Role In Allergic Inflammation Research Articles

Assessing serum cytokine and immunoglobulin levels in patients with allergic rhinitis and allergic rhinoconjunctivitis before and after treatment supplemented with macromycetes

Background: In recent decades, the prevalence of allergic rhinitis (AR) has been increasing all over the world including Ukraine. Allergic rhinoconjunctivitis (ARC) is one of the most common clinical forms of AR. An imbalance between pro-inflammatory and anti-inflammatory cytokines is known to have a key role in allergic inflammation. Purpose: To compare cytokine and immunoglobulin levels among patients with AR and ARC treated with different therapeutic options. Material and Methods: Forty patients with AR and ARC (age range, 20 to 46 years) were included in the study. Disease duration ranged from 6 months to 2 years. Patients were divided into two subgroups of 20 patients each. Patients of subgroup 1 received the basic therapy (a 10-mg loratadin tablet daily and mometasone furoate nasal spray at a dosage of 200 μg once daily), whereas patients of subgroup 2, the basic therapy plus polypore macromycetes (Astmagan), one capsule twice daily. Treatment course duration was 90 days. The control group was composed of 25 healthy individuals. A comprehensive clinical immunological examination was conducted at baseline and on the completion of the treatment course. Enzyme-linked immunosorbent assay kits were used to determine serum levels of immunoglobulins A (IgA), IgM, IgG, and IgE, and cytokines (gamma interferon (IFN-γ) and IL4). Results: At baseline, serum levels of IgA, IgM and IgE were almost twice as high (р = 0.0008; 0.0005; and 0.0001, respectively); IgG, 1.2 times higher (р = 0.001); pro-inflammatory cytokine IL4, 3.5 times higher (р = 0.0001); and anti-inflammatory cytokine IFN-γ, 2.4 times lower (р = 0.0001) in patients with AR and ARC compared to controls, and these differences were significant. Astmagan, when used as an adjunct to the basic treatment of AR and ARC, contributed to 8%, 17%, 16.2%, 7.3% and 6.0% greater decreases in the serum levels of IgA, IgM, IgE, IgG and IL4, respectively, and a 16.6% greater increase in the serum level of IFN-γ compared to the basic treatment only, and these differences were significant, with an improvement in immune response to therapy.

054 Combination of thymus and activation-regulated chemokine and soluble OX40 as a diagnostic biomarker for DIHS/DRESS

Drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms (DIHS/DRESS) is a severe drug-induced adverse reaction with fever, cutaneous eruptions, hematological abnormalities, organ dysfunction, and reactivation of human herpesvirus 6 (HHV-6). Although rapid diagnosis is necessary for the management of DIHS/DRESS, it is difficult to distinguish the early phase of DIHS/DRESS from other drug eruptions. We have previously reported that thymus and activation-regulated chemokine (TARC), which plays an important role in Th2-mediated immune-inflammatory processes such as atopic dermatitis, and serum soluble OX40 (CD134), which has an important role in allergic inflammation and functions as a cellular receptor for HHV-6 entry, can be a useful diagnostic marker for DIHS/DRESS. The sensitivity and specificity of sOX40 (cut-off value 213 pg/ml) for the diagnosis of DIHS/DRESS were 67% and 80%, respectively. Those of TARC (cut-off value 4000 pg/ml) were 72% and 77%, respectively. In this study, in order to reveal the relationship between serum soluble OX40 and TARC levels in the acute phase of DIHS/DRESS as well as the sensitivity and specificity of serological test using both soluble OX40 and TARC for diagnosis of DIHS/DRESS, we analyzed the sera of DIHS/DRESS patients presenting to our department. We found that the two markers were significantly correlated, and the combination of sOX40 and TARC significantly increased sensitivity to 85% but decreased specificity to 73%. The combined determination using sOX40 and TARC levels may be useful to increase the detection rate of DIHS/DRESS.

