51
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Garner LI, Hartland A, Breuning J, Brown MH. CD6 monoclonal antibodies differ in epitope, kinetics and mechanism of action. Immunology 2018; 155:273-282. [PMID: 29772075 DOI: 10.1111/imm.12952] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 05/08/2018] [Accepted: 05/11/2018] [Indexed: 12/22/2022] Open
Abstract
CD6 is a type I T-cell surface receptor that modulates antigen receptor signalling. Its activity is regulated by binding of its membrane proximal domain (domain 3) to a cell surface ligand, CD166. CD6 monoclonal antibodies (mAbs) specific for the membrane distal domain (domain 1) perturb CD6 function including itolizumab (Alzumab™), which has reached the clinic for treatment of autoimmune disease. We characterized molecular and functional properties of several CD6 mAbs including itolizumab to define potential mechanisms of action. Epitope mapping using the crystal structure of CD6 to design mutants identified two distinct binding sites on different faces of domain 1, one containing residue R77, crucial for MT605 and T12.1 binding and the other, E63, which is crucial for itolizumab and MEM98. Analysis of binding kinetics revealed that itolizumab has a lower affinity compared with other CD6 domain 1 mAbs. We compared potential agonistic (triggering) and antagonistic (blocking) properties of CD6 mAbs in assays where the mechanism of action was well defined. CD6 domain 1 and 3 mAbs were equally effective in triggering interleukin-2 production by a cell line expressing a chimeric antigen receptor containing the extracellular region of CD6. CD6 domain 1 mAbs hindered binding of multivalent immobilized CD166 but were inferior compared with blocking by soluble CD166 or a CD6 domain 3 mAb. Characterization of CD6 mAbs provides an insight into how their functional effects in vivo may be interpreted and their therapeutic use optimized.
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Affiliation(s)
- Lee I Garner
- Sir William Dunn School of Pathology, Oxford, UK
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53
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Consuegra-Fernández M, Lin F, Fox DA, Lozano F. Clinical and experimental evidence for targeting CD6 in immune-based disorders. Autoimmun Rev 2018. [DOI: 10.1016/j.autrev.2017.12.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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54
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Han J, Enyindah-Asonye G, Lin F, Smith JD. CD6 expression has no effect on atherosclerosis in apolipoprotein E-deficient mice. BMC Res Notes 2018; 11:229. [PMID: 29615096 PMCID: PMC5883413 DOI: 10.1186/s13104-018-3327-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 03/24/2018] [Indexed: 11/10/2022] Open
Abstract
OBJECTIVE To determine if deficiency of CD6, a cell surface protein on lymphocytes that alters natural antibody production, increases atherosclerosis in ApoE-deficient mice fed a chow or a western-type diet. RESULTS We compared cholesterol levels, IgM, B1a cells, and aortic root lesion areas in ApoE-deficient vs. CD6/ApoE double deficient mice. Feeding the high-fat western type diet increased all parameters, except for B1a cell numbers decreased. Sex also had an effect on many parameters with males having increased body weights, higher high density lipoprotein cholesterol, higher B1a cells, but smaller atherosclerotic lesions if chow fed mice; however, this sex effect on atherosclerosis was absent in mice fed the western-type diet. CD6 deficiency had no effect on atherosclerosis in both male and female mice on either diet. Thus, loss of CD6 on lymphocytes did not lead to expected reductions in B1a cells and protective IgM levels, and in turn did not alter atherosclerosis in mice.
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Affiliation(s)
- Juying Han
- Department of Cellular & Molecular Medicine, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, USA
| | - Gospel Enyindah-Asonye
- Department of Immunology, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, USA
| | - Feng Lin
- Department of Immunology, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, USA.
| | - Jonathan D Smith
- Department of Cellular & Molecular Medicine, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, USA.
