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.

An association between elevated telomerase reverse transcriptase expression and the immune tolerance disruption of dendritic cells.

BACKGROUND: To elucidate the mechanism of dysfunction of tolerogenic dendritic cells (DCs) is of significance. Telomerase involves the regulation of the cell fate and activities. The objective of this study is to investigate the role of telomerase reverse transcriptase (TERT) in regulating the tolerogenic feature of DCs. METHODS: The telomerase was assessed in DCs, which were collected from patients with allergic rhinitis (AR), healthy control (HC) subjects, and mice. RNAs were extracted from DCs, and analyzed by RNA sequencing (RNAseq), real-time quantitative RT-PCR, and Western blotting. RESULTS: The results showed that expression of TERT was higher in peripheral DCs of AR patients. The expression of IL10 in DCs was negatively correlated with the levels of TERT expression. Importantly, the levels of TERT mRNA in DCs were associated with the AR response in patients with AR. Endoplasmic reticulum (ER) stress promoted the expression of Tert in DCs. Sensitization with the ovalbumin-aluminum hydroxide protocol increased the expression of Tert in DCs by exacerbating ER stress. TERT interacting with c-Maf (the transcription factor of IL-10) inducing protein (CMIP) in DCs resulted in CMIP ubiquitination and degradation, and thus, suppressed the production of IL-10. Inhibition of Tert in DCs mitigated experimental AR. CONCLUSIONS: Elevated amounts of TERT were detected in DCs of patients with AR. The tolerogenic feature of DCs was impacted by TERT. Inhibited TERT attenuated experimental AR.

Characterization of the immune suppressive functions of eosinophils.

Eosinophils account for a significant portion of immune cells in the body. It is well known that eosinophils play a role in the pathogenesis of many diseases. In which the interaction between eosinophils and other immune cells is incompletely understood. The aim of this study is to characterize the immune suppressive functions of eosinophils. In this study, an irway allergy mouse model was established. Eosinophils were isolated from the airway tissues using flow cytometry cell sorting. The RAW264.7 cell line was used to test the immune suppressive functions of eosinophils. We observed that eosinophils had immune suppressive functions manifesting inhibiting immune cell proliferation and cytokine release from other immune cells. The eosinophil's immune suppressive functions were mediated by eosinophil-derived molecules, such as eosinophil peroxidase (EPX) and major basic protein (MBP). The expression of Ras-like protein in the brain 27a (Rab27a) was detected in eosinophils, which controlled the release of MBP and EPX by eosinophils. Eosinophil mediators had two contrast effects on inducing inflammatory responses or rendering immune suppressive effects, depending on the released amounts. Administration of an inhibitor of Rab27a at proper dosage could alleviate experimental airway allergy. To sum up, eosinophils have immune suppressive functions and are also inflammation inducers. Rab27a governs the release of EPX and MBP from eosinophils, which leads to immune suppression or inflammation. Modulation of Rab27a can alleviate airway allergy responses by modulating eosinophil's immune suppressive functions, which has the translational potential for the management of eosinophil-related diseases.

Nasal mucosal fibroblasts produce IL-4 to induce Th2 response.

Th2 polarization is essential for the pathogenesis of allergic rhinitis (AR). Th2 polarization's mechanism requires further understanding. IL-4 is the primary cytokine involved in Th2 response. Fibroblasts play a role in immune regulation. This study aims to elucidate the role of nasal mucosal fibroblast-derived IL-4 in the induction of Th2 responses. Nasal mucosal tissues were obtained from surgically removed samples from patients with nasal polyps, whether with or without AR. Fibroblasts were isolated from the tissues by flow cytometry cell sorting, and analyzed by RNA sequencing (RNAseq). The data from RNAseq showed that nasal fibroblasts expressed genes of GATA3, CD80, CD83, CD86, STAT6, IL2, IL4, IL5, IL6, IL13 and costimulatory factor. The data were verified by RT-qPCR. The level of gene activity was positively correlated with those of AR-related cytokines present in nasal secretions. Nasal fibroblasts release IL-4 upon activation. Nasal fibroblasts had the ability to transform naive CD4+ T cells into Th2 cells, which can be eliminated by inhibiting IL-4 receptor or CD28 in CD4+ T cells. To sum up, nasal mucosal fibroblasts produce IL-4, which can induce Th2 cell development. The data implicate that nasal fibroblasts are involved in the pathogenesis of nasal allergy.

Multifunctional nanogel loaded with cerium oxide nanozyme and CX3CL1 protein: Targeted immunomodulation and retinal protection in uveitis rat model.

