title: Chemokine expression in the monocytic cell line THP-1 in response to purified shiga toxin 1 and/or lipopolysaccharides.
abstract: Infections with Shiga toxin (Stx)-producing bacteria are associated with bloody diarrhea and postdiarrheal sequelae, including hemolytic uremic syndrome and central nervous system (CNS) abnormalities. Stx-induced intestinal, renal, and CNS vascular lesions may involve a localized production of proinflammatory cytokines in target organs, as tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) up-regulate Stx receptor globotriaosylceramide (Gb(3)) expression on vascular endothelial cells. However, leukocyte recruitment to injured sites may also exacerbate vascular damage. A cytokine macroarray analysis of transcripts derived from macrophage-like THP-1 cells treated with Stx1, lipopolysaccharides (LPS), or both demonstrated a consistent up-regulation of TNF-alpha, IL-1beta, and four genes encoding the chemokines interleukin-8 (IL-8), macrophage inflammatory protein-1alpha (MIP-1alpha), MIP-1beta, and growth-related oncogene beta (GRO-beta). Real-time PCR analysis verified the macroarray results. Northern blot analyses after the addition of the transcriptional inhibitor actinomycin D revealed increased IL-8 mRNA stability in THP-1 cells treated with Stx1 or Stx1 plus LPS. Finally, enzyme-linked immunosorbent assay data for Stx1- plus LPS-treated cells demonstrated a poor correlation between IL-8, MIP-1alpha, MIP-1beta, and GRO-beta mRNA levels and protein production, indicating a posttranscriptional regulatory effect. Our data suggest that in response to Stx1 and LPS, macrophages may be a source of chemokines that promote tissue damage through leukocyte recruitment and activation.
authors.affiliation: Department of Medical Microbiology and Immunology, 407 Reynolds Medical Building, Texas A&M University System Health Science Center, College Station, TX 77843-1114, USA.
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Harrison
authors.forename: Christel
authors.initials: C
authors.lastname: van den Hoogen
authors.forename: Wilhelmina C E
authors.initials: WC
authors.lastname: van Haaften
authors.forename: Vernon L
authors.initials: VL
authors.lastname: Tesh
mesh_terms: D045744:Cell Line, Tumor; D054405:Chemokine CCL3; D054407:Chemokine CCL4; D018925:Chemokines / Q000235:genetics*; D016207:Cytokines / Q000235:genetics; D006801:Humans; D016209:Interleukin-8 / Q000096:biosynthesis / Q000235:genetics; D008070:Lipopolysaccharides / Q000494:pharmacology*; D019402:Macrophage Inflammatory Proteins / Q000096:biosynthesis; D020411:Oligonucleotide Array Sequence Analysis; D016133:Polymerase Chain Reaction; D022622:Shiga Toxin 1 / Q000494:pharmacology*
chemical_list: D054405:Chemokine CCL3; D054407:Chemokine CCL4; D018925:Chemokines; D016207:Cytokines; D016209:Interleukin-8; D008070:Lipopolysaccharides; D019402:Macrophage Inflammatory Proteins; D022622:Shiga Toxin 1