NRF2 is a spatiotemporal metabolic hub essential for the polyfunctionality of Th2 cells.

Upon encountering allergens, CD4+ T cells differentiate into IL-4-producing Th2 cells in lymph nodes, which later transform into polyfunctional Th2 cells producing IL-5 and IL-13 in inflamed tissues. However, the precise mechanism underlying their polyfunctionality remains elusive. In this study, we elucidate the pivotal role of NRF2 in polyfunctional Th2 cells in murine models of allergic asthma and in human Th2 cells. We found that an increase in reactive oxygen species (ROS) in immune cells infiltrating the lungs is necessary for the development of eosinophilic asthma and polyfunctional Th2 cells in vivo. Deletion of the ROS sensor NRF2 specifically in T cells, but not in dendritic cells, significantly abolished eosinophilia and polyfunctional Th2 cells in the airway. Mechanistically, NRF2 intrinsic to T cells is essential for inducing optimal oxidative phosphorylation and glycolysis capacity, thereby driving Th2 cell polyfunctionality independently of IL-33, partially by inducing PPARγ. Treatment with an NRF2 inhibitor leads to a substantial decrease in polyfunctional Th2 cells and subsequent eosinophilia in mice and a reduction in the production of Th2 cytokines from peripheral blood mononuclear cells in asthmatic patients. These findings highlight the critical role of Nrf2 as a spatial and temporal metabolic hub that is essential for polyfunctional Th2 cells, suggesting potential therapeutic implications for allergic diseases.

Monoclonal antibodies for moderate-to-severe atopic dermatitis: a look at phase III and beyond.

INTRODUCTION: The understanding of atopic dermatitis (AD) pathogenesis has rapidly expanded in recent years, catalyzing the development of new targeted monoclonal antibody treatments for AD. AREAS COVERED: This review aims to summarize the latest clinical and molecular data about monoclonal antibodies that are in later stages of development for AD, either in Phase 3 trials or in the pharmacopoeia for up to 5 years, highlighting the biologic underpinning of each drug's mechanism of action and the potential modulation of the AD immune profile. EXPERT OPINION: The therapeutic pipeline of AD treatments is speedily progressing, introducing the potential for a personalized medical approach in the near future. Understanding how targeting pathogenic players in AD modifies disease progression and symptomatology is key in improving therapeutic choices for patients and identifying ideal patient candidates.

Allergic Conjunctivitis: Review of Current Types, Treatments, and Trends.

Allergic conjunctivitis is an allergen-induced immune response secondary to the binding of immunoglobulin-E (IgE) to sensitized mast cells. Approximately 40% of North Americans and 20% of the world's population are impacted by some form of allergy and it continues to increase in prevalence, especially among children. Specified IgE antibodies can be found in almost all cases of exposure to seasonal or perennial allergens. Activation and degranulation of mast cells lead to increased tear levels of histamine, tryptase, leukotrienes, cytokines, and prostaglandins. The release of these factors initiates the recruitment of inflammatory cells in the conjunctival mucosa, which causes the late-phase reaction. Signs and symptoms of ocular allergies include itching, tearing, chemosis, and hyperemia, which can lead to decreased productivity and poor quality of life. Many treatment options are available to improve symptoms, including, mast cell stabilizers, antihistamines, dual-acting agents, steroids, nonsteroidal anti-inflammatory drugs (NSAIDS), and other off-label treatment modalities. This review article provides an overview of different types of allergic conjunctivitis, its pathology and immunology, and recommended methods of treatment.

Airway epithelial-derived exosomes induce acute asthma exacerbation after respiratory syncytial virus infection.

