
- Institut Curie, Section Recherche, 26 rue d'Ulm, 75005, Paris, France.
| | - Eliane Piaggio
- INSERM U932, 26 rue d'Ulm, 75005, Paris, France
- Institut Curie, Section Recherche, 26 rue d'Ulm, 75005, Paris, France
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60
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Mould AW, Morgan MAJ, Nelson AC, Bikoff EK, Robertson EJ. Blimp1/Prdm1 Functions in Opposition to Irf1 to Maintain Neonatal Tolerance during Postnatal Intestinal Maturation. PLoS Genet 2015; 11:e1005375. [PMID: 26158850 PMCID: PMC4497732 DOI: 10.1371/journal.pgen.1005375] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 06/19/2015] [Indexed: 11/18/2022] Open
Abstract
The neonatal intestine is a very complex and dynamic organ that must rapidly adapt and remodel in response to a barrage of environmental stimuli during the first few postnatal weeks. Recent studies demonstrate that the zinc finger transcriptional repressor Blimp1/Prdm1 plays an essential role governing postnatal reprogramming of intestinal enterocytes during this period. Functional loss results in global changes in gene expression patterns, particularly in genes associated with metabolic function. Here we engineered a knock-in allele expressing an eGFP-tagged fusion protein under control of the endogenous regulatory elements and performed genome wide ChIP-seq analysis to identify direct Blimp1 targets and further elucidate the function of Blimp1 in intestinal development. Comparison with published human and mouse datasets revealed a highly conserved core set of genes including interferon-inducible promoters. Here we show that the interferon-inducible transcriptional activator Irf1 is constitutively expressed throughout fetal and postnatal intestinal epithelium development. ChIP-seq demonstrates closely overlapping Blimp1 and Irf1 peaks at key components of the MHC class I pathway in fetal enterocytes. The onset of MHC class I expression coincides with down-regulated Blimp1 expression during the suckling to weaning transition. Collectively, these experiments strongly suggest that in addition to regulating the enterocyte metabolic switch, Blimp1 functions as a gatekeeper in opposition to Irf1 to prevent premature activation of the MHC class I pathway in villus epithelium to maintain tolerance in the neonatal intestine. The transcriptional repressor Blimp1/Prdm1 plays a pivotal role in the metabolic switch that occurs in the small intestine during the suckling to weaning transition. Notably, expression profiling of perinatal Blimp1-deficient small intestine revealed premature activation of metabolic genes normally restricted to post-weaning enterocytes. To further elucidate the function of Blimp1 in intestinal development, we engineered a novel Blimp1-eGFP-fusion knock-in mouse strain to perform ChIP-seq analysis. In addition to identifying which metabolic genes are direct Blimp1 targets, ChIP-seq analysis revealed a highly conserved Blimp1/Irf-1 overlapping sites that function to control MHC class I antigen processing during acquisition of neonatal tolerance in the first weeks after birth during early colonization of the intestinal tract by commensal microorganisms. Moreover, immunohistochemical analysis of human fetal intestine suggests that a BLIMP1/IRF-1 axis may also function in human intestinal epithelium development.
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Affiliation(s)
- Arne W. Mould
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Marc A. J. Morgan
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Andrew C. Nelson
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Elizabeth K. Bikoff
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
- * E-mail: (EKB); (EJR)
| | - Elizabeth J. Robertson
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
- * E-mail: (EKB); (EJR)
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61
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Swaminathan S, Kelleher AD. MicroRNA modulation of key targets associated with T cell exhaustion in HIV-1 infection. Curr Opin HIV AIDS 2015; 9:464-71. [PMID: 25023625 DOI: 10.1097/coh.0000000000000089] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
PURPOSE OF REVIEW The emergence of studies linking microRNAs (miRNAs), a species of small RNA molecules important in gene regulation, with HIV-1 infection has led to a better understanding of the complex molecular changes that occur following infection. We aim to discuss these changes and show how miRNAs may be involved with regulating key immunomodulatory molecules linked to T cell exhaustion at the post-transcriptional level. RECENT FINDINGS Blimp-1 is a recently described T cell exhaustion marker. Reduced levels of miR-9 have been shown to have a functional role in the higher levels of Blimp-1 in CD4 T cells from patients with HIV-1 infection. Reduced levels of let-7 miRNAs have been linked to higher levels of IL-10, again with potential pathophysiological significance in HIV-1 infection. The advent of deep sequencing technologies is allowing detection of virally derived miRNAs expressed at extremely low levels, although some controversy still exists. SUMMARY miRNAs have emerged as important players in the T cell dysfunction observed with HIV-1 infection. It is likely that they may emerge as novel markers of T cell dysfunction and provide potential targets for new therapeutics to reverse dysfunction.
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Affiliation(s)
- Sanjay Swaminathan
- aDepartment of Clinical Immunology, Westmead and Blacktown Hospitals bSydney Medical School, University of Sydney cSchool of Medicine, University of Western Sydney, Sydney dImmunovirology Laboratory, St Vincent's Centre for Applied Medical Research, Darlinghurst eThe Kirby Institute, University of New South Wales, Kensington, New South Wales, Australia
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62
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The interplay of effector and regulatory T cells in cancer. Curr Opin Immunol 2015; 33:101-11. [PMID: 25728990 DOI: 10.1016/j.coi.2015.02.003] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 01/19/2015] [Accepted: 02/06/2015] [Indexed: 01/05/2023]
Abstract
Regulatory T (Treg) cells suppress effector T (Teff) cells and prevent immune-mediated rejection of cancer. Much less appreciated are mechanisms by which Teff cells antagonize Treg cells. Herein, we consider how complex reciprocal interactions between Teff and Treg cells shape their population dynamics within tumors. Under states of tolerance, including during tumor escape, suppressed Teff cells support Treg cell populations through antigen-dependent provision of interleukin (IL)-2. During immune activation, Teff cells can lose this supportive capacity and directly antagonize Treg cell populations to neutralize their immunosuppressive function. While this latter state is rarely achieved spontaneously within tumors, we propose that therapeutic induction of immune activation has the potential to stably disrupt immunosuppressive population states resulting in durable cancer regression.
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63
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Boulet S, Daudelin JF, Labrecque N. IL-2 induction of Blimp-1 is a key in vivo signal for CD8+ short-lived effector T cell differentiation. THE JOURNAL OF IMMUNOLOGY 2014; 193:1847-54. [PMID: 25015830 DOI: 10.4049/jimmunol.1302365] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
During infection or vaccination, only a small proportion of CD8(+) T cells differentiate into memory cells. The mechanisms underlying the differentiation of CD8(+) T cells into short-lived effector cells (SLECs) or memory precursor effector cells are poorly defined. It was recently shown in infectious models that the transcriptional repressor B lymphocyte-induced maturation protein 1 (Blimp-1) enhances the formation of SLECs. The factors controlling Blimp-1 expression leading to the in vivo formation of SLECs are still not known. However, it has been shown that cytokines such as IL-2 induce Blimp-1 expression in vitro. In this study, we took advantage of the low-inflammation model of dendritic cell immunization to study the role of the IL-2/Blimp-1 axis in SLEC differentiation as well as the importance of Blimp-1 expression in memory precursor effector cells for proper CD8(+) memory generation. Our results show that Blimp-1 deficiency affects effector differentiation and function in the absence of inflammation. Unexpectedly, memory generation was not affected in Blimp-1-deficient OT-I cells responding to vaccination. In addition, modulation of the bioavailability of IL-2 by injection either of a blocking Ab or of the cytokine, demonstrates a link between IL-2, Blimp-1 induction, and SLEC formation in wild-type cells. Conversely, injection of IL-2 had less effect on Blimp-1-deficient CD8(+) T cells, indicating that the effect of IL-2 on in vivo SLEC differentiation is mediated by Blimp-1. In conclusion, IL-2 induction of Blimp-1 expression is a key regulator of SLEC differentiation in vivo.