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55
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Zhang L, Li Y, Qiu W, Bell BA, Dvorina N, Baldwin WM, Singer N, Kern T, Caspi RR, Fox DA, Lin F. Targeting CD6 for the treatment of experimental autoimmune uveitis. J Autoimmun 2018; 90:84-93. [PMID: 29472120 DOI: 10.1016/j.jaut.2018.02.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 02/07/2018] [Accepted: 02/09/2018] [Indexed: 11/19/2022]
Abstract
OBJECTIVE CD6 is emerging as a new target for treating many pathological conditions in which T cells are integrally involved, but even the latest data from studies of CD6 gene engineered mice were still contradictory. To address this issue, we studied experimental autoimmune uveitis (EAU), a model of autoimmune uveitis, in wild-type (WT) and CD6 knockout (KO) mice. METHODS After EAU induction in WT and CD6 KO mice, we evaluated ocular inflammation and compared retinal antigen-specific T-cell responses using scanning laser ophthalmoscopy, spectral-domain optical coherence tomography, histopathology, and T cell recall assays. Uveitogenic T cells from WT and CD6 KO mice were adoptively transferred into WT naïve mice to confirm the impact of CD6 on T cells. In addition, we immunized CD6 KO mice with recombinant CD6 protein to develop mouse anti-mouse CD6 monoclonal antibodies (mAbs) in which functional antibodies exhibiting cross-reactivity with human CD6 were screened and identified for treatment studies. RESULTS In CD6 KO mice with EAU, we found significantly decreased retinal inflammation and reduced autoreactive T-cell responses, and confirmed the impaired uveitogenic capacity of T cells from these mice in an adoptive transfer experiment. Notably, one of these cross-reactive mAbs significantly ameliorated retinal inflammation in EAU induced by the adoptive transfer of uveitogenic T cells. CONCLUSIONS Together, these data strongly suggest that CD6 plays a previously unknown, but pivotal role in autoimmune uveitis, and may be a promising new treatment target for this blinding disease. In addition, the newly developed mouse anti-mouse/human CD6 mAbs could be valuable tools for testing CD6-targeted therapies in other mouse models of human diseases.
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MESH Headings
- Adoptive Transfer
- Animals
- Antibodies, Monoclonal/metabolism
- Antigens, CD/genetics
- Antigens, CD/immunology
- Antigens, CD/metabolism
- Antigens, Differentiation, T-Lymphocyte/genetics
- Antigens, Differentiation, T-Lymphocyte/immunology
- Antigens, Differentiation, T-Lymphocyte/metabolism
- Autoimmune Diseases/immunology
- Cells, Cultured
- Humans
- Inflammation/immunology
- Mice
- Mice, Inbred C57BL
- Mice, Inbred DBA
- Mice, Knockout
- Models, Animal
- Molecular Targeted Therapy
- Retina/immunology
- T-Lymphocytes/immunology
- T-Lymphocytes/transplantation
- Uveitis/immunology
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Affiliation(s)
- Lingjun Zhang
- Department of Immunology, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Yan Li
- Department of Immunology, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Wen Qiu
- Department of Immunology, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Brent A Bell
- Cole Eye Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Nina Dvorina
- Department of Immunology, Cleveland Clinic, Cleveland, OH 44195, USA
| | - William M Baldwin
- Department of Immunology, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Nora Singer
- Department of Medicine and Pediatrics, MetroHealth Medical Center, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Timothy Kern
- Department of Medicine and Ophthalmology, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Rachel R Caspi
- Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - David A Fox
- Division of Rheumatology and Clinical Autoimmunity Center of Excellence, University of Michigan, Ann Arbor, MI 48109, USA
| | - Feng Lin
- Department of Immunology, Cleveland Clinic, Cleveland, OH 44195, USA.