Acute asthma exacerbation refers to the progressive deterioration of asthma symptoms that is always triggered by virus infection represented by respiratory syncytial virus (RSV). After RSV infection, exaggerated Th2-mediated pulmonary inflammation is the critical pathological response of asthmatic patients with acute exacerbation. Significantly, airway epithelial cells, being the primary targets of RSV infection, play a crucial role in controlling the pulmonary inflammatory response by releasing airway epithelial cell-derived exosomes (AEC-Exos), which potentially influence the development of asthma. However, the specific role of AEC-Exos in acute asthma exacerbation after RSV infection remains obscure. The purpose of this study was to determine the distinct function of AEC-Exos in exacerbating acute asthma following RSV infection. Blockade of exosomes by GW reduce the enhanced pulmonary inflammation significantly. Specifically, the enhanced Th2 inflammation was induced by AEC-Exos thorough transportation of hsa-miR-155-5p-Sirtuin 1 (SIRT1) pathway during acute asthma exacerbation. Targeted inhibition of hsa-miR-155-5p blocks the exaggerated Th2 inflammation effectively in mice with acute asthma exacerbation. In summary, our study showed that during acute asthma exacerbation after RSV infection, AEC-Exos promote the enhanced Th2 inflammation through transportation of increased hsa-miR-155-5p, which was mediated partly through SIRT1-mediated pathway. hsa-miR-155-5p is a potential biomarker for early prediction of acute asthma exacerbation.

Effects of dexmedetomidine and ketorolac applied for patient­controlled analgesia on the balance of Th1/Th2 and level of VEGF in patients undergoing laparoscopic surgery for cervical cancer: A randomized controlled trial.

The aim of the present study was to explore the effects of dexmedetomidine (DEX) combined with ketorolac on postoperative patient-controlled analgesia (PCA), the balance of Th1/Th2 and the level of vascular endothelial growth factor (VEGF) in patients with cervical cancer following laparoscopic radical surgery. A total of 70 women with cervical cancer undergoing laparoscopic radical hysterectomy were enrolled in the study to randomly receive postoperative dexmedetomidine combined with ketorolac analgesia (DK group) and postoperative sufentanil analgesia (SUF group). The primary outcomes were the serum levels of interleukin-4 (IL-4), interferon-γ (IFN-γ) and VEGF, and the IFN-γ/IL-4 ratio 30 min before induction (T0), and 24 and 48 h after surgery. Secondary outcomes included numerical rating scale scores at 0 h (T0), 4 h (T1), 12 h (T2), 24 h (T3) and 48 h (T4) postoperatively, cumulative times of rescue analgesia, as well as the incidence of postoperative side effects within 48 h from surgery. Patients in the DK group reported similar analgesic effects as patients in the SUF group at T2, T3 and T4, and the incidence of postoperative nausea and vomiting was significantly lower in the DK group. In the DK group, the serum concentration of IFN-γ and IFN-γ/IL-4 ratio at 24 and 48 h after surgery were higher compared with those in the SUF group. Conversely, the serum concentrations of IL-4 at 24 h after surgery and VEGF at 24 and 48 h after surgery were significantly lower. The results indicated that the combination of DEX and ketorolac for PCA significantly improved postoperative pain and decreased the serum level of VEGF, which are associated with tumor angiogenesis. In addition, it maintained the homeostasis of postoperative immune dysfunction of patients with cervical cancer by shifting the balance between type 1 T helper cells and type 2 T helper cell (Th1/Th2 balance) to Th1 (registration no. ChiCTR1900027979; December 7, 2019).

Giardia intestinalis reshapes mucosal immunity toward a Type 2 response that attenuates inflammatory bowel-like diseases.

Diarrheal diseases are the second leading cause of death in children worldwide. Epidemiological studies show that co-infection with Giardia intestinalis decreases the severity of diarrhea. Here, we show that Giardia is highly prevalent in the stools of asymptomatic school-aged children. It orchestrates a Th2 mucosal immune response, characterized by increased antigen-specific Th2 cells, IL-25, Type 2-associated cytokines, and goblet cell hyperplasia. Giardia infection expanded IL-10-producing Th2 and GATA3+ Treg cells that promoted chronic carriage, parasite transmission, and conferred protection against Toxoplasma gondii-induced lethal ileitis and DSS-driven colitis by downregulating proinflammatory cytokines, decreasing Th1/Th17 cell frequency, and preventing collateral tissue damage. Protection was dependent on STAT6 signaling, as Giardia-infected STAT6-/- mice no longer regulated intestinal bystander inflammation. Our findings demonstrate that Giardia infection reshapes mucosal immunity toward a Type 2 response, which confers a mutualistic protection against inflammatory disease processes and identifies a critical role for protists in regulating mucosal defenses.