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Affiliation(s)
- Salix Boulet
- Maisonneuve-Rosemont Hospital Research Center, Montreal, Quebec H1T 2M4, Canada
| | | | - Nathalie Labrecque
- Maisonneuve-Rosemont Hospital Research Center, Montreal, Quebec H1T 2M4, Canada; Department of Medicine, University of Montreal, Montreal, Quebec H3C 3J7, Canada; and Department of Microbiology, Immunology and Infectiology, University of Montreal, Montreal, Quebec H3C 3J7, Canada
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Parish IA, Marshall HD, Staron MM, Lang PA, Brüstle A, Chen JH, Cui W, Tsui YC, Perry C, Laidlaw BJ, Ohashi PS, Weaver CT, Kaech SM. Chronic viral infection promotes sustained Th1-derived immunoregulatory IL-10 via BLIMP-1. J Clin Invest 2014; 124:3455-68. [PMID: 25003188 DOI: 10.1172/jci66108] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 05/22/2014] [Indexed: 01/19/2023] Open
Abstract
During the course of many chronic viral infections, the antiviral T cell response becomes attenuated through a process that is regulated in part by the host. While elevated expression of the immunosuppressive cytokine IL-10 is involved in the suppression of viral-specific T cell responses, the relevant cellular sources of IL-10, as well as the pathways responsible for IL-10 induction, remain unclear. In this study, we traced IL-10 production over the course of chronic lymphocytic choriomeningitis virus (LCMV) infection in an IL-10 reporter mouse line. Using this model, we demonstrated that virus-specific T cells with reduced inflammatory function, particularly Th1 cells, display elevated and sustained IL-10 expression during chronic LCMV infection. Furthermore, ablation of IL-10 from the T cell compartment partially restored T cell function and reduced viral loads in LCMV-infected animals. We found that viral persistence is needed for sustained IL-10 production by Th1 cells and that the transcription factor BLIMP-1 is required for IL-10 expression by Th1 cells. Restimulation of Th1 cells from LCMV-infected mice promoted BLIMP-1 and subsequent IL-10 expression, suggesting that constant antigen exposure likely induces the BLIMP-1/IL-10 pathway during chronic viral infection. Together, these data indicate that effector T cells self-limit their responsiveness during persistent viral infection via an IL-10-dependent negative feedback loop.
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65
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Lu P, Youngblood BA, Austin JW, Mohammed AUR, Butler R, Ahmed R, Boss JM. Blimp-1 represses CD8 T cell expression of PD-1 using a feed-forward transcriptional circuit during acute viral infection. ACTA ACUST UNITED AC 2014; 211:515-27. [PMID: 24590765 PMCID: PMC3949569 DOI: 10.1084/jem.20130208] [Citation(s) in RCA: 118] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The transcription factor Blimp-1 represses PD-1 expression in effector CD8+ T cells during acute LCMV infection. Programmed cell death 1 (PD-1) is an inhibitory immune receptor that regulates T cell function, yet the molecular events that control its expression are largely unknown. We show here that B lymphocyte–induced maturation protein 1 (Blimp-1)–deficient CD8 T cells fail to repress PD-1 during the early stages of CD8 T cell differentiation after acute infection with lymphocytic choriomeningitis virus (LCMV) strain Armstrong. Blimp-1 represses PD-1 through a feed-forward repressive circuit by regulating PD-1 directly and by repressing NFATc1 expression, an activator of PD-1 expression. Blimp-1 binding induces a repressive chromatin structure at the PD-1 locus, leading to the eviction of NFATc1 from its site. These data place Blimp-1 at an important phase of the CD8 T cell effector response and provide a molecular mechanism for its repression of PD-1.
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Affiliation(s)
- Peiyuan Lu
- Department of Microbiology and Immunology and Emory Vaccine Center, Emory University School of Medicine, Atlanta, GA 30322
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66
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van Aalderen MC, Remmerswaal EBM, ten Berge IJM, van Lier RAW. Blood and beyond: properties of circulating and tissue-resident human virus-specific αβ CD8(+) T cells. Eur J Immunol 2014; 44:934-44. [PMID: 24448915 DOI: 10.1002/eji.201344269] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 01/02/2014] [Accepted: 01/16/2014] [Indexed: 01/11/2023]
Abstract
CD8(+) αβ T-cell responses form an essential line of defence against viral infections. An important part of the mechanisms that control the generation and maintenance of these responses have been elucidated in experimental mouse models. In recent years it has become clear that CD8(+) T-cell responses in humans not only show similarities, but also display differences to those occurring in mice. Furthermore, while several viral infections occur primarily in specialised organ systems, for obvious reasons, most human CD8(+) T-cell investigations were performed on cells deriving from the circulation. Indeed, several lines of evidence now point to essential functional differences between virus-specific CD8(+) memory T cells found in the circulation and those providing protection in organ systems, such as the lungs. In this review, we will focus on summarising recent insights into human CD8(+) T-cell differentiation in response to several viruses and emphasise that for a complete understanding of anti-viral immunity, it is pivotal to scrutinize such responses in both blood and tissue.
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Affiliation(s)
- Michiel C van Aalderen
- Department of Experimental Immunology, Academic Medical Centre, Amsterdam, The Netherlands; Renal Transplant Unit, Department of Internal Medicine, Academic Medical Centre, Amsterdam, The Netherlands
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Khattar M, Miyahara Y, Schroder PM, Xie A, Chen W, Stepkowski SM. Interleukin-21 is a critical regulator of CD4 and CD8 T cell survival during priming under Interleukin-2 deprivation conditions. PLoS One 2014; 9:e85882. [PMID: 24416451 PMCID: PMC3887105 DOI: 10.1371/journal.pone.0085882] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 12/06/2013] [Indexed: 12/29/2022] Open
Abstract
Optimal T cell activation and expansion require binding of the common gamma-chain (γc) cytokine Interleukin-2 (IL-2) to its cognate receptor that in turn engages a γc/Janus tyrosine kinase (Jak)3 signaling pathway. Because of its restricted expression by antigen-activated T cells and its obligatory role in promoting their survival and proliferation, IL-2 has been considered as a selective therapeutic target for preventing T cell mediated diseases. However, in order to further explore IL-2 targeted therapy, it is critical to precisely understand its role during early events of T cell activation. In this study, we delineate the role of IL-2 and other γc cytokines in promoting the survival of CD4 and CD8 T cells during early phases of priming. Under IL-2 inhibitory conditions (by neutralizing anti-IL-2 mAbs), the survival of activated CD8+ T cells was reduced, whereas CD4+ T cells remained much more resistant. These results correlated with reduced Bcl-2 expression, and mitochondrial membrane potential in CD8+ T cells in comparison to CD4+ T cells. However, using transwell co-culture assays we have found that CD4+ T cells could rescue the survival of CD8+ T cells even under IL-2 deprived conditions via secretion of soluble factors. A cytokine screen performed on CD8+ T cells cultured alone revealed that IL-21, another γc cytokine, was capable of rescuing their survival under IL-2 deprivation. Indeed, blocking the IL-21 signaling pathway along with IL-2 neutralization resulted in significantly reduced survival of both CD4+ and CD8+ T cells. Taken together, we have shown that under IL-2 deprivation conditions, IL-21 may act as the major survival factor promoting T cell immune responses. Thus, investigation of IL-2 targeted therapies may need to be revisited to consider blockade of the IL-21 signaling pathways as an adjunct to provide more effective control of T cell immune responses.
