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Koren T, Yifa R, Amer M, Krot M, Boshnak N, Ben-Shaanan TL, Azulay-Debby H, Zalayat I, Avishai E, Hajjo H, Schiller M, Haykin H, Korin B, Farfara D, Hakim F, Kobiler O, Rosenblum K, Rolls A. Insular cortex neurons encode and retrieve specific immune responses. Cell 2021; 184:6211. [PMID: 34890554 DOI: 10.1016/j.cell.2021.11.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Koren T, Yifa R, Amer M, Krot M, Boshnak N, Ben-Shaanan TL, Azulay-Debby H, Zalayat I, Avishai E, Hajjo H, Schiller M, Haykin H, Korin B, Farfara D, Hakim F, Kobiler O, Rosenblum K, Rolls A. Insular cortex neurons encode and retrieve specific immune responses. Cell 2021; 184:5902-5915.e17. [PMID: 34752731 DOI: 10.1016/j.cell.2021.10.013] [Citation(s) in RCA: 103] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 09/05/2021] [Accepted: 10/12/2021] [Indexed: 02/07/2023]
Abstract
Increasing evidence indicates that the brain regulates peripheral immunity, yet whether and how the brain represents the state of the immune system remains unclear. Here, we show that the brain's insular cortex (InsCtx) stores immune-related information. Using activity-dependent cell labeling in mice (FosTRAP), we captured neuronal ensembles in the InsCtx that were active under two different inflammatory conditions (dextran sulfate sodium [DSS]-induced colitis and zymosan-induced peritonitis). Chemogenetic reactivation of these neuronal ensembles was sufficient to broadly retrieve the inflammatory state under which these neurons were captured. Thus, we show that the brain can store and retrieve specific immune responses, extending the classical concept of immunological memory to neuronal representations of inflammatory information.
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Affiliation(s)
- Tamar Koren
- Department of Immunology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel; Department of Neuroscience, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Re'ee Yifa
- Department of Immunology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel; Department of Neuroscience, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Mariam Amer
- Department of Immunology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel; Department of Neuroscience, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Maria Krot
- Department of Immunology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel; Department of Neuroscience, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Nadia Boshnak
- Department of Immunology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel; Department of Neuroscience, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Tamar L Ben-Shaanan
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA, USA
| | - Hilla Azulay-Debby
- Department of Immunology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel; Department of Neuroscience, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Itay Zalayat
- Department of Immunology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel; Department of Neuroscience, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Eden Avishai
- Department of Immunology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel; Department of Neuroscience, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Haitham Hajjo
- Department of Immunology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel; Department of Neuroscience, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Maya Schiller
- Department of Immunology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel; Department of Neuroscience, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Hedva Haykin
- Department of Immunology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel; Department of Neuroscience, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Ben Korin
- Department of Research Biology, Genentech, South San Francisco, CA, USA
| | - Dorit Farfara
- Department of Immunology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel; Department of Neuroscience, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Fahed Hakim
- Pediatric Pulmonary Unit, Rambam Health Care Campus, Haifa, Israel; Cancer Research Center, EMMS Hospital, Nazareth, Israel
| | - Oren Kobiler
- Sackler School of Medicine, Tel Aviv University, Israel
| | - Kobi Rosenblum
- Sagol Department of Neurobiology, University of Haifa, Haifa, Israel; Center for Gene Manipulation in the Brain, University of Haifa, Haifa, Israel
| | - Asya Rolls
- Department of Immunology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel; Department of Neuroscience, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel.