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56
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Pazhouhandeh M, Sahraian MA, Siadat SD, Fateh A, Vaziri F, Tabrizi F, Ajorloo F, Arshadi AK, Fatemi E, Piri Gavgani S, Mahboudi F, Rahimi Jamnani F. A systems medicine approach reveals disordered immune system and lipid metabolism in multiple sclerosis patients. Clin Exp Immunol 2018; 192:18-32. [PMID: 29194580 DOI: 10.1111/cei.13087] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 11/19/2017] [Accepted: 11/20/2017] [Indexed: 02/06/2023] Open
Abstract
Identification of autoimmune processes and introduction of new autoantigens involved in the pathogenesis of multiple sclerosis (MS) can be helpful in the design of new drugs to prevent unresponsiveness and side effects in patients. To find significant changes, we evaluated the autoantibody repertoires in newly diagnosed relapsing-remitting MS patients (NDP) and those receiving disease-modifying therapy (RP). Through a random peptide phage library, a panel of NDP- and RP-specific peptides was identified, producing two protein data sets visualized using Gephi, based on protein--protein interactions in the STRING database. The top modules of NDP and RP networks were assessed using Enrichr. Based on the findings, a set of proteins, including ATP binding cassette subfamily C member 1 (ABCC1), neurogenic locus notch homologue protein 1 (NOTCH1), hepatocyte growth factor receptor (MET), RAF proto-oncogene serine/threonine-protein kinase (RAF1) and proto-oncogene vav (VAV1) was found in NDP and was involved in over-represented terms correlated with cell-mediated immunity and cancer. In contrast, transcription factor RelB (RELB), histone acetyltransferase p300 (EP300), acetyl-CoA carboxylase 2 (ACACB), adiponectin (ADIPOQ) and phosphoenolpyruvate carboxykinase 2 mitochondrial (PCK2) had major contributions to viral infections and lipid metabolism as significant events in RP. According to these findings, further research is required to demonstrate the pathogenic roles of such proteins and autoantibodies targeting them in MS and to develop therapeutic agents which can ameliorate disease severity.
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Affiliation(s)
- M Pazhouhandeh
- Human Antibody Lab, Innovation Center, Pasteur Institute of Iran, Tehran, Iran
| | - M-A Sahraian
- MS Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - S D Siadat
- Human Antibody Lab, Innovation Center, Pasteur Institute of Iran, Tehran, Iran.,Department of Mycobacteriology and Pulmonary Research, Microbiology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - A Fateh
- Human Antibody Lab, Innovation Center, Pasteur Institute of Iran, Tehran, Iran.,Department of Mycobacteriology and Pulmonary Research, Microbiology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - F Vaziri
- Human Antibody Lab, Innovation Center, Pasteur Institute of Iran, Tehran, Iran.,Department of Mycobacteriology and Pulmonary Research, Microbiology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - F Tabrizi
- Human Antibody Lab, Innovation Center, Pasteur Institute of Iran, Tehran, Iran
| | - F Ajorloo
- Human Antibody Lab, Innovation Center, Pasteur Institute of Iran, Tehran, Iran.,Department of Biology, Faculty of Science, Islamic Azad University, East Tehran Branch, Tehran, Iran
| | - A K Arshadi
- Human Antibody Lab, Innovation Center, Pasteur Institute of Iran, Tehran, Iran
| | - E Fatemi
- Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - S Piri Gavgani
- Human Antibody Lab, Innovation Center, Pasteur Institute of Iran, Tehran, Iran
| | - F Mahboudi
- Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - F Rahimi Jamnani
- Human Antibody Lab, Innovation Center, Pasteur Institute of Iran, Tehran, Iran.,Department of Mycobacteriology and Pulmonary Research, Microbiology Research Center, Pasteur Institute of Iran, Tehran, Iran
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57
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Genetic and experimental evidence for the involvement of the CD6 lymphocyte receptor in psoriasis. Cell Mol Immunol 2017; 15:898-906. [PMID: 29225340 DOI: 10.1038/cmi.2017.119] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 09/27/2017] [Accepted: 09/28/2017] [Indexed: 12/16/2022] Open
Abstract
Psoriasis is a chronic inflammatory skin disease with a strong genetic background and is triggered by environmental factors. Available evidence supports CD6, a lymphocyte surface receptor mostly expressed by T cells, as a putative target in autoimmunity. Accordingly, a humanized anti-CD6 antibody has been assayed for the treatment of certain autoimmune disorders, including psoriasis. Here, we present novel evidence in mice and humans for a direct involvement of CD6 in psoriasis pathophysiology. First, an attenuated form of imiquimod-induced psoriasis-like skin inflammation was demonstrated in CD6-deficient mice, as deduced from lower epidermal thickness and local reduced production of pro-inflammatory cytokines, namely, interleukin-17A. Thus, isolated CD4+CD62L+ T cells from CD6-deficient mice displayed decreased in vitro T-helper type 17 polarization. Second, a statistically significant association between CD6 single-nucleotide polymorphisms (rs17824933, rs11230563 and rs12360861) and more severe forms of psoriasis was demonstrated in a cohort of 304 patients at three public hospitals from the metropolitan area of Barcelona. Taken together, these results provide new supportive evidence of the contribution of the CD6 lymphocyte receptor in psoriasis at both experimental and clinical levels.
