1
|
Clarkson BD, Grund EM, Standiford MM, Mirchia K, Westphal MS, Muschler LS, Howe CL. CD8+ T cells recognizing a neuron-restricted antigen injure axons in a model of multiple sclerosis. J Clin Invest 2023; 133:e162788. [PMID: 37676734 PMCID: PMC10617772 DOI: 10.1172/jci162788] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 09/06/2023] [Indexed: 09/09/2023] Open
Abstract
CD8+ T cells outnumber CD4+ cells in multiple sclerosis (MS) lesions associated with disease progression, but the pathogenic role and antigenic targets of these clonally expanded effectors are unknown. Based on evidence that demyelination is necessary but not sufficient for disease progression in MS, we previously hypothesized that CNS-infiltrating CD8+ T cells specific for neuronal antigens directly drive the axonal and neuronal injury that leads to cumulative neurologic disability in patients with MS. We now show that demyelination induced expression of MHC class I on neurons and axons and resulted in presentation of a neuron-specific neoantigen (synapsin promoter-driven chicken ovalbumin) to antigen-specific CD8+ T cells (anti-ovalbumin OT-I TCR-transgenic T cells). These neuroantigen-specific effectors surveilled the CNS in the absence of demyelination but were not retained. However, upon induction of demyelination via cuprizone intoxication, neuroantigen-specific CD8+ T cells proliferated, accumulated in the CNS, and damaged neoantigen-expressing neurons and axons. We further report elevated neuronal expression of MHC class I and β2-microglobulin transcripts and protein in gray matter and white matter tracts in tissue from patients with MS. These findings support a pathogenic role for autoreactive anti-axonal and anti-neuronal CD8+ T cells in MS progression.
Collapse
Affiliation(s)
- Benjamin D.S. Clarkson
- Department of Neurology
- Department of Laboratory Medicine and Pathology
- Center for Multiple Sclerosis and Autoimmune Neurology
| | | | | | | | | | | | - Charles L. Howe
- Department of Neurology
- Center for Multiple Sclerosis and Autoimmune Neurology
- Division of Experimental Neurology, Mayo Clinic, Rochester, Minnesota, USA
| |
Collapse
|
2
|
Lind L, Svensson A, Thörn K, Krzyzowska M, Eriksson K. CD8 + T cells in the central nervous system of mice with herpes simplex infection are highly activated and express high levels of CCR5 and CXCR3. J Neurovirol 2021; 27:145-153. [PMID: 33492607 PMCID: PMC7831625 DOI: 10.1007/s13365-020-00940-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 11/09/2020] [Accepted: 12/27/2020] [Indexed: 12/25/2022]
Abstract
Herpes simplex virus type 2 (HSV-2) is a neurotropic virus that can cause meningitis, an inflammation of the meninges in the central nervous system. T cells are key players in viral clearance, and these cells migrate from peripheral blood into the central nervous system upon infection. Several factors contribute to T cell migration, including the expression of chemokines in the inflamed tissue that attract T cells through their expression of chemokine receptors. Here we investigated CD8+ T cell profile in the spinal cord in a mouse model of herpes simplex virus type 2 neuroinflammation. Mice were infected with HSV-2 and sacrificed when showing signs of neuroinflammation. Cells and/or tissue from spinal cord, spleen, and blood were analyzed for expression of activation markers, chemokine receptors, and chemokines. High numbers of CD8+ T cells were present in the spinal cord following genital HSV-2-infection. CD8+ T cells were highly activated and HSV-2 glycoprotein B -specific effector cells, some of which showed signs of recent degranulation. They also expressed high levels of many chemokine receptors, in particular CCR2, CCR4, CCR5, and CXCR3. Investigating corresponding receptor ligands in spinal cord tissue revealed markedly increased expression of the cognate ligands CCL2, CCL5, CCL8, CCL12, and CXCL10. This study shows that during herpesvirus neuroinflammation anti-viral CD8+ T cells accumulate in the CNS. CD8+ T cells in the CNS also express chemotactic receptors cognate to the chemotactic gradients in the spinal cord. This indicates that anti-viral CD8+ T cells may migrate to infected areas in the spinal cord during herpesvirus neuroinflammation in response to chemotactic gradients.
