title: Unusual surface distribution of concanavalin A reflects a cytoskeletal defect in neutrophils in Shwachman's syndrome.
abstract: Schwachman's syndrome is characterised by pancreatic insufficiency and frequent infections. Absolute polymorphonuclear leucocyte (PMN) counts are low in many patients, and the PMN show abnormal chemotaxis. It was postulated that a cytoskeletal defect might underlie these abnormalities, and a cytoskeleton-dependent function, the surface distribution and mobility of concanavalin-A receptors, was studied on neutrophils from Schwachman's syndrome patients. Approximately a third of the neutrophils in each patient showed a patched distribution of fluorescein-conjugated concanavalin A (FITC-con A) rather than the usual diffuse staining pattern. These patched neutrophils also bound larger amounts of FITC-con A than diffusely stained or capped PMN from the same patient. Antitubulin treatment did not alter the proportion of patched PMN. These findings suggest that a cytoskeletal defect underlies the patching of FITC-con A on the PMN surface. This defect could also contribute to the abnormal chemotaxis and frequent infections found in Shwachman's syndrome patients.
mesh_terms: D000293:Adolescent; D000380:Agranulocytosis / Q000097:blood*; D002462:Cell Membrane / Q000378:metabolism; D002633:Chemotaxis; D002675:Child, Preschool; D003208:Concanavalin A / Q000378:metabolism; D003599:Cytoskeleton / Q000648:ultrastructure; D004198:Disease Susceptibility; D010188:Exocrine Pancreatic Insufficiency / Q000097:blood*; D006801:Humans; D007239:Infections / Q000276:immunology*; D009503:Neutropenia / Q000097:blood*; D009504:Neutrophils / Q000648:ultrastructure*; D011952:Receptors, Concanavalin A / Q000032:analysis*; D013194:Staining and Labeling; D013577:Syndrome
chemical_list: D011952:Receptors, Concanavalin A; D003208:Concanavalin A