Immune tolerance prevents stroke

Immune mechanisms can precipitate cerebrovascular thrombosis and hemorrhage, but the involvement of immunologic tolerance mechanisms in suppressing local vessel activation and prevention of stroke has been unclear. In September 3 Stroke, Hidetaka Takeda and colleagues at the National Institutes of Health, Bethesda, USA, show that induction of mucosal tolerance to E-selectin prevents ischaemic and hemorrhagic stroke in a rat model of stroke (Stroke 2002, 33:2156–2164).

Takeda et al. used spontaneously hypertensive rats, genetically prone to stroke and observed that nasal instillation of E-selectin — specifically expressed on activated endothelium — potently inhibited the development of ischaemic and hemorrhagic strokes in rats with untreated hypertension. In addition, they showed that intranasal exposure to E-selectin induced immunologic tolerance, which reduced endothelial activation and immune responses following intravenous lipopolysaccharide challenge.

These data suggest that immunologic tolerance may be further developed as a novel stroke prevention strategy in susceptible individuals, conclude the authors.