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Affiliation(s)
- Mithun Khattar
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine, Toledo, Ohio, United States of America
| | - Yoshihiro Miyahara
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine, Toledo, Ohio, United States of America
| | - Paul M. Schroder
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine, Toledo, Ohio, United States of America
| | - Aini Xie
- Transplant Immunology Center, Houston Methodist Research Institute, Houston, Texas, United States of America
| | - Wenhao Chen
- Transplant Immunology Center, Houston Methodist Research Institute, Houston, Texas, United States of America
- * E-mail: (SS); (WC)
| | - Stanislaw M. Stepkowski
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine, Toledo, Ohio, United States of America
- * E-mail: (SS); (WC)
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Identification and expression profiles of prdm1 in medaka Oryzias latipes. Mol Biol Rep 2013; 41:617-26. [PMID: 24343424 DOI: 10.1007/s11033-013-2899-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 12/09/2013] [Indexed: 12/13/2022]
Abstract
Mouse Prdm1, also known as Blimp1, plays important roles in maturation and survival of lymphoid cells, as well as in organogenesis of muscle, limb, sensor organs and primordial germ cells. The homologues of mouse prdm1 have been identified in a diverse of animals including zebrafish and fugu. Here, we report the identification and expression profiles of two homologues of prdm1, namely prdm1a and prdm1b in medaka, Oryzias latipes. The transcripts of prdm1a and prdm1b were detectable in all the tissues including immune organs such as gill, spleen, kidney, liver and intestine that we have checked on. The transcripts of prdm1a could be detected in the embryonic shield at mid-gastrula stage and later in the somite, eye, otic vesicle, branchial arches, fin, intestine and cloaca during embryogenesis using in situ hybridization. Moreover, the expression of prdm1a in the liver of both medaka and zebrafish could be up-regulated by the immune stimuli including lipopolysaccharide, polyI:C and the grass carp reovirus, similarly to the up-regulation of IL1B. These results indicate that Prdm1a may play important roles in embryogenesis and also in immune response in fish.
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Berglund LJ, Avery DT, Ma CS, Moens L, Deenick EK, Bustamante J, Boisson-Dupuis S, Wong M, Adelstein S, Arkwright PD, Bacchetta R, Bezrodnik L, Dadi H, Roifman CM, Fulcher DA, Ziegler JB, Smart JM, Kobayashi M, Picard C, Durandy A, Cook MC, Casanova JL, Uzel G, Tangye SG. IL-21 signalling via STAT3 primes human naive B cells to respond to IL-2 to enhance their differentiation into plasmablasts. Blood 2013; 122:3940-50. [PMID: 24159173 PMCID: PMC3854113 DOI: 10.1182/blood-2013-06-506865] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 10/10/2013] [Indexed: 12/19/2022] Open
Abstract
B-cell responses are guided by the integration of signals through the B-cell receptor (BCR), CD40, and cytokine receptors. The common γ chain (γc)-binding cytokine interleukin (IL)-21 drives humoral immune responses via STAT3-dependent induction of transcription factors required for plasma cell generation. We investigated additional mechanisms by which IL-21/STAT3 signaling modulates human B-cell responses by studying patients with STAT3 mutations. IL-21 strongly induced CD25 (IL-2Rα) in normal, but not STAT3-deficient, CD40L-stimulated naïve B cells. Chromatin immunoprecipitation confirmed IL2RA as a direct target of STAT3. IL-21-induced CD25 expression was also impaired on B cells from patients with IL2RG or IL21R mutations, confirming a requirement for intact IL-21R signaling in this process. IL-2 increased plasmablast generation and immunoglobulin secretion from normal, but not CD25-deficient, naïve B cells stimulated with CD40L/IL-21. IL-2 and IL-21 were produced by T follicular helper cells, and neutralizing both cytokines abolished the B-cell helper capacity of these cells. Our results demonstrate that IL-21, via STAT3, sensitizes B cells to the stimulatory effects of IL-2. Thus, IL-2 may play an adjunctive role in IL-21-induced B-cell differentiation. Lack of this secondary effect of IL-21 may amplify the humoral immunodeficiency in patients with mutations in STAT3, IL2RG, or IL21R due to impaired responsiveness to IL-21.
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Affiliation(s)
- Lucinda J Berglund
- Immunology Research Program, Garvan Institute of Medical Research, Darlinghurst, NSW, Australia
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70
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Waysbort N, Russ D, Chain BM, Friedman N. Coupled IL-2-dependent extracellular feedbacks govern two distinct consecutive phases of CD4 T cell activation. THE JOURNAL OF IMMUNOLOGY 2013; 191:5822-30. [PMID: 24244020 DOI: 10.4049/jimmunol.1301575] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
T cells integrate cell-specific Ag receptor signaling with shared signals mediated by secreted cytokines, which often involve regulatory feedback loops. IL-2 signaling, for example, reduces the synthesis of IL-2 and increases the synthesis of IL-2Rα-chain, whereas both genes require TCR signaling for their activation. The ways by which T cells dynamically integrate these private and public signals during activation are not well understood. We combined robotics, multiparameter flow cytometry, and real-time quantitative PCR to analyze T cell activation at high temporal resolution over several days. Two distinct temporal phases of T cell activation were evident. First, Ag-dependent signals activated low IL-2Rα and high IL-2 production, independent of IL-2 signaling. Subsequently, secreted IL-2 acted as a shared resource driving high IL-2Rα expression, reduced IL-2 synthesis, and cell proliferation. This transition was independent of continued TCR signaling. Our data allowed the determination of the parameters of the IL-2-mediated extracellular positive and negative feedback circuits and demonstrated that the two loops are coupled and become activated at a similar level of IL-2 signaling. We propose that temporal separation of private and shared signals allows T cells to first integrate Ag-specific responses and subsequently share information leading to collective decision making.
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Affiliation(s)
- Nir Waysbort
- Department of Immunology, Weizmann Institute of Science, Rehovot 76100, Israel
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71
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Miskov-Zivanov N, Turner MS, Kane LP, Morel PA, Faeder JR. The duration of T cell stimulation is a critical determinant of cell fate and plasticity. Sci Signal 2013; 6:ra97. [PMID: 24194584 DOI: 10.1126/scisignal.2004217] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Variations in T cell receptor (TCR) signal strength, as indicated by differential activation of downstream signaling pathways, determine the fate of naïve T cells after encounter with antigen. Low-strength signals favor differentiation into regulatory T (T(reg)) cells containing the transcription factor Foxp3, whereas high-strength signals favor generation of interleukin-2-producing T helper (T(H)) cells. We constructed a logic circuit model of TCR signaling pathways, a major feature of which is an incoherent feed-forward loop involving both TCR-dependent activation of Foxp3 and its inhibition by mammalian target of rapamycin (mTOR), leading to the transient appearance of Foxp3(+) cells under T(H) cell-generating conditions. Experiments confirmed this behavior and the prediction that the immunosuppressive cytokine TGF-β (transforming growth factor-β) could generate T(reg) cells even during continued Akt-mTOR signaling. We predicted that sustained mTOR activity could suppress FOXP3 expression upon TGF-β removal, suggesting a possible mechanism for the experimentally observed instability of Foxp3(+) cells. Our model predicted, and experiments confirmed, that transient stimulation of cells with high-dose antigen generated T(H), T(reg), and nonactivated cells in proportions depending on the duration of TCR stimulation. Experimental analysis of cells after antigen removal identified three populations that correlated with these T cell fates. Further analysis of simulations implicated a negative feedback loop involving Foxp3, the phosphatase PTEN, and Akt-mTOR in determining fate. These results suggest that there is a critical time after TCR stimulation during which heterogeneity in the differentiating population of cells leads to increased plasticity of cell fate.
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Affiliation(s)
- Natasa Miskov-Zivanov
- 1Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15260, USA
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72
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Shin HM, Kapoor V, Guan T, Kaech SM, Welsh RM, Berg LJ. Epigenetic modifications induced by Blimp-1 Regulate CD8⁺ T cell memory progression during acute virus infection. Immunity 2013; 39:661-75. [PMID: 24120360 PMCID: PMC3808842 DOI: 10.1016/j.immuni.2013.08.032] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Accepted: 06/24/2013] [Indexed: 11/29/2022]
Abstract
The transcription factor Blimp-1 regulates the overall accumulation of virus-specific CD8⁺ T cells during acute viral infections. We found that increased proliferation and survival of Blimp-1-deficient CD8⁺ T cells resulted from sustained expression of CD25 and CD27 and persistent cytokine responsiveness. Silencing of Il2ra and Cd27 reduced the Blimp-1-deficient CD8⁺ T cell response. Genome-wide chromatin immunoprecipitation (ChIP) sequencing analysis identified Il2ra and Cd27 as direct targets of Blimp-1. At the peak of the antiviral response, but not earlier, Blimp-1 recruited the histone-modifying enzymes G9a and HDAC2 to the Il2ra and Cd27 loci, thereby repressing expression of these genes. In the absence of Blimp-1, Il2ra and Cd27 exhibited enhanced histone H3 acetylation and reduced histone H3K9 trimethylation. These data elucidate a central mechanism by which Blimp-1 acts as an epigenetic regulator and enhances the numbers of short-lived effector cells while suppressing the development of memory-precursor CD8⁺ T cells.
