Nano-silica particles synergistically IgE-mediated mast cell activation exacerbating allergic inflammation in mice.

Background: Allergic respiratory diseases have increased dramatically due to air pollution over the past few decades. However, studies are limited on the effects of inorganic components and particulate matter with different particle sizes in smog on allergic diseases, and the possible molecular mechanism of inducing allergies has not been thoroughly studied. Methods: Four common mineral elements with different particle sizes in smog particles were selected, including Al2O3, TiO2, Fe2O3, and SiO2. We studied the relationship and molecular mechanism of smog particle composition, particle size, and allergic reactions using mast cells, immunoglobulin E (IgE)-mediated passive cutaneous anaphylaxis (PCA) model, and an ovalbumin (OVA)-induced asthmatic mouse model in vitro and in vivo, combined with transmission electron microscopy, scanning transmission X-ray microscopy analysis, and transcriptome sequencing. Results: Only 20 nm SiO2 particles significantly increased ß-hexosaminidase release, based on dinitrophenol (DNP)-human serum albumin (HSA) stimulation, from IgE-sensitized mast cells, while other particles did not. Meanwhile, the PCA model showed that Evan's blue extravasation in mice was increased after treatment with nano-SiO2 particles. Nano-SiO2 particles exposure in the asthmatic mouse model caused an enhancement of allergic airway inflammation as manifested by OVA-specific serum IgE, airway hyperresponsiveness, lung inflammation injury, mucous cell metaplasia, cytokine expression, mast cell activation, and histamine secretion, which were significantly increased. Nano-SiO2 particles exposure did not affect the expression of FcϵRI or the ability of mast cells to bind IgE but synergistically activated mast cells by enhancing the mitogen-activated protein kinase (MAPK) signaling pathway, especially the phosphorylation levels of the extracellular signal-regulated kinase (ERK)1/2. The ERK inhibitors showed a significant inhibitory effect in reducing ß-hexosaminidase release. Conclusion: Our results indicated that nano-SiO2 particles stimulation might synergistically activate IgE-sensitized mast cells by enhancing the MAPK signaling pathway and that nano-SiO2 particles exposure could exacerbate allergic inflammation. Our experimental results provide useful information for preventing and treating allergic diseases.

Prediction of clinical efficacy of subcutaneous immunotherapy for Artemisia sieversiana pollen allergic rhinitis by serum metabolomics.

BACKGROUND/PURPOSE: Specific immunotherapy is the only effective etiological treatment for allergic rhinitis, but subcutaneous immunotherapy has a slow onset and poor compliance. Predicting the clinical efficacy of subcutaneous immunotherapy in advance can reduce unnecessary medical costs and resource waste. This study aimed to identify metabolites that could predict the efficacy of subcutaneous immunotherapy on seasonal allergic rhinitis by serum metabolomics. METHODS: Patients (n = 43) with Artemisia sieversiana pollen allergic rhinitis were enrolled and treated with subcutaneous immunotherapy for one year. Patients were divided into the ineffective group (n = 10) and effective group (n = 33) according to the therapeutic index. Serum samples were collected before treatment. Metabolomics was determined by liquid chromatography-mass spectrometry combined with gas chromatography-mass spectrometry and analyzed differential compounds and related metabolic pathways. RESULTS: A total of 129 differential metabolites (P < 0.05) were identified and 4 metabolic pathways, namely taurine and hypotaurine metabolism, pentose and glucuronate interconversions, pentose phosphate pathway, and alanine, aspartate, and glutamate metabolism, were involved. CONCLUSION: Some metabolites, such as hypotaurine, taurine, and l-alanine, have the potential to become predictive biomarkers for effective subcutaneous immunotherapy.

Identification of Per a 13 as a novel allergen in American cockroach.