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Schiller M, Azulay-Debby H, Boshnak N, Elyahu Y, Korin B, Ben-Shaanan TL, Koren T, Krot M, Hakim F, Rolls A. Optogenetic activation of local colonic sympathetic innervations attenuates colitis by limiting immune cell extravasation. Immunity 2021; 54:1022-1036.e8. [PMID: 33932356 PMCID: PMC8116309 DOI: 10.1016/j.immuni.2021.04.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 01/16/2021] [Accepted: 04/09/2021] [Indexed: 02/07/2023]
Abstract
The sympathetic nervous system is composed of an endocrine arm, regulating blood adrenaline and noradrenaline, and a local arm, a network of fibers innervating immune organs. Here, we investigated the impact of the local arm of the SNS in an inflammatory response in the colon. Intra-rectal insertion of an optogenetic probe in mice engineered to express channelrhodopsin-2 in tyrosine hydroxylase cells activated colonic sympathetic fibers. In contrast to systemic application of noradrenaline, local activation of sympathetic fibers attenuated experimental colitis and reduced immune cell abundance. Gene expression profiling showed decreased endothelial expression of the adhesion molecule MAdCAM-1 upon optogenetic stimulation; this decrease was sensitive to adrenergic blockers and 6-hydroxydopamine. Antibody blockade of MAdCAM-1 abrogated the optogenetic effect on immune cell extravasation into the colon and the pathology. Thus, sympathetic fibers control colonic inflammation by regulating immune cell extravasation from circulation, a mechanism likely relevant in multiple organs.
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Affiliation(s)
- Maya Schiller
- Department of Immunology, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, 3525422, Haifa, Israel; Department of Neuroscience, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, 3525422, Haifa, Israel; The Technion Integrated Cancer Center, Technion-Israel Institute of Technology, 3525422, Haifa, Israel
| | - Hilla Azulay-Debby
- Department of Immunology, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, 3525422, Haifa, Israel; Department of Neuroscience, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, 3525422, Haifa, Israel; The Technion Integrated Cancer Center, Technion-Israel Institute of Technology, 3525422, Haifa, Israel
| | - Nadia Boshnak
- Department of Immunology, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, 3525422, Haifa, Israel; Department of Neuroscience, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, 3525422, Haifa, Israel; The Technion Integrated Cancer Center, Technion-Israel Institute of Technology, 3525422, Haifa, Israel
| | - Yehezqel Elyahu
- Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, 8410501, Beer-Sheva, Israel
| | - Ben Korin
- Department of Immunology, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, 3525422, Haifa, Israel; Department of Neuroscience, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, 3525422, Haifa, Israel; The Technion Integrated Cancer Center, Technion-Israel Institute of Technology, 3525422, Haifa, Israel
| | - Tamar L Ben-Shaanan
- Department of Immunology, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, 3525422, Haifa, Israel; Department of Neuroscience, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, 3525422, Haifa, Israel; The Technion Integrated Cancer Center, Technion-Israel Institute of Technology, 3525422, Haifa, Israel
| | - Tamar Koren
- Department of Immunology, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, 3525422, Haifa, Israel; Department of Neuroscience, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, 3525422, Haifa, Israel; The Technion Integrated Cancer Center, Technion-Israel Institute of Technology, 3525422, Haifa, Israel
| | - Maria Krot
- Department of Immunology, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, 3525422, Haifa, Israel; Department of Neuroscience, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, 3525422, Haifa, Israel; The Technion Integrated Cancer Center, Technion-Israel Institute of Technology, 3525422, Haifa, Israel
| | - Fahed Hakim
- Cancer Research Center, EMMS Nazareth, 16100, Nazareth, Israel; Azrieli faculty of medicine, Bar-Ilan university, 1311502, Safad, Israel
| | - Asya Rolls
- Department of Immunology, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, 3525422, Haifa, Israel; Department of Neuroscience, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, 3525422, Haifa, Israel; The Technion Integrated Cancer Center, Technion-Israel Institute of Technology, 3525422, Haifa, Israel.
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Korin B, Avraham S, Azulay-Debby H, Farfara D, Hakim F, Rolls A. Short-term sleep deprivation in mice induces B cell migration to the brain compartment. Sleep 2020; 43:5573803. [PMID: 31553459 DOI: 10.1093/sleep/zsz222] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 07/09/2019] [Indexed: 12/18/2022] Open
Abstract
Increasing evidence highlight the involvement of immune cells in brain activity and its dysfunction. The brain's immune compartment is a dynamic ensemble of cells that can fluctuate even in naive animals. However, the dynamics and factors that can affect the composition of immune cells in the naive brain are largely unknown. Here, we examined whether acute sleep deprivation can affect the brain's immune compartment (parenchyma, meninges, and choroid plexus). Using high-dimensional mass cytometry analysis, we broadly characterized the effects of short-term sleep deprivation on the immune composition in the mouse brain. We found that after 6 h of sleep deprivation, there was a significant increase in the abundance of B cells in the brain compartment. This effect can be accounted for, at least in part, by the elevated expression of the migration-related receptor, CXCR5, on B cells and its ligand, cxcl13, in the meninges following sleep deprivation. Thus, our study reveals that short-term sleep deprivation affects the brain's immune compartment, offering a new insight into how sleep disorders can affect brain function and potentially contribute to neurodegeneration and neuroinflammation.
