title: Interleukin-4 gene expression in mercury-induced autoimmunity.
abstract: Mercuric chloride (HgCl2) induces autoimmunity in Brown Norway (BN) rats, with necrotizing vasculitis in the gut. Circumstantial evidence implicates the Th2 subset of CD4+ T lymphocytes, which produces IL-4. We developed a quantitative polymerase chain reaction (PCR) technique to quantify IL-4 gene expression. A phagemid containing rat IL-4 cDNA was modified to act as the template for a synthetic RNA construct; a known amount of synthetic RNA was added to total RNA from spleen and caecum of BN rats at various times after HgCl2, followed by reverse transcriptase PCR. IL-4 gene expression increased markedly in spleen and caecum after HgCl2. Splenic levels peaked by 10 days at approximately five-times baseline, then returned towards normal as the autoimmune response was spontaneously regulated. Caecal IL-4 expression peaked at 48 h, at which time we observed a previously unreported early phase of tissue injury, with necrotizing vasculitis qualitatively similar to that reported previously in the later phases of the model. These data support a key role for IL-4 in this experimental model of autoimmunity. The quantitative PCR technique can be modified for analysis of other cytokines, allowing further investigation of the role of T cell subsets in this model.
authors.affiliation: Department of Medicine, University of Cambridge, UK.
authors.forename: K M
authors.initials: KM
authors.lastname: Gillespie
authors.forename: F J
authors.initials: FJ
authors.lastname: Qasim
authors.forename: L M
authors.initials: LM
authors.lastname: Tibbatts
authors.forename: S
authors.initials: S
authors.lastname: Thiru
authors.forename: D B
authors.initials: DB
authors.lastname: Oliveira
authors.forename: P W
authors.initials: PW
authors.lastname: Mathieson
mesh_terms: D000818:Animals; D001327:Autoimmune Diseases / Q000139:chemically induced / Q000276:immunology* / Q000473:pathology; D001483:Base Sequence; D002432:Cecum / Q000276:immunology / Q000473:pathology; D015847:Interleukin-4 / Q000096:biosynthesis* / Q000235:genetics; D008627:Mercuric Chloride; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D051381:Rats; D011914:Rats, Inbred BN; D013154:Spleen / Q000276:immunology; D015854:Up-Regulation / Q000187:drug effects; D018366:Vasculitis, Leukocytoclastic, Cutaneous / Q000139:chemically induced / Q000276:immunology / Q000473:pathology
chemical_list: D015847:Interleukin-4; D008627:Mercuric Chloride