Efficacy and action mechanisms of compound Shen Chan decoction on experimental models of atopic dermatitis.

Shen chan decoction (SCD) as a significant Traditional Chinese medicine (TCM) to treat atopic dermatitis (AD), but its mechanism of action has not been clarified, so we started the present study, first possible effects of SCD on AD were predicted using network pharmacology. Next, dinitrochlorobenzene was used to establish a mouse model of AD. After successful modelling, the SCD were administered intragastrically to treat the mice. Eventually, the KEGG pathway enrichment analysis indicated that SCD improved AD mainly through effects on inflammation and the gut microbiota. The experimental findings revealed that SCD treatment attenuated AD symptoms and downregulate the characteristic immune factors, namely IL-4, IL-6 and IgE. Moreover, it promoted a balance between Th1/Th2 cells. Furthermore, the itch signaling pathways involving H1R/PAR-2/TRPV1 were inhibited. The 16S rRNA sequencing results indicated that SCD administration influenced the Firmicutes/Bacteroidetes ratio at the phylum level by augmenting the relative proportions of Lactobacillaceae and Muribaculaceae at the family and genus levels, while decreasing the abundances of Lactococcus and Ruminococcus. These findings suggest that internal administration of SCD is an effective therapeutic approach for AD. We suggest that SCD may be an alternative therapy for the treatment of AD.Additionally, it could offer valuable insights into the pathogenesis of AD and the development of innovative therapeutic agents.

Canine peripheral non-conventional TCRαß+ CD4-CD8α- double-negative T cells show T helper 2-like and regulatory properties.

The dog is an important companion animal and also serves as model species for human diseases. Given the central role of T cells in immune responses, a basic understanding of canine conventional T cell receptor (TCR)αß+ T cells, comprising CD4+ single-positive (sp) T helper (Th) and CD8α+ sp cytotoxic T cell subsets, is available. However, characterization of canine non-conventional TCRαß+ CD4+CD8α+ double-positive (dp) and TCRαß+ CD4-CD8α- double-negative (dn) T cells is limited. In this study, we performed a comprehensive analysis of canine dp and dn T cells in comparison with their conventional counterparts. TCRαß+ T cells from peripheral blood of healthy dogs were sorted according to their CD4/CD8α phenotype into four populations (i.e. CD4+ sp, CD8α+ sp, dp, and dn) and selected surface markers, transcription factors and effector molecules were analyzed ex vivo and after in vitro stimulation by RT-qPCR. Novel characteristics of canine dp T cells were identified, expanding the previously characterized Th1-like phenotype to Th17-like and Th2-like properties. Overall, mRNA expression of various Th cell-associated cytokines (i.e. IFNG, IL17A, IL4, IL13) in dp T cells upon stimulation highlights their versatile immunological potential. Furthermore, we demonstrated that the CD4-CD8α- dn phenotype is stable during in vitro stimulation. Strikingly, dn T cells were found to express highest mRNA levels of type 2 effector cytokines (IL4, IL5, and IL13) upon stimulation. Their strong ability to produce IL-4 was confirmed at the protein level. Upon stimulation, the percentage of IL-4-producing cells was even higher in the non-conventional dn than in the conventional CD4+ sp population. Constitutive transcription of IL1RL1 (encoding IL-33Rα) further supports Th2-like properties within the dn T cell population. These data point to a role of dn T cells in type 2 immunity. In addition, the high potential of dn T cells to transcribe the gene encoding the co-inhibitory receptor CTLA-4 and to produce the inhibitory cytokine IL-10 indicates putative immunosuppressive capacity of this population. In summary, this study reveals important novel aspects of canine non-conventional T cells providing the basis for further studies on their effector and/or regulatory functions to elucidate their role in health and disease.

Exposure to ephedrine attenuates Th1/Th2 imbalance underlying OVA-induced asthma through airway epithelial cell-derived exosomal lnc-TRPM2-AS.

