title: Degradation of human secretory immunoglobulin A by Blastocystis.
abstract: Microbial immunoglobulin A (IgA) proteases cleave human secretory IgA, promoting the mucosal adhesion of pathogens. To investigate if the enteric protozoan Blastocystis degrades human secretory IgA, cell lysate and conditioned medium from two species were exposed to immunoglobulin A. Secretory IgA was cleaved by both cell lysate and conditioned medium with mainly cysteine proteinase activity in B. hominis B isolate and aspartic proteinase activity in B. ratii WR1 isolate. These findings suggest that Blastocystis proteases may play a role in parasite survival in vivo.
authors.affiliation: Laboratory of Molecular and Cellular Parasitology, Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597.
authors.forename: Manoj K
authors.initials: MK
authors.lastname: Puthia
authors.forename: Aparna
authors.initials: A
authors.lastname: Vaithilingam
authors.forename: Jia
authors.initials: J
authors.lastname: Lu
authors.forename: Kevin S W
authors.initials: KS
authors.lastname: Tan
mesh_terms: D000818:Animals; D016282:Aspartic Acid Endopeptidases / Q000378:metabolism; D016844:Blastocystis / Q000201:enzymology* / Q000254:growth & development / Q000472:pathogenicity; D016845:Blastocystis hominis / Q000201:enzymology* / Q000254:growth & development / Q000472:pathogenicity; D017077:Culture Media, Conditioned / Q000378:metabolism; D003546:Cysteine Endopeptidases / Q000378:metabolism; D006801:Humans; D007071:Immunoglobulin A, Secretory / Q000378:metabolism*; D051381:Rats
chemical_list: D017077:Culture Media, Conditioned; D007071:Immunoglobulin A, Secretory; D003546:Cysteine Endopeptidases; D016282:Aspartic Acid Endopeptidases