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Eosinophils (Eos) are the canonical effector cells in allergic rhinitis (AR) and many inflammatory diseases. The mechanism of eosinophilia occurring in the lesion sites is not fully understood yet. Twist1 protein (Twist, in short) is an apoptosis inhibitor that also has immune regulatory functions. This study aims to investigate the role of Twist in the pathogenesis of eosinophilia in AR. In this study, surgically removed human nasal mucosal samples were obtained from patients with chronic sinusitis and nasal polyps with AR (the AR group) or without AR (the nAR group). Eos were isolated from the samples by flow cytometry. We found that abundant Eos were obtained from the surgically removed nasal mucosa tissues of both nAR and AR groups. Significantly higher Ras activation was detected in AR Eos than that in nAR Eos. Ras activation was associated with the apoptosis resistance in AR Eos. The Twist (an apoptosis inhibitor) expression was higher in AR Eos, which was positively correlated with the Ras activation status. The sensitization to IgG induced Twist expression in Eos, in which Ras activated the MAPK-HIF-1α pathway, the latter promoted the Twist gene transcription. Twist bound Rac GTPase activating protein-1 to sustain the Ras activation in Eos. Ras activation sustained the apoptosis resistance in Eos. In conclusion, high Ras activation was detected in the AR nasal mucosal tissue-isolated Eos. IgG-sensitization induced Ras activation and Twist expression in Eos, that conferred Eos the apoptosis resistance., (Copyright © 2021. Published by Elsevier Inc.)

Background: The eosinophilic inflammation plays a critical role in myocarditis (Mcd); its underlying mechanism remains to be further elucidated. This study aims to investigate the role of Bcl2-like protein 12 (Bcl2L12) in inducing the defects of apoptosis in eosinophils (Eos) of the heart tissues. Methods: Human explant heart samples were collected. Eosinophilia and myocarditis (Mcd)-like inflammation were induced in the mouse heart by immunizing with murine cardiac α-myosin heavy chain (MyHCα) peptides. Results: Markedly more Eos were observed in heart tissues from patients with Mcd than those from patients with dilated cardiomyopathy. Eos isolated from Mcd hearts showed the signs of apoptosis defects. The Eo counts in the Mcd heart tissues were positively correlated with the Bcl2L12 expression in Eos isolated from the heart tissues. Exposure to interleukin 5 in the culture induced the expression of Bcl2L12 in Eos. Bcl2L12 bound c-Myc, the transcription factor of Fas ligand (FasL), to prevent c-Myc from binding to the FasL promoter, to restrict the FasL gene transcription in Eos. Inhibition of Bcl2L12 prevented the induction of eosinophilia and Mcd-like inflammation in the mouse heart. Conclusions: The Bcl2L12 expression contributes to apoptosis defects in Eos of the Mcd heart. Blocking Bcl2L12 prevents the eosinophilia induction and alleviates Mcd-like inflammation in mice., (Copyright © 2020 Chen, Zhao, Miao, Liu, Yang, Liu, Yang and Song.)

T helper (Th)2 polarization plays an important role in the pathogenesis of allergic diseases; the underlying mechanism remains to be further investigated. B cell lymphoma protein-2 like protein-12 (Bcl2L12) has the anti-apoptotic function. This study aims to elucidate the contribution of Bcl2L12 to Th2 polarization in patients with allergic rhinitis (AR). In this study, human CD4 + T cells were isolated from blood samples collected from AR patients and healthy control (HC) subjects. The immune response profiles of CD4 + T cells were analyzed by immunologic approaches. The results showed that AR CD4 + T cells (CD4 + T cells collected from AR patients) showed defects of apoptosis. The expression of FasL in AR CD4 + T cells was lower than that of HC CD4 + T cells. Serum IL-5 levels were negatively correlated with the expression of FasL in AR CD4 + T cells. Exposure of CD4 + T cells to IL-5 in the culture suppressed the expression of FasL and increased the expression of Bcl2L12. IL-5 increased the levels of Bcl2L12 in CD4 + T cells, the latter bound to the FasL promoter to prevent FasL gene transcription. Inhibition of Bcl2L12 restored the apoptosis machinery in AR CD4 + T cells. In conclusion, overexpression of Bcl2L12 in CD4 + T cells compromises the apoptosis machinery; the latter can be restored by inhibition of Bcl2L12. BcL2L12 in CD4 + T cells may be a novel target for the treatment of AR and other allergic disorders., (©2019 Society for Leukocyte Biology.)

Background: Skewed T helper (Th)2 response plays a crucial role in the pathogenesis of allergic diseases. The therapeutic efficacy for allergic diseases is unsatisfactory currently. This study aims to regulate the skewed Th2 response with CARsomes. Methods: The CARsome consisted of an epitope of Dermatophagoides farina‐1 (Derf1), a segment of the anti‐DEC205 antibody, the scFv, and an open reading frame of perforin. This fusion protein binds to DEC205 molecule on the surface of exosomes derived from dendritic cells (DC). The effects of CARsome on inducing antigen (Ag)‐specific Th2 cell apoptosis were assessed both in vivo and in vitro. Results: Exposure to CARsomes in the culture induced Ag‐specific Th2 cell apoptosis. Injection of CARsomes through the vein puncture also induced Ag‐specific Th2 cell apoptosis in the lungs of sensitized mice. CARsomes could induce Ag‐specific regulatory T cells. Administration of CARsomes efficiently inhibited experimental allergic airway inflammation. Conclusions: The CARsomes can inhibit allergic airway inflammation by inducing Ag‐specific Th2 cell apoptosis and induce Ag‐specific regulatory T cells. The data suggest that CARsomes have the translational potential to be used to treat allergic airway inflammation. [ABSTRACT FROM AUTHOR]