Effectively addressing retinal issues represents a pivotal aspect of blindness-related diseases. Novel approaches involving reducing inflammation and rebalancing the immune response are paramount in the treatment of these conditions. This study delves into the potential of a nanogel system comprising polyethylenimine-benzene boric acid-hyaluronic acid (PEI-PBA-HA). We have evaluated the collaborative impact of cerium oxide nanozyme and chemokine CX3CL1 protein for targeted immunomodulation and retinal protection in uveitis models. Our nanogel system specifically targets the posterior segment of the eyes. The synergistic effect in this area reduces oxidative stress and hampers the activation of microglia, thereby alleviating the pathological immune microenvironment. This multifaceted drug delivery system disrupts the cycle of oxidative stress, inflammation, and immune response, suppressing initial immune cells and limiting local retinal structural damage induced by excessive immune reactions. Our research sheds light on interactions within retinal target cells, providing a promising avenue for the development of efficient and innovative drug delivery platforms.

Subconjunctival injection of rapamycin-loaded polymeric microparticles for effective suppression of noninfectious uveitis in rats.

Noninfective uveitis is a major cause of vision impairment, and corticosteroid medication is a mainstay clinical strategy that causes severe side effects. Rapamycin (RAPA), a potent immunomodulator, is a promising treatment for noninfective uveitis. However, because high and frequent dosages are required, it is a great challenge to implement its clinical translation for noninfective uveitis therapy owing to its serious toxicity. In the present study, we engineered an injectable microparticulate drug delivery system based on biodegradable block polymers (i.e., polycaprolactone-poly (ethylene glycol)-polycaprolactone, PCEC) for efficient ocular delivery of RAPA via a subconjunctival injection route and investigated its therapeutic efficacy in an experimental autoimmune uveitis (EAU) rat model. RAPA-PCEC microparticles were fabricated using the emulsion-evaporation method and thoroughly characterized using scanning electron microscopy, fourier transform infrared spectroscopy, X-ray diffraction, and differential scanning calorimetry. The formed microparticles exhibited slow in vitro degradation over 28 days, and provided both in vitro and in vivo sustained release of RAPA over 4 weeks. Additionally, a single subconjunctival injection of PCEC microparticles resulted in high ocular tolerance. More importantly, subconjunctival injection of RAPA-PCEC microparticles significantly attenuated the clinical signs of EAU in a dose-dependent manner by reducing inflammatory cell infiltration (i.e., CD45+ cells and Th17 cells) and inhibiting microglial activation. Overall, this injectable microparticulate system may be promising vehicle for intraocular delivery of RAPA for the treatment of noninfective uveitis.

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.

Endoplasmic reticulum stress drives macrophages to produce IL-33 to favor Th2 polarization in the airways.

Interleukin (IL)-33 is a key driver of T helper 2 (Th2) cell polarization. Endoplasmic reticulum (ER) stress plays a role in the skewed T cell activation. The objective of this project is to elucidate the role of IL-33 derived from macrophages in inducing Th2 polarization in the airways. In this study, bronchoalveolar lavage fluids (BALF) were collected from patients with asthma and healthy control subjects. Macrophages were isolated from the BALF by flow cytometry cell sorting. An asthmatic mouse model was established using the ovalbumin/alum protocol. The results showed that increased IL33 gene activity and ER stress-related molecules in BALF-derived M2a macrophages was observed in asthmatic patients. Levels of IL33 gene activity in M2a cells were positively correlated with levels of asthma response in asthma patients. Sensitization exacerbated the ER stress in the airway macrophages, which increased the expression of IL-33 in macrophages of airway in sensitized mice. Conditional ablation of Il33 or Perk or Atf4 genes in macrophages prevented induction of airway allergy in mice. In conclusion, asthma airway macrophages express high levels of IL-33 and at high ER stress status. Inhibition of IL-33 or ER stress in macrophages can effectively alleviate experimental asthma.

Undersized telomeres in regulatory T cells link to the pathogenesis of allergic rhinitis.

