Shin-Young Na1, Eva Mracsko1, Arthur Liesz1, Thomas Hünig1, Roland Veltkamp2. 1. From the Department of Neurology, University Heidelberg, Germany (S.-Y.N., E.M., A.L., R.V.); Institute for Stroke and Dementia Research, Munich, Germany (A.L.); Munich Cluster for Systems Neurology (SyNergy), Munich, Germany (A.L.); Institute for Virology and Immunobiology, University Würzburg, Germany (T.H.); and Division of Brain Sciences, Imperial College, London, UK (R.V.). 2. From the Department of Neurology, University Heidelberg, Germany (S.-Y.N., E.M., A.L., R.V.); Institute for Stroke and Dementia Research, Munich, Germany (A.L.); Munich Cluster for Systems Neurology (SyNergy), Munich, Germany (A.L.); Institute for Virology and Immunobiology, University Würzburg, Germany (T.H.); and Division of Brain Sciences, Imperial College, London, UK (R.V.). Roland.Veltkamp@med.uni-heidelberg.de.
Abstract
BACKGROUND AND PURPOSE: Neuroinflammation plays an important role in ischemic brain injury. Regulatory T cells (Treg) are important endogenous immune modulators. We tested the hypothesis that Treg amplification with a CD28 superagonistic monoclonal antibody (CD28SA) reduces brain damage in murine cerebral ischemia. METHODS: Cerebral ischemia was induced by coagulation of the distal middle cerebral artery or by 60 minutes filament occlusion of the proximal middle cerebral artery in C57BL6 mice. 150 μg CD28SA was injected intraperitoneally 3 or 6 hours after ischemia onset. Outcome was determined by infarct volumetry and behavioral testing. Brain-infiltrating leukocyte subpopulations were analyzed by flow cytometry and immunohistochemistry 3 and 7 days after middle cerebral artery occlusion. RESULTS: CD28SA reduced infarct size in both models and attenuated functional deficit 7 days after stroke induction. Mice treated with CD28SA increased numbers of Treg in spleen and brain. Tregs were functionally active and migrated into the brain where they accumulated and proliferated in the peri-infarct area. More than 60% of brain infiltrating Treg produced interleukin-10 in CD28SA compared with 30% in control. CONCLUSIONS: In vivo expansion and amplification of Treg by CD28SA attenuates the inflammatory response and improves outcome after experimental stroke.
BACKGROUND AND PURPOSE: Neuroinflammation plays an important role in ischemic brain injury. Regulatory T cells (Treg) are important endogenous immune modulators. We tested the hypothesis that Treg amplification with a CD28 superagonistic monoclonal antibody (CD28SA) reduces brain damage in murine cerebral ischemia. METHODS:Cerebral ischemia was induced by coagulation of the distal middle cerebral artery or by 60 minutes filament occlusion of the proximal middle cerebral artery in C57BL6 mice. 150 μg CD28SA was injected intraperitoneally 3 or 6 hours after ischemia onset. Outcome was determined by infarct volumetry and behavioral testing. Brain-infiltrating leukocyte subpopulations were analyzed by flow cytometry and immunohistochemistry 3 and 7 days after middle cerebral artery occlusion. RESULTS:CD28SA reduced infarct size in both models and attenuated functional deficit 7 days after stroke induction. Mice treated with CD28SA increased numbers of Treg in spleen and brain. Tregs were functionally active and migrated into the brain where they accumulated and proliferated in the peri-infarct area. More than 60% of brain infiltrating Treg produced interleukin-10 in CD28SA compared with 30% in control. CONCLUSIONS: In vivo expansion and amplification of Treg by CD28SA attenuates the inflammatory response and improves outcome after experimental stroke.