BACKGROUND: Cockroaches are an important source of indoor allergens. Environmental exposure to cockroach allergens is closely associated with the development of immunoglobulin E (IgE)-mediated allergic diseases. However, the allergenic components in the American cockroaches are not fully studied yet. In order to develop novel diagnostic and therapeutic strategies for cockroach allergy, it is necessary to comprehensively investigate this undescribed allergen in the American cockroach. METHODS: The full-length cDNA of the potential allergen was isolated from the cDNA library of the American cockroach by PCR cloning. Both the recombinant and natural protein molecules were purified and characterized. The allergenicity was further analyzed by enzyme linked immunosorbent assay, immunoblot, and basophil activation test using sera from cockroach allergic patients. RESULTS: A novel allergen belonging to glyceraldehyde 3-phosphate dehydrogenase (GAPDH) was firstly identified in the American cockroach and named as Per a 13. The cDNA of this allergen is 1255 base pairs in length and contains an open reading frame of 999 base pairs, encoding 332 amino acids. The purified Per a 13 was fully characterized and assessed to react with IgEs from 49.3 % of cockroach allergic patients, and patients with allergic rhinitis were more sensitized to it. Moreover, the allergenicity was further confirmed by immunoblot and basophil activation test. CONCLUSIONS: We firstly identified GAPDH (Per a 13) in the American cockroach, which is a novel type of inhalant allergen derived from animal species. These findings could be useful in developing novel diagnostic and therapeutic strategies for cockroach allergy.

Leukotriene A4 Hydrolase Is a Candidate Predictive Biomarker for Successful Allergen Immunotherapy.

Background: Allergic rhinitis is a common disorder that affects 10% to 40% of the population worldwide. Allergen immunotherapy (AIT) represents the only therapy that has the potential to resolve clinical symptoms of allergic rhinitis. However, up to 30% of patients do not respond to AIT. Biomarkers predicting the clinical efficacy of AIT as early as possible would significantly improve the patient selection and reduce unnecessary societal costs. Methods: Artemisia pollen allergic patients who received at least 1-year AIT were enrolled. Clinical responses before and after 1-year AIT were evaluated to determine AIT responders. Artemisia specific IgE and IgG4 levels were measured by using ImmunoCAP and enzyme-linked immunosorbent assay (ELISA) separately. Stepwise regression analysis was performed to identify which rhinitis-relevant parameters explained the most variability in AIT results. Liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based proteomics was applied to identify the potential candidate biomarkers in the sera of responders and non-responders collected before and after 1-year therapy. The diagnostic performance of the potential biomarkers was then assessed using enzyme-linked immunosorbent assay (ELISA) in 30 responders and 15 non-responders. Results: Artemisia specific IgE and IgG4 levels were elevated only in the responders. Regression analysis of allergic rhinitis-relevant parameters provided a robust model that included two most significant variables (sneeze and nasal congestion). Thirteen candidate biomarkers were identified for predicting AIT outcomes. Based on their association with allergy and protein fold change (more than 1.1 or less than 0.9), four proteins were identified to be potential biomarkers for predicting effective AIT. However, further ELISA revealed that only leukotriene A4 hydrolase (LTA4H) was consistent with the proteomics data. The LTA4H level in responders increased significantly (P < 0.001) after 1-year therapy, while that of non-responders remained unchanged. Assessment of LTA4H generated area under curve (AUC) value of 0.844 (95% confidence interval: 0.727 to 0.962; P < 0.05) in distinguishing responders from the non-responders, suggesting that serum LTA4H might be a potential biomarker for predicting the efficiency of AIT. Conclusion: Serum LTA4H may be a potential biomarker for early prediction of an effective AIT.

Clinical Efficacy Evaluation of 1-Year Subcutaneous Immunotherapy for Artemisia sieversiana Pollen Allergic Rhinitis by Serum Metabolomics.

Subcutaneous immunotherapy is the only treatment that improves the natural progression of allergic rhinitis and maintains long-term outcomes after discontinuation of the drug. Metabolomics is increasingly applied in the study of allergic diseases, including allergic rhinitis. However, little is known about the discovery of metabolites that can evaluate clinical efficacy and possible mechanisms of Artemisia sieversiana pollen subcutaneous immunotherapy. Thirty-three patients with Artemisia sieversiana pollen allergic rhinitis significantly improved after 1-year subcutaneous immunotherapy treatment, while ten patients were ineffective. Pre- and post-treatment serum samples from these patients were analyzed by metabolomics based on the combined detection of liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry. As a result, L-Tyrosine can be a potential biomarker because of its opposite trend in effective patients and ineffective patients. And mechanism of immunotherapy may be closely related to NO and nitric oxide synthase. The discovery of potential biomarkers and metabolic pathways has contributed to the in-depth study of mechanisms of subcutaneous immunotherapy treatment of Artemisia sieversiana pollen allergic rhinitis.

