title: Characterization of IgM-binding protein: A pIgR-like molecule expressed by intestinal epithelial cells in the common carp (Cyprinus carpio L.).
abstract: The adaptive mucosal immune system seems to be an important defence mechanism for fish, but the binding of immunoglobulin M (IgM) in mucosal organs has yet to be clarified in fish. The present study was designed to search for the protein that binds IgM in the intestinal epithelium and determine its distribution in mucosa-associated lymphoid tissues of the common carp (Cyprinus carpio L.). The serum-derived carp IgM fraction was isolated by Sephadex G-200 and assessed for purity by SDS-PAGE under reducing conditions. Serum IgM was subsequently used in affinity chromatography of IgM-sepharose for isolation of a specific binding protein from the intestinal epithelium. The resultant adsorbed protein (IgM-binding protein) demonstrated a single band using SDS-PAGE, with a relative molecular mass of 43.5 kDa. These results demonstrate for the first time that IgM-sepharose can be used as affinity chromatography to purify membrane proteins that bind IgM in fish. Using immunohistochemistry, we found that the distribution of IgM-binding protein in intestinal tissues was abundant, while that of splenic leukocytes were undetectable. Our study indicates that IgM-binding protein might be involved in transportation of IgM in intestine tissues, which is distinct from the IgM receptor on splenocytes.
authors.affiliation: Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Science, Shandong Normal University, No. 88 East Wenhua Road, Jinan 250014, PR China.
authors.forename: Fumiao
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Science, Shandong Normal University, No. 88 East Wenhua Road, Jinan 250014, PR China.
authors.forename: Dezhi
authors.initials: D
authors.lastname: Liu
authors.affiliation: Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Science, Shandong Normal University, No. 88 East Wenhua Road, Jinan 250014, PR China.
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.affiliation: Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Science, Shandong Normal University, No. 88 East Wenhua Road, Jinan 250014, PR China.
authors.forename: Ting
authors.initials: T
authors.lastname: Li
authors.affiliation: Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Science, Shandong Normal University, No. 88 East Wenhua Road, Jinan 250014, PR China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Chang
authors.affiliation: Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Science, Shandong Normal University, No. 88 East Wenhua Road, Jinan 250014, PR China. Electronic address: an.liguo58@gmail.com.
authors.forename: Liguo
authors.initials: L
authors.lastname: An
authors.affiliation: Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Science, Shandong Normal University, No. 88 East Wenhua Road, Jinan 250014, PR China. Electronic address: yanggw@sdnu.edu.cn.
authors.forename: Guiwen
authors.initials: G
authors.lastname: Yang
mesh_terms: D000818:Animals; D002347:Carps / Q000276:immunology*; D002846:Chromatography, Affinity; D029941:Fish Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D018928:Immunity, Mucosal; D007075:Immunoglobulin M / Q000097:blood / Q000378:metabolism*; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000276:immunology; D008221:Lymphoid Tissue / Q000276:immunology; D008222:Lymphokines / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D008970:Molecular Weight; D011961:Receptors, Fc / Q000378:metabolism; D012685:Sepharose; D013154:Spleen / Q000276:immunology; D014018:Tissue Distribution
chemical_list: D029941:Fish Proteins; D007075:Immunoglobulin M; D008222:Lymphokines; D011961:Receptors, Fc; C035311:immunoglobulin M receptor; C013059:immunoglobulin-binding factors; D012685:Sepharose
keywords: Common carp; IgM-binding protein; Intestine; Mucosa-associated lymphoid tissue