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Affiliation(s)
- Hyun Mu Shin
- Dept. of Pathology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Varun Kapoor
- Dept. of Pathology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Tianxia Guan
- Dept. of Immunobiology, Yale University School of Medicine, New Haven, Connecticut 06520, USA and Howard Hughes Medical Institute
| | - Susan M. Kaech
- Dept. of Immunobiology, Yale University School of Medicine, New Haven, Connecticut 06520, USA and Howard Hughes Medical Institute
| | - Raymond M. Welsh
- Dept. of Pathology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Leslie J. Berg
- Dept. of Pathology, University of Massachusetts Medical School, Worcester, MA 01655, USA
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73
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Ets-1 facilitates nuclear entry of NFAT proteins and their recruitment to the IL-2 promoter. Proc Natl Acad Sci U S A 2013; 110:15776-81. [PMID: 24019486 DOI: 10.1073/pnas.1304343110] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
E26 transformation-specific sequence 1 (Ets-1), the prototype of the ETS family of transcription factors, is critical for the expression of IL-2 by murine Th cells; however, its mechanism of action is still unclear. Here we show that Ets-1 is also essential for optimal production of IL-2 by primary human Th cells. Although Ets-1 negatively regulates the expression of Blimp1, a known suppressor of IL-2 expression, ablation of B lymphocyte-induced maturation protein 1 (Blimp1) does not rescue the expression of IL-2 by Ets-1-deficient Th cells. Instead, Ets-1 physically and functionally interacts with the nuclear factor of activated T-cells (NFAT) and is required for the recruitment of NFAT to the IL-2 promoter. In addition, Ets-1 is located in both the nucleus and cytoplasm of resting Th cells. Nuclear Ets-1 quickly exits the nucleus in response to calcium-dependent signals and competes with NFAT proteins for binding to protein components of noncoding RNA repressor of NFAT complex (NRON), which serves as a cytoplasmic trap for phosphorylated NFAT proteins. This nuclear exit of Ets-1 precedes rapid nuclear entry of NFAT and Ets-1 deficiency results in impaired nuclear entry, but not dephosphorylation, of NFAT proteins. Thus, Ets-1 promotes the expression of IL-2 by modulating the activity of NFAT.
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74
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Thaventhiran JED, Fearon DT, Gattinoni L. Transcriptional regulation of effector and memory CD8+ T cell fates. Curr Opin Immunol 2013; 25:321-8. [PMID: 23747000 PMCID: PMC3766771 DOI: 10.1016/j.coi.2013.05.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Revised: 05/10/2013] [Accepted: 05/15/2013] [Indexed: 12/12/2022]
Abstract
Immunity to intracellular pathogens and cancer relies on the generation of robust CD8(+) T cell effector responses as well as the establishment of immunological memory. During a primary immune response CD8(+) T cells experience diverse extracellular environmental cues and cell-cell interactions that trigger downstream transcriptional programs ultimately guiding a CD8(+) T cell to undertake either an effector or a memory cell fate. Here, we discuss our current understanding of the signaling pathways and transcriptional networks that regulate effector and memory commitment in CD8(+) T lymphocytes.
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Affiliation(s)
- James E D Thaventhiran
- Centre for Lung Infection, Papworth Hospital NHS Foundation Trust, Papworth Everard, Cambridge, United Kingdom.
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75
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Choi YS, Yang JA, Crotty S. Dynamic regulation of Bcl6 in follicular helper CD4 T (Tfh) cells. Curr Opin Immunol 2013; 25:366-72. [PMID: 23688737 DOI: 10.1016/j.coi.2013.04.003] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Revised: 04/16/2013] [Accepted: 04/19/2013] [Indexed: 12/11/2022]
Abstract
Our bodies are continuously exposed to various types of infectious pathogens. Vaccinations are the most cost effective way to protect our bodies against a variety of infectious microbes. The efficacy of most vaccines relies on protective antibody production and generation of memory B cells. These two key components develop mostly from B cells that participate in germinal center reactions. Recent efforts have highlighted the critical role of follicular helper CD4 T (Tfh) cells in the generation of germinal centers. Given that Bcl6 is a major transcription factor for Tfh differentiation, here we review recent developments in the understanding of signaling molecules that regulate Bcl6 expression in CD4 T cells, as a potential target for development of more efficacious vaccines.
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Affiliation(s)
- Youn Soo Choi
- Division of Vaccine Discovery, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037, United States
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76
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Mitchell DM, Williams MA. Disparate roles for STAT5 in primary and secondary CTL responses. THE JOURNAL OF IMMUNOLOGY 2013; 190:3390-8. [PMID: 23440411 DOI: 10.4049/jimmunol.1202674] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
IL-2 signals during the primary response to infection are essential in shaping CD8(+) T cell fate decisions. How CD8(+) T cells integrate IL-2 signals in the development of functional memory is not well understood. Because IL-2 induces potent activation of the STAT5 transcription factor, we tested the role of STAT5 in CD8(+) memory T cell differentiation and function using a model system in which STAT5 activity is inducibly abrogated upon CD8(+) T cell activation. We report that STAT5 activity is broadly important for the expansion and effector function of all effector CTL subsets. After pathogen clearance, STAT5 was required for the survival of effector phenotype memory CTLs during the contraction phase. However, despite its role in supporting full primary CD8(+) T cell expansion, and unlike IL-2, STAT5 activity is not required for the development of memory CD8(+) T cells capable of robust secondary expansion upon rechallenge. Our findings highlight differential requirements for survival signals between primary and secondary effector CTL, and demonstrate that IL-2-dependent programming of memory CD8(+) T cells capable of secondary expansion and secondary effector differentiation is largely STAT5 independent.
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Affiliation(s)
- Diana M Mitchell
- Department of Pathology, University of Utah, Salt Lake City, UT 84112, USA
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77
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Cannons JL, Lu KT, Schwartzberg PL. T follicular helper cell diversity and plasticity. Trends Immunol 2013; 34:200-7. [PMID: 23395212 DOI: 10.1016/j.it.2013.01.001] [Citation(s) in RCA: 100] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Revised: 12/21/2012] [Accepted: 01/02/2013] [Indexed: 12/23/2022]
Abstract
CD4(+) T helper (Th) cells play an instrumental role in orchestrating adaptive immune responses to invading pathogens through their ability to differentiate into specialized effector subsets. Part of this customized response requires the development of T follicular helper (Tfh) cells, which provide help to B cells for the generation of germinal centers (GCs) and long-term protective humoral responses. Although initially viewed as terminally differentiated, we now recognize that Th cell subsets, including Tfh cells, display substantial flexibility and overlap in their characteristics. In this review, we highlight advances in our understanding of Tfh cell development, cytokine production, and the potential plasticity that allows Tfh cells to possess characteristics of other effector Th cell populations.
