Friend or foe? – B cells in stroke

Stroke is one of the leading causes of mortality and morbidity worldwide. Upon cerebral ischemia, an inflammatory reaction takes place in the brain. Infiltration of different immune cell subsets as well as activation of resident microglia cells have been shown to have both beneficial and detrimental effects on stroke outcome. For a long time, research in the field of adaptive immunity after stroke has mostly focused on T lymphocytes and only recently, several publications shed light on the importance of B lymphocytes in the acute and chronic phases of ischemic stroke. In this review, we will focus on the role of B cells in the ischemic brain and describe possible antibody-dependent and antibody-independent mechanisms in the development of post-stroke cognitive deficits.