Collapse
Affiliation(s)
- Liza Lind
- Department of Rheumatology and Inflammation Research, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Alexandra Svensson
- Department of Rheumatology and Inflammation Research, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
| | - Karolina Thörn
- Department of Rheumatology and Inflammation Research, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Malgorzata Krzyzowska
- Department of Rheumatology and Inflammation Research, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Military Institute of Hygiene and Epidemiology, Kozielska 4, 01-163, Warsaw, Poland
| | - Kristina Eriksson
- Department of Rheumatology and Inflammation Research, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| |
Collapse
|
3
|
Clarkson BDS, LaFrance-Corey RG, Kahoud RJ, Farias-Moeller R, Payne ET, Howe CL. Functional deficiency in endogenous interleukin-1 receptor antagonist in patients with febrile infection-related epilepsy syndrome. Ann Neurol 2019; 85:526-537. [PMID: 30779222 PMCID: PMC6450741 DOI: 10.1002/ana.25439] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 02/15/2019] [Accepted: 02/15/2019] [Indexed: 01/01/2023]
Abstract
OBJECTIVE We recently reported successful treatment of a child with febrile infection-related epilepsy syndrome (FIRES), a subtype of new onset refractory status epilepticus, with the recombinant interleukin-1 (IL1) receptor antagonist (IL1RA) anakinra. On this basis, we tested whether endogenous IL1RA production or function is deficient in FIRES patients. METHODS Levels of IL1β and IL1RA were measured in serum and cerebrospinal fluid (CSF). The inhibitory activity of endogenous IL1RA was assessed using a cell-based reporter assay. IL1RN gene variants were identified by sequencing. Expression levels for the secreted and intracellular isoforms of IL1RA were measured in patient and control cells by real-time polymerase chain reaction. RESULTS Levels of endogenous IL1RA and IL1β were elevated in the serum and CSF of patients with FIRES (n = 7) relative to healthy controls (n = 10). Serum from FIRES patients drove IL1R signaling activity and potentiated IL1R signaling in response to exogenous IL1β in a cell-based reporter assay. Functional assessment of endogenous IL1RA activity in 3 FIRES patients revealed attenuated inhibition of IL1R signaling. Sequencing of IL1RN in our index patient revealed multiple variants. This was accompanied by reduced expression of intracellular but not secreted isoforms of IL1RA in the patient's peripheral blood mononuclear cells. INTERPRETATION Our findings suggest that FIRES is associated with reduced expression of intracellular IL1RA isoforms and a functional deficiency in IL1RA inhibitory activity. These observations may provide insight into disease pathogenesis for FIRES and other inflammatory seizure disorders and may provide a valuable biomarker for therapeutic decision-making. Ann Neurol 2019;85:526-537.
Collapse
Affiliation(s)
- Benjamin D S Clarkson
- Department of Neurology, Mayo Clinic, Rochester, MN.,Translational Neuroimmunology Laboratory, Mayo Clinic, Rochester, MN
| | - Reghann G LaFrance-Corey
- Department of Neurology, Mayo Clinic, Rochester, MN.,Translational Neuroimmunology Laboratory, Mayo Clinic, Rochester, MN
| | - Robert J Kahoud
- Department of Neurology, Mayo Clinic, Rochester, MN.,Department of Pediatrics, Mayo Clinic, Rochester, MN
| | | | - Eric T Payne
- Department of Neurology, Mayo Clinic, Rochester, MN
| | - Charles L Howe
- Department of Neurology, Mayo Clinic, Rochester, MN.,Translational Neuroimmunology Laboratory, Mayo Clinic, Rochester, MN.,Department of Immunology, Mayo Clinic, Rochester, MN.,Center for Multiple Sclerosis and Autoimmune Neurology, Mayo Clinic, Rochester, MN
| |
Collapse
|
4
|
Wu Y, Lin YH, Shi LL, Yao ZF, Xie XM, Jiang ZS, Tang J, Hu JG, Lü HZ. Temporal kinetics of CD8 + CD28 + and CD8 + CD28 - T lymphocytes in the injured rat spinal cord. J Neurosci Res 2016; 95:1666-1676. [PMID: 27898179 DOI: 10.1002/jnr.23993] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 10/09/2016] [Accepted: 10/31/2016] [Indexed: 01/13/2023]