Telomeres are an important biomarker in the cell destiny. The relationship between telomeres and regulatory T cells (Tregs) has not yet been investigated. The objective of this study is to evaluate the link between Tregs' telomere length and allergic rhinitis (AR)'s pathogenesis. Here, we report that low telomerase activity and high endoplasmic reticulum stress status were observed in Tregs from AR patients, as shown in the results. Immune regulatory molecules levels were correlated with the length of Tregs' telomeres. The immune-suppressive functions of Tregs were associated with the telomere length/Telomerase reverse transcriptase/Telomerase protein component 1 status in Tregs. The levels of telomere length/telomerase in airway Tregs were reduced by sensitization. Endoplasmic reticulum stress signaling pathway of proline-rich receptor-like protein kinase-eukaryotic translation initiation factor 2A (eIF2a) was associated with the regulation of telomerase. Inhibiting eIF2a had an effect on upregulating telomerase activity in Tregs and mitigating experimental AR.

The Olink proteomics profile in nasal secretion of patients with allergic rhinitis.

KEY POINTS: Nasal secretions of allergic rhinitis patients were analyzed by Olink proteomics. Fifteen differentially expressed proteins (DEPs) were identified. The DEPs were significantly correlated with the total nasal symptom scores of patients with allergic rhinitis.

The transcription factor XBP1 in dendritic cells promotes the TH2 cell response in airway allergy.

Dendritic cells (DCs) that express T cell immunoglobulin domain molecule-4 (TIM4), a cell surface receptor for phosphatidylserine, induce T helper 2 (TH2) cell responses and allergic reactions. We elucidated the role of the transcription factor X-box-binding protein-1 (XBP1) in the induction of the TH2 cell response through its role in generating TIM4+ DCs. We found that XBP1 was required for TIM4 mRNA and protein expression in airway DCs in response to the cytokine interleukin-2 (IL-2) and that this pathway was required for TIM4 expression on DCs in response to the allergens PM2.5 and Derf1. The IL-2-XBP1-TIM4 axis in DCs contributed to Derf1/PM2.5-induced, aberrant TH2 cell responses in vivo. An interaction between the guanine nucleotide exchange factor Son of sevenless-1 (SOS1) and the GTPase RAS promoted XBP1 and TIM4 production in DCs. Targeting the XBP1-TIM4 pathway in DCs prevented or alleviated experimental airway allergy. Together, these data suggest that XBP1 is required for TH2 cell responses by inducing the development of TIM4+ DCs, which depends on the IL-2-XBP1-SOS1 axis. This signaling pathway provides potential therapeutic targets for the treatment of TH2 cell-dependent inflammation or allergic diseases.

BRCA1 Insufficiency Induces a Hypersialylated Acidic Tumor Microenvironment That Promotes Metastasis and Immunotherapy Resistance.

Cancer metastasis is an extremely complex process affected by many factors. An acidic microenvironment can drive cancer cell migration toward blood vessels while also hampering immune cell activity. Here, we identified a mechanism mediated by sialyltransferases that induces an acidic tumor-permissive microenvironment (ATPME) in BRCA1-mutant and most BRCA1-low breast cancers. Hypersialylation mediated by ST8SIA4 perturbed the mammary epithelial bilayer structure and generated an ATPME and immunosuppressive microenvironment with increased PD-L1 and PD1 expressions. Mechanistically, BRCA1 deficiency increased expression of VEGFA and IL6 to activate TGFß-ST8SIA4 signaling. High levels of ST8SIA4 led to accumulation of polysialic acid (PSA) on mammary epithelial membranes that facilitated escape of cancer cells from immunosurveillance, promoting metastasis and resistance to αPD1 treatment. The sialyltransferase inhibitor 3Fax-Peracetyl Neu5Ac neutralized the ATPME, sensitized cancers to immune checkpoint blockade by activating CD8 T cells, and inhibited tumor growth and metastasis. Together, these findings identify a potential therapeutic option for cancers with a high level of PSA. SIGNIFICANCE: BRCA1 deficiency generates an acidic microenvironment to promote cancer metastasis and immunotherapy resistance that can be reversed using a sialyltransferase inhibitor.

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

The current study aims to characterize the counteraction of M2 cells in response to Endoplasmic reticulum (ER) stress. ER stress was detected in bronchoalveolar lavage fluids (BALF) Mϕs, which was at unresolved state in asthma patients. A positive correlation was detected between ER stress in Mϕs and lung functions/allergic mediators/Th2 cytokines in BALF or specific IgE in the serum. Levels of immune regulatory mediator in the BALF were negatively correlated to ER stress in BALF Mϕs. The ER stress state influenced the immune regulatory property of BALF Mϕ. Exposure to environmental pollutant, 3-metheyl-4-nitrophenol, exacerbated ER stress in Mϕ, which affected the Mϕ phenotyping. Exacerbation of ER stress suppressed the expression of IL-10 and programmed cell death protein-1 (PD-1) in Mϕs by increasing the expression of the ring finger protein 20 (Rnf20). Conditional inhibition of Rnf20 in Mϕs attenuated experimental airway allergy.

