101. Nlrp3 Inflammasome Inhibitor MCC950 Ameliorates Obliterative Bronchiolitis by Inhibiting Th1/Th17 Response and Promoting Treg Response After Orthotopic Tracheal Transplantation in Mice.
- Author
-
Xu KY, Tong S, Wu CY, Ding XC, Chen JL, Ming Y, and Wang SH
- Subjects
- Animals, Bronchiolitis Obliterans immunology, Disease Models, Animal, Furans, Heterocyclic Compounds, 4 or More Rings therapeutic use, Humans, Indenes, Inflammasomes immunology, Male, Mice, NLR Family, Pyrin Domain-Containing 3 Protein antagonists & inhibitors, NLR Family, Pyrin Domain-Containing 3 Protein immunology, Postoperative Complications immunology, Sulfonamides, Sulfones therapeutic use, T-Lymphocytes, Regulatory drug effects, T-Lymphocytes, Regulatory immunology, Th1 Cells drug effects, Th1 Cells immunology, Th17 Cells drug effects, Th17 Cells immunology, Trachea transplantation, Bronchiolitis Obliterans drug therapy, Heterocyclic Compounds, 4 or More Rings pharmacology, Inflammasomes antagonists & inhibitors, Lung Transplantation adverse effects, Postoperative Complications drug therapy, Sulfones pharmacology
- Abstract
Background: Obliterative bronchiolitis (OB) remains the major complication limiting long-term survival of patients after lung transplantation. We aimed to explore the effects of the selective NACHT, LRR, and PYD domains-containing protein 3 (Nlrp3) inflammasome inhibitor MCC950 on the pathogenesis of OB., Methods: Mouse orthotopic tracheal transplants were performed to mimic OB. MCC950 (50 mg/kg) or saline was intraperitoneally injected daily. The luminal occlusion rate and collagen deposition were evaluated by hematoxylin and eosin and Masson's trichrome staining, respectively. Infiltration of CD4+, CD8+ T cells, and neutrophils was detected with immunohistochemical staining. The frequencies of T helper 1 cell (Th1), T helper 17 cell (Th17), and regulatory T cells (Treg) were measured by flow cytometry. Cytokine levels were measured by ELISA kits., Results: MCC950 treatment significantly inhibited Nlrp3 inflammasome activation after allogeneic tracheal transplant and markedly decreased the luminal occlusion rate and collagen deposition in the allograft. The numbers of infiltrating CD4+, CD8+ T cells, and neutrophils in the allograft were also significantly reduced by MCC950 treatment. MCC950 dramatically decreased the frequencies of Th1/Th17 cells and the levels of interferon gamma/interleukin (IL)-17A and increased the Treg cell frequencies and IL-10 level; however, these effects were abolished by the addition of IL-1β and IL-18 both in vitro and in vivo. OB was also rescued by the addition of IL-1β and/or IL-18., Conclusions: Blocking Nlrp3 inflammasome activation with MCC950 ameliorates OB lesions. The mechanistic analysis showed that MCC950 regulated the balance of Th1/Th17 and Treg cells and that this process is partially mediated by inhibition of IL-1β and IL-18. Therefore, targeting the Nlrp3 inflammasome is a promising strategy for controlling OB after lung transplantation.
- Published
- 2020
- Full Text
- View/download PDF