A germline STAT6 gain-of-function variant is associated with early-onset allergies

The signal transducer and activator of transcription 6 (STAT6) signaling pathway plays a central role in allergic inflammation. To date, however, there have been no descriptions of STAT6 gain-of-function variants leading to allergies in humans. We report a STAT6 gain-of-function variant associated with early-onset multiorgan allergies in a family with 3 affected members. Exome sequencing and immunophenotyping of T-helper cell subsets were conducted. The function of the STAT6 protein was analyzed by Western blot, immunofluorescence, electrophoretic mobility shift assays, and luciferase assays. Gastric organoids obtained from the index patient were used to study downstream effector cytokines. We identified a heterozygous missense variant (c.1129G>A;p.Glu377Lys) in the DNA binding domain of STAT6 that was de novo in the index patient's father and was inherited by 2 of his 3 children. Severe atopic dermatitis and food allergy were key presentations. Clinical heterogeneity was observed among the affected individuals. Higher levels of peripheral blood TH2 lymphocytes were detected. The mutant STAT6 displayed a strong preference for nuclear localization, increased DNA binding affinity, and spontaneous transcriptional activity. Moreover, gastric organoids showed constitutive activation of STAT6 downstream signaling molecules. A germline STAT6 gain-of-function variant results in spontaneous activation of the STAT6 signaling pathway and is associated with an early-onset and severe allergic phenotype in humans. These observations enhance our knowledge of the molecular mechanisms underlying allergic diseases and will potentially contribute to novel therapeutic interventions.

Neuropathic pain and itch: mechanisms in allergic conjunctivitis.

Allergic conjunctivitis is highly prevalent and affects up to one third of the general population. The current understanding of the pathophysiology and therapeutic strategies center around the type 2 inflammatory pathway. However, there is an increasing body of evidence that suggests neurogenic mechanisms also play a role in allergic inflammation, with a substantial proportion of allergic conjunctivitis patients experiencing both ocular itch and pain. Unmyelinated C fibres on the ocular surface transmit histaminergic itch and can be directly activated by mast cell mediators. The conjunctival mucosa also contains TRPV1+ (histamine-dependent) and TRPA1+ (histamine-independent) neurons that enhance ocular pain and itch in allergic conjunctivitis. Allergen-complexed IgE also binds directly to FcεRI expressed on peripheral neurons. Environmental aeroallergens can also directly stimulate neuronal nociceptors to release inflammatory substances. Allergic inflammation thus stimulates nerve terminals to release vasoactive and inflammatory neuropeptides, leading to a cyclical neuronal dysregulation that augments mast cell activity. These repetitive cycles lead to both peripheral and central sensitization and neuronal plasticity, resulting in decreased itch/pain thresholds and a heightened itch/pain response. Neurogenic mechanisms including peripheral and central sensitization may drive chronic ocular itch and pain secondary to allergic inflammation. Research into these pathways may help to identify therapeutic targets in allergic conjunctivitis patients with refractory symptoms.

Inhibition effect of PPAR-γ signaling on mast cell-mediated allergic inflammation through down-regulation of PAK1/ NF-κB activation

As a ligand-activated transcription factor, peroxisome proliferator-activated receptor gamma (PPAR-γ) plays a crucial role in allergic inflammation. Recently, the nuclear factor kappa B (NF-κB) pathway and PAK1 have been indicated to be associated with allergic diseases. However, the effect of PPAR-γ on NF-κB and PAK1 production in food allergies is not known. This study aims to 1) systematically validate that the activation of PPAR-γ attenuates allergic reactions and 2) elucidate the mechanism by which PPAR-γ regulates mast cell degranulation. Brown Norway rats were separated into control, ovalbumin, ovalbumin + rosiglitazone, and ovalbumin + GW9662 groups. In vivo experiments demonstrated that rosiglitazone administration markedly inhibited the clinical symptoms and the serum levels of immunoglobulins E and G1. In addition, cytokine release was regulated by activated PPAR-γ and characterized by increased levels of IFN-γ and decreased levels of IL-4, IL-5, and TNF-α. Our data showed that activated PPAR-γ has the potential to alleviate food allergies by enhancing intestinal mucosal integrity and tight junctions. Moreover, we found that PPAR-γ activation inhibited mast cell degranulation both in vivo and in vitro. Our in vitro findings also showed that the activated PPAR-γ signal could inhibit PAK1 phosphorylation and the expression of p65. Furthermore, the interaction between p65 and p-PAK1 during ovalbumin treatment was attenuated after PPAR-γ activation. Collectively, these results demonstrate that PPAR-γ is an important regulator of mast cell degranulation and the Th2-type response, which sheds new light on the importance of PPAR-γ in food allergies.