Abstract
This study aims to explore the temporal changes of cytotoxic CD8+ CD28+ and regulatory CD8+ CD28- T-cell subsets in the lesion microenvironment after spinal cord injury (SCI) in rats, by combination of immunohistochemistry (IHC) and flow cytometry (FCM). In the sham-opened spinal cord, few CD8+ T cells were found. After SCI, the CD8+ T cells were detected at one day post-injury (dpi), then markedly increased and were significantly higher at 3, 7, and 14 dpi compared with one dpi (p < 0.01), the highest being seven dpi. In CD8+ T cells, more than 90% were CD28+ , and there were only small part of CD28- ( < 10%). After 14 days, the infiltrated CD8+ T cells were significantly decreased, and few could be found in good condition at 21 and 28 dpi. Annexin V and propidium iodide (PI) staining showed that the percentages of apoptotic/necrotic CD8+ cells at 14 dpi and 21 dpi were significantly higher than those of the other early time-points (p < 0.01). These results indicate that CD8+ T cells could rapidly infiltrate into the injured spinal cords and survive two weeks, however, cytotoxic CD8+ T cells were dominant. Therefore, two weeks after injury might be the "time window" for treating SCI by prolonging survival times and increasing the fraction of CD8+ regulatory T-cells. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Yan Wu
- Clinical Laboratory, the First Affiliated Hospital of Bengbu Medical College, Anhui, 233004, P.R. China.,Anhui Key Laboratory of Tissue Transplantation, the First Affiliated Hospital of Bengbu Medical College, Anhui, 233004, P.R. China.,Department of Immunology, Bengbu Medical College, and Anhui Key Laboratory of Infection and Immunity at Bengbu Medical College, Anhui, 233030, P.R. China
| | - Yu-Hong Lin
- Anhui Key Laboratory of Tissue Transplantation, the First Affiliated Hospital of Bengbu Medical College, Anhui, 233004, P.R. China.,Department of Immunology, Bengbu Medical College, and Anhui Key Laboratory of Infection and Immunity at Bengbu Medical College, Anhui, 233030, P.R. China
| | - Ling-Ling Shi
- Clinical Laboratory, the First Affiliated Hospital of Bengbu Medical College, Anhui, 233004, P.R. China.,Anhui Key Laboratory of Tissue Transplantation, the First Affiliated Hospital of Bengbu Medical College, Anhui, 233004, P.R. China.,Department of Immunology, Bengbu Medical College, and Anhui Key Laboratory of Infection and Immunity at Bengbu Medical College, Anhui, 233030, P.R. China
| | - Zong-Feng Yao
- Clinical Laboratory, the First Affiliated Hospital of Bengbu Medical College, Anhui, 233004, P.R. China.,Anhui Key Laboratory of Tissue Transplantation, the First Affiliated Hospital of Bengbu Medical College, Anhui, 233004, P.R. China
| | - Xiu-Mei Xie
- Clinical Laboratory, the First Affiliated Hospital of Bengbu Medical College, Anhui, 233004, P.R. China.,Anhui Key Laboratory of Tissue Transplantation, the First Affiliated Hospital of Bengbu Medical College, Anhui, 233004, P.R. China
| | - Zheng-Song Jiang
- Anhui Key Laboratory of Tissue Transplantation, the First Affiliated Hospital of Bengbu Medical College, Anhui, 233004, P.R. China.,Department of Immunology, Bengbu Medical College, and Anhui Key Laboratory of Infection and Immunity at Bengbu Medical College, Anhui, 233030, P.R. China
| | - Jie Tang
- Clinical Laboratory, the First Affiliated Hospital of Bengbu Medical College, Anhui, 233004, P.R. China.,Department of Immunology, Bengbu Medical College, and Anhui Key Laboratory of Infection and Immunity at Bengbu Medical College, Anhui, 233030, P.R. China
| | - Jian-Guo Hu
- Clinical Laboratory, the First Affiliated Hospital of Bengbu Medical College, Anhui, 233004, P.R. China.,Anhui Key Laboratory of Tissue Transplantation, the First Affiliated Hospital of Bengbu Medical College, Anhui, 233004, P.R. China
| | - He-Zuo Lü
- Clinical Laboratory, the First Affiliated Hospital of Bengbu Medical College, Anhui, 233004, P.R. China.,Anhui Key Laboratory of Tissue Transplantation, the First Affiliated Hospital of Bengbu Medical College, Anhui, 233004, P.R. China.,Department of Immunology, Bengbu Medical College, and Anhui Key Laboratory of Infection and Immunity at Bengbu Medical College, Anhui, 233030, P.R. China
