title: A Novel Murine Anti-Lactoferrin Monoclonal Antibody Activates Human Polymorphonuclear Leukocytes through Membrane-Bound Lactoferrin and TLR4.
abstract: Soluble lactoferrin (LTF) is a versatile molecule that not only regulates the iron homeostasis, but also harbors direct microbicidal and immunomodulating abilities in mammalian body fluids. In contrast, little is known about the function of membrane-bound LTF (mbLTF), although its expression on human polymorphonuclear leukocytes (huPMNs) has been reported for decades. Given that LTF/anti-LTF antibodies represent a potential diagnostic/prognostic biomarker and a therapeutic target in patients with immune disorders, we wished, in the present study, to generate a novel human LTF- (huLTF-) specific mAb suitable for detailed analyses on the expression and function of mbLTF as well as for deciphering the underlying mechanisms. By using the traditional hybridoma cell fusion technology, we obtained a murine IgG1 (kappa) mAb, M-860, against huLTF. M-860 recognizes a conformational epitope of huLTF as it binds to natural, but not denatured, huLTF in ELISA. Moreover, M-860 detects mbLTF by FACS and captures endogenous huLTF in total cell lysates of huPMNs. Functionally, M-860 induces the activation of huPMNs partially through TLR4 but independently of phagocytosis. M-860 is thus a powerful tool to analyze the expression and function of human mbLTF, which will further our understanding of the roles of LTF in health and disease.
authors.affiliation: Institutes of Biology and Medical Sciences, Soochow University, Suzhou, Jiangsu 215123, China.
authors.forename: Xiao-Min
authors.initials: XM
authors.lastname: Hu
authors.affiliation: Institutes of Biology and Medical Sciences, Soochow University, Suzhou, Jiangsu 215123, China.
authors.forename: Yan-Rui
authors.initials: YR
authors.lastname: Xu
authors.affiliation: Institutes of Biology and Medical Sciences, Soochow University, Suzhou, Jiangsu 215123, China.
authors.forename: Ru
authors.initials: R
authors.lastname: Yan
authors.affiliation: Institutes of Biology and Medical Sciences, Soochow University, Suzhou, Jiangsu 215123, China.
authors.forename: Shu-Liang
authors.initials: SL
authors.lastname: Sun
authors.affiliation: Institutes of Biology and Medical Sciences, Soochow University, Suzhou, Jiangsu 215123, China.
authors.forename: Hong-Liang
authors.initials: HL
authors.lastname: Dong
authors.affiliation: Institutes of Biology and Medical Sciences, Soochow University, Suzhou, Jiangsu 215123, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.affiliation: Institutes of Biology and Medical Sciences, Soochow University, Suzhou, Jiangsu 215123, China.
authors.forename: Xiao-Ming
authors.initials: XM
authors.lastname: Gao
mesh_terms: D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology / Q000494:pharmacology; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000494:pharmacology; D001826:Body Fluids / Q000378:metabolism; D006801:Humans; D006825:Hybridomas / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D007501:Iron / Q000378:metabolism*; D007781:Lactoferrin / Q000096:biosynthesis* / Q000276:immunology / Q000378:metabolism*; D008566:Membranes / Q000378:metabolism; D051379:Mice; D009504:Neutrophils / Q000378:metabolism; D051197:Toll-Like Receptor 4 / Q000276:immunology / Q000378:metabolism*
chemical_list: D000888:Antibodies, Anti-Idiotypic; D000911:Antibodies, Monoclonal; D007074:Immunoglobulin G; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4; D007501:Iron; D007781:Lactoferrin