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58
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Consuegra-Fernández M, Isamat M, Lozano F. Commentary: CD6 As a Potential Target for Treating Multiple Sclerosis. Front Immunol 2017; 8:1217. [PMID: 29033937 PMCID: PMC5626862 DOI: 10.3389/fimmu.2017.01217] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2017] [Accepted: 09/14/2017] [Indexed: 01/07/2023] Open
Affiliation(s)
- Marta Consuegra-Fernández
- Immunoreceptors of the Innate and Adaptive System, Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain
| | - Marcos Isamat
- Immunoreceptors of the Innate and Adaptive System, Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain
| | - Francisco Lozano
- Immunoreceptors of the Innate and Adaptive System, Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain.,Servei d'Immunologia, Centre de Diagnòstic Biomèdic, Hospital Clínic de Barcelona, Barcelona, Spain.,Departament de Biomedicina, Universitat de Barcelona, Barcelona, Spain
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59
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Abstract
It has been proposed that CD6, an important regulator of T cells, functions by interacting with its currently identified ligand, CD166, but studies performed during the treatment of autoimmune conditions suggest that the CD6-CD166 interaction might not account for important functions of CD6 in autoimmune diseases. The antigen recognized by mAb 3A11 has been proposed as a new CD6 ligand distinct from CD166, yet the identity of it is hitherto unknown. We have identified this CD6 ligand as CD318, a cell surface protein previously found to be present on various epithelial cells and many tumor cells. We found that, like CD6 knockout (KO) mice, CD318 KO mice are also protected in experimental autoimmune encephalomyelitis. In humans, we found that CD318 is highly expressed in synovial tissues and participates in CD6-dependent adhesion of T cells to synovial fibroblasts. In addition, soluble CD318 is chemoattractive to T cells and levels of soluble CD318 are selectively and significantly elevated in the synovial fluid from patients with rheumatoid arthritis and juvenile inflammatory arthritis. These results establish CD318 as a ligand of CD6 and a potential target for the diagnosis and treatment of autoimmune diseases such as multiple sclerosis and inflammatory arthritis.
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60
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Bughani U, Saha A, Kuriakose A, Nair R, Sadashivarao RB, Venkataraman R, Patel S, Deshchougule AT, S. SK, Montero E, Pai HV, Palanivelu DV, Melarkode R, Nair P. T cell activation and differentiation is modulated by a CD6 domain 1 antibody Itolizumab. PLoS One 2017; 12:e0180088. [PMID: 28672038 PMCID: PMC5495335 DOI: 10.1371/journal.pone.0180088] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 06/09/2017] [Indexed: 12/24/2022] Open
Abstract
CD6 is associated with T-cell modulation and is implicated in several autoimmune diseases. We previously demonstrated that Itolizumab, a CD6 domain 1 (CD6D1) specific humanized monoclonal antibody, inhibited the proliferation and cytokine production by T lymphocytes stimulated with anti-CD3 antibody or when co-stimulated with ALCAM. Aberrant IL-17 producing CD4+ helper T-cells (Th17) have been identified as pivotal for the pathogenesis of certain inflammatory autoimmune disorders, including psoriasis. Itolizumab has demonstrated efficacy in human diseases known to have an IL-17 driven pathogenesis. Here, in in vitro experiments we show that by day 3 of human PBMC activation using anti-CD3 and anti-CD28 co-stimulation in a Th17 polarizing milieu, 15-35% of CD4+ T-cells overexpress CD6 and there is an establishment of differentiated Th17 cells. Addition of Itolizumab reduces the activation and differentiation of T cells to Th17 cells and decreases production of IL-17. These effects are associated with the reduction of key transcription factors pSTAT3 and RORγT. Further, transcription analysis studies in these conditions indicate that Itolizumab suppressed T cell activation by primarily reducing cell cycle, DNA transcription and translation associated genes. To understand the mechanism of this inhibition, we evaluated the effect of this anti-human CD6D1 mAb on ALCAM-CD6 as well as TCR-mediated T cell activation. We show that Itolizumab but not its F(ab')2 fragment directly inhibits CD6 receptor hyper-phosphorylation and leads to subsequent decrease in associated ZAP70 kinase and docking protein SLP76. Since Itolizumab binds to CD6 expressed only on human and chimpanzee, we developed an antibody binding specifically to mouse CD6D1. This antibody successfully ameliorated the incidence of experimental autoimmune encephalitis in the mice model. These results position CD6 as a key molecule in sustaining the activation and differentiation of T cells and an important target for modulating autoimmune diseases.