| |
Collapse
|
5
|
Suppressor of cytokine signaling 2 (SOCS2) contributes to encephalitis in a model of Herpes infection in mice. Brain Res Bull 2016; 127:164-170. [DOI: 10.1016/j.brainresbull.2016.09.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 09/09/2016] [Accepted: 09/15/2016] [Indexed: 11/22/2022]
|
6
|
Superior isolation of antigen-specific brain infiltrating T cells using manual homogenization technique. J Immunol Methods 2016; 439:23-28. [PMID: 27623324 DOI: 10.1016/j.jim.2016.09.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 09/02/2016] [Accepted: 09/06/2016] [Indexed: 11/23/2022]
Abstract
Effective recovery of activated brain infiltrating lymphocytes is critical for investigations involving murine neurological disease models. To optimize lymphocyte recovery, we compared two isolation methods using brains harvested from seven-day Theiler's murine encephalomyelitis virus (TMEV) and TMEV-OVA infected mice. Brains were processed using either a manual dounce based approach or enzymatic digestion using type IV collagenase. The resulting cell suspensions from these two techniques were transferred to a percoll gradient, centrifuged, and lymphocytes were recovered. Flow cytometric analysis of CD45hi cells showed greater percentage of CD44hiCD62lo activated lymphocytes and CD19+ B cells using the dounce method. In addition, we achieved a 3-fold greater recovery of activated virus-specific CD8 T cells specific for the immunodominant Db:VP2121-130 and engineered Kb:OVA257-264 epitopes through manual dounce homogenization approach as compared to collagenase digest. A greater percentage of viable cells was also achieved through dounce homogenization. Therefore, we conclude that manual homogenization is a superior approach to isolate activated T cells from the mouse brain.
Collapse
|
7
|
Legroux L, Pittet CL, Beauseigle D, Deblois G, Prat A, Arbour N. An optimized method to process mouse CNS to simultaneously analyze neural cells and leukocytes by flow cytometry. J Neurosci Methods 2015; 247:23-31. [DOI: 10.1016/j.jneumeth.2015.03.021] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 03/03/2015] [Accepted: 03/18/2015] [Indexed: 11/24/2022]
|
8
|
Sauer BM, Schmalstieg WF, Howe CL. Axons are injured by antigen-specific CD8(+) T cells through a MHC class I- and granzyme B-dependent mechanism. Neurobiol Dis 2013; 59:194-205. [PMID: 23899663 DOI: 10.1016/j.nbd.2013.07.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 07/02/2013] [Accepted: 07/17/2013] [Indexed: 01/19/2023] Open
Abstract
Axon injury is a central determinant of irreversible neurological deficit and disease progression in patients with multiple sclerosis (MS). CD8(+) lymphocytes (CTLs) within inflammatory demyelinated MS lesions correlate with acute axon injury and neurological deficits. The mechanisms of these correlations are unknown. We interrogated CTL-mediated axon injury using the transgenic OT-I antigen-specific CTL model system in conjunction with a chambered cortical neuron culture platform that permitted the isolated manipulation of axons independent of neuron cell bodies and glia. Interferon gamma upregulated, through a dose dependent mechanism, the axonal expression of functional major histocompatibility complex class I (MHC I) molecules competent to present immunologically-relevant antigens derived from endogenously expressed proteins. Antigen-specific CTLs formed cytotoxic immune synapses with and directly injured axons expressing antigen-loaded MHC I molecules. CTL-mediated axon injury was mechanistically dependent upon axonal MHC I antigen presentation, T cell receptor specificity and axoplasmic granzyme B activity. Despite extensive distal CTL-mediated axon injury, acute neuron cell body apoptosis was not observed. These findings present a novel model of immune-mediated axon injury and offer anti-axonal CTLs and granzyme B as targets for the therapeutic protection of axons and prevention of neurological deficits in MS patients.