Differential Regulation of Allergic Airway Inflammation by Acetylcholine.

Acetylcholine (ACh) from neuronal and non-neuronal sources plays an important role in the regulation of immune responses and is associated with the development of several disease pathologies. We have previously demonstrated that group 2 innate lymphoid cell (ILC2)-derived ACh is required for optimal type 2 responses to parasitic infection and therefore sought to determine whether this also plays a role in allergic inflammation. Rora Cre+ Chat LoxP mice (in which ILC2s cannot synthesize ACh) were exposed to an allergenic extract of the fungus Alternaria alternata, and immune responses in the airways and lung tissues were analyzed. Airway neutrophilia and expression of the neutrophil chemoattractants CXCL1 and CXCL2 were enhanced 24 h after exposure, suggesting that ILC2-derived ACh plays a role in limiting excessive pulmonary neutrophilic inflammation. The effect of non-selective depletion of ACh was examined by intranasal administration of a stable parasite-secreted acetylcholinesterase. Depletion of airway ACh in this manner resulted in a more profound enhancement of neutrophilia and chemokine expression, suggesting multiple cellular sources for the release of ACh. In contrast, depletion of ACh inhibited Alternaria-induced activation of ILC2s, suppressing the expression of IL-5, IL-13, and subsequent eosinophilia. Depletion of ACh reduced macrophages with an alternatively activated M2 phenotype and an increase in M1 macrophage marker expression. These data suggest that ACh regulates allergic airway inflammation in several ways, enhancing ILC2-driven eosinophilia but suppressing neutrophilia through reduced chemokine expression.

Adhesion Promotes Allergic Rhinitis CD4+IL4+ T Cell Differentiation via ICAM1 and E-Selectin.

Neuroimmune communication plays an important role in allergic inflammation, but the neuroimmune regulation of allergic rhinitis remains unclear. The goal of this study was to investigate the role of CD4-positive T lymphocyte (CD4+ T cells) adhesion to D-U87 neuron-like cells in mediating allergic rhinitis CD4+ T cell differentiation. D-U87 neuron-like cells were derived from the human glioblastoma U87 cell line. CD4+ T cells were isolated from human peripheral blood using a magnetic separation technique. In vitro coculture of D-U87 neuron-like cells and CD4+ T cells was established. The number of adherent CD4+ T cells was counted using a fluorescence microscope. The percentages of CD4+IFNγ+ and CD4+IL4+ T cells and the levels of IFNγ and IL4 cytokines in the supernatant were measured by flow cytometry. The results showed that the number of adherent CD4+ T cells in patients with allergic rhinitis was significantly higher than that in healthy controls. In allergic rhinitis, the percentage of CD4+IL4+ T cells was significantly increased in the adherent group compared with that in the nonadherent group. Moreover, blocking ICAM1 and E-selectin decreased the number of adherent CD4+ T cells and the percentage of CD4+IL4+ T cells in allergic rhinitis. Adhesion contributes to CD4+IL4+ T cell differentiation in the in vitro coculture system of D-U87 neuron-like cells and allergic rhinitis CD4+ T cells, which may provide new insights into therapeutic strategies for allergic rhinitis.

IL-3 Expands Pre-Basophil and Mast Cell Progenitors by Upregulating the IL-3 Receptor Expression

Basophils and mast cells play a critical role in allergic inflammation and provide protective immunity against certain types of parasitic infections. Expansion of basophils and mast cells to the critical numbers is believed to be an essential step in enabling basophils and mast cells to carry out their protective functions. However, factors that drive basophil and mast cell expansion are still incompletely understood. We tested the roles of cytokines and growth factors IL-3, TSLP, GM-CSF, IL-5, SCF, IL-7, IL-25, and IL-33 in promoting the differentiation of pre-basophil and mast cell progenitors (pre-BMPs)in vitro.We found that while GM-CSF only expanded basophils, IL-3 promoted the differentiation of pre-BMPs into both basophils and mast cells. We found that IL-3 expanded the number of pre-BMPsin vivo. We showed that IL-3 upregulatedIl3ramRNA and protein expression on pre-BMPs, supporting that IL-3 expands pre-BMPs in part by upregulating the IL-3 receptor expression. Although Gata2 mRNA expression was upregulated by IL-3 treatment in pre-BMPs, it is dispensable for IL-3-mediated upregulation of IL-3 receptor expression. Our study reveals a novel mechanism through which IL-3 expands basophil and mast cells.