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Affiliation(s)
- Usha Bughani
- Research and Development, Biocon Research Limited, Bangalore, India
| | - Arindam Saha
- Research and Development, Biocon Research Limited, Bangalore, India
| | - Anshu Kuriakose
- Research and Development, Biocon Research Limited, Bangalore, India
| | - Reshmi Nair
- Research and Development, Biocon Research Limited, Bangalore, India
| | | | | | - Swati Patel
- Research and Development, Biocon Research Limited, Bangalore, India
| | | | - Satish Kumar S.
- Research and Development, Biocon Research Limited, Bangalore, India
| | - Enrique Montero
- Research and Development, Biocon Research Limited, Bangalore, India
| | - Harish V. Pai
- Research and Development, Biocon Research Limited, Bangalore, India
| | | | | | - Pradip Nair
- Research and Development, Biocon Research Limited, Bangalore, India
- * E-mail:
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61
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Carrasco E, Escoda-Ferran C, Climent N, Miró-Julià C, Simões IT, Martínez-Florensa M, Sarukhan A, Carreras E, Lozano F. Human CD6 Down-Modulation following T-Cell Activation Compromises Lymphocyte Survival and Proliferative Responses. Front Immunol 2017; 8:769. [PMID: 28713387 PMCID: PMC5492662 DOI: 10.3389/fimmu.2017.00769] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 06/16/2017] [Indexed: 11/30/2022] Open
Abstract
Available evidence indicates that the CD6 lymphocyte surface receptor is involved in T-cell developmental and activation processes, by facilitating cell-to-cell adhesive contacts with antigen-presenting cells and likely modulating T-cell receptor (TCR) signaling. Here, we show that in vitro activation of human T cells under different TCR-ligation conditions leads to surface downregulation of CD6 expression. This phenomenon was (i) concomitant to increased levels of soluble CD6 (sCD6) in culture supernatants, (ii) partially reverted by protease inhibitors, (iii) not associated to CD6 mRNA down-regulation, and (iv) reversible by stimulus removal. CD6 down-modulation inversely correlated with the upregulation of CD25 in both FoxP3− (Tact) and FoxP3+ (Treg) T-cell subsets. Furthermore, ex vivo analysis of peripheral CD4+ and CD8+ T cells with activated (CD25+) or effector memory (effector memory T cell, CD45RA−CCR7−) phenotype present lower CD6 levels than their naïve or central memory (central memory T cell, CD45RA−CCR7+) counterparts. CD6lo/− T cells resulting from in vitro T-cell activation show higher apoptosis and lower proliferation levels than CD6hi T cells, supporting the relevance of CD6 in the induction of proper T-cell proliferative responses and resistance to apoptosis. Accordingly, CD6 transfectants also showed higher viability when exposed to TCR-independent apoptosis-inducing conditions in comparison with untransfected cells. Taken together, these results provide insight into the origin of sCD6 and the previously reported circulating CD6-negative T-cell subset in humans, as well as into the functional consequences of CD6 down-modulation on ongoing T-cell responses, which includes sensitization to apoptotic events and attenuation of T-cell proliferative responses.