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Affiliation(s)
- Jennifer L Cannons
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
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78
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Cervia D, Catalani E, Belardinelli MC, Perrotta C, Picchietti S, Alimenti C, Casini G, Fausto AM, Vallesi A. The protein pheromone Er-1 of the ciliate Euplotes raikovi stimulates human T-cell activity: Involvement of interleukin-2 system. Exp Cell Res 2013; 319:56-67. [DOI: 10.1016/j.yexcr.2012.10.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Revised: 10/12/2012] [Accepted: 10/13/2012] [Indexed: 12/24/2022]
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79
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Di Zazzo E, De Rosa C, Abbondanza C, Moncharmont B. PRDM Proteins: Molecular Mechanisms in Signal Transduction and Transcriptional Regulation. BIOLOGY 2013; 2:107-41. [PMID: 24832654 PMCID: PMC4009873 DOI: 10.3390/biology2010107] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 12/27/2012] [Accepted: 01/05/2013] [Indexed: 01/03/2023]
Abstract
PRDM (PRDI-BF1 and RIZ homology domain containing) protein family members are characterized by the presence of a PR domain and a variable number of Zn-finger repeats. Experimental evidence has shown that the PRDM proteins play an important role in gene expression regulation, modifying the chromatin structure either directly, through the intrinsic methyltransferase activity, or indirectly through the recruitment of chromatin remodeling complexes. PRDM proteins have a dual action: they mediate the effect induced by different cell signals like steroid hormones and control the expression of growth factors. PRDM proteins therefore have a pivotal role in the transduction of signals that control cell proliferation and differentiation and consequently neoplastic transformation. In this review, we describe pathways in which PRDM proteins are involved and the molecular mechanism of their transcriptional regulation.
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Affiliation(s)
- Erika Di Zazzo
- Department of Medicine and health sciences, University of Molise, via De Sanctis snc, Campobasso 86100, Italy.
| | - Caterina De Rosa
- Department of Biochemistry, Biophysics and general Pathology, Second University of Naples, via L. De Crecchio 7, Napoli 80138, Italy.
| | - Ciro Abbondanza
- Department of Biochemistry, Biophysics and general Pathology, Second University of Naples, via L. De Crecchio 7, Napoli 80138, Italy.
| | - Bruno Moncharmont
- Department of Medicine and health sciences, University of Molise, via De Sanctis snc, Campobasso 86100, Italy.
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80
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Seddiki N, Phetsouphanh C, Swaminathan S, Xu Y, Rao S, Li J, Sutcliffe EL, Denyer G, Finlayson R, Gelgor L, Cooper DA, Zaunders J, Kelleher AD. The microRNA-9/B-lymphocyte-induced maturation protein-1/IL-2 axis is differentially regulated in progressive HIV infection. Eur J Immunol 2012; 43:510-20. [DOI: 10.1002/eji.201242695] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Revised: 09/27/2012] [Accepted: 10/30/2012] [Indexed: 11/06/2022]
Affiliation(s)
- Nabila Seddiki
- St Vincent's Centre for Applied Medical Research; Darlinghurst NSW Australia
- National Centre in HIV Epidemiology and Clinical Research; University of NSW; Kensington NSW Australia
| | - Chansavath Phetsouphanh
- St Vincent's Centre for Applied Medical Research; Darlinghurst NSW Australia
- National Centre in HIV Epidemiology and Clinical Research; University of NSW; Kensington NSW Australia
| | - Sanjay Swaminathan
- St Vincent's Centre for Applied Medical Research; Darlinghurst NSW Australia
- National Centre in HIV Epidemiology and Clinical Research; University of NSW; Kensington NSW Australia
| | - Yin Xu
- St Vincent's Centre for Applied Medical Research; Darlinghurst NSW Australia
- National Centre in HIV Epidemiology and Clinical Research; University of NSW; Kensington NSW Australia
| | - Sudha Rao
- The John Curtin School of Medical Research; Australian National University; Canberra City ACT Australia
| | - Jasmine Li
- The John Curtin School of Medical Research; Australian National University; Canberra City ACT Australia
| | - Elissa L. Sutcliffe
- The John Curtin School of Medical Research; Australian National University; Canberra City ACT Australia
| | - Gareth Denyer
- Biochemistry, School of Molecular Bioscience; The University of Sydney; Sydney NSW Australia
| | | | - Linda Gelgor
- St Vincent's Centre for Applied Medical Research; Darlinghurst NSW Australia
- National Centre in HIV Epidemiology and Clinical Research; University of NSW; Kensington NSW Australia
| | - David A. Cooper
- St Vincent's Centre for Applied Medical Research; Darlinghurst NSW Australia
- National Centre in HIV Epidemiology and Clinical Research; University of NSW; Kensington NSW Australia
| | - John Zaunders
- St Vincent's Centre for Applied Medical Research; Darlinghurst NSW Australia
| | - Anthony D. Kelleher
- St Vincent's Centre for Applied Medical Research; Darlinghurst NSW Australia
- National Centre in HIV Epidemiology and Clinical Research; University of NSW; Kensington NSW Australia
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81
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Salehi S, Bankoti R, Benevides L, Willen J, Couse M, Silva JS, Dhall D, Meffre E, Targan S, Martins GA. B lymphocyte-induced maturation protein-1 contributes to intestinal mucosa homeostasis by limiting the number of IL-17-producing CD4+ T cells. THE JOURNAL OF IMMUNOLOGY 2012; 189:5682-93. [PMID: 23162130 DOI: 10.4049/jimmunol.1201966] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The transcription factor B lymphocyte-induced maturation protein-1 (Blimp-1) plays important roles in embryonic development and immunity. Blimp-1 is required for the differentiation of plasma cells, and mice with T cell-specific deletion of Blimp-1 (Blimp-1CKO mice) develop a fatal inflammatory response in the colon. Previous work demonstrated that lack of Blimp-1 in CD4(+) and CD8(+) T cells leads to intrinsic functional defects, but little is known about the functional role of Blimp-1 in regulating differentiation of Th cells in vivo and their contribution to the chronic intestinal inflammation observed in the Blimp1CKO mice. In this study, we show that Blimp-1 is required to restrain the production of the inflammatory cytokine IL-17 by Th cells in vivo. Blimp-1CKO mice have greater numbers of IL-17-producing TCRβ(+)CD4(+)cells in lymphoid organs and in the intestinal mucosa. The increase in IL-17-producing cells was not restored to normal levels in wild-type and Blimp-1CKO-mixed bone marrow chimeric mice, suggesting an intrinsic role for Blimp-1 in constraining the production of IL-17 in vivo. The observation that Blimp-1-deficient CD4(+) T cells are more prone to differentiate into IL-17(+)/IFN-γ(+) cells and cause severe colitis when transferred to Rag1-deficient mice provides further evidence that Blimp-1 represses IL-17 production. Analysis of Blimp-1 expression at the single cell level during Th differentiation reveals that Blimp-1 expression is induced in Th1 and Th2 but repressed by TGF-β in Th17 cells. Collectively, the results described here establish a new role for Blimp-1 in regulating IL-17 production in vivo.
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Affiliation(s)
- Soofia Salehi
- F. Widjaja Foundation Inflammatory Bowel and Immunobiology Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
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82
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Transcriptional control of effector and memory CD8+ T cell differentiation. Nat Rev Immunol 2012; 12:749-61. [PMID: 23080391 DOI: 10.1038/nri3307] [Citation(s) in RCA: 1079] [Impact Index Per Article: 89.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
During an infection, T cells can differentiate into multiple types of effector and memory T cells, which help to mediate pathogen clearance and provide long-term protective immunity. These cells can vary in their phenotype, function and location, and in their long-term fate in terms of their ability to populate the memory T cell pool. Over the past decade, the signalling pathways and transcriptional programmes that regulate the formation of heterogeneous populations of effector and memory CD8(+) T cells have started to be characterized, and this Review discusses the major advances in these areas.