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Affiliation(s)
- Ben Korin
- Department of Neuroscience, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel.,Department of Immunology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Shimrit Avraham
- Department of Cell Biology and Cancer Science, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Hilla Azulay-Debby
- Department of Neuroscience, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel.,Department of Immunology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Dorit Farfara
- Department of Neuroscience, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel.,Department of Immunology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Fahed Hakim
- Pediatric Pulmonary Unit, Rambam Health Care Campus, Haifa, Israel.,Cancer Research Center, EMMS Hospital, Nazareth, Israel
| | - Asya Rolls
- Department of Neuroscience, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel.,Department of Immunology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel.,Technion Integrated Cancer Center (TICC), Technion - Israel Institute of Technology, Haifa, Israel
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Ben-Shaanan TL, Schiller M, Azulay-Debby H, Korin B, Boshnak N, Koren T, Krot M, Shakya J, Rahat MA, Hakim F, Rolls A. Modulation of anti-tumor immunity by the brain's reward system. Nat Commun 2018; 9:2723. [PMID: 30006573 PMCID: PMC6045610 DOI: 10.1038/s41467-018-05283-5] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 06/25/2018] [Indexed: 02/07/2023] Open
Abstract
Regulating immunity is a leading target for cancer therapy. Here, we show that the anti-tumor immune response can be modulated by the brain's reward system, a key circuitry in emotional processes. Activation of the reward system in tumor-bearing mice (Lewis lung carcinoma (LLC) and B16 melanoma) using chemogenetics (DREADDs), resulted in reduced tumor weight. This effect was mediated via the sympathetic nervous system (SNS), manifested by an attenuated noradrenergic input to a major immunological site, the bone marrow. Myeloid derived suppressor cells (MDSCs), which develop in the bone marrow, became less immunosuppressive following reward system activation. By depleting or adoptively transferring the MDSCs, we demonstrated that these cells are both necessary and sufficient to mediate reward system effects on tumor growth. Given the central role of the reward system in positive emotions, these findings introduce a physiological mechanism whereby the patient's psychological state can impact anti-tumor immunity and cancer progression.
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Affiliation(s)
- Tamar L Ben-Shaanan
- Department of Immunology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, 3525422, Haifa, Israel.,Department of Neuroscience, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, 3525422, Haifa, Israel.,The Technion Integrated Cancer Center, Technion - Israel Institute of Technology, 3525422, Haifa, Israel
| | - Maya Schiller
- Department of Immunology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, 3525422, Haifa, Israel.,Department of Neuroscience, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, 3525422, Haifa, Israel.,The Technion Integrated Cancer Center, Technion - Israel Institute of Technology, 3525422, Haifa, Israel
| | - Hilla Azulay-Debby
- Department of Immunology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, 3525422, Haifa, Israel.,Department of Neuroscience, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, 3525422, Haifa, Israel.,The Technion Integrated Cancer Center, Technion - Israel Institute of Technology, 3525422, Haifa, Israel
| | - Ben Korin
- Department of Immunology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, 3525422, Haifa, Israel.,Department of Neuroscience, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, 3525422, Haifa, Israel.,The Technion Integrated Cancer Center, Technion - Israel Institute of Technology, 3525422, Haifa, Israel
| | - Nadia Boshnak
- Department of Immunology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, 3525422, Haifa, Israel.,Department of Neuroscience, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, 3525422, Haifa, Israel.,The Technion Integrated Cancer Center, Technion - Israel Institute of Technology, 3525422, Haifa, Israel
| | - Tamar Koren
- Department of Immunology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, 3525422, Haifa, Israel.,Department of Neuroscience, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, 3525422, Haifa, Israel.,The Technion Integrated Cancer Center, Technion - Israel Institute of Technology, 3525422, Haifa, Israel
| | - Maria Krot
- Department of Immunology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, 3525422, Haifa, Israel.,Department of Neuroscience, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, 3525422, Haifa, Israel.,The Technion Integrated Cancer Center, Technion - Israel Institute of Technology, 3525422, Haifa, Israel
| | - Jivan Shakya
- Department of Immunology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, 3525422, Haifa, Israel.,The Immunotherapy Lab, Carmel Medical Center, 3436212, Haifa, Israel
| | - Michal A Rahat
- Department of Immunology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, 3525422, Haifa, Israel.,The Immunotherapy Lab, Carmel Medical Center, 3436212, Haifa, Israel
| | - Fahed Hakim
- Department of Immunology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, 3525422, Haifa, Israel. .,Pediatric Pulmonary Unit, Rambam Health Care Campus, 3109601, Haifa, Israel. .,Cancer Research Center, EMMS Hospital, 16100, Nazareth, Israel.
