251. pDCs in lung and skin fibrosis in a bleomycin-induced model and patients with systemic sclerosis.
- Author
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Kafaja S, Valera I, Divekar AA, Saggar R, Abtin F, Furst DE, Khanna D, and Singh RR
- Subjects
- Adult, Animals, Antibiotics, Antineoplastic adverse effects, Bleomycin adverse effects, Bronchoalveolar Lavage Fluid cytology, CD4-Positive T-Lymphocytes metabolism, Case-Control Studies, Chemokines genetics, Chemotaxis genetics, Disease Models, Animal, Female, Fibrosis chemically induced, Fibrosis genetics, Fibrosis immunology, Gene Expression, Humans, Imatinib Mesylate therapeutic use, Inflammation genetics, Interleukin-4 metabolism, Male, Mice, Protein Kinase Inhibitors therapeutic use, Receptors, Chemokine genetics, Scleroderma, Systemic blood, Scleroderma, Systemic drug therapy, Scleroderma, Systemic immunology, Severity of Illness Index, Spleen pathology, Transforming Growth Factor beta1 genetics, Transforming Growth Factor beta1 metabolism, Young Adult, Dendritic Cells pathology, Fibrosis pathology, Lung pathology, Scleroderma, Systemic pathology, Skin pathology
- Abstract
Fibrosis is the end result of most inflammatory conditions, but its pathogenesis remains unclear. We demonstrate that, in animals and humans with systemic fibrosis, plasmacytoid DCs (pDCs) are unaffected or are reduced systemically (spleen/peripheral blood), but they increase in the affected organs (lungs/skin/bronchoalveolar lavage). A pivotal role of pDCs was shown by depleting them in vivo, which ameliorated skin and/or lung fibrosis, reduced immune cell infiltration in the affected organs but not in spleen, and reduced the expression of genes and proteins implicated in chemotaxis, inflammation, and fibrosis in the affected organs of animals with bleomycin-induced fibrosis. As with animal findings, the frequency of pDCs in the lungs of patients with systemic sclerosis correlated with the severity of lung disease and with the frequency of CD4+ and IL-4+ T cells in the lung. Finally, treatment with imatinib that has been reported to reduce and/or prevent deterioration of skin and lung fibrosis profoundly reduced pDCs in lungs but not in peripheral blood of patients with systemic sclerosis. These observations suggest a role for pDCs in the pathogenesis of systemic fibrosis and identify the increased trafficking of pDCs to the affected organs as a potential therapeutic target in fibrotic diseases.
- Published
- 2018
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