title: High molecular weight gingipains from Porphyromonas gingivalis induce cytokine responses from human macrophage-like cells via a nonproteolytic mechanism.
abstract: Periodontal disease is an oral inflammatory disease affecting the supporting structures of teeth. Porphyromonas gingivalis, a major pathogenic agent for the disease, expresses a number of virulence factors, including cysteine proteases called the gingipains. The arginine- and lysine-specific gingipains, HRgpA and Kgp, respectively, are expressed as high molecular weight forms containing both catalytic and adhesin subunits. We examined the expression pattern of cytokines and their receptors in differentiated macrophages following exposure to active and inactive forms of the gingipains, using a cDNA array, quantitative PCR and ELISA analysis. Amongst other pro-inflammatory cytokines, results from the cDNA array suggested that interleukin-1beta, granulocyte-macrophage colony stimulatory factor and interferon-gamma were upregulated after exposure of the macrophages to the gingipains. Quantitative PCR analysis substantiated these observations and indicated that active or inactive forms of the high molecular weight gingipains were able to upregulate expression of transcripts for these cytokines. The strongly enhanced production of interleukin-1beta and granulocyte-macrophage colony stimulatory factor by differentiated macrophages in response to active or inactive forms of the high molecular weight gingipains was confirmed at the protein level by ELISA analysis. The results indicate that the adhesin subunits of the gingipains mediate strong upregulation of the expression of pro-inflammatory cytokines in macrophages.
authors.affiliation: Cooperative Research Centre for Oral Health Sciences, Monash University, Clayton, Vic., Australia.
authors.forename: Rebecca E
authors.initials: RE
authors.lastname: Fitzpatrick
authors.forename: Andrea
authors.initials: A
authors.lastname: Aprico
authors.forename: Lakshmi C
authors.initials: LC
authors.lastname: Wijeyewickrema
authors.forename: Charles N
authors.initials: CN
authors.lastname: Pagel
authors.forename: David M
authors.initials: DM
authors.lastname: Wong
authors.forename: Jan
authors.initials: J
authors.lastname: Potempa
authors.forename: Eleanor J
authors.initials: EJ
authors.lastname: Mackie
authors.forename: Robert N
authors.initials: RN
authors.lastname: Pike
mesh_terms: D018829:Adhesins, Bacterial / Q000502:physiology*; D016866:Bacteroidaceae Infections / Q000276:immunology* / Q000382:microbiology; D002460:Cell Line; D003546:Cysteine Endopeptidases / Q000502:physiology*; D016207:Cytokines / Q000096:biosynthesis*; D000080867:Gingipain Cysteine Endopeptidases; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000096:biosynthesis; D006801:Humans; D007113:Immunity, Innate; D007371:Interferon-gamma / Q000096:biosynthesis; D053583:Interleukin-1beta / Q000096:biosynthesis; D008264:Macrophages / Q000276:immunology*; D016966:Porphyromonas gingivalis / Q000201:enzymology*; D021122:Protein Subunits / Q000502:physiology; D015854:Up-Regulation
chemical_list: D018829:Adhesins, Bacterial; D016207:Cytokines; D000080867:Gingipain Cysteine Endopeptidases; D053583:Interleukin-1beta; D021122:Protein Subunits; D007371:Interferon-gamma; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D003546:Cysteine Endopeptidases