Correction: Synergistic activation of pro-inflammatory type-2 CD8 + T lymphocytes by lipid mediators in severe eosinophilic asthma

Type-2 CD8+ T-cell formation relies on interleukin-33 and is linked to asthma exacerbations

CD4+ T helper 2 (Th2) cells and group 2 innate lymphoid cells are considered the main producers of type-2 cytokines that fuel chronic airway inflammation in allergic asthma. However, CD8+ cytotoxic T (Tc) cells - critical for anti-viral defense - can also produce type-2 cytokines (referred to as 'Tc2' cells). The role of Tc cells in asthma and virus-induced disease exacerbations remains poorly understood, including which micro-environmental signals and cell types promote Tc2 cell formation. Here we show increased circulating Tc2 cell abundance in severe asthma patients, reaching peak levels during exacerbations and likely emerging from canonical IFNγ+ Tc cells through plasticity. Tc2 cell abundance is associated with increased disease burden, higher exacerbations rates and steroid insensitivity. Mouse models of asthma recapitulate the human disease by showing extensive type-2 skewing of lung Tc cells, which is controlled by conventional type-1 dendritic cells and IFNγ. Importantly, we demonstrate that the alarmin interleukin-33 (IL-33) critically promotes type-2 cytokine production by lung Tc cells in experimental allergic airway inflammation. Our data identify Tc cells as major producers of type-2 cytokines in severe asthma and during exacerbations that are remarkably sensitive to alterations in their inflammatory tissue micro-environment, with IL-33 emerging as an important regulator of Tc2 formation.

Wuhu Decoction Regulates Dendritic Cell Autophagy in the Treatment of Respiratory Syncytial Virus (RSV)-Induced Mouse Asthma by AMPK/ULK1 Signaling Pathway

BACKGROUND Dendritic cell autophagy plays a pivotal role in asthma. Wuhu decoction can significantly improve respiratory syncytial virus (RSV) bronchiolitis and delay its development into asthma. The aim of the present study was to explore the therapeutic effect and mechanism of Wuhu decoction on RSV -induced asthma in mice. MATERIAL AND METHODS Establishment of asthmatic mice model was induced by RSV. Hematoxylin-eosin staining, periodic acid-Schiff (PAS) staining, and Masson trichrome staining were performed to observe pathological changes in the lungs. The levels of CD4⁺ T, CD8⁺ T, and CD4⁺ CD25⁺ T in blood were analyzed by flow cytometry. The contents of interleukin (IL)-4, interferon-gamma (IFN-γ), IL-10, and IL-13 in serum were measured by enzyme-linked immunosorbent assay (ELISA). The number of autophagosomes in dendritic cells (DCs) of lung tissue was observed by transmission electron microscope. The DCs of lung tissue were isolated by magnetic bead sorting. The levels of LC3-II, Beclin-1, and LC3-I in DCs and MMP-9, TIMP-1, AMPK, p-AMPK, ULK1, and LK1 expression in lung tissues were detected by western blot. Real-time polymerase chain reaction (PCR) detected the expression of AMPK and ULK1 genes. RESULTS Wuhu decoction can effectively alleviate chronic airway inflammation and airway remodeling and reduce airway hyperresponsiveness. Moreover, Wuhu decoction can significantly enhance the level of autophagy in DCs of lung tissue and promote the expression of AMPK and ULK1 in lung tissue. CONCLUSIONS Wuhu decoction may improve the RSV-induced asthmatic symptoms by enhancing autophagy of DCs in lung tissue dependent on the AMPK/ULK1 signaling pathway.