Serum Soluble OX40 as a Diagnostic and Prognostic Biomarker for Drug-Induced Hypersensitivity Syndrome/Drug Reaction with Eosinophilia and Systemic Symptoms

Drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms (DIHS/DRESS) is a severe adverse drug reaction commonly associated with the reactivation of human herpesvirus 6 (HHV-6). There are currently no adequate biomarkers for the early diagnosis and detection of DIHS/DRESS. Notably, OX40 (CD134) has an important role in allergic inflammation and functions as a cellular receptor for HHV-6 entry. We previously reported that the membrane-bound form of OX40 in CD4+ T cells was upregulated in DIHS/DRESS. We sought to investigate the clinical significance of serum soluble OX40 (sOX40) in DIHS/DRESS. Serum sOX40 levels in patients with DIHS/DRESS (n= 39), maculopapular exanthema/erythema multiforme (n= 17), Stevens-Johnson syndrome/toxic epidermal necrolysis (n= 13), or autoimmune bullous diseases (n= 5), and levels in healthy volunteers (n= 5) were examined by enzyme-linked immunosorbent assay. Copy numbers of HHV-6, HHV-7, and cytomegalovirus in peripheral blood mononuclear cells were quantified using real-time PCR. Serum sOX40 levels in patients with DIHS/DRESS in the acute stage were elevated in parallel with high OX40 expression on CD4+ T cells. Serum sOX40 levels were significantly positively correlated with disease severity and serum levels of thymus and activation-regulated chemokine, IL-5, and IL-10. Human herpesvirus 6-positive patients had higher sOX40 levels than did HHV-6-negative patients, and serum sOX40 levels were correlated with HHV-6 DNA loads. Serum sOX40 levels can be a useful diagnostic marker for DIHS/DRESS that reflect disease severity. Elevated serum sOX40 levels also predict HHV-6 reactivation in patients with DIHS/DRESS.

Allergic Inflammation Caused by Dimerized Translationally Controlled Tumor Protein is Attenuated by Cardamonin

We demonstrated in our previous reports that dimeric form of translationally controlled tumor protein (dTCTP) initiates a variety of allergic phenomena. In the present study, we examined whether and how dTCTP’s role in allergic inflammation can be modulated or negated. The possible potential of cardamonin as an anti-allergic agent was assessed by ELISA using BEAS-2B cells and OVA-challenged allergic mouse model. The interaction between cardamonin and dTCTP was confirmed by SPR assay. Cardamonin was found to reduce the secretion of IL-8 caused by dTCTP in BEAS-2B cells by interacting with dTCTP. This interaction between dTCTP and cardamonin was confirmed through kinetic analysis (KD = 4.72 ± 0.07 μM). Also, cardamonin reduced the migration of various inflammatory cells in the bronchoalveolar lavage fluid (BALF), inhibited OVA specific IgE secretion and bronchial remodeling. In addition, cardamonin was observed to have an anti-allergic response by inhibiting the activity of NF-κB. Cardamonin exerts anti-allergic anti-inflammatory effect by inhibiting dTCTP, suggesting that it may be useful in the therapy of allergic diseases.

Behind the scenes with basophils: an emerging therapeutic target.

SummaryThough basophils were originally viewed as redundant blood ‘mast cells’, the implementation of flow cytometry has established basophils as unique leukocytes with critical immunomodulatory functions. Basophils play an active role in allergic inflammation, autoimmunity, and hematological malignancies. They are distinguishable from other leukocytes by their characteristic metachromatic deep-purple cytoplasmic, round granules. Mature basophils are phenotypically characterized by surface expression of IL-3Rα (CD123); IL-3 drives basophil differentiation, degranulation, and synthesis of inflammatory mediators including type 2 cytokines. Basophil degranulation is the predominant source of histamine in peripheral blood, promoting allergic responses. Basophils serve as a bridge between innate and adaptive immunity by secreting IL-4 which supports eosinophil migration, monocyte differentiation into macrophages, B-cell activation, and CD4 T-cell differentiation into Th2 cells. Further, basophilia is a key phenomenon in myeloid neoplasms, especially chronic myeloid leukemia (CML) for which it is a diagnostic criterion. Increased circulating basophils, often with aberrant immunophenotype, have been detected in patients with CML and other myeloproliferative neoplasms (MPNs). The significance of basophils’ immunoregulatory functions in malignant and non-malignant diseases is an active area of research. Ongoing and future research can inform the development of immunotherapies that target basophils to impact allergic, autoimmune, and malignant disease states. This review article aims to provide an overview of basophil biology, identification strategies, and roles and dysregulation in diseases.

