title: Characterization of a low molecular weight glycolipid antigen from Cryptosporidium parvum.
abstract: Cryptosporidium parvum, an Apicomplexan parasite of the mammalian gut epithelium, causes a diarrheal illness in a wide range of hosts and is transmitted by contamination of food or water with oocyst-laden feces from an infected animal. We have identified a glycosylinositol phospholipid from the sporozoite stage of the parasite that is frequently recognized by serum antibodies from human cryptosporidiosis patients. The humoral immune response is dominated by IgG1 subclass antibodies but can also include IgA and IgM antibodies. The glycosylinositol phospholipids were purified by butanol extraction of a Triton X-114-soluble fraction followed by octyl-Sepharose column chromatography and preparative high performance TLC and were shown to include at least 5 species. By using mass spectrometry and radiolabeled neutral glycan analysis, we found that the structure of the dominant glycosylinositol phospholipid antigen contained a C18:0 lyso-acylglycerol, a C16:0-acylated inositol, and an unsubstituted mannose3-glucosamine glycan core. Other diacyl species were also identified, most notably a series of glycosylinositol phospholipids having an acyl-linked C20:0 to C28:0 lipid on the inositol ring. Less abundant species having three acyl-linked fatty acids and species with an additional 1-3 hexoses linked to the mannose core were also observed. We are currently working to determine the role that these glycolipids may play in the development of disease and in the clearance of infection.
authors.affiliation: Division of Parasitic Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30341, USA. jpriest@cdc.gov
authors.forename: Jeffrey W
authors.initials: JW
authors.lastname: Priest
authors.forename: Angela
authors.initials: A
authors.lastname: Mehlert
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Arrowood
authors.forename: Michael W
authors.initials: MW
authors.lastname: Riggs
authors.forename: Michael A J
authors.initials: MA
authors.lastname: Ferguson
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002240:Carbohydrate Sequence; D002241:Carbohydrates / Q000737:chemistry; D002855:Chromatography, Thin Layer; D003457:Cryptosporidiosis / Q000097:blood / Q000469:parasitology; D016785:Cryptosporidium parvum / Q000737:chemistry*; D003902:Detergents / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D006017:Glycolipids / Q000737:chemistry*; D006801:Humans; D007070:Immunoglobulin A / Q000737:chemistry; D007074:Immunoglobulin G / Q000737:chemistry; D007075:Immunoglobulin M / Q000737:chemistry; D007294:Inositol / Q000737:chemistry; D007477:Ions; D013058:Mass Spectrometry; D008956:Models, Chemical; D008969:Molecular Sequence Data; D017830:Octoxynol; D010743:Phospholipids / Q000378:metabolism; D011092:Polyethylene Glycols / Q000494:pharmacology; D011134:Polysaccharides / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization; D013997:Time Factors
chemical_list: D002241:Carbohydrates; D003902:Detergents; D006017:Glycolipids; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007477:Ions; D010743:Phospholipids; D011134:Polysaccharides; D011092:Polyethylene Glycols; D007294:Inositol; D017830:Octoxynol; C010615:Nonidet P-40