Histamine H1 receptor (H1R) and histamine H4 receptor (H4R) are essential in allergic inflammation. The roles of H4R have been characterized in T cell subsets, whereas the functional properties of H4R in monocytes remain unclear. In the current study, the responses of H4R in peripheral monocytes from patients with allergic rhinitis (AR) were investigated. The results confirmed that H4R has the functional effects of mediating cytokine production (i.e., down-regulating IFN-gamma and up-regulating IL-6) in cells from a monocyte cell line following challenge with histamine. We demonstrated that when monocytes from AR patients were stimulated with allergen extracts of house dust mite (HDM), IFN-gamma secretion was dependent on H4R activity, but IL-6 secretion was based on H1R activity. Furthermore, a combination of H1R and H4R antagonists was more effective at blocking the inflammatory response in monocytes than treatment with either type of antagonist alone.
Background; The identification of house dust mite (HDM) allergens and epitopes is important for allergy diagnosis and treatment. We sought to identify the Dermatophagoides pteronyssinus group 24 allergen (Der p 24) and to identify its immunodominant IgE epitope(s). Methods: Der p 24 cDNA was cloned and expressed in a pET expression system. The IgE binding activity of purified recombinant (r)Der p 24 was evaluated by western blotting. Truncated Der p 24 proteins and overlapping synthetic polypeptides were subjected to IgE binding assays. Balb/c mice were immunized to investigate IgE epitope induction of IgE production. IgE binding of the 32N-terminal residues of Der p 24 was compared to other Der p epitopes in enzyme-linked immunosorbent assays and dot blot assays. Human skin prick tests (SPTs) were performed. Results: We cloned and expressed Der p 24 cDNA (GenBank accession no. KP893174.1). HDM allergic sera bound rDer p 24 in vitro and 5/10 HDM allergic patients (50%) had positive SPT reactions to rDer p 24. The immunodominant IgE epitope of Der p 24 was localized to the N-terminal 32-residue region, which produced a high specific IgE antibody titer in vivo and promoted mast cell beta-hexosaminidase release. The IgE binding activity this N-terminal epitope of Der p 24 was stronger than that of Der p 1 or Der p 2 IgE epitopes. Conclusions: We identified Der p 24 as a major HDM allergen with strong IgE binding activity via an immunodominant IgE epitope in the N-terminal 32-residue region, which triggers IgE production in vivo. The identified Der p 24 epitope may support HDM allergy diagnosis and treatment.
Data regarding clinical relevance of house dust mite (HDM) components over allergen immunotherapy (AIT) for allergic rhinitis (AR) are lacking. 18 adult AR patients receiving HDM-AIT for 52 weeks were followed up to assess serum levels of sIgE and sIgG4 to HDM components. The study showed that Der p1, p2, p23, Der f1 and f2, are important sensitizing components of HDM, of which Der p1 appears to be the most clinically relevant allergenic component for effective AIT.
Background: Interleukin(IL)-25, IL-33, and thymic stromal lymphopoietin (TSLP) underlie the crosstalk between epithelial cells and dendritic cells (DCs) during the development of Th2 responses. This study aimed to measure the expressions of IL-17RB, ST2 and TSLPR, receptor of IL-25, IL-33, and TSLP respectively, on myeloid DCs in nasal polyps (NP) and evaluate their association with local Th2 inflammation and disease severity in patients with NP. Methods: Samples were collected from 30 NP patients and 16 control subjects recruited prospectively. The mRNA expression of cytokines, including TSLP, IL-25 and IL-33, as well as interferon (IFN)-gamma, IL-4, IL-5, IL-13 and IL-17A in NP and control tissues was examined by qualitative polymerase chain reaction (qPCR). The expression of IL-17RB, ST2 and TSLPR as well as other surface markers on myeloid DCs (mDCs) was examined by flow cytometry. Results: Increased numbers of total and activated mDCs were found in NP patients. mDCs demonstrated significantly higher expression of IL-17RB, ST2 and TSLPR than those in control tissues. The activated mDCs exhibited upregulations of OX40L and ICOSL, but down-regulation of PDL1 in NP. Moreover, the IL-17RB, ST2 and TSLPR levels on mDCs were positively correlated with IL-25, IL-33 and TSLP mRNA levels, respectively, in NP. Furthermore, IL-17RB and ST2 expressions on mDCs were correlated with the IL-5 mRNA level as well as eosinophil number in NP. Importantly, the IL-17RB expression on mDCs and the OX40L expression on activated mDCs in NP were positively correlated with CT score and total nasal symptom score. Conclusions: Increased expressions of IL-17RB and ST2 on mDCs are associated with enhanced local Th2 inflammation in NP, suggesting that mDCs might play a role in IL-25- and IL-33-induced type 2 responses and eosinophilic inflammation in NP.