Although various anti-inflammatory medications, such as ephedrine, are employed to manage cough-variant asthma, their underlying mechanisms are yet to be fully understood. Recent studies suggest that exosomes derived from airway epithelial cells (AECs) contain components like messenger RNAs (mRNAs), micro-RNAs (miRNAs), and long noncoding RNA (lncRNA), which play roles in the occurrence and progression of airway inflammation. This study investigates the influence of AEC-derived exosomes on the efficacy of ephedrine in treating cough-variant asthma. We established a mouse model of asthma and measured airway resistance and serum inflammatory cell levels. Real-time polymerase chain reaction (RT-qPCR), Western blotting, and enzyme-linked immunosorbent assay (ELISA) analyses were used to assess gene and protein expression levels. Exosomes were isolated and characterized. RNA immunoprecipitation (RIP) and RNA pull-down assays were conducted to examine the interaction between hnRNPA2B1 and lnc-TRPM2-AS1. In the ovalbumin (OVA)-challenged mouse model, ephedrine treatment reduced inflammatory responses, airway resistance, and Th1/Th2 cell imbalance. Exosomes from OVA-treated AECs showed elevated levels of lnc-TRPM2-AS1, which were diminished following ephedrine treatment. The exosomal lnc-TRPM2-AS1 mediated the Th1/Th2 imbalance in CD4+ T cells, with its packaging into exosomes being facilitated by hnRNPA2B1. This study unveils a novel mechanism by which ephedrine ameliorates OVA-induced CD4+ T cell imbalance by suppressing AEC-derived exosomal lnc-TRPM2-AS1. These findings could provide a theoretical framework for using ephedrine in asthma treatment.

IKZF1 and UBR4 gene variants drive autoimmunity and TH2 polarization in IgG4-related disease.

Immunoglobulin G4-related disease (IgG4-RD) is a systemic immune-mediated' fibroinflammatory disease. The pathomechanisms remain poorly understood. Here, we identified gene variants in familial IgG4-RD and determined their functional consequences. All three affected members shared mutations of the transcription factor IKAROS, encoded by IKZF1, and the E3 ubiquitin ligase UBR4. The IKAROS mutation increased binding to the FYN promoter resulting in higher transcription of FYN in T cells. The UBR4 mutation prevented the lysosomal degradation of the phosphatase CD45. In the presence of elevated FYN, CD45 functioned as a positive regulatory loop, lowering the threshold for T cell activation. Consequently, T cells from affected family members were hyperresponsive to stimulation. When transduced with a low avidity, autoreactive T cell receptor, they responded to the autoantigenic peptide. In parallel, the high expression of FYN in T cells biased their differentiation towards TH2 polarization by stabilizing the transcription factor JunB. This bias is consistent with the frequent atopic manifestations in IgG4-RD patients including our afflicted family members. Building on the functional consequences of these two mutations, we propose a disease model that is not only instructive for IgG4-RD but also for atopic diseases for autoimmune diseases associated with an IKZF1 risk haplotype.

IL-2 amplifies quantitative TCR signalling inputs to drive Th1 and Th2 differentiation.

The activation of CD4+ T-cells in a T cell receptor (TCR)-dependent antigen-specific manner is a central characteristic of the adaptive immune response. In addition to ensuring that CD4+ T-cells recognise their cognate antigen during activation, TCR-mediated signalling can also direct the outcome of differentiation. In both in vivo and in vitro model systems, strong TCR signalling has been demonstrated to drive Th1 differentiation, whereas weak TCR signalling drives Th2 responses. During the process of differentiation, TCR signal strength acts as a quantitative component in combination with the qualitative effects imparted by cytokines to polarise distinct T-helper lineages. Here, we investigated the role of interleukin 2 (IL-2) signalling in determining the outcome of TCR-dependent differentiation. IL-2 production was initiated as an early response to TCR-induced activation and was regulated by the strength of TCR signalling initially received. In the absence of IL-2, TCR dependent differentiation was found to be abolished. However, proliferative responses and early markers of activation were maintained, including the upregulation of GATA3, Tbet and Foxp3 at 24 h post-stimulation. Demonstrating that IL-2 signalling has a key role in stabilising and amplifying lineage-specific transcirption factor expression during differentiation. Further, activation of IL-2-deficient T-cells in the presence of exogenous cytokines was sufficient to restore differentiation whilst maintaining transcriptional signatures imparted during initial TCR signalling. Combined, our data demonstrate that the integration of quantitative TCR-dependent signalling and qualitative IL-2 signalling is essential for determining the fate of CD4+ T-cells during differentiation.