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83
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Ma CS, Deenick EK, Batten M, Tangye SG. The origins, function, and regulation of T follicular helper cells. ACTA ACUST UNITED AC 2012; 209:1241-53. [PMID: 22753927 PMCID: PMC3405510 DOI: 10.1084/jem.20120994] [Citation(s) in RCA: 397] [Impact Index Per Article: 33.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The generation of high-affinity antibodies (Abs) plays a critical role in the neutralization and clearance of pathogens and subsequent host survival after natural infection with a variety of microorganisms. Most currently available vaccines rely on the induction of long-lived protective humoral immune responses by memory B cells and plasma cells, underscoring the importance of Abs in host protection. Ab responses against most antigens (Ags) require interactions between B cells and CD4(+) T helper cells, and it is now well recognized that T follicular helper cells (Tfh) specialize in providing cognate help to B cells and are fundamentally required for the generation of T cell-dependent B cell responses. Perturbations in the development and/or function of Tfh cells can manifest as immunopathologies, such as immunodeficiency, autoimmunity, and malignancy. Unraveling the cellular and molecular requirements underlying Tfh cell formation and maintenance will help to identify molecules that could be targeted for the treatment of immunological diseases that are characterized by insufficient or excessive Ab responses.
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Affiliation(s)
- Cindy S Ma
- Immunology Program, Garvan Institute of Medical Research, Darlinghurst, NSW 2010, Australia
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84
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Thiele S, Wittmann J, Jäck HM, Pahl A. miR-9 enhances IL-2 production in activated human CD4+ T cells by repressing Blimp-1. Eur J Immunol 2012; 42:2100-8. [DOI: 10.1002/eji.201142203] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
| | - Jürgen Wittmann
- Division of Molecular Immunology, Department of Internal Medicine III, Nikolaus-Fiebiger-Center; University of Erlangen-Nürnberg; Erlangen; Germany
| | - Hans-Martin Jäck
- Division of Molecular Immunology, Department of Internal Medicine III, Nikolaus-Fiebiger-Center; University of Erlangen-Nürnberg; Erlangen; Germany
| | - Andreas Pahl
- Division of Pharmacology and Toxicology, Department of Experimental and Clinical Pharmacology and Toxicology; University of Erlangen-Nürnberg; Erlangen; Germany
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85
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Activation of the Hippo pathway by CTLA-4 regulates the expression of Blimp-1 in the CD8+ T cell. Proc Natl Acad Sci U S A 2012; 109:E2223-9. [PMID: 22745171 DOI: 10.1073/pnas.1209115109] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
During the primary response, the commitment of the CD8(+) T cell to Blimp-1 expression and the terminal differentiation that Blimp-1 induces must be timed so as not to impair the process of clonal expansion. We determined whether the Hippo pathway, which links cell-cell contact to differentiation in other cell lineages, controls Blimp-1 expression. Activating the CD8(+) T cell with antigen and IL-2 causes expression of the core Hippo pathway components, including the pivotal transcriptional cofactor Yap. Contact between activated CD8(+) T cells induces Hippo pathway-mediated Yap degradation and Blimp-1 expression; a Hippo-resistant, stable form of Yap suppresses Blimp-1 expression. Cytotoxic T lymphocyte antigen 4 (CTLA-4) and CD80 comprise the receptor-ligand pair that mediates contact-dependent Hippo pathway activation. In vivo, CD8(+) T cells expressing Hippo resistant-Yap or lacking CTLA-4 have diminished expression of the senescence marker, KLRG1, during a viral infection. The CTLA-4/Hippo pathway/Blimp-1 system may couple terminal differentiation of CD8(+) T cell with the magnitude of clonal expansion.
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86
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Le Gallou S, Caron G, Delaloy C, Rossille D, Tarte K, Fest T. IL-2 requirement for human plasma cell generation: coupling differentiation and proliferation by enhancing MAPK-ERK signaling. THE JOURNAL OF IMMUNOLOGY 2012; 189:161-73. [PMID: 22634617 DOI: 10.4049/jimmunol.1200301] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Mature B cell differentiation involves a well-established transcription factor cascade. However, the temporal dynamics of cell signaling pathways regulating transcription factor network and coordinating cell proliferation and differentiation remain poorly defined. To gain insight into the molecular processes and extrinsic cues required for B cell differentiation, we set up a controlled primary culture system to differentiate human naive B cells into plasma cells (PCs). We identified T cell-produced IL-2 to be critically involved in ERK1/2-triggered PC differentiation. IL-2 drove activated B cell differentiation toward PC independently of its proliferation and survival functions. Indeed, IL-2 potentiated ERK activation and subsequent BACH2 and IRF8 downregulation, sustaining BLIMP1 expression, the master regulator for PC differentiation. Inhibition of the MAPK-ERK pathway, unlike STAT5 signaling, impaired IL-2-induced PC differentiation and rescued the expression profile of BACH2 and IRF8. These results identify IL-2 as a crucial early input in mature B cell fate commitment.
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Affiliation(s)
- Simon Le Gallou
- INSERM, Unité Mixte de Recherche 917, Rennes F-35043, France
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87
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Altin JA, Goodnow CC, Cook MC. IL-10+ CTLA-4+ Th2 inhibitory cells form in a Foxp3-independent, IL-2-dependent manner from Th2 effectors during chronic inflammation. THE JOURNAL OF IMMUNOLOGY 2012; 188:5478-88. [PMID: 22547705 DOI: 10.4049/jimmunol.1102994] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Activated Th cells influence other T cells via positive feedback circuits that expand and polarize particular types of response, but little is known about how they may also initiate negative feedback against immunopathological reactions. In this study, we demonstrate the emergence, during chronic inflammation, of GATA-3(+) Th2 inhibitory (Th2i) cells that express high levels of inhibitory proteins including IL-10, CTLA-4, and granzyme B, but do so independently of Foxp3. Whereas other Th2 effectors promote proliferation and IL-4 production by naive T cells, Th2i cells suppress proliferation and IL-4 production. We show that Th2i cells develop directly from Th2 effectors, in a manner that can be promoted by effector cytokines including IL-2, IL-10, and IL-21 ex vivo and that requires T cell activation through CD28, Card11, and IL-2 in vivo. Formation of Th2i cells may act as an inbuilt activation-induced feedback inhibition mechanism against excessive or chronic Th2 responses.
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Affiliation(s)
- John A Altin
- Department of Immunology, John Curtin School of Medical Research, Australian National University, Canberra, Australian Capital Territory 0200, Australia
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88
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Ballesteros-Tato A, León B, Graf BA, Moquin A, Adams PS, Lund FE, Randall TD. Interleukin-2 inhibits germinal center formation by limiting T follicular helper cell differentiation. Immunity 2012; 36:847-56. [PMID: 22464171 DOI: 10.1016/j.immuni.2012.02.012] [Citation(s) in RCA: 405] [Impact Index Per Article: 33.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Revised: 01/23/2012] [Accepted: 02/27/2012] [Indexed: 01/06/2023]
Abstract
T follicular helper (Tfh) cells promote T cell-dependent humoral immune responses by providing T cell help to B cells and by promoting germinal center (GC) formation and long-lived antibody responses. However, the cellular and molecular mechanisms that control Tfh cell differentiation in vivo are incompletely understood. Here we show that interleukin-2 (IL-2) administration impaired influenza-specific GCs, long-lived IgG responses, and Tfh cells. IL-2 did not directly inhibit GC formation, but instead suppressed the differentiation of Tfh cells, thereby hindering the maintenance of influenza-specific GC B cells. Our data demonstrate that IL-2 is a critical factor that regulates successful Tfh and B cell responses in vivo and regulates Tfh cell development.
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Affiliation(s)
- André Ballesteros-Tato
- Department of Medicine, Division of Allergy, Immunology and Rheumatology, University of Rochester, Rochester, NY 14642, USA
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89
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Abstract
The discovery that Bcl-6 was the transcriptional regulator of follicular helper T (Tfh) cells completed the recognition of this population as an effector subset specialized in the provision of help to B cells. Improved reagents and recent models that allow tracking of Bcl-6-expressing T cells have revealed that the decision to become a Tfh cell occurs soon after T cells are primed by dendritic cells and start dividing, before interaction with B cells. The latter are important for sustaining Bcl-6 expression. Bcl-6 coordinates a signaling program that changes expression or function of multiple guidance receptors, leading to Tfh cell localization within germinal centers. This program is not unique to CD4(+) helper T cells; FoxP3(+) regulatory T cells and NKT cells co-opt the follicular differentiation pathway to enter the follicle and become specialized follicular cells. This review will focus on recent insights into the early events that determine Tfh cell differentiation.