| | - Asya Rolls
- Department of Immunology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, 3525422, Haifa, Israel. .,Department of Neuroscience, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, 3525422, Haifa, Israel. .,The Technion Integrated Cancer Center, Technion - Israel Institute of Technology, 3525422, Haifa, Israel.
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Korin B, Ben-Shaanan TL, Schiller M, Dubovik T, Azulay-Debby H, Boshnak NT, Koren T, Rolls A. High-dimensional, single-cell characterization of the brain's immune compartment. Nat Neurosci 2017; 20:1300-1309. [DOI: 10.1038/nn.4610] [Citation(s) in RCA: 219] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 06/28/2017] [Indexed: 12/11/2022]
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Kladnitsky O, Rozenfeld J, Azulay-Debby H, Efrati E, Zelikovic I. The claudin-16 channel gene is transcriptionally inhibited by 1,25-dihydroxyvitamin D. Exp Physiol 2014; 100:79-94. [PMID: 25557732 DOI: 10.1113/expphysiol.2014.083394] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 10/20/2014] [Indexed: 01/12/2023]
Abstract
NEW FINDINGS What is the central question of this study? In the kidney, the bulk of the filtered Mg(2+) is reabsorbed in the thick ascending limb by paracellular conductance, mediated by the tight junction protein, claudin-16, which is encoded by the gene CLDN16. The role of 1,25-dihydroxyvitamin D [1,25(OH)2 VitD] in renal Mg(2+) handling is unclear. We aimed to explore the molecular mechanisms underlying the effect of 1,25(OH)2 VitD on claudin-16-mediated Mg(2+) transport. What is the main finding and its importance? Paracellular, claudin-16-mediated Mg(2+) transport is transcriptionally repressed by 1,25(OH)2 VitD, probably via a Ca(2+)-sensing receptor-dependent mechanism. This renal effect of 1,25(OH)2 VitD may serve as an adaptive mechanism to the 1,25(OH)2 VitD-induced enteric hyperabsorption of dietary Mg(2+). Magnesium is reabsorbed in the thick ascending limb by paracellular conductance, mediated by the CLDN16-encoded tight junction protein, claudin-16. However, the role of 1,25-dihydroxyvitamin D [1,25(OH)2 VitD] in renal Mg(2+) handling is unclear. We have shown that Mg(2+) depletion increases and 1,25(OH)2 VitD inhibits CLDN16 transcription. We have now explored further the molecular mechanisms underlying the effect of 1,25(OH)2 VitD on claudin-16-mediated Mg(2+) transport. Adult mice received parenteral 1,25(OH)2 VitD or 1,25(OH)2 VitD combined with either high-Mg(2+) or low-Mg(2+) diets. Administration of 1,25(OH)2 VitD enhanced urinary excretion of Mg(2+) and Ca(2+). The 1,25(OH)2 VitD also increased renal Ca(2+)-sensing receptor (CaSR) mRNA and decreased renal claudin-16 and claudin-19 mRNA and claudin-16 protein, but did not affect renal claudin-2 mRNA. The 1,25(OH)2 VitD reversed the expected increase in claudin-16 mRNA in Mg(2+)-depleted animals. Comparably treated HEK 293 cells showed similar changes in claudin-16 mRNA, but 1,25(OH)2 VitD did not alter mRNA of the TRPM6 Mg(2+) channel. A luciferase reporter vector containing 2.5 kb of 5'-flanking DNA sequence from human CLDN16 (hCLDN16) was transfected into HEK 293 and OK cells. The hCLDN16 promoter activity was modestly decreased by 1,25(OH)2 VitD, but markedly inhibited in HEK 293 cells coexpressing CaSR. Coexpression in OK cells of dominant-negative CaSR completely abolished inhibition of hCLDN16 promoter activity by 1,25(OH)2 VitD. The 1,25(OH)2 VitD-induced decrease in hCLDN16 promoter activity was attenuated in Mg(2+)-depleted HEK 293 cells. In conclusion, 1,25(OH)2 VitD transcriptionally inhibits claudin-16 expression by a mechanism sensitive to CaSR and Mg(2+). This renal effect of 1,25(OH)2 VitD may serve as an adaptive response to the 1,25(OH)2 VitD-induced increase in intestinal Mg(2+) absorption.