Peroxidase-mediated mucin cross-linking drives pathologic mucus gel formation in IL-13-stimulated airway epithelial cells.

Mucus plugs occlude airways to obstruct airflow in asthma. Studies in patients and in mouse models show that mucus plugs occur in the context of type 2 inflammation, and studies in human airway epithelial cells (HAECs) show that interleukin 13 (IL-13) activated cells generate pathologic mucus independently of immune cells. To determine how HAECs autonomously generate pathologic mucus, we used a magnetic microwire rheometer to characterize the viscoelastic properties of mucus secreted under varying conditions. We found that normal HAEC mucus exhibits viscoelastic liquid behavior and that mucus secreted by IL-13 activated HAECs exhibits solid-like behavior caused by mucin cross-linking. In addition, IL-13 activated HAECs show increased peroxidase activity in apical secretions, and an overlaid thiolated polymer (thiomer) solution shows an increase in solid behavior that is prevented by peroxidase inhibition. Furthermore, gene expression for thyroid peroxidase (TPO), but not lactoperoxidase (LPO), is increased in IL-13 activated HAECs and both TPO and LPO catalyze the formation of oxidant acids that cross-link thiomer solutions. Finally, gene expression for TPO in airway epithelial brushings is increased in asthma patients with high airway mucus plug scores. Together, our results show that IL-13 activated HAECs autonomously generate pathologic mucus via peroxidase-mediated cross-linking of mucin polymers.

The extracellular serine protease from Staphylococcus epidermidis elicits a type 2-biased immune response in atopic dermatitis patients.

Background: Atopic dermatitis (AD) is a chronic, relapsing inflammatory skin disease with skin barrier defects and a misdirected type 2 immune response against harmless antigens. The skin microbiome in AD is characterized by a reduction in microbial diversity with a dominance of staphylococci, including Staphylococcus epidermidis (S. epidermidis). Objective: To assess whether S. epidermidis antigens play a role in AD, we screened for candidate allergens and studied the T cell and humoral immune response against the extracellular serine protease (Esp). Methods: To identify candidate allergens, we analyzed the binding of human serum IgG4, as a surrogate of IgE, to S. epidermidis extracellular proteins using 2-dimensional immunoblotting and mass spectrometry. We then measured serum IgE and IgG1 binding to recombinant Esp by ELISA in healthy and AD individuals. We also stimulated T cells from AD patients and control subjects with Esp and measured the secreted cytokines. Finally, we analyzed the proteolytic activity of Esp against IL-33 and determined the cleavage sites by mass spectrometry. Results: We identified Esp as the dominant candidate allergen of S. epidermidis. Esp-specific IgE was present in human serum; AD patients had higher concentrations than controls. T cells reacting to Esp were detectable in both AD patients and healthy controls. The T cell response in healthy adults was characterized by IL-17, IL-22, IFN-γ, and IL-10, whereas the AD patients' T cells lacked IL-17 production and released only low amounts of IL-22, IFN-γ, and IL-10. In contrast, Th2 cytokine release was higher in T cells from AD patients than from healthy controls. Mature Esp cleaved and activated the alarmin IL-33. Conclusion: The extracellular serine protease Esp of S. epidermidis can activate IL-33. As an antigen, Esp elicits a type 2-biased antibody and T cell response in AD patients. This suggests that S. epidermidis can aggravate AD through the allergenic properties of Esp.

Tumor-Infiltrating T Cells in Skin Basal Cell Carcinomas and Squamous Cell Carcinomas: Global Th1 Preponderance with Th17 Enrichment-A Cross-Sectional Study.