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90
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Abstract
Resting naive CD8(+) T cells have an astounding capacity to react to pathogens by massive expansion and differentiation into cytotoxic effector cells that migrate to all corners of the body to clear the infection. The initial interaction with antigen-presenting cells in the central lymphoid organs drives an orchestrated program of differentiation aimed at producing sufficient numbers of effectors to get the job done without resulting in clonal exhaustion. Interactions with antigen-presenting cells and other immune cells continue at the site of infection to regulate further on-site expansion and differentiation, all with the goal of protecting the host with minimal bystander tissue damage. Here we review recent advances in CD8(+) T cell recognition of antigen in lymphoid as well as in nonlymphoid tissues in the periphery, and how CD8(+) T cell expansion and differentiation are controlled in these contexts.
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Affiliation(s)
- Nu Zhang
- Department of Immunology and the Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA.
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91
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Wu X, Rosenbaum JT, Adamus G, Zhang GL, Duan J, Weinberg A, Zhang Z. Activation of OX40 prolongs and exacerbates autoimmune experimental uveitis. Invest Ophthalmol Vis Sci 2011; 52:8520-6. [PMID: 21948545 DOI: 10.1167/iovs.11-7664] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE T cells are essential for the development of autoimmune uveitis. Although the costimulatory molecule OX40 promotes T-cell function and expansion, it is unclear whether OX40 is implicated in ocular inflammation. The purpose of this study was to examine the role of OX40 in uveitis. METHODS Experimental autoimmune uveitis (EAU) was induced in B10.RIII mice by subcutaneous injection of interphotoreceptor retinoid-binding protein peptide 161-180 (IRBP(161-180)). Some mice received an intravenous administration of OX40-activating antibody on days 0 and 4 after IRBP(161-180) sensitization or on days 10 and 14 of uveitis onset. The severity of EAU was evaluated by histology at different time points. In addition, ocular inflammatory cytokine expression was determined by real time-PCR, and peripheral activated CD4(+)CD44(+)CD62L(-) T cells and IL-7Rα expression were analyzed by flow cytometry. The activated CD4(+)CD44(+) lymphocytes were rechallenged with IRBP(161-180) in vitro to assess their antigen recall response. RESULTS The authors demonstrated a marked OX40 expression by infiltrating lymphocytes in enucleated human eyes with end-stage inflammation. In addition, the administration of OX40-activating antibody prolonged and exacerbated the disease course of EAU. Moreover, activation of OX40 not only increased CD4(+)CD44(+)CD62L(-) lymphocyte number, it upregulated IL-7Rα expression in the activated T-cell population. Lastly, these cells exhibited a stronger interferon-γ response to IRBP(161-180) restimulation in vitro. CONCLUSIONS The results reveal a pathogenic role of OX40 in uveitis. Furthermore, the upregulation of IL-7R in CD4(+)CD44(+) lymphocytes suggests that the activation of OX40 promotes the generation or expansion of uveitogenic memory T cells.
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Affiliation(s)
- Xiumei Wu
- Department of Pediatrics, Oregon Health & Science University, Portland, OR 97239, USA
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92
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Pepper M, Pagán AJ, Igyártó BZ, Taylor JJ, Jenkins MK. Opposing signals from the Bcl6 transcription factor and the interleukin-2 receptor generate T helper 1 central and effector memory cells. Immunity 2011; 35:583-95. [PMID: 22018468 DOI: 10.1016/j.immuni.2011.09.009] [Citation(s) in RCA: 348] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Revised: 08/19/2011] [Accepted: 09/20/2011] [Indexed: 02/07/2023]
Abstract
Listeria monocytogenes infection generates T helper 1 (Th1) effector memory cells and CC chemokine receptor 7 (CCR7)(+) cells resembling central memory cells. We tracked endogenous L. monocytogenes-specific CD4(+) T cells to determine how these memory cells are formed. Two effector cell populations were already present several days after infection. One highly expressed the T-bet transcription factor and produced Th1 memory cells in an interleukin-2 (IL-2) receptor-dependent fashion. The other resided in the T cell areas, expressed CCR7 and CXC chemokine receptor 5 (CXCR5), and like follicular helper cells depended on the Bcl6 transcription factor and inducible costimulator ligand on B cells. The CCR7(+)CXCR5(+) effector cells produced similar memory cells that generated diverse effector cell populations in a secondary response. Thus, Th1 effector memory and follicular helper-like central memory cells are produced from early effector cell populations that diverge in response to signals from the IL-2 receptor, Bcl6, and B cells.
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Affiliation(s)
- Marion Pepper
- Department of Microbiology, Center for Immunology, University of Minnesota Medical School, Minneapolis, MN 55455, USA
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93
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Castro I, Yu A, Dee MJ, Malek TR. The basis of distinctive IL-2- and IL-15-dependent signaling: weak CD122-dependent signaling favors CD8+ T central-memory cell survival but not T effector-memory cell development. THE JOURNAL OF IMMUNOLOGY 2011; 187:5170-82. [PMID: 21984699 DOI: 10.4049/jimmunol.1003961] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Recent work suggests that IL-2 and IL-15 induce distinctive levels of signaling through common receptor subunits and that such varied signaling directs the fate of Ag-activated CD8(+) T cells. In this study, we directly examined proximal signaling by IL-2 and IL-15 and CD8(+) T cell primary and memory responses as a consequence of varied CD122-dependent signaling. Initially, IL-2 and IL-15 induced similar p-STAT5 and p-S6 activation, but these activities were only sustained by IL-2. Transient IL-15-dependent signaling is due to limited expression of IL-15Rα. To investigate the outcome of varied CD122 signaling for CD8(+) T cell responses in vivo, OT-I T cells were used from mouse models where CD122 signals were attenuated by mutations within the cytoplasmic tail of CD122 or intrinsic survival function was provided in the absence of CD122 expression by transgenic Bcl-2. In the absence of CD122 signaling, generally normal primary response occurred, but the primed CD8(+) T cells were not maintained. In marked contrast, weak CD122 signaling supported development and survival of T central-memory (T(CM)) but not T effector-memory (T(EM)) cells. Transgenic expression of Bcl-2 in CD122(-/-) CD8(+) T cells also supported the survival and persistence of T(CM) cells but did not rescue T(EM) development. These data indicate that weak CD122 signals readily support T(CM) development largely through providing survival signals. However, stronger signals, independent of Bcl-2, are required for T(EM) development. Our findings are consistent with a model whereby low, intermediate, and high CD122 signaling support T(CM) memory survival, T(EM) programming, and terminal T effector cell differentiation, respectively.
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Affiliation(s)
- Iris Castro
- Department of Microbiology and Immunology, Miller School of Medicine, University of Miami, Miami, FL 33101, USA
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94
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Cubedo E, Maurin M, Jiang X, Lossos IS, Wright KL. PRDM1/Blimp1 downregulates expression of germinal center genes LMO2 and HGAL. FEBS J 2011; 278:3065-75. [PMID: 21722313 DOI: 10.1111/j.1742-4658.2011.08227.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Human germinal center-associated lymphoma (HGAL) and LIM domain only-2 (LMO2) are proteins highly expressed in germinal center (GC) B lymphocytes. HGAL and LMO2 are also expressed in GC-derived lymphomas and distinguish biologically distinct subgroups of diffuse large B-cell lymphomas (DLBCL) associated with improved survival. However, little is known about their regulation. PRDM1/Blimp1 is a master regulator of terminal B cell differentiation and may also function as a tumor suppressor in the pathogenesis of DLBCL, where it is frequently inactivated by mutations and deletions. We now demonstrate that both HGAL and LMO2 are directly regulated by the transcription repressor PRDM1. In vivo studies demonstrate that PRDM1 directly binds to the recognition sites within the upstream promoters of both HGAL and LMO2. PRDM1 binding suppresses endogenous protein and mRNA levels of HGAL and LMO2. In addition, promoter analysis reveals that site-specific binding of PRDM1 to the promoters is capable of repressing transcriptional activity. This inhibitory effect of PRDM1 suggests that it has a key role in the loss of HGAL and LMO2 expression upon differentiation of GC B cells to plasma cells and may also contribute to absence of HGAL and LMO2 expression in post-GC lymphoid tumors.
