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Analysis of Monocyte Recruitment During Inflammation by Intravital Imaging. Methods Mol Biol 2023; 2608:451-467. [PMID: 36653722 DOI: 10.1007/978-1-0716-2887-4_25] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Monocytes play essential roles in the inflammatory and anti-inflammatory processes that take place during an immune response, acting both within the vascular network and interstitially. Monocytes are activated, mobilized, and recruited in response to an inflammatory stimulus or different forms of tissue injury. The recruitment of circulating monocytes to the inflamed tissue is essential to resolving the injury.Monocyte recruitment is a multistep process that begins with a decrease in rolling velocity, is followed by adhesion to the endothelium and crawling over the luminal vessel surface, and culminates in monocyte transmigration into the surrounding tissue. Intravital microscopy is a powerful visualization tool for the study of leukocyte behavior and function, intercellular interactions, cell trafficking, and recruitment in pathological and physiological conditions. This modality is therefore widely used for the detailed analysis of the immune response to multiple insults and the molecular mechanisms underlying monocyte interactions within the vascular system in vivo. This chapter describes a protocol for the use of intravital microscopy to analyze monocyte recruitment from the blood vessel to the inflammatory site.
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McIntyre LL, Greilach SA, Othy S, Sears-Kraxberger I, Wi B, Ayala-Angulo J, Vu E, Pham Q, Silva J, Dang K, Rezk F, Steward O, Cahalan MD, Lane TE, Walsh CM. Regulatory T cells promote remyelination in the murine experimental autoimmune encephalomyelitis model of multiple sclerosis following human neural stem cell transplant. Neurobiol Dis 2020. [PMID: 32276110 DOI: 10.1016/j.nbd.2020.14868] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2023] Open
Abstract
Multiple sclerosis (MS) is a chronic, inflammatory autoimmune disease that affects the central nervous system (CNS) for which there is no cure. In MS, encephalitogenic T cells infiltrate the CNS causing demyelination and neuroinflammation; however, little is known about the role of regulatory T cells (Tregs) in CNS tissue repair. Transplantation of neural stem and progenitor cells (NSCs and NPCs) is a promising therapeutic strategy to promote repair through cell replacement, although recent findings suggest transplanted NSCs also instruct endogenous repair mechanisms. We have recently described that dampened neuroinflammation and increased remyelination is correlated with emergence of Tregs following human NPC transplantation in a murine viral model of immune-mediated demyelination. In the current study we utilized the prototypic murine autoimmune model of demyelination experimental autoimmune encephalomyelitis (EAE) to test the efficacy of hNSC transplantation. Eight-week-old, male EAE mice receiving an intraspinal transplant of hNSCs during the chronic phase of disease displayed remyelination, dampened neuroinflammation, and an increase in CNS CD4+CD25+FoxP3+ regulatory T cells (Tregs). Importantly, ablation of Tregs abrogated histopathological improvement. Tregs are essential for maintenance of T cell homeostasis and prevention of autoimmunity, and an emerging role for Tregs in maintenance of tissue homeostasis through interactions with stem and progenitor cells has recently been suggested. The data presented here provide direct evidence for collaboration between CNS Tregs and hNSCs promoting remyelination.
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Affiliation(s)
- Laura L McIntyre
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA 92697, United States of America.
| | - Scott A Greilach
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA 92697, United States of America
| | - Shivashankar Othy
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA, 92697, United States of America
| | - Ilse Sears-Kraxberger
- Reeve-Irvine Research Center, Department of Anatomy & Neurobiology, University of California, Irvine, Irvine, CA 92697, United States of America
| | - Brian Wi
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA 92697, United States of America
| | - Julio Ayala-Angulo
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA 92697, United States of America
| | - Estelle Vu
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA 92697, United States of America
| | - Quan Pham
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA 92697, United States of America
| | - Jorge Silva
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA 92697, United States of America
| | - Kody Dang
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA 92697, United States of America
| | - Fady Rezk
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA 92697, United States of America
| | - Oswald Steward
- Reeve-Irvine Research Center, Department of Anatomy & Neurobiology, University of California, Irvine, Irvine, CA 92697, United States of America
| | - Michael D Cahalan
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA, 92697, United States of America
| | - Thomas E Lane
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, 92697, United States of America
| | - Craig M Walsh
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA 92697, United States of America.