KIAA1429 acts as an oncogenic factor in breast cancer by regulating CDK1 in an N6-methyladenosine-independent manner.

Most N6-methyladenosine (m6A) associated regulatory proteins (i.e., m6A writer, eraser, and reader proteins) are involved in the pathogenesis of various cancers, mostly in m6A-dependent manners. As a component in the m6A 'writers', KIAA1429 is reported to be an RNA-binding protein and involved in the m6A modification, mRNA splicing and processing. Till now, the functions of KIAA1429 in tumorigenesis and related mechanism have not been reported. In the present study, we found KIAA1429 was highly expressed in breast cancer tissues, but frequently down-regulated in non-cancerous breast tissues. The overall survival of breast cancer patients with high-expression KIAA1429 was significantly shorter than those with low-expression KIAA1429. Then, we demonstrated that KIAA1429 was associated with breast cancer proliferation and metastasis in vivo and in vitro. The potential targeting genes of KIAA1429 in breast cancer were identified by RNA immunoprecipitation sequencing. One of these genes is cyclin-dependent kinase 1 (CDK1), which plays an oncogenic role in cancers. Furthermore, we confirmed that KIAA1429 played its oncogenic role in breast cancer by regulating CDK1 by an m6A-independent manner. 5'-fluorouracil was found to be very effective in reducing the expression of KIAA1429 and CDK1 in breast cancer. These findings indicated that KIAA1429 could promote breast cancer progression and was correlated with pathogenesis. It may represent a promising therapeutic strategy on breast cancer, especially in combination with CDK1 treatment.

Canis familiaris allergen Can f 7: Expression, purification and analysis of B cell epitopes in Chinese children with dog allergies.

Dogs are a major source of indoor allergens. However, the prevalence of dog allergies in China remains unclear, especially in children. In the present study, Can f 7, a canine allergen belonging to the Niemann pick type C2 protein family, was selected to study its sensitization rate in Chinese children with dog allergies. The Can f 7 gene was subcloned into a pET­28a vector and expressed in Escherichia coli BL21 (DE3) cells. Recombinant Can f 7 was purified by nickel affinity chromatography, identified by SDS­PAGE electrophoresis, and had its allergenicity assessed by western blot, ELISA and basophil activation tests. Through a series of bioinformatical approaches, B­cell epitopes, secondary structures, and 3 dimensional (3D) homology modeling of Can f 7 were predicted. The activity of the B cell epitopes was verified by ELISA. The recombinant Can f 7 showed a distinct band with a molecular weight of 14 kDa. Six of 20 sera from dog­allergic children reacted positively to the Can f 7. Can f 7 induced an ~4.0­fold increase in cluster of differentiation 63 and C­C motif chemokine receptor R3 expression in basophils sensitized with the serum of dog­allergic children compared with those of non­allergic controls. The secondary structure analysis showed that Can f 7 contains 6 ß­sheets. Five B cell epitopes of Can f 7 were predicted, and two of these were confirmed by ELISA. These results indicate that Can f 7 is an important canine allergen in Chinese children and provide novel data for further research concerning the use of Can f 7 in the diagnosis and treatment of Chinese children with canine allergy symptoms.

Expression, purification and epitope analysis of Pla a 2 allergen from Platanus acerifolia pollen.

Platanus acerifolia is one of the major sources of outdoor allergens to humans, and can induce allergic asthma, rhinitis, dermatitis and other allergic diseases. Pla a 2 is a polygalacturonase and represents the major allergen identified in P. acerifolia pollen. The aim of the present study was to express and purify Pla a 2, and to predict B and T cell epitopes of Pla a 2. The gene encoding Pla a 2 was cloned into the pET28a vector and subsequently transfected into ArcticExpress™ (DE3) Escherichia coli cells; purified Pla a 2 was analyzed by western blot analysis. The results of the present study revealed that the Pla a 2 allergen has the ability to bind immunoglobulin E within the sera of patients allergic to P. acerifolia pollen. In addition, the B cell epitopes of Pla a 2 were predicted using the DNAStar Protean system, Bioinformatics Predicted Antigenic Peptides and BepiPred 1.0 software; T cell epitopes were predicted using NetMHCIIpan ­3.0 and ­2.2. In total, eight B cell epitopes (15­24, 60­66, 78­86, 109­124, 232­240, 260­269, 298­306 and 315­322) and five T cell epitopes (62­67, 86­91, 125­132, 217­222 and 343­350) were predicted in the present study. These findings may be used to improve allergen immunotherapies and reduce the frequency of pollen­associated allergic reactions.