Targeting the RhoA-GEF-H1 pathway of mast cells attenuates experimental airway allergy.

Mast cells are the major effector cells in allergic diseases. RhoA and its downstream pathway is associated with the pathogenesis of airway allergy. The objective of this study is to test a hypothesis that modulating the RhoA-GEF-H1 axis in mast cells can attenuate airway allergy. An airway allergic disorder (AAD) mouse model was employed. Mast cells were isolated from AAD mouse airway tissues to be analyzed by RNA sequencing. We observed that mast cells isolated from the respiratory tract of AAD mice were resistant to apoptosis. Mast cell mediator levels in nasal lavage fluid were correlated with apoptosis resistance in AAD mice. Activation of RhoA in AAD mast cells was related to resistance to apoptosis. Mast cells isolated from the airway tissues in AAD mouse exhibited strong RhoA-GEF-H1 expression. The RhoA-GEF-H1 axis was associated with the lower FasL expression in AAD mast cells. Activation of the RhoA-GEF-H1 axis promoted the production of mediators in mast cells. Inhibition of GEF-H1 facilitated the SIT-induced mast cell apoptosis and enhanced the therapeutic efficacy of AAD. In conclusion, RhoA-GEF-H1 activities are associated with resistance to apoptosis in mast cells isolated from sites of allergic lesions. The state of apoptosis resistance in mast cells is associated with the state of AAD disease. Inhibition of GEF-H1 restores the sensitivity of mast cells to apoptosis inducers, and alleviates experimental AAD in mice.

[Mechanism of Der f 1/IGF-1 nanoparticle promoting the production of regulatory T cell].

Objective:To prepare PLGA nanoparticles loaded with Der f 1/IGF-1（Der f 1/IGF-1 NPs） and investigate their role in promoting the formation of Treg cells. Methods:NPs coated with Der f 1/IGF-1 were prepared by double emulsion method and their physicochemical properties and cumulative release rate in vitro were analyzed. After pretreatment, BMDC was divided into Saline group, Blank NPs group, Der f 1/IGF-1 group and Der f 1/IGF-1 NPs group. Determination of the expression of IL-10 and TGF-ß in BMDC by ELISA. The number of Treg cells was detected by flow cytometry. Results:The results showed that Der f 1/IGF-1 NPs were spherical structures, with good dispersion, particle size less than 200 nm, negative charge and stable slow-release effect of Zeta potential. After BMDC pretreatment, the expression levels of TGF-ß and IL-10 in BMDC cells in the Der f 1/IGF-1 NPs group were significantly increased compared with the Blank NPs group, and the difference was statistically significant（P<0.001）. After co-culture with CD4+ T cells, the proportion of Treg cells produced in the Der f 1/IGF-1 NPs group was significantly increased, and the difference was statistically significant（P<0.001）. Conclusion:Der f 1/IGF-1 NPs can induce Treg cell generation in vitro. This study provides a new and more effective method for the reconstruction of immune tolerance dysfunction.

Rnf20 inhibition enhances immunotherapy by improving regulatory T cell generation.

BACKGROUND: Allergic disorders are common all over the world. The pathogenesis of allergy is unclear. Therapies for allergic disorders require improvement. Endoplasmic reticulum (ER) stress is one of the factors influencing immune response. The purpose of this study is to improve the effectiveness of immunotherapy for experimental respiratory allergy by targeting the ER stress signal pathway. METHODS: Committed CD4+ T cells were isolated from blood samples collected from patients with allergic rhinitis (AR) and TCR ovalbumin transgenic mice. The effects of TCR engagement and 3-methyl-4-nitrophenol (MNP) on inducing ER stress in committed CD4+ T cells were evaluated. RESULTS: ER stress was detected in antigen-specific CD4+ T cells (sCD4+ T cells) of AR patients. The environmental pollutant MNP increased the expression of the X-binding protein-1 (XBP1) in the committed CD4+ T cells during the TCR engagement. XBP1 mediated the effects of MNP on inhibiting regulatory T cell (Treg) generation. The effects of MNP on induction of protein 20 (Rnf20) in CD4+ T cells were mediated by XBP1. Inhibition of Rnf20 rescued the Treg development from MNP-primed sCD4+ T cells. The ablation of Rnf20 improved the immunotherapy of AR through the restoration of the Treg generation. CONCLUSIONS: ER stress can be detected in CD4+ T cells in TCR engagement. Exposure to MNP exacerbates ER stress in committed CD4+ T cells. Regulation of the ER stress-related Rnf20 expression can restore the generation of Treg from CD4+ T cells of subjects with allergic diseases.