Dexamethasone and lidocaine suppress eosinophilopoiesis from umbilical cord blood cells

BackgroundEosinophils play an important role in allergic inflammation. Glucocorticosteroids have been used as an anti-inflammatory medication for inflammatory diseases involving eosinophil infiltration. Some effect of nebulized lidocaine has been reported when treating certain patients with asthma, which is also an inflammatory disease. The goal of this study was to examine the effects of dexamethasone and lidocaine on eosinophil proliferation and differentiation using a model of human umbilical cord blood mononuclear cells (UCMC) cultured with IL-5.MethodsUCMC were cultured with IL-5 (5 ng/mL) for 4 weeks. The effects of dexamethasone and lidocaine on the number and morphology of eosinophilic cells were visualized with Wright-Giemsa and cyanide-resistant peroxidase stains. Moreover, the effect on eosinophil-derived neurotoxin (EDN) and eosinophil peroxidase (EPX) contents in cultured cells were evaluated using radioimmunoassay.ResultsThe number of eosinophilic cells and EDN and EPX content in cultured cells increased in a time-dependent manner in the presence of IL-5. Dexamethasone treatment slightly decreased the number of eosinophilic cells in one week, but this effect was lost in 2–4 weeks. Macrophages in cultured UCMC treated with dexamethasone contained more eosinophil granule proteins. Both EDN and EPX content in cultured cells were reduced by dexamethasone. Lidocaine decreased the number of eosinophilic cells and reduced both EDN and EPX contents in cultured cells.ConclusionsDexamethasone suppressed the production of eosinophil granule proteins and may also induce apoptosis of eosinophils, while lidocaine suppresses eosinophilopoiesis.

Basophils and their effector molecules in allergic disorders.

Basophils are the rarest granulocytes which represent <1% of peripheral blood leukocytes. Basophils bear several phenotypic similarities to tissue-resident mast cells and therefore had been erroneously considered as blood-circulating mast cells. However, recent researches have revealed that basophils play nonredundant roles in allergic inflammation, protective immunity against parasitic infections and regulation of innate and acquired immunity. Basophils are recruited to inflamed tissues and activated in an IgE-dependent or IgE-independent manner to release a variety of effector molecules. Such molecules, including IL-4, act on various types of cells and play versatile roles, including the induction and termination of allergic inflammation and the regulation of immune responses. Recent development of novel therapeutic agents has enabled us to gain further insights into basophil biology in human disorders. In this review, we highlight the recent advances in the field of basophil biology with a particular focus on the role of basophils in allergic inflammation. Further studies on basophils and their effector molecules will help us identify novel therapeutic targets for treating allergic disorders.

Adhesion molecule cross-linking and cytokine exposure modulate IgE- and non-IgE-dependent basophil activation.

SummaryBasophils are known for their role in allergic inflammation, which makes them suitable targets in allergy diagnostics such as the basophil activation test (BAT) and the microfluidic immunoaffinity basophil activation test (miBAT). Beside their role in allergy, basophils have an immune modulatory role in both innate immunity and adaptive immunity. To accomplish this mission, basophils depend on the capability to migrate from blood to extravascular tissues, which includes interactions with endothelial cells, extracellular matrix and soluble mediators. Their receptor repertoire is well known, but less is known how these receptor–ligand interactions impact the degranulation process and the responsiveness to subsequent activation. As the consequences of these interactions are crucial to fully appreciate the role of basophils in immune modulation and to enable optimization of the miBAT, we explored how basophil activation status is regulated by cytokines and cross‐linking of adhesion molecules. The expression of adhesion molecules and activation markers on basophils from healthy blood donors was analysed by flow cytometry. Cross‐linking of CD203c, CD62L, CD11b and CD49d induced a significant upregulation of CD63 and CD203c. To mimic in vivo conditions, valid also for miBAT, CD62L and CD49d were cross‐linked followed by IgE‐dependent activation (anti‐IgE), which caused a reduced CD63 expression compared with anti‐IgE activation only. IL‐3 and IL‐33 priming caused increased CD63 expression after IgE‐independent activation (fMLP). Together, our data suggest that mechanisms operational both in the microfluidic chip and in vivo during basophil adhesion may impact basophil anaphylactic and piecemeal degranulation procedures and hence their immune regulatory function.

