Neutrophilic defensins penetrate the blood-brain barrier.
Defensins are small, cationic, cyclic peptides that are abundantly stored in granules of neutrophils. Defensins non-specifically interact with membranes by forming weakly ion-selective pores. Here we demonstrate immunolocalization of defensin-secreting cells in human brain. Defensins, secreted by activated granulocytes, apparently are not prevented by the blood-brain barrier (BBB) from diffusing across cerebral endothelium to penetrate the neuropil for a considerable distance from the granulocyte. This is in contrast to other neutrophil proteins like the granule-associated enzyme elastase or the cytosolic protein MRP-14, which are strictly localized to the cytoplasm or granules of neutrophils. Thus, defensins, known chemokinetic and chemotactic molecules, display a unique distribution at BBB sites.
Schluesener
H
H
Institute of Brain Research, University of Tübingen, Germany.
Meyermann
R
R
D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation / Q000378:metabolism; D001798:Blood Proteins / Q000032:analysis / Q000378:metabolism*; D001812:Blood-Brain Barrier / Q000502:physiology*; D001921:Brain / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000378:metabolism; D040502:Calgranulin B; D023082:Defensins; D006801:Humans; D007150:Immunohistochemistry; D009504:Neutrophils / Q000737:chemistry / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation; D001798:Blood Proteins; D002135:Calcium-Binding Proteins; D040502:Calgranulin B; D023082:Defensins