title: High-throughput sequencing reveals key genes and immune homeostatic pathways activated in myeloid dendritic cells by Porphyromonas gingivalis 381 and its fimbrial mutants.
abstract: The human microbiome consists of highly diverse microbial communities that colonize our skin and mucosal surfaces, aiding in maintenance of immune homeostasis. The keystone pathogen Porphyromonas gingivalis induces a dysbiosis and disrupts immune homeostasis through as yet unclear mechanisms. The fimbrial adhesins of P. gingivalis facilitate biofilm formation, invasion of and dissemination by blood dendritic cells; hence, fimbriae may be key factors in disruption of immune homeostasis. In this study we employed RNA-sequencing transcriptome profiling to identify differentially expressed genes (DEGs) in human monocyte-derived dendritic cells (MoDCs) in response to in vitro infection/exposure by Pg381 or its isogenic mutant strains that solely express minor-Mfa1 fimbriae (DPG3), major-FimA fimbriae (MFI) or are deficient in both fimbriae (MFB) relative to uninfected control. Our results yielded a total of 479 DEGs that were at least two-fold upregulated and downregulated in MoDCs significantly (P ≤ 0.05) by all four strains and certain DEGs that were strain-specific. Interestingly, the gene ontology biological and functional analysis shows that the upregulated genes in DPG3-induced MoDCs were more significant than other strains and associated with inflammation, immune response, anti-apoptosis, cell proliferation, and other homeostatic functions. Both transcriptome and quantitative polymerase chain reaction results show that DPG3, which solely expresses Mfa1, increased ZNF366, CD209, LOX1, IDO1, IL-10, CCL2, SOCS3, STAT3 and FOXO1 gene expression. In conclusion, we have identified key DC-mediated immune homeostatic pathways that could contribute to dysbiosis in periodontal infection with P. gingivalis.
authors.affiliation: Department of Periodontics, Georgia Regents University, Augusta, GA, USA.
authors.forename: P
authors.initials: P
authors.lastname: Arjunan
authors.affiliation: Department of Periodontics, Georgia Regents University, Augusta, GA, USA.
authors.forename: A
authors.initials: A
authors.lastname: El-Awady
authors.affiliation: Department of Energy, Joint Genome Institute, Walnut Creek, CA, USA.
authors.forename: R O
authors.initials: RO
authors.lastname: Dannebaum
authors.affiliation: Department of Energy, Joint Genome Institute, Walnut Creek, CA, USA.|Department of Biochemistry, National University of Singapore, Singapore.
authors.forename: G
authors.initials: G
authors.lastname: Kunde-Ramamoorthy
authors.affiliation: Department of Periodontics, Georgia Regents University, Augusta, GA, USA.
authors.forename: C W
authors.initials: CW
authors.lastname: Cutler
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics / Q000276:immunology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D003713:Dendritic Cells / Q000276:immunology* / Q000382:microbiology*; D036781:Fimbriae Proteins / Q000235:genetics / Q000378:metabolism; D010861:Fimbriae, Bacterial / Q000235:genetics / Q000276:immunology*; D015870:Gene Expression; D059014:High-Throughput Nucleotide Sequencing / Q000379:methods; D006801:Humans; D007111:Immunity, Cellular; D064307:Microbiota / Q000235:genetics / Q000276:immunology; D009000:Monocytes / Q000276:immunology; D009154:Mutation; D022423:Myeloid Cells / Q000187:drug effects / Q000276:immunology* / Q000382:microbiology*; D010518:Periodontitis / Q000276:immunology / Q000382:microbiology; D016966:Porphyromonas gingivalis / Q000276:immunology*; D017423:Sequence Analysis, RNA; D059467:Transcriptome
chemical_list: D018829:Adhesins, Bacterial; D001426:Bacterial Proteins; C545438:Mfa1 protein, Porphyromonas gingivalis; D036781:Fimbriae Proteins
keywords: Porphyromonas gingivalis; RNA-seqencing; dendritic cells; dysbiosis; immune homeostasis; microbiome