TAFA4-IL-10 axis potentiate immunotherapy for airway allergy by induction of specific regulatory T cells.

Allergen-specific immunotherapy (AIT) is the main treatment for allergic diseases. The therapeutic efficacy of AIT has to be improved. Neuropeptides, such as TAFA4, have immune-regulating features. The objective of this study is to promote the efficacy of AIT in experimental allergic rhinitis (AR) by the concurrent use of TAFA chemokine as a family member 4 (TAFA4). In this study, an AR mouse model was developed using ovalbumin (OVA) as the specific antigen. The AR response was assessed in mice after treatment with AIT or/and TAFA4. We found that exposure to TAFA4 activated dendritic cells (DCs) in the airway tissues. Activation of DC by TAFA4 resulted in the expression of IL-10. TAFA4 also promoted the activities of c-Maf inducing protein. The FPR1-MyD88-AKT signal pathway was associated with the TAFA4-induced Il10 expression in the DCs. Co-administration of AIT/TAFA4 attenuated the AR response in mice by inducing antigen-specific Tr1 cells. In conclusion, TAFA4 induces the expression of IL-10 in DCs. Acting as an adjuvant, TAFA4 significantly improves AIT's therapeutic efficacy against AR by inducing antigen-specific Tr1 cells.

Single subcutaneous injection of the minocycline nanocomposite-loaded thermosensitive hydrogel for the effective attenuation of experimental autoimmune uveitis.

Autoimmune uveitis induces a serious pathological and inflammatory response in the retina/choroid and results in vision impairment and blindness. Here, we report a minocycline (Mino) nanocomposite-loaded hydrogel offering a high drug payload and sustained drug release for the effective control of ocular inflammation via a single subcutaneous injection. In the presence of divalent cations (i.e., Ca2+), Mino was found to co-assemble with a phosphorylated peptide (i.e., NapGFFpY) via electrostatic interaction and consequently generating Mino nanocomposite. The drug entrapment efficiency (EE) of the Mino nanocomposite varied from 29.93 ± 0.76% to 67.90 ± 6.57%, depending on different component concentrations. After incorporation into 30 wt% poly (D,L-lactide)-b-poly (ethylene glycol)-b-poly (D,L-lactide) (PDLLA-PEG-PDLLA) thermosensitive hydrogel, the resulting Mino nanocomposite-loaded hydrogel provided a sustained drug release over 21 days. In the experimental autoimmune uveitis (EAU) rat model, a single subcutaneous injection of the Mino nanocomposite-loaded hydrogel effectively alleviated ocular inflammation in a dose-dependent manner. As indicated by optical coherence tomography (OCT) and electroretinogram (ERG) measurements, the Mino nanocomposite-loaded hydrogel treatment not only remarkably reduced destruction of the retina by EAU, but also greatly rescued retinal functions. Moreover, the proposed Mino nanocomposite-loaded hydrogel exerted its therapeutic effect on EAU primarily through a significant reduction of the influx of leukocytes and Th17 cells as well as suppression of microglia activation and apoptosis in the retina. Overall, the proposed Mino nanocomposite-loaded hydrogel might be a promising strategy for the clinical management of EAU.

S100A9-CXCL12 activation in BRCA1-mutant breast cancer promotes an immunosuppressive microenvironment associated with resistance to immunotherapy.

Immune checkpoint blockade (ICB) is a powerful approach for cancer therapy although good responses are only observed in a fraction of cancer patients. Breast cancers caused by deficiency of breast cancer-associated gene 1 (BRCA1) do not have an improved response to the treatment. To investigate this, here we analyze BRCA1 mutant mammary tissues and tumors derived from both BRCA1 mutant mouse models and human xenograft models to identify intrinsic determinants governing tumor progression and ICB responses. We show that BRCA1 deficiency activates S100A9-CXCL12 signaling for cancer progression and triggers the expansion and accumulation of myeloid-derived suppressor cells (MDSCs), creating a tumor-permissive microenvironment and rendering cancers insensitive to ICB. These oncogenic actions can be effectively suppressed by the combinatory treatment of inhibitors for S100A9-CXCL12 signaling with αPD-1 antibody. This study provides a selective strategy for effective immunotherapy in patients with elevated S100A9 and/or CXCL12 protein levels.