Background: Chronic rhinosinusitis (CRS), commonly divided into CRS with nasal polyps (CRSwNP) and without nasal polyps (CRSsNP) is an inflammatory disease which mechanism remain unclear. Leucine-rich repeat kinase 2 (LRRK2) has been proved to be a negative regulator of inflammation response while its role in pathogenesis of CRS has yet to be revealed. This research study was designed to investigate the relationship between the expression level and biologic role of LRRK2 in CRS. Methods: Expression of LRRK2 mRNA and noncoding repressor of NFAT (NRON) were examined by qRT-PCR. Protein levels of LRRK2 were performed by western blot and immunohistochemistry. Nuclear factor of activated T cells (NFAT) nuclear translocation was analyzed by immunohistochemistry. Additionally, LRRK2 mRNA and NRON expression in response to specific inflammatory stimulation was measured in human nasal epithelia cells (HNECs). Results: The expression of LRRK2 was increased in CRSsNP patients (p < 0.05) and positively correlated with the expression levels of CD3 and Charot-Leyden crystal. Meanwhile, the NRON expression level is much lower in CRSsNP patients compared to both the control group and CRSwNP group (p < 0.05). Marked enhanced NFAT nuclear localization was observed in CRSwNP groups compared with the CRSsNP and control group (p < 0.0001). And the overexpression of LRRK2 was significantly regulated by lipopolysaccharide (LPS) in HNECs (p < 0.05). Moreover, IL-17A can increase LRRK2 expression and suppress NRON expression in vitro and dexamethasone can rescue the NRON inhibition. Conclusion: LRRK2 and NRON may play different role in CRSsNP and CRSwNP. The molecular mechanisms identified here may aid in the design of novel therapeutic strategies to improve clinical outcomes.
Background: The pathogenesis of Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) is not fully understood. Our previous study reported that chemokine CCL27 was overexpressed in serum of SJS/TEN patients. The objective of this study was to investigate the levels of CCL27 and TNF-alpha in serum and blister fluid from patients with SJS/TEN during the acute stage or resolution phase. Methods: A total of 27 patients with SJS/TEN and 39 healthy donors were recruited to the study. Serum and vesicular levels of CCL27 and TNF-alpha were determined by enzyme-linked immunosorbent assays. Results: Serum levels of CCL27 and TNF-alpha were significantly elevated in patients with SJS/TEN during the acute stage as compared to the resolution phase and also compared with levels observed in normal controls (P = 0.001/< 0.001; P = 0.012/< 0.001). Serum TNF-alpha levels were significantly higher in patients with SJS/TEN during the resolution phase compared with normal controls (P < 0.001). Serum CCL27 levels were positively correlated with TNF-alpha levels during the acute stage (r(s) = 0.660; P < 0.001). Blister fluid exhibited much lower CCL27 levels than serum did during the acute stage (P = 0.008). TNF-alpha levels were much higher in vesicles in contrast to serum from acute stage (P = 0.040) as well as serum from resolution phase (P = 0.029). Conclusions: Our study demonstrated roles of CCL27 and TNF-alpha in promoting the course of SJS/TEN. CCL27 may act early in the course of disease, via the circulation, whereas TNF-alpha acts throughout the course of disease, in skin lesions.
House dust mites are small arthropods that produce proteins-found in their feces, body parts, and eggs-that are major triggers of human allergies worldwide. The goal of this review is to describe the current methods used to identify these allergens. A literature search for allergen identification methods employed between 1995 and 2016 revealed multiple techniques that can be broadly grouped into discovery and confirmation phases.The discovery phase employs screening for mite proteins that can bind IgEs in sera from animals or patients allergic to dust mites. The confirmation phase employs biochemical methods to isolate either native or recombinant mite proteins, confirms the IgE binding of the purified allergens, and uses either in vitro or in vivo assays to demonstrate that the purified antigen can stimulate an immune response. The methods used in the two phases are defined and their strengths and weaknesses are discussed. The majority of HDM-allergic patients may respond to just a small subset of proteins, but new protein discovery methods are still warranted in order to develop a complete panel of HDM allergens for component resolved diagnosis and patient-tailored therapies.
Background: Spider mites, including Tetranychus urticae, Panonychus citri, and Panonychus ulmi, are common pests in gardens, greenhouses, and orchards. Exposure, particularly occupational exposure, to these organisms may lead to the development of respiratory or contact allergies. However, the prevalence of sensitivity to spider mites is unclear. Methods: We examined the literature to generate an estimate of the global prevalence of allergies to spider mites. Results: Electronic databases were searched and twenty-three studies reporting the prevalence of sensitivity to spider mites (based on skin prick tests or IgE-based detection systems) in an aggregate total of 40,908 subjects were selected for analysis. The estimated overall rate of spider mite sensitivity was 22.9% (95% CI 19-26.8%). Heterogeneity was high and meta-regression analysis considering variables such as published year, country, number of study subjects, methods for allergen detection (skin prick test, ImmunoCAP, RAST testing, or intradermal test), and mite species revealed no single significant source. Twelve of the 23 studies reported rates of monosensitization (i.e., patients responsive to spider mites but no other tested allergen), yielding a global average of 7% (95% CI 5-9%), hence spider mites represent a unique source of allergens. Conclusions: Spider mites are an important cause of allergic symptoms. However, the publication bias and heterogeneity evident in this study indicate that further trials using standardized detection methods are needed to determine the association of exposure and symptoms as well as the specific patient characteristics that influence developing spider mite sensitivity.
