Friederike Langhauser1, Peter Kraft1, Eva Göb1, Jonas Leinweber1, Michael K Schuhmann1, Kristina Lorenz1, Mathias Gelderblom1, Stefan Bittner1, Sven G Meuth1, Heinz Wiendl1, Tim Magnus1, Christoph Kleinschnitz2. 1. From the Department of Neurology, University Clinic of Würzburg, Würzburg, Germany (F.L., P.K., E.G., J.L., M.K.S., C.K.); the Institute of Clinical Epidemiology and Biometry, Comprehensive Heart Failure Center (P.K.) and Institute of Pharmacology and Toxicology (K.L.), University of Würzburg, Würzburg, Germany; Department of Neurology, University Hospital Hamburg-Eppendorf, Hamburg, Germany (M.G., T.M.); and Department of Neurology (S.B., S.G.M., H.W.) and Institute of Physiology-Neuropathophysiology (S.G.M.), University of Münster, Münster, Germany. 2. From the Department of Neurology, University Clinic of Würzburg, Würzburg, Germany (F.L., P.K., E.G., J.L., M.K.S., C.K.); the Institute of Clinical Epidemiology and Biometry, Comprehensive Heart Failure Center (P.K.) and Institute of Pharmacology and Toxicology (K.L.), University of Würzburg, Würzburg, Germany; Department of Neurology, University Hospital Hamburg-Eppendorf, Hamburg, Germany (M.G., T.M.); and Department of Neurology (S.B., S.G.M., H.W.) and Institute of Physiology-Neuropathophysiology (S.G.M.), University of Münster, Münster, Germany. christoph.kleinschnitz@uni-wuerzburg.de.
Abstract
BACKGROUND AND PURPOSE: T lymphocytes have recently been identified as key mediators of tissue damage in ischemic stroke. The interaction between very late antigen-4 (VLA-4) and vascular adhesion molecule-1 is crucial for the transvascular egress of T lymphocytes, and inhibition of this interaction by specific antibodies is a powerful strategy to combat autoimmune neuroinflammation. However, whether pharmacological blocking of T-lymphocyte trafficking is also protective during brain ischemia is still unclear. We investigated the efficacy of a monoclonal antibody directed against VLA-4 in mouse models of ischemic stroke. METHODS: Transient and permanent middle cerebral artery occlusion was induced in male C57Bl/6 mice. Animals treated with a monoclonal anti-CD49d antibody (300 μg) 24 hours before or 3 hours after the onset of cerebral ischemia and stroke outcome, including infarct size, functional status, and mortality, were assessed between day 1 and day 7. The numbers of immune cells invading the ischemic brain were determined by immunocytochemistry and flow cytometry. RESULTS: Blocking of VLA-4 significantly reduced the invasion of T lymphocytes and neutrophils on day 5 after middle cerebral artery occlusion and inhibited the upregulation of vascular adhesion molecule-1. However, the anti-CD49d antibody failed to influence stroke outcome positively irrespective of the model or the time point investigated. CONCLUSIONS: Pharmacological inhibition of the VLA-4/vascular adhesion molecule-1 axis in experimental stroke was ineffective in our hands. Our results cast doubt on the effectiveness of anti-CD49d as a stroke treatment. Further translational studies should be performed before testing anti-VLA-4 antibodies in patients with stroke.
BACKGROUND AND PURPOSE: T lymphocytes have recently been identified as key mediators of tissue damage in ischemic stroke. The interaction between very late antigen-4 (VLA-4) and vascular adhesion molecule-1 is crucial for the transvascular egress of T lymphocytes, and inhibition of this interaction by specific antibodies is a powerful strategy to combat autoimmune neuroinflammation. However, whether pharmacological blocking of T-lymphocyte trafficking is also protective during brain ischemia is still unclear. We investigated the efficacy of a monoclonal antibody directed against VLA-4 in mouse models of ischemic stroke. METHODS: Transient and permanent middle cerebral artery occlusion was induced in male C57Bl/6 mice. Animals treated with a monoclonal anti-CD49d antibody (300 μg) 24 hours before or 3 hours after the onset of cerebral ischemia and stroke outcome, including infarct size, functional status, and mortality, were assessed between day 1 and day 7. The numbers of immune cells invading the ischemic brain were determined by immunocytochemistry and flow cytometry. RESULTS: Blocking of VLA-4 significantly reduced the invasion of T lymphocytes and neutrophils on day 5 after middle cerebral artery occlusion and inhibited the upregulation of vascular adhesion molecule-1. However, the anti-CD49d antibody failed to influence stroke outcome positively irrespective of the model or the time point investigated. CONCLUSIONS: Pharmacological inhibition of the VLA-4/vascular adhesion molecule-1 axis in experimental stroke was ineffective in our hands. Our results cast doubt on the effectiveness of anti-CD49d as a stroke treatment. Further translational studies should be performed before testing anti-VLA-4 antibodies in patients with stroke.
Authors: Eva Göb; Stefan Bittner; Nicole Bobak; Peter Kraft; Kerstin Göbel; Friederike Langhauser; György A Homola; Marc Brede; Thomas Budde; Sven G Meuth; Christoph Kleinschnitz Journal: Pflugers Arch Date: 2014-10-15 Impact factor: 3.657