title: Using dendritic cells to evaluate how Burkholderia cenocepacia clonal isolates from a chronically infected cystic fibrosis patient subvert immune functions.
abstract: Infection with Burkholderia cepacia complex (Bcc) bacteria is a threat to cystic fibrosis (CF) patients, commonly leading to a fatal pneumonia, the cepacia syndrome. It causes a massive production of pro-inflammatory cytokines and leucocyte recruitment to airway epithelium without resolving infection and contributing to tissue lesion. To dissect how Bcc bacteria subvert the immune response, we developed a co-culture model with human dendritic cells (DCs) and B. cenocepacia clonal variants isolated from a chronically infected CF patient, who died with cepacia syndrome. We demonstrated that the two late variants were sevenfold and 17-fold (respectively) more internalized by DCs than the variant that initiated infection. The late variants showed improved survival within DCs (60.29 and 52.82 CFU/DC) compared to the initial variant (0.38 CFU/DC). All clonal isolates induced high expression of inflammatory cytokines IL-8, IL-6, IL-1β, IL-12, IL-23, TNF-α and IL-1β. This pro-inflammatory trait was significantly more pronounced in DCs infected with the late variants than in DCs infected with the variant that initiated patient's infection. All infected DCs failed to upregulate maturation markers, HLA-DR, CD80, CD86 and CD83. Nevertheless, these infected DCs activated approximately twice more T cells than non-infected DCs. Similar T cell activation was observable with respective conditioned media, suggesting a non-antigen-specific activation. Our data indicate that during prolonged infection, B. cenocepacia acquires ability to survive intracellularly, inducing inflammation, while refraining DC's maturation and stimulating non-antigen-specific T cell responses. The co-culture model here developed may be broadly applied to study B. cenocepacia-induced immunomodulation.
authors.affiliation: Centro de Estudos de Doenças Crónicas, CEDOC, NOVA Medical School/Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Lisbon, Portugal.|Faculdade de Engenharia, Universidade Lusófona de Humanidades e Tecnologias, Lisbon, Portugal.
authors.forename: M
authors.initials: M
authors.lastname: Guadalupe Cabral
authors.affiliation: Centro de Estudos de Doenças Crónicas, CEDOC, NOVA Medical School/Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Lisbon, Portugal.|Instituto Gulbenkian de Ciência, Oeiras, Portugal.
authors.forename: Marília
authors.initials: M
authors.lastname: Pereira
authors.affiliation: Centro de Estudos de Doenças Crónicas, CEDOC, NOVA Medical School/Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Lisbon, Portugal.|UCIBIO, Departamento Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516, Caparica, Portugal.
authors.forename: Zélia
authors.initials: Z
authors.lastname: Silva
authors.affiliation: Centro de Estudos de Doenças Crónicas, CEDOC, NOVA Medical School/Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Lisbon, Portugal.
authors.forename: Inês
authors.initials: I
authors.lastname: Iria
authors.affiliation: iBB-Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal.
authors.forename: Carla
authors.initials: C
authors.lastname: Coutinho
authors.affiliation: Centro de Estudos de Doenças Crónicas, CEDOC, NOVA Medical School/Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Lisbon, Portugal.
authors.forename: Andreia
authors.initials: A
authors.lastname: Lopes
authors.affiliation: iBB-Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal.
authors.forename: Isabel
authors.initials: I
authors.lastname: Sá-Correia
authors.affiliation: Centro de Estudos de Doenças Crónicas, CEDOC, NOVA Medical School/Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Lisbon, Portugal. p.videira@fct.unl.pt.|UCIBIO, Departamento Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516, Caparica, Portugal. p.videira@fct.unl.pt.|CDG & Allies - Professionals and Patient Associations International Network (CDG & Allies - PPAIN), Caparica, Portugal. p.videira@fct.unl.pt.
authors.forename: Paula A
authors.initials: PA
authors.lastname: Videira
mesh_terms: D015415:Biomarkers; D019121:Burkholderia Infections / Q000175:diagnosis / Q000209:etiology* / Q000382:microbiology; D057508:Burkholderia cenocepacia / Q000276:immunology / Q000302:isolation & purification; D002454:Cell Differentiation / Q000276:immunology; D002470:Cell Survival / Q000276:immunology; D003550:Cystic Fibrosis / Q000150:complications* / Q000276:immunology* / Q000378:metabolism; D016207:Cytokines / Q000096:biosynthesis / Q000235:genetics; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D015870:Gene Expression; D006801:Humans; D016130:Immunophenotyping; D050296:Microbial Viability / Q000276:immunology; D009894:Opportunistic Infections; D010587:Phagocytosis / Q000276:immunology; D010641:Phenotype; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism
chemical_list: D015415:Biomarkers; D016207:Cytokines
keywords: Burkholderia cenocepacia; Clonal isolates; Cystic fibrosis; Dendritic cells; Immune escape; Maturation