title: Non-opsonic phagocytosis of Trichophyton mentagrophytes arthroconidia by human neutrophils in vitro.
abstract: A non-opsonic mechanism of binding and phagocytosis by human neutrophils of Trichophyton mentagrophytes arthroconidia is described. This was in direct contrast to the complement dependency of Candida albicans phagocytosis. Both serum complement and specific antibody to T. mentagrophytes promoted maximal phagocytosis (61% and 40% of neutrophils, respectively, contained arthroconidia). Increasing the ratio of arthroconidia to neutrophils did not increase non-opsonic phagocytosis (18-26%). Phagocytosis of arthroconidia exposed to trypsin in the absence of opsonin was not affected (18%). However, proteinase and chitinase reduced the level of non-opsonic and opsonic phagocytosis to negligible levels (6.3% and 4.5%, respectively). When mannose was added to neutrophils, mannose receptors on the phagocyte membrane were partially blocked when arthroconidia were opsonised, but this did not reduce the level of non-opsonic phagocytosis. The non-opsonic mechanism proposed here may have direct relevance in skin sites poor in opsonins.
authors.affiliation: Department of Dermatology, University of Glasgow.
authors.forename: M D
authors.initials: MD
authors.lastname: Richardson
authors.forename: Y
authors.initials: Y
authors.lastname: Bell
mesh_terms: D002478:Cells, Cultured; D002688:Chitinases / Q000378:metabolism; D003165:Complement System Proteins / Q000276:immunology; D010450:Endopeptidases / Q000378:metabolism; D006801:Humans; D037181:Lectins, C-Type; D008358:Mannose / Q000378:metabolism; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D009504:Neutrophils / Q000276:immunology* / Q000378:metabolism; D009895:Opsonin Proteins / Q000276:immunology; D010587:Phagocytosis; D011956:Receptors, Cell Surface / Q000037:antagonists & inhibitors; D014249:Trichophyton / Q000276:immunology* / Q000378:metabolism; D014357:Trypsin / Q000378:metabolism
chemical_list: D037181:Lectins, C-Type; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D009895:Opsonin Proteins; D011956:Receptors, Cell Surface; D003165:Complement System Proteins; D002688:Chitinases; D010450:Endopeptidases; D014357:Trypsin; D008358:Mannose