title: Involvement of fibrocytes in allergen-induced T cell responses and rhinovirus infections in asthma.
abstract: Allergen exposure and rhinovirus infections that propagate from the upper to the lower airways are the most frequent causes of asthma exacerbation. In patients at increased risk of disease exacerbations, chronic airway inflammation is associated with the airway recruitment of circulating fibrocytes, bone marrow-derived CD34(+)CD45RO(+)CD11b(+)CD13(+)HLA-DR(+) progenitors that have antigen-presenting function and fibroblast-like properties. This study demonstrates that allergen-pulsed circulating fibrocytes from patients with allergic asthma are potent inducer of the predominant release of the T helper type (Th)2 cytokines IL-4 and IL-5 from autologous naïve and memory CD4(+) T cells. This study also provides evidence that circulating fibrocytes from allergic asthmatics are susceptible to rhinovirus infection. Infected cells release high amounts of pro-inflammatory cytokines with minimal production of IFN-α/β. Moreover, allergen-pulsed fibrocytes support prolonged rhinovirus replication and release larger quantities of pro-inflammatory cytokines upon rhinovirus infection than unpulsed fibrocytes. Thus, fibrocytes may amplify allergen-induced, Th2 cell-driven inflammatory responses and promote further inflammation by functioning as a reservoir for rhinovirus replication in asthmatic airways. Through these mechanisms, fibrocytes may play an important role in the provocation of disease exacerbations.
authors.affiliation: Avail Biomedical Research Institute, Basel, Switzerland.
authors.forename: Mirko
authors.initials: M
authors.lastname: Isgrò
authors.forename: Lorenza
authors.initials: L
authors.lastname: Bianchetti
authors.forename: Maurizio A
authors.initials: MA
authors.lastname: Marini
authors.forename: Sabrina
authors.initials: S
authors.lastname: Mattoli
mesh_terms: D000328:Adult; D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology / Q000473:pathology / Q000821:virology; D039741:Antigens, Dermatophagoides / Q000502:physiology; D001249:Asthma / Q000276:immunology* / Q000473:pathology / Q000821:virology; D001854:Bone Marrow Cells / Q000276:immunology* / Q000473:pathology* / Q000821:virology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000473:pathology / Q000821:virology; D002908:Chronic Disease; D016207:Cytokines / Q000502:physiology; D003713:Dendritic Cells / Q000276:immunology / Q000473:pathology / Q000821:virology; D006367:HeLa Cells; D006801:Humans; D007156:Immunologic Memory; D007249:Inflammation / Q000276:immunology / Q000473:pathology / Q000821:virology; D008213:Lymphocyte Activation / Q000276:immunology; D008264:Macrophages / Q000276:immunology / Q000473:pathology / Q000821:virology; D010850:Picornaviridae Infections / Q000276:immunology* / Q000473:pathology / Q000821:virology; D012229:Rhinovirus / Q000276:immunology*; D013234:Stem Cells / Q000276:immunology / Q000473:pathology / Q000821:virology; D018418:Th2 Cells / Q000276:immunology* / Q000473:pathology / Q000821:virology
chemical_list: D039741:Antigens, Dermatophagoides; D016207:Cytokines
keywords: 50% tissue culture infective dose; Ab; Allergy; Asthma; COL1; COL1A1; FB; Fibrocyte; HDM; MDM; MOI; Myeloid dendritic cell; PBMC; RV; Rhinovirus; T helper type; T lymphocyte; TCID(50); TT; Th; UV; antibody; fibrocyte; house dust mite; m; mDC; monoclonal; monocyte-derived macrophage; multiplicity of infections; myeloid dendritic cell; peripheral blood mononuclear cell; rhinovirus; tetanus toxoid; type I pro-collagen; ultraviolet light; α-SMA; α-smooth muscle actin; α1 chain of type I pro-collagen