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Affiliation(s)
- Orly Kladnitsky
- Laboratory of Developmental Nephrology, Department of Physiology and Biophysics, Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
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Edry E, Azulay-Debby H, Melamed D. TOLL-like receptor ligands stimulate aberrant class switch recombination in early B cell precursors. Int Immunol 2008; 20:1575-85. [PMID: 18974086 DOI: 10.1093/intimm/dxn117] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
TOLL-like receptor (TLR) ligands stimulate class switch recombination (CSR) in mature B cells. We showed earlier that developing B cells in the bone marrow (BM) express TLR9 and are responsive to CpG DNA. Since CSR is a critical process for synthesis of effector antibodies, we studied the competence of precursor B cells to undergo CSR in response to TLR ligands, and the regulation of these cells. We found that CSR is induced throughout B lymphopoiesis in response to CpG and to LPS. However, sequencing analysis revealed aberrant joining of the switch junctions. In addition, we found that this CSR is independent of IgM expression and/or VDJ assembly and is directed to a specific isotype by cytokines. Finally, we found that activation of the switched precursor B cells is regulated by Fas. Thus, BM B cells can be activated by TLR ligands to undergo CSR and to secrete non-IgM antibodies. However, the effector potential of these cells is regulated by the Fas pathway.
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Affiliation(s)
- Efrat Edry
- Department of Immunology, Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
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Abstract
Polyclonal activation of developing B cells is an injurious process, because most of these cells are nontolerant and express autoreactive receptors. CpG DNA is a polyclonal activator of mature B cells, but its effect on developing B cells is unclear. We tested whether developing, nontolerant B cells are responsive to mitogenic stimulation by CpG DNA and whether such a stimulus can interfere with the establishment of central tolerance. We found that developing B cells express Toll-like receptor 9 and undergo a polyclonal response to CpG DNA stimulation, as revealed by proliferation and differentiation to antibody-producing cells. In vitro and ex vivo experiments revealed that stimulation with CpG DNA protects immature B cells from negative selection imposed by apoptosis and receptor editing and results in the production of autoantibodies. Finally, we found that in vivo administration of CpG DNA activates immature B cells in the bone marrow and suppresses the expression of recombination-activating genes in a mouse model of central tolerance and receptor editing. These results suggest that mitogenic signals provided by CpG DNA stimulate nontolerant immature B cells in the bone marrow and have the potential to interfere with central tolerance.
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Affiliation(s)
- Hilla Azulay-Debby
- Department of Immunology, Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
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Abstract
The random assembly of immunoglobulin (Ig) genes often creates a B cell receptor that is self-reactive, and such cells are subjected to negative selection. A primary mechanism to extinguish this self-reactivity is receptor editing, which allows continued recombination of Ig genes and replacement of the self-reactive receptor with a new innocuous receptor. Recent data now suggest that receptor editing may also promote autoimmunity in an autoimmune context. This mechanism has also been implicated in the process of B cell positive selection and maturation. Here we discuss the contribution of receptor editing in B-lymphopoiesis and its importance for B cell tolerance and autoimmunity.
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Affiliation(s)
- Hilla Azulay-Debby
- Department of Immunology, Bruce Rappaport Faculty of Medicine, Technion, Israel Institute of Technology, Haifa, Israel
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