Background: Chronic rhinosinusitis with nasal polyps (CRSwNP) is a heterogeneous inflammatory disease usually characterized by chronic eosinophilia in the sinonasal mucosa, which often requires glucocorticoid (GC) therapy. However, the therapeutic response varies markedly between individuals. The objective of this study was to evaluate the diagnostic values of sinus computed tomography (CT) for GC-sensitivity in patients with CRSwNP. Methods: We conducted a prospective, single-blinded study of 47 consecutive patients with CRSwNP. These patients were given a course of oral prednisone (30 mg daily for 14 days) and subsequently classified into objectively GC-sensitive and -insensitive subgroup according to the change in nasal polyp size score, or subjectively GC-sensitive and -insensitive subgroup according to the change in total nasal symptom score. The following parameters were compared between GC-sensitive and GC-insensitive subgroups: Lund-Mackay scores, olfactory cleft (OC) scores, and blood eosinophil counts and ratio (percentage of the total white blood cells). Results: 25/47 (53.2%) and 29/47 (61.7%) patients were objectively and subjectively sensitive to GC therapy, respectively. The OC score and the blood eosinophil counts and ratio in GC-sensitive subgroup were significantly higher than those in GC-insensitive subgroup, defined either objectively or subjectively. Multivariate logistic regression revealed that OC score was independent risk factor for objective or subjective GC-sensitivity. The OC score exhibited comparable accuracy with the blood eosinophil ratio as predictor of objective and subjective GC-sensitivity (the OC score AUC = 0.775 and 0.829, respectively). A OC score of 3.5 could act as a reliable indicator for predicting the clinical response to GC therapy in CRSwNP. Conclusion: Our prospective findings validate the potential value of sinus CT scan in predicting GC-sensitivity in CRSwNP patients.
Allergic diseases are inflammatory disorders that involve many types of cells and factors, including allergens, immunoglobulin (Ig)E, mast cells, basophils, cytokines and soluble mediators. Among them, IgE plays a vital role in the development of acute allergic reactions and chronic inflammatory allergic diseases, making its control particularly important in the treatment of IgE-mediated allergic diseases. This review provides an overview of the current state of IgE targeted therapy development, focusing on three areas of translational research: IgE neutralization in blood; IgE-effector cell elimination; and IgE(+) B cell reduction. IgE-targeted medicines such as FDA approved drug Xolair (Omalizumab) represent a promising avenue for treating IgE-mediated allergic diseases given the pernicious role of IgE in disease progression. Additionally, targeted therapy for IgE-mediated allergic diseases may be advanced through cellular treatments, including the modification of effector cells.
Background: As the development of urbanization in China, the morbidity of allergic disease rise up prominently even in children, which may be partially associated with the excessively clean environment. It has been reported that common microorganism in rural environment shows protective effects on allergic disease by modulating TLRs-Tregs/Th cell axis. But the mechanism of this protection still needs to be elucidated in detail. We investigated the effects of maternal exposure to farming environment on the neonatal innate immune system, especially on the TLR-Treg-Th (Th1,Th2, Th9, and Th17) axis, in the Jilin province of China. Methods: Eighty-four non-farming and 42 farming pregnant women were recruited. Endotoxins and glucans in dust from the living rooms of the pregnant mothers were measured. Cord blood mononuclear cells were challenged with phytohemagglutinin, lipopolysaccharide, or peptidoglycan. Proliferative response of lymphocyte was measured by 3H-TdR incorporation methods, CD4+CD25+FOXP3-FT cells percentage was assessed with flow cytometry,Tregs specific genes (FOXP3, LAG3, GITR, CTLA-4 and TGF-13) and TLR2, TLR4 genes expression were detected by RT-PCR, specific cytokines of Th1, Th2, Th9, Th17 and Tregs were measured with flow cytometer, suppressive capacity of Tregs was tested by culturing with effector cells in vitro, and TLR2/4 gene polymorphism was detected. Results: Higher endotoxin content was observed in the living rooms of the farming mothers. Compared with that in the non-farming group, in farming neonatal CBMCs, lymphocyte proliferation declined; the IFN-gamma/IL-13 ratio increased; and the quantity of Tregs and gene expression of FOXP3, GITR, CTLA4 and TLR2 increased significantly (P < 0.05). Isolated Tregs suppressed the proliferation of effector T cells and IL-13 production more strongly in vitro (P = 0.04, 0.03, respectively), and the TLR2 polymorphism affected FOXP3 expression and IFN-gamma and IL-13 production. Conclusions: Maternal exposure to farming affected the quantity and function of neonatal Tregs upon stimulation with PPG and LPS, which partly contributed to reducing the risk for allergic diseases in the offspring. The results of our study will lay the theoretical foundation for allergic disease prevention in early life.