title: In vivo treatment with anti-interleukin-13 antibodies significantly reduces the humoral immune response against an oral immunogen in mice.
abstract: Interleukin-13 (IL-13) is a cytokine which significantly enhances the proliferation and differentiation of B lymphocytes. We therefore evaluated its role in the formation of a humoral immune response in vivo. Upon oral immunization with the B subunit of Escherichia coli heat-labile enterotoxin (LT-B), rapid up-regulation of IL-13 mRNA expression in the mesenteric lymph nodes of LT-B intubated mice occurred. This result suggested that IL-13 might be involved in the formation of a mucosal antibody response against LT-B if this cytokine was in fact secreted. To test this possibility, the coding region for murine IL-13 was cloned into the pFLAG-1 expression vector. Recombinant murine IL-13 was purified from bacterial lysates and used as an immunogen to produce polyclonal anti-IL-13 antibodies. Groups of BALB/c mice treated in vivo with anti-IL-13 antibody 2 days before and on the day of oral immunization with LT-B had significantly reduced intestinal IgA and serum IgG and IgA anti-LT-B antibody responses when compared to mice treated with control antibody. Furthermore, groups of mice primed with LT-B and then treated with anti-IL-13 antibody prior to oral immunization with a second dose of LT-B also had significantly reduced intestinal IgA and serum IgG and IgA anti-LT-B antibody titres compared to controls. In vitro LT-B restimulation experiments using splenic mononuclear leucocytes isolated from LT-B primed mice treated with anti-IL-13 antibody demonstrated decreased expression of IL-4 and IL-13 mRNA and decreased IL-4 secretion when compared to controls. Together these results demonstrate an important role for IL-13 in the formation of a humoral immune response at mucosal surfaces.
authors.affiliation: Department of Microbiology and Immunology, Tulane University Medical Center, New Orleans, LA 70112, USA.
authors.forename: K L
authors.initials: KL
authors.lastname: Bost
authors.forename: R H
authors.initials: RH
authors.lastname: Holton
authors.forename: T K
authors.initials: TK
authors.lastname: Cain
authors.forename: J D
authors.initials: JD
authors.lastname: Clements
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis*; D001427:Bacterial Toxins / Q000008:administration & dosage / Q000276:immunology*; D001483:Base Sequence; D004768:Enterotoxins / Q000008:administration & dosage / Q000276:immunology*; D004926:Escherichia coli / Q000276:immunology*; D029968:Escherichia coli Proteins; D005260:Female; D007070:Immunoglobulin A / Q000096:biosynthesis; D007074:Immunoglobulin G / Q000096:biosynthesis; D018664:Interleukin-12 / Q000096:biosynthesis / Q000235:genetics; D018793:Interleukin-13 / Q000096:biosynthesis / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics; D011994:Recombinant Proteins / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D001427:Bacterial Toxins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D018793:Interleukin-13; D012333:RNA, Messenger; D011994:Recombinant Proteins; D018664:Interleukin-12; C027538:heat-labile enterotoxin, E coli