Julia Holstein1, Farzan Solimani2, Carolin Baum3, Katharina Meier4, Robert Pollmann3, Dario Didona3, Tobias Tekath5, Martin Dugas5, Nicolas Casadei6, Christoph Hudemann3, Alexandra Polakova3, Jakob Matthes6, Iris Schäfer1, Amir S Yazdi7, Rüdiger Eming3, Michael Hertl3, Wolfgang Pfützner3, Kamran Ghoreschi8, Christian Möbs3. 1. Department of Dermatology, University Medical Center, Eberhard Karls Universität Tübingen, Tübingen, Germany. 2. Department of Dermatology, Venereology and Allergology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany; Department of Dermatology and Allergology, Philipps-Universität Marburg, Marburg, Germany. 3. Department of Dermatology and Allergology, Philipps-Universität Marburg, Marburg, Germany. 4. Department of Dermatology, Venereology and Allergology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany. 5. Institute of Medical Informatics, University of Münster, Münster, Germany. 6. Institute of Medical Genetics and Applied Genomics, Eberhard Karls Universität Tübingen, Tübingen, Germany. 7. Department of Dermatology and Allergology, Uniklinik RWTH Aachen, Aachen, Germany. 8. Department of Dermatology, Venereology and Allergology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany. Electronic address: kamran.ghoreschi@charite.de.
Abstract
BACKGROUND: TH2 cells were thought to be a pivotal factor for initiation of the autoimmune blistering disease pemphigus. However, the role of other T-cell subsets in pemphigus pathogenesis remained unclear. OBJECTIVE: We aimed to characterize the exact phenotype of T cells responsible for the development of pemphigus. METHODS: Whole transcriptome shotgun sequencing was performed to determine differential gene expression in pemphigus lesions and skin of healthy individuals. The cutaneous cytokine signature was further evaluated by real-time quantitative PCR. In peripheral blood, the distribution of TH cell and folliclular helper (TFH) cell subsets was analyzed by flow cytometry. Finally, the capacity of TH and TFH cell subsets to induce desmoglein (Dsg)-specific autoantibodies by memory B cells was evaluated in coculture experiments. RESULTS: Transcriptome analysis of skin samples identified an IL-17A-dominated immune signature in patients with pemphigus, and Kyoto Encyclopedia of Genes and Genomes pathway analysis confirmed the dominance of the IL-17A signaling pathway. Increased expression of IL17A and associated cytokines was also detected by real-time quantitative PCR comparing lesional with perilesional or healthy skin. Interestingly, utilization of flow cytometry showed that patients with active pemphigus had elevated levels of circulating IL-17+, TH17, TFH17, and TFH17.1 cells. Notably, levels of TH17 and TFH17 cells correlated with levels of Dsg-specific CD19+CD27+ memory B cells, and patients with acute pemphigus showed higher levels of Dsg3-autoreactive TFH17 cells. Coculture experiments revealed TFH17 cells as primarily responsible for inducing Dsg-specific autoantibody production by B cells. CONCLUSION: Our findings show that TFH17 cells are critically involved in the pathogenesis of pemphigus and offer novel targets for therapeutic intervention.
BACKGROUND: TH2 cells were thought to be a pivotal factor for initiation of the autoimmune blistering disease pemphigus. However, the role of other T-cell subsets in pemphigus pathogenesis remained unclear. OBJECTIVE: We aimed to characterize the exact phenotype of T cells responsible for the development of pemphigus. METHODS: Whole transcriptome shotgun sequencing was performed to determine differential gene expression in pemphigus lesions and skin of healthy individuals. The cutaneous cytokine signature was further evaluated by real-time quantitative PCR. In peripheral blood, the distribution of TH cell and folliclular helper (TFH) cell subsets was analyzed by flow cytometry. Finally, the capacity of TH and TFH cell subsets to induce desmoglein (Dsg)-specific autoantibodies by memory B cells was evaluated in coculture experiments. RESULTS: Transcriptome analysis of skin samples identified an IL-17A-dominated immune signature in patients with pemphigus, and Kyoto Encyclopedia of Genes and Genomes pathway analysis confirmed the dominance of the IL-17A signaling pathway. Increased expression of IL17A and associated cytokines was also detected by real-time quantitative PCR comparing lesional with perilesional or healthy skin. Interestingly, utilization of flow cytometry showed that patients with active pemphigus had elevated levels of circulating IL-17+, TH17, TFH17, and TFH17.1 cells. Notably, levels of TH17 and TFH17 cells correlated with levels of Dsg-specific CD19+CD27+ memory B cells, and patients with acute pemphigus showed higher levels of Dsg3-autoreactive TFH17 cells. Coculture experiments revealed TFH17 cells as primarily responsible for inducing Dsg-specific autoantibody production by B cells. CONCLUSION: Our findings show that TFH17 cells are critically involved in the pathogenesis of pemphigus and offer novel targets for therapeutic intervention.