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Affiliation(s)
- Esther Carrasco
- Grup d'Immunoreceptors del Sistema Innat i Adaptatiu, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Cristina Escoda-Ferran
- Grup d'Immunoreceptors del Sistema Innat i Adaptatiu, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Núria Climent
- IDIBAPS-AIDS Research Group, HIVACAT, Barcelona, Spain
| | - Cristina Miró-Julià
- Grup d'Immunoreceptors del Sistema Innat i Adaptatiu, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Inês T Simões
- Grup d'Immunoreceptors del Sistema Innat i Adaptatiu, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Mario Martínez-Florensa
- Grup d'Immunoreceptors del Sistema Innat i Adaptatiu, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Adelaida Sarukhan
- Institut National de la Santé et de la Recherche Médicale (INSERM), Paris, France
| | - Esther Carreras
- Grup d'Immunoreceptors del Sistema Innat i Adaptatiu, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Francisco Lozano
- Grup d'Immunoreceptors del Sistema Innat i Adaptatiu, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,Servei d'Immunologia, Hospital Clínic de Barcelona, Barcelona, Spain.,Departament de Biomedicina, Facultat de Medicina, Universitat de Barcelona, Barcelona, Spain
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62
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Consuegra-Fernández M, Martínez-Florensa M, Aranda F, de Salort J, Armiger-Borràs N, Lozano T, Casares N, Lasarte JJ, Engel P, Lozano F. Relevance of CD6-Mediated Interactions in the Regulation of Peripheral T-Cell Responses and Tolerance. Front Immunol 2017; 8:594. [PMID: 28611770 PMCID: PMC5447708 DOI: 10.3389/fimmu.2017.00594] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 05/04/2017] [Indexed: 11/13/2022] Open
Abstract
The CD6 lymphocyte receptor has been involved in the pathophysiology of different autoimmune disorders and is now considered a feasible target for their treatment. In vitro data show the relevance of CD6 in the stabilization of adhesive contacts between T-cell and antigen-presenting cells, and the modulation of T-cell receptor signals. However, the in vivo consequences of such a function are yet undisclosed due to the lack of suitable genetically modified animal models. Here, the in vitro and in vivo challenge of CD6-deficient (CD6-/-) cells with allogeneic cells was used as an approach to explore the role of CD6 in immune responses under relative physiological stimulatory conditions. Mixed lymphocyte reaction (MLR) assays showed lower proliferative responses of splenocytes from CD6-/- mice together with higher induction of regulatory T cells (Treg, CD4+CD25+FoxP3+) with low suppressive activity on T and B-cell proliferation. In line with these results, CD6-/- mice undergoing a lupus-like disorder induced by chronic graft-versus-host disease (cGvHD) showed higher serum titers of anti-double-stranded DNA and nucleosome autoantibodies. This occurred together with reduced splenomegaly, which was associated with lower in vivo bromodesoxyuridine incorporation of spleen cells and with increased percentages of spleen follicular B cells (B2, CD21+CD23hi) and Treg cells. Interestingly, functional analysis of in vivo-generated CD6-/- Treg cells exhibited defective suppressive activity. In conclusion, the data from MLR and cGvHD-induced lupus-like models in CD6-/- mice illustrate the relevance of CD6 in T (and B) cell proliferative responses and, even more importantly, Treg induction and suppressive function in the in vivo maintenance of peripheral tolerance.
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Affiliation(s)
- Marta Consuegra-Fernández
- Immunoreceptors of the Innate and Adaptive System Group, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Mario Martínez-Florensa
- Immunoreceptors of the Innate and Adaptive System Group, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Fernando Aranda
- Immunoreceptors of the Innate and Adaptive System Group, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - José de Salort
- Immunology Unit, Department of Biomedical Sciences, School of Medicine, University of Barcelona, Barcelona, Spain
| | - Noelia Armiger-Borràs
- Immunoreceptors of the Innate and Adaptive System Group, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Teresa Lozano
- Program of Immunology and Immunotherapy, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain
| | - Noelia Casares
- Program of Immunology and Immunotherapy, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain
| | - Juan José Lasarte
- Program of Immunology and Immunotherapy, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain
| | - Pablo Engel
- Immunoreceptors of the Innate and Adaptive System Group, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,Immunology Unit, Department of Biomedical Sciences, School of Medicine, University of Barcelona, Barcelona, Spain
| | - Francisco Lozano
- Immunoreceptors of the Innate and Adaptive System Group, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,Immunology Unit, Department of Biomedical Sciences, School of Medicine, University of Barcelona, Barcelona, Spain.,Immunology Department, Centre de Diagnòstic Biomèdic, Hospital Clínic of Barcelona, Barcelona, Spain
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