Lysophosphatidic Acid Regulates the Differentiation of Th2 Cells and Its Antagonist Suppresses Allergic Airway Inflammation

Background: Lysophosphatidic acid (LPA), a prototypic member of a large family of lysophospholipids, has been recently shown to play a role in immune responses to respiratory diseases. The involvement of LPA in allergic airway inflammation has been reported, but the mechanism remains unclear. Object: We analyzed the biological activity of LPA in vitro and in vivo and investigated its role in allergic inflammation in mice using an LPA receptor 2 (LPA2) antagonist. Methods: We used a murine model with acute allergic inflammation, in which mice are sensitized and challenged with house dust mite, and analyzed airway hyperresponsiveness (AHR), pathological findings, Th2 cytokines, and IL-33 in bronchoalveolar lavage fluid (BALF) and lung homogenates. The effect of LPA on Th2 differentiation and cytokine production was examined in vitro using naive CD4⁺ T cells isolated from splenocytes. We also investigated in vivo the effects of LPA on intranasal administration in mice. Results: The LPA2 antagonist suppressed the increase of AHR, the number of total cells, and eosinophils in BALF and lung tissue. It also decreased the production of IL-13 in BALF and IL-33 and CCL2 in the lung. LPA promoted Th2 cell differentiation and IL-13 production by Th2 cells in vitro. Nasal administration of LPA significantly increased the number of total cells and IL-13 in BALF via regulating the production of IL-33 and CCL-2-derived infiltrating macrophages. Conclusion: These findings suggest that LPA plays an important role in allergic airway inflammation and that the blockade of LPA2 might have therapeutic potential for bronchial asthma.

Interleukin-9 Inhibits Lung Metastasis of Melanoma through Stimulating Anti-Tumor M1 Macrophages.

Interleukin-9 (IL-9) is well known for its role in allergic inflammation. For cancer, both pro- and anti-tumor effects of IL-9 were controversially reported, but the impact of IL-9 on tumor metastasis has not yet been clarified. In this study, IL-9 was expressed as a secretory form (sIL-9) and a membrane-bound form (mbIL-9) on B16F10 melanoma cells. The mbIL-9 was engineered as a chimeric protein with the transmembrane and cytoplasmic region of TNF-α. The effect of either mbIL-9 or sIL-9 expressing cells were analyzed on the metastasis capability of the cancer cells. After three weeks of tumor implantation into C57BL/6 mice through the tail vein, the number of tumor modules in lungs injected with IL-9 expressing B16F10 was 5-fold less than that of control groups. The percentages of CD4+ T cells, CD8+ T cells, NK cells, and M1 macrophages considerably increased in the lungs of the mice injected with IL-9 expressing cells. Among them, the M1 macrophage subset was the most significantly enhanced. Furthermore, peritoneal macrophages, which were stimulated with either sIL-9 or mbIL-9 expressing transfectant, exerted higher anti-tumor cytotoxicity compared with that of the mock control. The IL-9-stimulated peritoneal macrophages were highly polarized to M1 phenotype. Stimulation of RAW264.7 macrophages with sIL-9 or mbIL-9 expressing cells also significantly increased the cytotoxicity of those macrophages against wild-type B16F10 cells. These results clearly demonstrate that IL-9 can induce an anti-metastasis effect by enhancing the polarization and proliferation of M1 macrophages.

Chronic pharyngitis, a condition of a problem. An algorithm for the diagnosis of chronic pharyngitis of an allergic nature

The article describes the status of the problem of chronic pharyngitis – the lack of modern etiopathogenetic classification, subjective review approach to diagnosis, etc. The role of allergic inflammation in the formation of chronic pharyngitis was evaluated and the diagnostic algorithm was proposed.

Basophil degranulation in response to IgE ligation is controlled by a distinctive circadian clock in asthma.

