The most important cytokine involved in the induction, maintenance, and amplification of airway eosinophilia in asthma is interleukin-5 (IL-5), released by both T helper 2 (Th2) lymphocytes and group 2 innate lymphoid cells (ILC2).
Then, various biological processes were examined, including airway eosinophilia; mucus hypersecretion; elevation of OVA-specific IgE, expression of Th2 cytokines and chemokine levels; expression of eotaxin 2 and CCR3; and airway hyper responsiveness (AHR).
Upstream Regulator Analysis revealed that not only T-helper 2 (Th2) and the eosinophilia-related molecules (interleukin 4 [IL4], IL5, and colony stimulating factor 2 [CSF2]) reported so far, but also cell cycle regulators (cyclin dependent kinase inhibitor 1A [CDKNA1] and cyclin D1 [CCND1]) and a tissue fibrosis-related molecule (transforming growth factor β [TGFβ]) were identified in ECRSwNP.
These medications target the type 2 inflammatory pathway, which is characterized by activation of cytokines, including interleukin (IL)-4, IL-5, and IL-13, which results in eosinophilia, high FeNO, and atopic features.
And the periostin levels was positively associated with the basement membrane thickness, goblet cell hyperplasia and tissue eosinophilia polyp tissues, as well as the clinical parameters (computed tomography scores, polyp size, and polyp recurrence after endoscopic surgery).
Whereas IL-33, IL-25 and thymic stromal lymphopoietin (TSLP) are involved in induction of FAP-induced ILC-mediated airway eosinophilia, IL-33-rather than IL-25 and/or TSLP-was critical for the eosinophilia in our model.
PJE treatment inhibited OVA-induced inflammatory cell infiltration, eosinophilia, Th2 activation, and GATA-3 expression in the lung, reduced the interleukin (IL)-5 and IL-13 levels in BALF, down-regulated Th2 activation in vitro, and inhibited the macrophage production of inducible nitric oxide, cyclooxygenase-2, tumor necrosis factor-α, and IL-6.
Furthermore, serum and sputum IL-33 levels were higher in COPD subjects with sputum eosinophilia than in those with a sputum eosinophil count ≤3% (p < 0.001 for both).
In both models, targeted deletion of RORα in mouse T<sub>regs</sub> led to exaggerated eosinophilia driven by interleukin-5 (IL-5) production by ILC2s and T<sub>H</sub>2 cells.
Whereas IL-33, IL-25 and thymic stromal lymphopoietin (TSLP) are involved in induction of FAP-induced ILC-mediated airway eosinophilia, IL-33-rather than IL-25 and/or TSLP-was critical for the eosinophilia in our model.
In vivo, rIL-35 dramatically reduced LPS-induced airway eosinophilia in EBI3-deficient mice, with concomitant reduction of CCL11 and CCL24, whereas neutralization of IL-35 significantly increased airway eosinophils in LPS-treated wild-type mice.
In vivo, rIL-35 dramatically reduced LPS-induced airway eosinophilia in EBI3-deficient mice, with concomitant reduction of CCL11 and CCL24, whereas neutralization of IL-35 significantly increased airway eosinophils in LPS-treated wild-type mice.
Eosinophilic bronchitis is usually a Type 2 (T2)-driven process and therefore a sputum eosinophilia of greater than 3% usually indicates a response to treatment with corticosteroids or novel therapies directed against T2 cytokines such as IL-4, IL-5, and IL-13.
A specific focus regards the correlation between the level of PO and lung diseases and the identification of PO also as an inflammatory key effector in asthma, strongly associated with airways eosinophilia.