title: Propionibacterium acnes promotes Th17 and Th17/Th1 responses in acne patients.
abstract: Propionibacterium acnes is a Gram-positive commensal bacterium thought to be involved in the pathogenesis of acne vulgaris. Although the ability of P. acnes in the initiation of pro-inflammatory responses is well documented, little is known about adaptive immune responses to this bacterium. The observation that infiltrating immune cells consist mainly of CD4(+) T cells in the perifollicular space of early acne lesions suggests that helper T cells may be involved in immune responses caused by the intra-follicular colonization of P. acnes. A recent report showing that P. acnes can induce IL-17 production by T cells suggests that acne might be a T helper type 17 (Th17)-mediated disease. In line with this, we show in this work that, in addition to IL-17A, both Th1 and Th17 effector cytokines, transcription factors, and chemokine receptors are strongly upregulated in acne lesions. Furthermore, we found that, in addition to Th17, P. acnes can promote mixed Th17/Th1 responses by inducing the concomitant secretion of IL-17A and IFN-γ from specific CD4(+) T cells in vitro. Finally, we show that both P. acnes-specific Th17 and Th17/Th1 cells can be found in the peripheral blood of patients suffering from acne and, at lower frequencies, in healthy individuals. We therefore identified P. acnes-responding Th17/Th1 cells as, to our knowledge, a previously unreported CD4(+) subpopulation involved in inflammatory acne.
authors.affiliation: Department of Dermatology, University Hospital, Zürich, Switzerland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Kistowska
authors.affiliation: Department of Dermatology, University Hospital, Zürich, Switzerland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Meier
authors.affiliation: Department of Dermatology, University Hospital, Zürich, Switzerland.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Proust
authors.affiliation: Department of Dermatology and Venereology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland.
authors.forename: Laurence
authors.initials: L
authors.lastname: Feldmeyer
authors.affiliation: Department of Dermatology, University Hospital, Zürich, Switzerland.
authors.forename: Antonio
authors.initials: A
authors.lastname: Cozzio
authors.affiliation: Department of Dermatology, University Hospital, Zürich, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kuendig
authors.affiliation: Department of Dermatology, University Hospital, Zürich, Switzerland.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Contassot
authors.affiliation: Department of Dermatology, University Hospital, Zürich, Switzerland. Electronic address: lars.french@usz.ch.
authors.forename: Lars E
authors.initials: LE
authors.lastname: French
mesh_terms: D000152:Acne Vulgaris / Q000276:immunology* / Q000382:microbiology*; D000328:Adult; D016908:Gram-Positive Bacterial Infections / Q000276:immunology* / Q000382:microbiology; D006801:Humans; D016130:Immunophenotyping; D007371:Interferon-gamma / Q000276:immunology; D053765:Interleukin-12 Subunit p35 / Q000276:immunology; D020381:Interleukin-17 / Q000276:immunology; D053583:Interleukin-1beta / Q000276:immunology; D053759:Interleukin-23 / Q000276:immunology; D008297:Male; D009000:Monocytes / Q000276:immunology / Q000382:microbiology; D011425:Propionibacterium acnes / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology* / Q000382:microbiology; D058504:Th17 Cells / Q000276:immunology* / Q000382:microbiology; D055815:Young Adult
chemical_list: C508858:IL12A protein, human; C508717:IL17A protein, human; D053765:Interleukin-12 Subunit p35; D020381:Interleukin-17; D053583:Interleukin-1beta; D053759:Interleukin-23; D007371:Interferon-gamma