Collapse
Affiliation(s)
- Brian M Sauer
- Medical Scientist Training Program, College of Medicine, Mayo Clinic, Rochester, MN 55905, USA; Department of Neurology, College of Medicine, Mayo Clinic, Rochester, MN 55905, USA; Neurobiology of Disease Training Program, College of Medicine, Mayo Clinic, Rochester, MN 55905, USA; Department of Neuroscience, College of Medicine, Mayo Clinic, Rochester, MN 55905, USA
| | | | | |
Collapse
|
9
|
Platelet-activating factor receptor is essential for the development of experimental cerebral malaria. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 180:246-55. [PMID: 22079430 DOI: 10.1016/j.ajpath.2011.09.038] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Revised: 08/31/2011] [Accepted: 09/16/2011] [Indexed: 01/01/2023]
Abstract
Cerebral malaria is a severe form of the disease that may result, in part, from an overt inflammatory response during infection by Plasmodium falciparum. The understanding of the pathogenesis of cerebral malaria may aid in the development of better therapeutic strategies for patients. The immune response in cerebral malaria involves elevation of circulating levels of cytokines and chemokines associated with leukocyte accumulation and breakdown of the blood-brain barrier in the central nervous system. Platelet-activating factor (PAF) is a mediator of inflammation shown to orchestrate inflammatory processes, including recruitment of leukocytes and increase of vascular permeability. Using mice lacking the PAF receptor (PAFR(-/-)), we investigated the relevance of this molecule for the outcome and the neuroinflammatory process triggered by P. berghei ANKA, an experimental model of cerebral malaria. In PAFR(-/-) mice, lethality was markedly delayed and brain inflammation was significantly reduced, as demonstrated by histology, accumulation, and activation of CD8(+) T cells, changes in vascular permeability and activation of caspase-3 on endothelial cells and leukocytes. Similarly, treatment with the PAFR antagonist UK-74,505 delayed lethality. Taken together, the results suggest that PAFR signaling is crucial for the development of experimental cerebral malaria. Mechanistically, PAFR activation is crucial for the cascade of events leading to changes in vascular permeability, accumulation, and activation of CD8(+) T cells and apoptosis of leukocytes and endothelial cells.
Collapse
|
10
|
Amaral DCG, Rachid MA, Vilela MC, Campos RDL, Ferreira GP, Rodrigues DH, Lacerda-Queiroz N, Miranda AS, Costa VV, Campos MA, Kroon EG, Teixeira MM, Teixeira AL. Intracerebral infection with dengue-3 virus induces meningoencephalitis and behavioral changes that precede lethality in mice. J Neuroinflammation 2011; 8:23. [PMID: 21388530 PMCID: PMC3061920 DOI: 10.1186/1742-2094-8-23] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Accepted: 03/09/2011] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Dengue, one of the most important arboviral diseases of humans, may cause severe systemic disease. Although dengue virus (DENV) has been considered to be a non-neurotropic virus, dengue infection has been associated recently with a series of neurological syndromes, including encephalitis. In this work, we evaluated behavioral changes and inflammatory parameters in C57BL/6 mice infected with non-adapted dengue virus 3 (DENV-3) genotype I. METHODS C57BL/6 mice received 4×10(3) PFU of DENV-3 by an intracranial route. We evaluated the trafficking of leukocytes in brain microvasculature using intravital microscopy, and evaluated chemokine and cytokine profiling by an ELISA test at 3 and 6 days post infection (p.i.). Furthermore, we determined myeloperoxidase activity and immune cell populations, and also performed histopathological analysis and immunostaining for the virus in brain tissue. RESULTS All animals developed signs of encephalitis and died by day 8 p.i. Motor behavior and muscle tone and strength parameters declined at day 7 p.i. We observed increased leukocyte rolling and adhesion in brain microvasculature of infected mice at days 3 and 6 p.i. The infection was followed by significant increases in IFN-γ, TNF-α, CCL2, CCL5, CXCL1, and CXCL2. Histological analysis showed evidence of meningoencephalitis and reactive gliosis. Increased numbers of neutrophils, CD4+ and CD8+ T cells were detected in brain of infected animals, notably at day 6 p.i. Cells immunoreactive for anti-NS-3 were visualized throughout the brain. CONCLUSION Intracerebral infection with non-adapted DENV-3 induces encephalitis and behavioral changes that precede lethality in mice.
