Endoplasmic reticulum stress impairs the immune regulation property of macrophages in asthmatic patients

Probiotic nucleotides increase IL-10 expression in airway macrophages to mitigate airway allergy

BACKGROUND

Dysfunctional immune regulation plays a crucial role in the pathogenesis of airway allergies. Macrophages are one of the components of the immune regulation cells. The aim of this study is to elucidate the role of lysine demethylase 5 A (KDM5A) in maintaining macrophages' immune regulatory ability.

METHODS

DNA was extracted from Lactobacillus rhamnosus GG to be designated as LgDNA. LgDNA was administered to the mice through nasal instillations. M2 macrophages (M2 cells) were isolated from the airway tissues using flow cytometry.

RESULTS

We found that airway M2 cells of mice with airway Th2 polarization had reduced amounts of IL-10 and KDM5A. Mice with Kdm5a deficiency in M2 cells showed the airway Th2 polarization. The expression of Kdm5a in airway M2 cells was enhanced by nasal instillations containing LgDNA. KDM5A mediated the effects of LgDNA on inducing the Il10 expression in airway M2 cells. Administration of LgDNA mitigated experimental airway allergy.

CONCLUSIONS

M2 macrophages in the airway tissues of mice with airway allergy show low levels of KDM5A. By upregulating KDM5A expression, LgDNA can increase Il10 expression and reconcile airway Th2 polarization.

Oligodeoxynucleotides containing CpG motifs (CpG-ODN) restores immune regulatory functions of airway macrophages of patients with asthma

Allergic asthma is characterized by the polarization of Th2 cells and impaired immune regulation. Macrophages occupy the largest proportion of airway immune cells. This study aims to discover the mechanism that hinders the immune regulatory functions of airway macrophages. In this study, macrophages were isolated from cells in bronchoalveolar lavage fluids (BALF) collected from asthma patients and normal control (NC) subjects. The results indicated that macrophages occupied the largest portion of the cellular components in BALF. The frequency of IL-10+ macrophage was significantly lower in asthma patients than in NC subjects. The expression of IL-10 in macrophages of BALF was associated with the levels of asthma-related parameters. The immune-suppressive functions of BALF M0 cells were defective in asthma patients. The inducibility of IL-10 expression was impaired in BALF macrophages of asthma patients, which could be restored by exposing to CpG. In conclusion, the induction of IL-10 in macrophages of BALF in asthma patients was impaired, and it could be restored by exposure to CpG.

TRIM41 contributes to the pathogenesis of airway allergy by compromising dendritic cells' tolerogenic properties

Dendritic cells (DC) play a crucial role in the initiation of immune responses. TRIM41, an E3 ubiquitin ligase, can facilitate targeting protein degradation. The purpose of this study is to analyze the role of TRIM41 in the pathogenesis of airway allergy (AA) and the impact of regulating TRIM41 on suppressing AA. We observed that the airway DCs of AA mice had a higher expression of Trim41. The expression of Trim41 in airway DCs was associated with the DCs' tolerogenic functions of AA mice. The AA responses, including increased amounts of eosinophil peroxidase, mast cell protease-1, Th2 cytokines, and specific IgE in bronchoalveolar lavage fluids, were positively correlated with the Trim41 expression in mouse airway DCs. TRIM41 induced c-Maf degradation and interfered with the Il10 expression in airway DCs, which could be counteracted by inhibiting TRIM41. Regulation of TRIM41 mitigated experimental AA responses.

Psychological stress to ovalbumin peptide-specific T-cell receptor transgenic mice impairs the suppressive ability of type 1 regulatory T cell

Numerous diseases of the immune system can be traced back to the malfunctioning of the regulatory T cells. The aetiology is unclear. Psychological stress can cause disruption to the immune regulation. The synergistic effects of psychological stress and immune response on immune regulation have yet to be fully understood. The intention of this study is to analyse the interaction between psychological stress and immune responses and how it affects the functional status of type 1 regulatory T (Tr1) cells. In this study, ovalbumin peptide T-cell receptor transgenic mice were utilised. Mice were subjected to restraint stress to induce psychological stress. An airway allergy murine model was established, in which a mouse strain with RING finger protein 20 (Rnf20)-deficient CD4+ T cells were used. The results showed that concomitant exposure to restraint stress and immune response could exacerbate endoplasmic reticulum stress in Tr1 cells. Corticosterone was responsible for the elevated expression of X-box protein-1 (XBP1) in mouse Tr1 cells after exposure to both restraint stress and immune response. XBP1 mediated the effects of corticosterone on inducing Rnf20 in Tr1 cells. The reduction of the interleukin-10 expression in Tr1 cells was facilitated by Rnf20. Inhibition of Rnf20 alleviated experimental airway allergy by restoring the immune regulatory ability of Tr1 cells. In conclusion, the functions of Tr1 cells are negatively impacted by simultaneous exposure to psychological stress and immune response. Tr1 cells' immune suppressive functions can be restored by inhibiting Rnf20, which has the translational potential for the treatment of diseases of the immune system.