Basal cell carcinomas (BCCs) and squamous cell carcinomas (SCCs) are high-incidence, non-melanoma skin cancers (NMSCs). The success of immune-targeted therapies in advanced NMSCs led us to anticipate that NMSCs harbored significant populations of tumor-infiltrating lymphocytes with potential anti-tumor activity. The main aim of this study was to characterize T cells infiltrating NMSCs. Flow cytometry and immunohistochemistry were used to assess, respectively, the proportions and densities of T cell subpopulations in BCCs (n = 118), SCCs (n = 33), and normal skin (NS, n = 30). CD8+ T cells, CD4+ T cell subsets, namely, Th1, Th2, Th17, Th9, and regulatory T cells (Tregs), CD8+ and CD4+ memory T cells, and γδ T cells were compared between NMSCs and NS samples. Remarkably, both BCCs and SCCs featured a significantly higher Th1/Th2 ratio (~four-fold) and an enrichment for Th17 cells. NMSCs also showed a significant enrichment for IFN-γ-producing CD8+T cells, and a depletion of γδ T cells. Using immunohistochemistry, NMSCs featured denser T cell infiltrates (CD4+, CD8+, and Tregs) than NS. Overall, these data favor a Th1-predominant response in BCCs and SCCs, providing support for immune-based treatments in NMSCs. Th17-mediated inflammation may play a role in the progression of NMSCs and thus become a potential therapeutic target in NMSCs.

Cang-ai volatile oil alleviates nasal inflammation via Th1/Th2 cell imbalance regulation in a rat model of ovalbumin-induced allergic rhinitis.

We previously revealed that Cang-ai volatile oil (CAVO) regulates T-cell activity, enhancing the immune response in people with chronic respiratory diseases. However, the effects of CAVO on allergic rhinitis (AR) have not been investigated. Herein, we established an ovalbumin (OVA)-induced AR rat model to determine these effects. Sprague-Dawley (SD) rats were exposed to OVA for 3 weeks. CAVO or loratadine (positive control) was given orally once daily for 2 weeks to OVA-exposed rats. Behavior modeling nasal allergies was observed. Nasal mucosa, serum, and spleen samples of AR rats were analyzed. CAVO treatment significantly reduced the number of nose rubs and sneezes, and ameliorated several hallmarks of nasal mucosa tissue remodeling: inflammation, eosinophilic infiltration, goblet cell metaplasia, and mast cell hyperplasia. CAVO administration markedly upregulated expressions of interferon-γ, interleukin (IL)-2, and IL-12, and downregulated expressions of serum tumor necrosis factor-α, IL-4, IL-5, IL-6, IL-13, immunoglobulin-E, and histamine. CAVO therapy also increased production of IFN-γ and T-helper type 1 (Th1)-specific T-box transcription factor (T-bet) of the cluster of differentiation-4+ T-cells in splenic lymphocytes, and protein and mRNA expressions of T-bet in nasal mucosa. In contrast, levels of the Th2 cytokine IL-4 and Th2-specific transcription factor GATA binding protein-3 were suppressed by CAVO. These cumulative findings demonstrate that CAVO therapy can alleviate AR by regulating the balance between Th1 and Th2 cells.

Cysteinyl leukotriene receptor-1 as a potential target for host-directed therapy during chronic schistosomiasis in murine model.

Schistosomiasis remains the most devastating neglected tropical disease, affecting over 240 million people world-wide. The disease is caused by the eggs laid by mature female worms that are trapped in host's tissues, resulting in chronic Th2 driven fibrogranulmatous pathology. Although the disease can be treated with a relatively inexpensive drug, praziquantel (PZQ), re-infections remain a major problem in endemic areas. There is a need for new therapeutic drugs and alternative drug treatments for schistosomiasis. The current study hypothesized that cysteinyl leukotrienes (cysLTs) could mediate fibroproliferative pathology during schistosomiasis. Cysteinyl leukotrienes (cysLTs) are potent lipid mediators that are known to be key players in inflammatory diseases, such as asthma and allergic rhinitis. The present study aimed to investigate the role of cysLTR1 during experimental acute and chronic schistosomiasis using cysLTR1-/- mice, as well as the use of cysLTR1 inhibitor (Montelukast) to assess immune responses during chronic Schistosoma mansoni infection. Mice deficient of cysLTR1 and littermate control mice were infected with either high or low dose of Schistosoma mansoni to achieve chronic or acute schistosomiasis, respectively. Hepatic granulomatous inflammation, hepatic fibrosis and IL-4 production in the liver was significantly reduced in mice lacking cysLTR1 during chronic schistosomiasis, while reduced liver pathology was observed during acute schistosomiasis. Pharmacological blockade of cysLTR1 using montelukast in combination with PZQ reduced hepatic inflammation and parasite egg burden in chronically infected mice. Combination therapy led to the expansion of Tregs in chronically infected mice. We show that the disruption of cysLTR1 is dispensable for host survival during schistosomiasis, suggesting an important role cysLTR1 may play during early immunity against schistosomiasis. Our findings revealed that the combination of montelukast and PZQ could be a potential prophylactic treatment for chronic schistosomiasis by reducing fibrogranulomatous pathology in mice. In conclusion, the present study demonstrated that cysLTR1 is a potential target for host-directed therapy to ameliorate fibrogranulomatous pathology in the liver during chronic and acute schistosomiasis in mice.