Collapse
Affiliation(s)
- Debora C G Amaral
- Laboratório de Imunofarmacologia, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas (ICB), UFMG, Belo Horizonte, Brazil
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Deb C, LaFrance-Corey RG, Schmalstieg WF, Sauer BM, Wang H, German CL, Windebank AJ, Rodriguez M, Howe CL. CD8+ T cells cause disability and axon loss in a mouse model of multiple sclerosis. PLoS One 2010; 5:e12478. [PMID: 20814579 PMCID: PMC2930011 DOI: 10.1371/journal.pone.0012478] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2010] [Accepted: 08/05/2010] [Indexed: 11/18/2022] Open
Abstract
Background The objective of this study was to test the hypothesis that CD8+ T cells directly mediate motor disability and axon injury in the demyelinated central nervous system. We have previously observed that genetic deletion of the CD8+ T cell effector molecule perforin leads to preservation of motor function and preservation of spinal axons in chronically demyelinated mice. Methodology/Principal Findings To determine if CD8+ T cells are necessary and sufficient to directly injure demyelinated axons, we adoptively transferred purified perforin-competent CD8+ spinal cord-infiltrating T cells into profoundly demyelinated but functionally preserved perforin-deficient host mice. Transfer of CD8+ spinal cord-infiltrating T cells rapidly and irreversibly impaired motor function, disrupted spinal cord motor conduction, and reduced the number of medium- and large-caliber spinal axons. Likewise, immunodepletion of CD8+ T cells from chronically demyelinated wildtype mice preserved motor function and limited axon loss without altering other disease parameters. Conclusions/Significance In multiple sclerosis patients, CD8+ T cells outnumber CD4+ T cells in active lesions and the number of CD8+ T cells correlates with the extent of ongoing axon injury and functional disability. Our findings suggest that CD8+ T cells may directly injure demyelinated axons and are therefore a viable therapeutic target to protect axons and motor function in patients with multiple sclerosis.
Collapse
Affiliation(s)
- Chandra Deb
- Department of Neurology, Mayo Clinic College of Medicine, Rochester, Minnesota, United States of America
| | - Reghann G. LaFrance-Corey
- Department of Neurology, Mayo Clinic College of Medicine, Rochester, Minnesota, United States of America
| | - William F. Schmalstieg
- Department of Neurology, Mayo Clinic College of Medicine, Rochester, Minnesota, United States of America
| | - Brian M. Sauer
- Neurobiology of Disease PhD Program, Mayo Clinic College of Medicine, Rochester, Minnesota, United States of America
| | - Huan Wang
- Neurosurgery, Mayo Clinic College of Medicine, Rochester, Minnesota, United States of America
| | - Christopher L. German
- Neurobiology of Disease PhD Program, Mayo Clinic College of Medicine, Rochester, Minnesota, United States of America
| | - Anthony J. Windebank
- Department of Neurology, Mayo Clinic College of Medicine, Rochester, Minnesota, United States of America
| | - Moses Rodriguez
- Department of Neurology, Mayo Clinic College of Medicine, Rochester, Minnesota, United States of America
| | - Charles L. Howe
- Department of Neurology, Mayo Clinic College of Medicine, Rochester, Minnesota, United States of America
- Neuroscience, Mayo Clinic College of Medicine, Rochester, Minnesota, United States of America
- Neurobiology of Disease PhD Program, Mayo Clinic College of Medicine, Rochester, Minnesota, United States of America
- * E-mail:
| |
Collapse
|