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Affiliation(s)
- Elena Cubedo
- Department of Medicine and Molecular and Cellular Pharmacology, Sylvester Comprehensive Cancer Center, University of Miami, Miami, FL, USA
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95
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Abstract
Signaling through the interleukin-2 receptor (IL-2R) contributes to T-cell tolerance by controlling three important aspects of regulatory T-cell (Treg) biology. IL-2 is essential for thymic Treg development and regulates Treg homeostasis and suppressive function. Analogous to activated conventional T lymphocytes, IL-2R signaling also plays an important part in Treg cell growth, survival, and effector differentiation. However, Treg cells somewhat distinctively assimilate IL-2R signaling. In particular, Treg cells require essentially only IL-2-dependent receptor proximal signal transducer and activator of transcription 5 (Stat5) activation, as they contain inhibitory pathways to minimize IL-2R-dependent activation of the phosphatidyinositol 3-kinase/Akt pathway. Moreover, many IL-2R-dependent activities, including full induction of Foxp3 expression, in Treg cells require minimal and transient Stat5 activation. Thus, Treg cells are equipped to sense and then develop and function within biological niches containing minimal IL-2. These distinguishing features of IL-2R signaling provide a mechanistic underpinning for using IL-2 as an agent to selectively target Treg cells in immunotherapy to induce tolerance in autoimmune diseases and in allogeneic transplant recipients.
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Affiliation(s)
- Guoyan Cheng
- Department of Microbiology and Immunology, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
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96
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Landin AM, Frasca D, Harrison P, Scallan M, Riley RL, Blomberg BB. E47 retroviral rescue of intrinsic B-cell defects in senescent mice. Aging Cell 2011; 10:327-37. [PMID: 21241451 PMCID: PMC4710514 DOI: 10.1111/j.1474-9726.2011.00673.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
In aging, immune responses are dramatically impaired, specifically the ability to produce protective antibodies. We previously showed that with age there is a B-cell intrinsic decrease in class switch recombination (CSR) because of a decrease in activation-induced cytidine deaminase (AID). One mechanism we have demonstrated for decreased AID includes increased mRNA degradation of the transcription factor E47, critical for AID transcription. Here, we show by means of a retroviral construct containing the DsRED reporter and the 3'UTR of E47 that the 3'UTR lowers mRNA expression, and particularly in B cells from old mice. This is the first demonstration that the E47 3'UTR directly regulates its degradation. The AID mRNA was not differentially regulated by degradation in aging. Therefore, we have here further established critical components for decreased AID with age. The major aim of this study was to establish conditions for the rescue of the intrinsic defect of aged B cells with retroviral addition of the coding region of E47 in splenic B cells to restore their ability to produce optimal AID and class switch to IgG. In this study, we show that young and old primary B cells overexpressing a stable E47 mRNA up-regulate E47, AID, and CSR and improve B-cell immune responses in senescent murine B cells. Our results provide a proof of principle for the rescue of intrinsic B-cell defects and the humoral immune response in senescence.
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Affiliation(s)
- Ana M. Landin
- Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL 33101, USA
- Department of Physiology, School of Life Sciences, University College Cork, Cork, Ireland
| | - Daniela Frasca
- Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL 33101, USA
| | - Patrick Harrison
- Department of Physiology, School of Life Sciences, University College Cork, Cork, Ireland
| | - Martina Scallan
- Department of Microbiology, School of Life Sciences, University College Cork, Cork, Ireland
| | - Richard L. Riley
- Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL 33101, USA
| | - Bonnie B. Blomberg
- Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL 33101, USA
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97
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Cretney E, Xin A, Shi W, Minnich M, Masson F, Miasari M, Belz GT, Smyth GK, Busslinger M, Nutt SL, Kallies A. The transcription factors Blimp-1 and IRF4 jointly control the differentiation and function of effector regulatory T cells. Nat Immunol 2011; 12:304-11. [DOI: 10.1038/ni.2006] [Citation(s) in RCA: 443] [Impact Index Per Article: 34.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2009] [Accepted: 02/04/2011] [Indexed: 12/13/2022]
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98
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Cox MA, Harrington LE, Zajac AJ. Cytokines and the inception of CD8 T cell responses. Trends Immunol 2011; 32:180-6. [PMID: 21371940 DOI: 10.1016/j.it.2011.01.004] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Revised: 01/07/2011] [Accepted: 01/14/2011] [Indexed: 01/01/2023]
Abstract
The activation and differentiation of CD8 T cells is a necessary first step that endows these cells with the phenotypic and functional properties required for the control of intracellular pathogens. The induction of the CD8 T cell responses typically results in the development of a massive overall population of effector cells, comprising both highly functional but short-lived terminally differentiated cells, as well as a smaller subset of precursors that are predisposed to survive and transition into the memory T cell pool. In this review, we discuss how inflammatory cytokines and IL-2 bias the initial response towards short-lived effector generation, and also highlight the potential counterbalancing role of IL-21.
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Affiliation(s)
- Maureen A Cox
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294, United States
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99
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A role for Blimp1 in the transcriptional network controlling natural killer cell maturation. Blood 2011; 117:1869-79. [DOI: 10.1182/blood-2010-08-303123] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Abstract
Natural killer (NK) cells are innate lymphocytes capable of immediate effector functions including cytokine production and cytotoxicity. Compared with B and T cells, the factors that control the peripheral maturation of NK cells are poorly understood. We show that Blimp1, a transcriptional repressor required for the differentiation of plasma cells and short-lived effector T cells, is expressed by NK cells throughout their development. Interleukin 15 (IL-15) is required for the early induction of Blimp1 in NK cells, with expression increasing in the most mature subsets of mouse and human NK cells. We show that Blimp1 is required for NK-cell maturation and homeostasis and for regulating their proliferative potential. It is also essential for high granzyme B expression, but not for most cytokine production and cytotoxicity. Surprisingly, interferon regulatory factor 4 (IRF4) and B-cell lymphoma 6 (Bcl6), 2 transcription factors crucial for the regulation of Blimp1 in B and T cells, are largely dispensable for Blimp1 expression in NK cells. T-bet deficiency, however, leads to attenuated Blimp1 expression. We have identified NK cells as the first hematopoietic cell type in which the IRF4-Blimp1-Bcl6 regulatory axis is not in operation, highlighting the distinct nature of the NK-cell gene-regulatory network.
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100
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Sun J, Dodd H, Moser EK, Sharma R, Braciale TJ. CD4+ T cell help and innate-derived IL-27 induce Blimp-1-dependent IL-10 production by antiviral CTLs. Nat Immunol 2011; 12:327-34. [PMID: 21297642 PMCID: PMC3079402 DOI: 10.1038/ni.1996] [Citation(s) in RCA: 144] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2010] [Accepted: 01/11/2011] [Indexed: 01/08/2023]
Abstract
Interleukin (IL)-10 is an important regulatory cytokine that can modulate excessive immune mediated injury. Several distinct cell types have been demonstrated to produce IL-10, including most recently CD8+ cytotoxic T lymphocytes (CTLs) responding to respiratory virus infection. Here we report that CD4+ T cell help in the form of IL-2 is required for IL-10 production by CTLs, but not for the induction of CTL effector cytokines. We show that IL-2 derived from CD4+ helper T cells cooperates with innate immune cell-derived IL-27 to amplify IL-10 production by CTLs through a Blimp-1-dependent mechanism. These findings reveal a previously unrecognized pathway that coordinates signals derived from innate and helper T cells to control the production of a regulatory cytokine by CTLs during acute viral infection.
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Affiliation(s)
- Jie Sun
- The Beirne B. Carter Center for Immunology Research, The University of Virginia, Charlottesville, Virginia, USA
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