Granzyme B-inhibitor serpina3n induces neuroprotection in vitro and in vivo.

Yohannes Haile,Fabrizio Giuliani,Camille Olechowski,R Chris Bleackley,Bradley Kerr,Katia Carmine-Simmen

doi:10.1186/s12974-015-0376-7

Abstract

BackgroundMultiple sclerosis (MS) is an autoimmune inflammatory and neurodegenerative disease of the central nervous system (CNS). It is widely accepted that inflammatory cells play major roles in the pathogenesis of MS, possibly through the use of serine protease granzyme B (GrB) secreted from the granules of cytotoxic T cells. We have previously identified GrB as a mediator of axonal injury and neuronal death. In this study, our goal was to evaluate the effect of GrB inhibition in the human system in vitro, and in vivo in EAE using the newly isolated GrB-inhibitor serpina3n.MethodsWe used a well-established in vitro model of neuroinflammation characterized by a co-culture system between human fetal neurons and lymphocytes. In vivo, we induced EAE in 10- to 12-week-old female C57/BL6 mice and treated them intravenously with serpina3n.ResultsIn the in vitro co-culture system, pre-treatment of lymphocytes with serpina3n prevented neuronal killing and cleavage of the cytoskeletal protein alpha-tubulin, a known substrate for GrB. Moreover, in EAE, 50 μg serpina3n substantially reduced the severity of the disease. This dose was administered intravenously twice at days 7 and 20 post EAE induction. serpina3n treatment reduced axonal and neuronal injury compared to the vehicle-treated control group and maintained the integrity of myelin. Interestingly, serpina3n treatment did not seem to reduce the infiltration of immune cells (CD4+ and CD8+ T cells) into the CNS.ConclusionOur data suggest further studies on serpina3n as a potentially novel therapeutic strategy for the treatment of inflammatory-mediated neurodegenerative diseases such as MS.Electronic supplementary materialThe online version of this article (doi:10.1186/s12974-015-0376-7) contains supplementary material, which is available to authorized users.

Highlights

Multiple sclerosis (MS) is an inflammatory, neurodegenerative and demyelinating autoimmune disease of the central nervous system (CNS) and is the most common cause of non-traumatic chronic neurologic disability [1,2,3]
A known fact is that the level of lymphocyte infiltration into the CNS is well controlled under normal conditions; in inflammatory disease states, unlimited number of T-lymphocytes cross the blood brain barrier
Results serpina3n attenuates activated T cell-mediated neuronal death We have previously shown that activated T cells induce human neuronal death in vitro [11, 14] via the release of the serine protease granzyme B [14]

Summary

Introduction

Multiple sclerosis (MS) is an inflammatory, neurodegenerative and demyelinating autoimmune disease of the central nervous system (CNS) and is the most common cause of non-traumatic chronic neurologic disability [1,2,3]. A known fact is that the level of lymphocyte infiltration into the CNS is well controlled under normal conditions; in inflammatory disease states, unlimited number of T-lymphocytes cross the blood brain barrier (BBB) and enter the CNS compartment [6, 7]. These infiltrating T-lymphocytes are abundantly found within MS lesions [8, 9] and seem to be implicated in axonal pathology and neuronal death [10]. Our goal was to evaluate the effect of GrB inhibition in the human system in vitro, and in vivo in EAE using the newly isolated GrB-inhibitor serpina3n

Objectives

Methods

Results

Conclusion