Osteoimmune Interaction and TH-1/TH-2 Ratio in Jawbone Marrow Defects: An Underestimated Association - Original Research.

Introduction: Osteoimmunology recognizes the relationship between bone cells and immune cells. Chronic osteoimmune dysregulation is present in bone marrow defects of the jaw (BMDJ) as fatty-degenerative osteonecrosis (FDOJ). In comparison to samples from healthy jaw bone, the cytokine analysis of samples of BMDJ/FDOJ from 128 patients showed downregulated TNF-α and IL-6 expression and the singular overexpression of the chemokine RANTES/CCL5. Aim and Objectives: This paper raises the question of whether the osteoimmune defects due to incomplete wound healing in BMDJ/FDOJ in 128 patients are related to dysregulation of the Th1/Th2 ratio and regulatory T cell (T-reg) expression in a control group of 197 BMDJ/FDOJ patients, each presenting with BMDJ/FJOD and one of seven different immune disorders. Material and Methods: In the control group, serum concentrations of the cytokines IFN-y and IL-4 were determined after stimulated cytokine release and displayed as Th1/Th2 ratios. Results: Data show a shift in Th2 in more than 80% (n = 167) of the control cohort of 197 chronically ill patients with concomitant BMDJ/FDOJ. In these 167 subjects, the Th1/Th2 ratio was <6.1 demonstrating impaired immune regulation. Forty-seven subjects or 30% showed not only a shift in Th2 but also excessive T-reg overactivation with levels of >1.900 pg/mL, indicating strongly downregulated immune activity. Discussion: BMDJ/FDOJ is characterized by a lack of Th1 cytokines and an excessive expression of RANTES/CCL5 and IL-1ra and, thus, the inversion of an acute inflammatory cytokine pattern. In contrast, abdominal fat contains a very high proportion of regulatory Th1 cells and produces an inflammatory immune response through the high overexpression of TNF-α and IL-6. The lack of Th1 activation in BMDJ/FDOJ areas inhibits normal wound healing and supports the persistence of BMDJ/FDOJ. Conclusion: The Th1/Th2 ratio requires greater consideration, especially with respect to wound healing following dental surgical interventions, such as jaw surgery, implantation and augmentation, to avoid the emergence of the osteoimmune situation that is characteristic of BMDJ/FDOJ.

Impact of antigen loading in tolerogenic nanoparticles to mitigate Th2-mediated allergic lung inflammation.