Several factors may contribute to the circadian variability of clinical manifestations in asthma and allergy. Basophils play a pivotal role in allergic inflammation. However, evidence for a functional clock governing the effector function of these cells is sparse and contradictory. We have systematically sampled the 24-hour response of basophils to IgE- and non-IgE-dependent ligands in asthma to understand their possible contribution to the diurnal variations of allergic symptoms. Leukocytes were collected every 4hours for 24hours from 10 patients with moderate, persistent asthma and 10 matched, nonallergic controls, and then incubated with concentrations of anti-IgE, formyl-methionyl-leucylphenylalanine (fMLP), or the Ca2+ ionophore, A23187. Histamine release (HR) was tested for time-of-day- or disease-related variability by conventional statistics and for 24-hour rhythmicity by the cosinor method. HR induced by anti-IgE was significantly increased at 08:00 vs. 20:00 in basophils from asthmatics but not controls. No significant differences were seen at any time in the response to A23187, while the response to fMLP was significantly higher at 08:00 vs. 20:00 in controls but not asthmatics. The basophil response to anti-IgE, but not fMLP or A23187, varied significantly across the 24hours in asthma, and its amplitude, percent rhythm, and acrophase were comparable to those of peak expiratory flow or serum cortisol. Using an integrated statistical approach, we show that basophil responsiveness undergoes significant circadian variability and that distinct patterns of rhythmicity can be recognized depending on the signal delivered, the activation parameters assessed, and the disease status.

Emerging Roles of Th9 Cells as an Anti-tumor Helper T Cells

The newly discovered Th9 cells are the distinct subset of CD4+ T helper (Th) cells, which are involved in various pathophysiological conditions of an immune response. In addition to its role in allergic inflammation and elimination of extracellular pathogens, Th9 cells were found to play a key role in inducing anti-tumor immune response. Precisely, the anti-tumor functions of Th9 cells were found to be superior as compared to Th1 and other Th subsets. Th9 cells eliminate tumors via activating innate and adaptive immune cells, and in particular, generating a profound effector cytotoxic T lymphocyte (CTL) response against neo antigens. In addition, it was proposed that Th9 cells were found to induce effector functions of innate cells like dendritic cells, mast cells and NK cells, which further promote a robust anti-tumor immune response. In this review, we highlight the recent advances in differentiation and functions of Th9 cells in anti-tumor immunity.

Evidence for the induction of Th2 inflammation by group 2 innate lymphoid cells in response to prostaglandin D2 and cysteinyl leukotrienes in allergic rhinitis.

Group 2 innate lymphoid cells (ILC2s) play important roles in allergic inflammation. However, their roles in the pathophysiology of allergic rhinitis (AR) are poorly understood. Prevalence of ILC2s in the inferior nasal turbinate (INT) tissues and the activating mechanisms of ILC2s were examined in patients with house dust mite (HDM)-induced AR. Eighteen patients with HDM-induced AR and 13 control subjects were recruited. Fresh INT tissues and peripheral blood mononuclear cells (PBMCs) were analysed using flow cytometry. Nasal lavage fluids (NLF) were collected at 10minutes after the nasal provocation test (NPT) with HDM disc, and released mediators were measured by ELISA. Sorted ILC2s were cultured and stimulated with mediators associated with AR. The prevalence of ILC2s was significantly increased in nasal mucosa of patients with HDM-induced AR, and it was positively correlated with the number of infiltrating eosinophils. ILC2s in the INT tissues expressed a prostaglandin D2 (PGD2 ) receptor, chemoattractant receptor-homologous molecule-expressed TH2 cells (CRTH2) and a cysteinyl leukotriene (cysLTs) receptor, CysLT1. After NPT, the number of eosinophils and concentrations of PGD2 and cysLTs were significantly increased in the NLF from AR patients. PGD2 and cysLTs significantly induced IL-5 production from cultured PBMC-derived ILC2s dose-dependently. PGD2 -induced and cysLTs-induced productions of IL-5 and IL-13 from ILC2s were completely inhibited by ramatroban, a dual CRTH2 and thromboxane receptor antagonist, and montelukast, a CysLT1 antagonist, respectively. PGD2 -CRTH2 and cysLTs-CysLT1 axes may activate tissue-resident ILC2s to produce Th2 cytokines, IL-5 and IL-13, leading to the development of allergic inflammation in AR.