Critical Role for a Particular Immune Cell in Acute Ischemic Stroke

In mouse models of acute ischemic stroke, local expression of proinflammatory cytokines (particularly tumor-necrosis factor-α and interferon-γ) worsens damage. However, systemic administration of cytokine-blocking drugs has not been effective in limiting infarct size.

An international team postulated that a natural counterinflammatory immune response might limit damage caused by proinflammatory cytokines. Specifically, they focused on regulatory T cells (T_reg cells), a particular lymphocyte class that is important in preventing autoimmune diseases (JW Jun 12 2008). The investigators induced ischemic strokes in mice that had normal numbers of T_reg cells and mice that had depleted numbers. In the latter group, invasion by neutrophils and T cel…