Survivin is an anti-apoptosis protein that may be associated with the development of eosinophilia; the latter is associated with the pathogenesis of many immune disorders. Here we report that less apoptotic eosinophils (Eos) were induced in those isolated from mice suffering from food allergy (FA) than those from naive mice after treating with cisplatin in vitro. Exposure to cisplatin induced more Fas ligand (FasL) expression in Eos isolated from naive mice than in those of FA mouse. Survivin was detected in the intestinal tissue extracts in much higher amounts in the FA group than in the naive group. Immunohistochemistry showed that epithelial cells were the major source of survivin in the intestine. Exposure to IL-4 or IL-13 up-regulated the expression of survivin in intestinal epithelial cells. Survivin interfered with the expression of FasL in Eos. Inhibition of survivin attenuated the eosinophilia-related inflammation in the intestine. In conclusion, intestinal epithelial cell-produced survivin induced defects in apoptosis in Eos to contribute to eosinophilia in the intestine. Inhibition of survivin can suppress the eosinophilia-related intestinal inflammation. The data suggest that survivin may be a novel target for the treatment of FA. [ABSTRACT FROM AUTHOR]

T helper (Th)2 polarization plays an important role in the pathogenesis of allergic diseases; the underlying mechanism remains to be further investigated. B cell lymphoma protein‐2 like protein‐12 (Bcl2L12) has the anti‐apoptotic function. This study aims to elucidate the contribution of Bcl2L12 to Th2 polarization in patients with allergic rhinitis (AR). In this study, human CD4+ T cells were isolated from blood samples collected from AR patients and healthy control (HC) subjects. The immune response profiles of CD4+ T cells were analyzed by immunologic approaches. The results showed that AR CD4+ T cells (CD4+ T cells collected from AR patients) showed defects of apoptosis. The expression of FasL in AR CD4+ T cells was lower than that of HC CD4+ T cells. Serum IL‐5 levels were negatively correlated with the expression of FasL in AR CD4+ T cells. Exposure of CD4+ T cells to IL‐5 in the culture suppressed the expression of FasL and increased the expression of Bcl2L12. IL‐5 increased the levels of Bcl2L12 in CD4+ T cells, the latter bound to the FasL promoter to prevent FasL gene transcription. Inhibition of Bcl2L12 restored the apoptosis machinery in AR CD4+ T cells. In conclusion, overexpression of Bcl2L12 in CD4+ T cells compromises the apoptosis machinery; the latter can be restored by inhibition of Bcl2L12. BcL2L12 in CD4+ T cells may be a novel target for the treatment of AR and other allergic disorders. CD4+ T cells express Bcl2L12, which restricts FasL expression and induces apoptotic defects in CD4+ T cells. [ABSTRACT FROM AUTHOR]

Background: The biased T helper 2 (Th2) responses play a critical role in the pathogenesis of allergy. The underlying mechanism is not fully understood yet. Survivin can regulate multiple cellular activities. This study aims to elucidate the role of survivin in the development and maintenance of Th2 polarization. Methods: CD4+ T cells were isolated from blood samples collected from patients with allergic asthma (AS) and HS control (HS) subjects. Mice carrying CD4+ T cells with survivin knockout (KO mice) were employed to test the role of survivin in the development of the biased Th2 responses. Results: KO mice failed to induce airway allergy. Peripheral CD4+ T cells expressed survivin, which was higher in the AS group than that in the HS group. Naive CD4+ T cells with higher expression of survivin were prone to differentiating into Th2 cells. Survivin bound to the Il4 promoter in CD4+ T cells to enhance Il4 gene transcription. The expression of Fas was lower in CD4+ T cells of the AS group than that in the HS group. Overexpression of survivin suppressed the expression of Fas and impaired the activation‐induced cell death (AICD) of CD4+ T cells. Conclusion: Survivin facilitates the development of biased Th2 polarization through promoting expression of interleukin 4 (IL‐4) and impairing the AICD machinery of CD4+ T cells. To modulate the expression of survivin in CD4+ T cells has the translational potential in the treatment of allergic diseases. [ABSTRACT FROM AUTHOR]

Background and aims It is recognized that the air pollution is associated with the pathogenesis of airway diseases. This study aims to elucidate the role of the 3-methyl-4-nitrophenol (PNMC), one of the components of diesel-exhaust particles, in compromising the airway epithelial barrier integrity. Methods A549 cells, an airway epithelial cell line, were cultured to monolayers to be used as an in vitro epithelial barrier model. BALB/c mice were treated with nasal drops containing PNMC to test the effects of PNMC on alternating the airway epithelial barrier functions. Results Exposure of mice to PNMC induced nasal epithelial cell apoptosis and increased the permeability of the nasal epithelial barrier. PNMC increased casp8 and casp3 activities in nasal epithelial cells. Exposure to PNMC up regulated Fas and FasL expression in airway epithelial cells. Inhibition of caspase abolished the PNMC-induced airway epithelial barrier dysfunction. Conclusion Exposure of airway mucosa to PNMC induces epithelial cell apoptosis and compromises the epithelial barrier function, which can be prevented by the inhibition of caspases. [ABSTRACT FROM AUTHOR]