Allergic disease is a major global health concern that imposes significant life-altering and economic burdens on affected individuals. However, there is still no cure. Polymer-based nanoparticles (NP) have shown the potential to induce antigen (Ag)-specific immune tolerance in various Th1/17 and Th2-mediated immune disorders including autoimmunity and allergy. Common methods by which Ags are associated with NPs are through surface conjugation or encapsulation. However, these Ag delivery strategies can be associated with several caveats that dampen their effectiveness such as uncontrolled Ag loading, a high Ag burst release, and an increased immune recognition profile. We previously developed Ag-polymer conjugate NPs (acNPs) to overcome those noted limitations, while allowing for controlled delivery of precise quantities of Ag to innate immune cells for Ag-specific CD4 T cell modulation. Here, we utilized ovalbumin (OVA) protein-poly(lactic-co-glycolic acid) (PLGA) conjugate NPs (acNP-OVA) to elucidate the impact of Ag loading on the induction of Th2 tolerance using a prophylactic and therapeutic OVA/ALUM-induced mouse model of allergic lung inflammation (ALI) in comparison to Ag-encapsulated PLGA NPs (NP(Ag)). We demonstrate that acNP-OVA formulations reduced OVA-specific IgE and inhibited Th2 cytokine secretions in an Ag loading-dependent manner when administered prophylactically. Administration of acNP-OVA to pre-sensitized mice did not affect OVA-specific IgE and Th2 cytokines tended to be reduced, however, there was no clear Ag loading dependency. acNP-OVA with medium-to-low Ag loadings were well tolerated, while formulations with high Ag loadings, including NP(Ag) resulted in anaphylaxis. Overall, our results clarify the relationship between Ag loading and Ag-specific IgE and Th2 cytokine responses in a murine model of ALI, which provides insight useful for future design of tolerogenic NP-based immunotherapies.

Endogenous innate sensor NLRP3 is a key component in peritoneal macrophage dynamics required for cestode establishment.

The NLRP3 receptor can assemble inflammasome platforms to trigger inflammatory responses; however, accumulating evidence suggests that it can also display anti-inflammatory properties. Here, we explored the role of nucleotide-binding oligomerization domain pyrin-containing protein 3 (NLRP3) in Taenia crassiceps experimental infection, which requires immune polarization into a Th2-type profile and peritoneal influx of suppressive macrophages for successful colonization. NLRP3 deficient mice (NLRP3-/-) were highly resistant against T. crassiceps, relative to wild-type (WT) mice. Resistance in NLRP3-/- mice was associated with a diminished IL-4 output, high levels of IL-15, growth factor for both innate and adaptive lymphocytes, and a dramatic decrease in peritoneum-infiltrating suppressive macrophages. Also, a transcriptional analysis on bone marrow-derived macrophages exposed to Taenia-secreted antigens and IL-4 revealed that NLRP3-/- macrophages express reduced transcripts of relm-α and PD-1 ligands, markers of alternative activation and suppressive ability, respectively. Finally, we found that the resistance displayed by NLRP3-/- mice is transferred through intestinal microbiota exchange, since WT mice co-housed with NLRP3-/- mice were significantly more resistant than WT animals preserving their native microbiota. Altogether, these data demonstrate that NLRP3 is a component of innate immunity required for T. crassiceps to establish, most likely contributing to macrophage recruitment, and controlling lymphocyte-stimulating cytokines such as IL-15.

The stimulation of TH2 cells results in increased IL-5 and IL-13 production via the H4 receptor.

BACKGROUND: Atopic dermatitis (AD) is a chronic inflammatory skin disease resulting in decreased quality of life. Histamine and specifically the H4 receptor play a key role in the inflammatory process in AD and serve as targets for novel therapeutic approaches. OBJECTIVE: In the present study we aimed to elucidate the immunopathological mechanisms with which the H4 receptor impacts TH2 cells and contributes to AD pathophysiology. METHODS: Total CD4+ T cells obtained from healthy or AD individuals and in vitro differentiated TH2 cells were cultured under different conditions and the mRNA expression or protein production of target molecules were determined using quantitative real-time PCR and ELISA. RESULTS: H4 receptor mRNA expression was upregulated concentration dependent upon IL-4 stimulation in in vitro differentiated TH2 cells progressively during the differentiation. Transcriptomic analysis of in vitro differentiated TH2 versus TH1 cells revealed that the H4 receptor among other genes represents one of the highly upregulated genes in TH2 cells. Most importantly, increased amounts of IL-5 and IL-13 mRNA expression were detected in in vitro differentiated TH2 cells as well as protein secretion in the presence of histamine or of the H4 receptor-selective-agonist when compared to the untreated control. CONCLUSION: We show for the first time an H4 receptor dependent upregulation of the pro-inflammatory cytokines IL-5 and IL-13 in human TH2 cells by histamine. This suggests that the blockade of the H4 receptor may lead to downregulation of these cytokines and amelioration of AD symptoms as reported in first clinical studies.