Isolation of inflammatory cells from rat brain tissue after stroke

Cerebral stroke is still one of the main causes of death and acquired disabilities worldwide. The sole established therapeutic option is thrombolysis, which is severely limited by a narrow time window and several contraindications [1]. Cumulatively, only 5 - 13% of stroke patients benefit from clot lysis [2,3] whereas the remaining survivors have to be content with symptomatic and preventive treatments. The situation is even worse for patients suffering from hemorrhagic stroke where no causal treatment is available. Hence, numerous preclinical and clinical trials have been performed to test novel treatment options to ultimately reach more stroke patients [4].Amongst others, the modulation of inflammatory responses became a promising approach to treat cerebral ischemic and hemorrhagic stroke even days beyond the time window for thrombolysis [5]. The sterile inflammation after stroke was initially considered to be merely adverse and many pharmacological agents have been proposed to block this event [6]. However, recent evidence indicates a much more complex and partly conflicting picture [7]. Mostly by employing different knock-out mouse models, it has been emphasized that, in the early phase after stroke, T-cells act primarily detrimental [8,9] whereas B-cells seem to rather protect the injured brain [10]. The role of regulatory T-cells is still controversially discussed [11,12] and scarce knowledge is available about specific Th1, Th2 and Th17 responses [13] or the possible development of post-stroke autoimmunity and its sequelae [14].Hence it is clear that the identification and quantification of infiltrating inflammatory cells in animal models of stroke is critical for understanding the complex processes of post-stroke inflammation and for the identification of novel therapeutic targets. Multicolour flow cytometry has turned out to be the gold standard to achieve this goal since it allows the simultaneous identification and quantification of several immune cell su