The blood-brain barrier protects foreign antigens in the brain from immune attack.
To examine the role of the blood-brain barrier (BBB) in maintaining immune privilege in the brain, the BBB in the region of stably integrated mouse neural grafts implanted in neonatal rat brains was transiently disrupted by intracarotid infusion of hypertonic mannitol. This led to graft rejection and to prominent expression of major histocompatibility complex (MHC) antigens on cells adjacent to the graft. Grafts in control animals receiving an intracarotid infusion of isotonic saline showed only rare MHC expression and no increased incidence of rejection. Opening the barrier in the absence of a graft caused neither MHC expression nor cellular infiltration within the brain, suggesting that the effects of the hypertonic infusion were not produced by an indirect injury-mediated effect on the host brain. We conclude that the integrity of the blood-brain barrier is an important factor in the relative immune privilege of nonsyngeneic neural grafts.
Pollack
I F
IF
Department of Neurological Surgery, University of Pittsburgh School of Medicine, Pennsylvania 15261.
Lund
R D
RD
D000818:Animals; D000941:Antigens / Q000276:immunology*; D001812:Blood-Brain Barrier / Q000187:drug effects / Q000502:physiology*; D001921:Brain / Q000276:immunology*; D002339:Carotid Arteries; D006085:Graft Survival / Q000187:drug effects; D015395:Histocompatibility Antigens Class I / Q000032:analysis; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D006982:Hypertonic Solutions; D007150:Immunohistochemistry; D007267:Injections; D008353:Mannitol / Q000494:pharmacology; D051379:Mice; D008815:Mice, Inbred Strains; D009417:Nerve Tissue / Q000637:transplantation; D051381:Rats; D011919:Rats, Inbred Strains
D000941:Antigens; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II; D006982:Hypertonic Solutions; D008353:Mannitol