Effects of Natural Products through Inhibiting Endoplasmic Reticulum Stress on Attenuation of Idiopathic Pulmonary Fibrosis

With ever-increasing intensive studies of idiopathic pulmonary fibrosis (IPF), significant progresses have been made. Endoplasmic reticulum stress (ERS)/unfolded protein reaction (UPR) is associated with the development and progression of IPF, and targeting ERS/UPR may be beneficial in the treatment of IPF. Natural product is a tremendous source of new drug discovery, and accumulating studies have reported that many natural products show potential therapeutic effects for IPF via modulating one or more branches of the ERS signaling pathway. Therefore, this review focuses on critical roles of ERS in IPF development, and summarizes herbal preparations and bioactive compounds which protect against IPF through regulating ERS.

Direct exposure to CpG and specific antigens mitigate airway allergy through modulating dendritic cell properties

BACKGROUND

CpG oligodeoxynucleotide (CpG-ODN; CpG, in short) has been employed as an adjuvant in allergen specific immunotherapy (AIT) to treat allergic diseases. The underlying mechanism needs to be further explained. The aim of this study is to examine the mechanism by which CpG and dust mite extracts (DME, a specific antigen) alleviate experimental airway allergy.

METHODS

DME was used as the specific allergen to establish an airway allergy mouse model. The mice were directly exposed to DME and CpG through nasal instillations (the CpG.DME therapy). The response of DCs and allergic responses in the airways were assessed using immunological approaches.

RESULTS

The airway allergy reaction was effectively suppressed by CpG.DME therapy. The administration of CpG or DME alone did not have any significant suppressive effects on the airway allergic response. Direct exposure to CpG.DME induced type 1 DCs (DC1s) and plasmacytoid DCs (pDCs), while CpG alone induced DC1s and DME alone induced DC2s in the airway tissues. Both DC1s and pDCs were required for the induction of type 1 regulatory T cells in the airway tissues by CpG.DME therapy. Depletion of either pDCs or DC1s abolished the induction of Tr1 cells, and abolished the suppressive effects on airway allergic response by the CpG.DME therapy.

CONCLUSIONS

Direct exposure to CpG.DME induces DC1s and pDCs in the airway tissues. DC1s in synergy with pDCs induce type 1 regulatory T cells. The CpG.DME therapy is effective in suppressing allergic responses in mice with airway allergy.

Allergen specific immunotherapy regulates macrophage property in the airways

BACKGROUND

Allergen specific immunotherapy (AIT) has been widely used in allergy clinics. The therapeutic effects of it are to be improved. Macrophages occupy the largest proportion of airway immune cells. The aim of this study is to measure the effects of nasal instillation AIT (nAIT) on airway allergy by regulating macrophage functions.

METHODS

An airway allergy mouse model was established with the ovalbumin-alum protocol. nAIT was conducted for mice with airway allergy through nasal instillation. The effects of nAIT were compared with subcutaneous injection AIT (SCIT) and sublingual AIT (SLIT).

RESULTS

Mice with airway allergy showed the airway allergic response, including lung inflammation, airway hyper responsiveness, serum specific IgE, increase in the amounts of eosinophil peroxidase, mouse mast cell protease-1, and Th2 cytokines in bronchoalveolar lavage fluid. nAIT had a much better therapeutic effect on the airway allergic response than SCIT and SLIT. Mechanistically, we observed better absorption of allergen in macrophages, better production of IL-10 by macrophages, and better immune suppressive functions in macrophages in mice received nAIT than SCIT and SLIT.

CONCLUSIONS

The nAIT has a much better therapeutic effect on suppressing the airway allergic response, in which macrophages play a critical role.

Edaravone alleviated allergic airway inflammation by inhibiting oxidative stress and endoplasmic reticulum stress

Oxidative stress and endoplasmic reticulum stress (ERS) was associated with the development of asthma. Edaravone (EDA) plays a classical role to prevent the occurrence and development of oxidative stress-related diseases. Herein, we investigated the involvement and signaling pathway of EDA in asthma, with particular emphasis on its impact on type 2 innate lymphoid cells (ILC2) and CD4+T cells, and then further elucidated whether EDA could inhibit house dust mite (HDM)-induced allergic asthma by affecting oxidative stress and ERS. Mice received intraperitoneally injection of EDA (10 mg/kg, 30 mg/kg), dexamethasone (DEX) and N-acetylcysteine (NAC), with the latter two used as positive control drugs. DEX and high dose of EDA showed better therapeutic effects in alleviating airway inflammation and mucus secretion in mice, along with decreasing eosinophils and neutrophils in bronchoalveolar lavage fluid (BALF) than NAC. Further, the protein levels of IL-33 in lung tissues were inhibited by EDA, leading to reduced activation of ILC2s in the lung. EDA treatment alleviated the activation of CD4+ T cells in lung tissues of HDM-induced asthmatic mice and reduced Th2 cytokine secretion in BALF. ERS-related markers (p-eIF2α, IRE1α, CHOP, GRP78) were decreased after treatment of EDA compared to HDM group. Malondialdehyde (MDA), glutathione (GSH), hydrogen peroxide (H2O2), and superoxide dismutase (SOD) were detected to evaluate the oxidant stress in lung tissues. EDA showed a protective effect against oxidant stress. In conclusion, our findings demonstrated that EDA could suppress allergic airway inflammation by inhibiting oxidative stress and ERS, suggesting to serve as an adjunct medication for asthma in the future.