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Regulatory T cells promote remyelination in the murine experimental autoimmune encephalomyelitis model of multiple sclerosis following human neural stem cell transplant. Neurobiol Dis 2020; 140:104868. [PMID: 32276110 DOI: 10.1016/j.nbd.2020.104868] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 03/05/2020] [Accepted: 04/05/2020] [Indexed: 12/30/2022] Open
Abstract
Multiple sclerosis (MS) is a chronic, inflammatory autoimmune disease that affects the central nervous system (CNS) for which there is no cure. In MS, encephalitogenic T cells infiltrate the CNS causing demyelination and neuroinflammation; however, little is known about the role of regulatory T cells (Tregs) in CNS tissue repair. Transplantation of neural stem and progenitor cells (NSCs and NPCs) is a promising therapeutic strategy to promote repair through cell replacement, although recent findings suggest transplanted NSCs also instruct endogenous repair mechanisms. We have recently described that dampened neuroinflammation and increased remyelination is correlated with emergence of Tregs following human NPC transplantation in a murine viral model of immune-mediated demyelination. In the current study we utilized the prototypic murine autoimmune model of demyelination experimental autoimmune encephalomyelitis (EAE) to test the efficacy of hNSC transplantation. Eight-week-old, male EAE mice receiving an intraspinal transplant of hNSCs during the chronic phase of disease displayed remyelination, dampened neuroinflammation, and an increase in CNS CD4+CD25+FoxP3+ regulatory T cells (Tregs). Importantly, ablation of Tregs abrogated histopathological improvement. Tregs are essential for maintenance of T cell homeostasis and prevention of autoimmunity, and an emerging role for Tregs in maintenance of tissue homeostasis through interactions with stem and progenitor cells has recently been suggested. The data presented here provide direct evidence for collaboration between CNS Tregs and hNSCs promoting remyelination.
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Berg RW. Neuronal Population Activity in Spinal Motor Circuits: Greater Than the Sum of Its Parts. Front Neural Circuits 2017; 11:103. [PMID: 29311842 PMCID: PMC5742103 DOI: 10.3389/fncir.2017.00103] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Accepted: 11/29/2017] [Indexed: 11/27/2022] Open
Abstract
The core elements of stereotypical movements such as locomotion, scratching and breathing are generated by networks in the lower brainstem and the spinal cord. Ensemble activities in spinal motor networks had until recently been merely a black box, but with the emergence of ultra-thin Silicon multi-electrode technology it was possible to reveal the spiking activity of larger parts of the network. A series of experiments revealed unexpected features of spinal networks, such as multiple spiking regimes and lognormal firing rate distributions. The lognormality renders the widespread idea of a typical firing rate ± standard deviation an ill-suited description, and therefore these findings define a new arithmetic of motor networks. Focusing on the population activity behind motor pattern generation this review summarizes this advance and discusses its implications.
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Affiliation(s)
- Rune W. Berg
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Roberts DG, Johnsonbaugh HB, Spence RD, MacKenzie-Graham A. Optical Clearing of the Mouse Central Nervous System Using Passive CLARITY. J Vis Exp 2016. [PMID: 27404319 DOI: 10.3791/54025] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Traditionally, tissue visualization has required that the tissue of interest be serially sectioned and imaged, subjecting each tissue section to unique non-linear deformations, dramatically hampering one's ability to evaluate cellular morphology, distribution and connectivity in the central nervous system (CNS). However, optical clearing techniques are changing the way tissues are visualized. These approaches permit one to probe deeply into intact organ preparations, providing tremendous insight into the structural organization of tissues in health and disease. Techniques such as Clear Lipid-exchanged Acrylamide-hybridized Rigid Imaging-compatible Tissue-hYdrogel (CLARITY) achieve this goal by providing a matrix that binds important biomolecules while permitting light-scattering lipids to freely diffuse out. Lipid removal, followed by refractive index matching, renders the tissue transparent and readily imaged in 3 dimensions (3D). Nevertheless, the electrophoretic tissue clearing (ETC) used in the original CLARITY protocol can be challenging to implement successfully and the use of a proprietary refraction index matching solution makes it expensive to use the technique routinely. This report demonstrates the implementation of a simple and inexpensive optical clearing protocol that combines passive CLARITY for improved tissue integrity and 2,2'-thiodiethanol (TDE), a previously described refractive index matching solution.
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Affiliation(s)
- Dustin G Roberts
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles
| | - Hadley B Johnsonbaugh
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles
| | - Rory D Spence
- W.M. Keck Science Department, Claremont McKenna, Pitzer & Scripps Colleges
| | - Allan MacKenzie-Graham
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles;
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