Canis familiaris allergen Can f 6: expression, purification and analysis of B-cell epitopes in Chinese dog allergic children.

Dog allergy is common worldwide. However, the allergenicity of dog allergy is still unclear in China as well as in special group, such as children. In this study, we chose Can f 6, a major dog allergen which belongs to the lipocalin to study its allergenicity in Chinese dog allergic children. Can f 6 gene was subcloned into pET-28a vector and transformed into E. coli BL21 (DE3) cells for expression. The recombinant Can f 6 was purified by nickel affinity chromatography, identified by SDS-PAGE, and tested for its allergenicity by Western blot with sera and basophil activation test. Secondary structures, B cell epitopes and homology modeling of Can f 6 were predicted by using a series of bioinformatical approaches. And the verification of B cell epitopes was detected by ELISA. The recombinant allergen showed an explicit band with the molecular weight of 20 kDa by SDS-PAGE. Sera from 56.3 % (18/32) of dog-allergic children patients reacted with Can f 6. The induction of the expression of CD63 and CCR3 of dog allergic children in passively sensitized basophils was up to approximately 5.0 times higher than healthy subjects. The secondary structure of Can f 6 contains 3 α-helices, 9 ß-sheets and random coils. Five B cell epitopes of Can f 6 were predicted and were confirmed successfully by ELISA. The results showed Can f 6 is a major allergen in Chinese children, which provides a basis for further study of Can f 6 in diagnosis and treatment of symptoms in children in China. The structural information of Can f 6 will help to form a foundation for the future design of vaccines and therapies for Can f 6 related allergies.

Expression and purification of a major allergen, Pla a 1, from Platanus acerifolia pollen and the preparation of its monoclonal antibody.

Platanus acerifolia pollen is considered an important source of airborne allergens in numerous cities. Pla a 1 is a major allergen from P. acerifolia pollen. The present study aimed to express and purify Pla a 1, and to prepare its monoclonal antibody. In the present study, the Pla a 1 gene was subcloned into a pET­28a vector and transformed into the ArcticExpress™ (DE3) RP Escherichia coli host strain. The purified Pla a 1 was then used to immunize BALB/c mice. When serum detection was positive, spleen cells were isolated from the mice and fused with SP2/0 myeloma cells at a ratio of 10:1. Hybridoma cells were screened by indirect ELISA and limiting dilution. Positive cells were used to induce the formation of antibody­containing ascites fluid, and the antibodies were purified using protein A­agarose. The results of the present study demonstrated that recombinant Pla a 1 was successfully expressed and purified, and exhibited positive immunoglobulin E­binding to serum from patients allergic to P. acerifolia. A total of 11 hybridomas that steadily secreted anti­Pla a 1 antibody were obtained and an immunoblotting analysis indicated that all of these monoclonal antibodies specifically recognized the Pla a 1 protein. These results suggested that specific anti­Pla a 1 antibodies may be obtained, which can be used for the rapid detection of Pla a 1 allergens and in the preparation of vaccines against P. acerifolia pollen.

Expression, purification and epitope analysis of Pla a 3 allergen from Platanus acerifolia pollen.

Platanus acerifolia (P. acerifolia) is an important cause of pollinosis in cities. The use of allergen extracts on patients with allergic diseases is the most commonly applied method to attempt to treat pollinosis. Pla a 3, a non­specific lipid transfer protein, is a major allergen present in P. acerifolia pollen extracts. In the present study, the Pla a 3 gene was sub­cloned into a pSUMO­Mut vector using Stu I and Xho I sites and transformed into the Arctic Express™ (DE3) RP E. coli host strain. The purified Pla a 3 allergen was analyzed by western blotting and the results revealed that the Pla a 3 allergen has the ability to bind IgE in the P. acerifolia pollen of allergic patients' sera. Moreover, the authors predicted the potential B cell epitopes of the Pla a 3 allergen using the DNAStar Protean system, the Bioinformatics Predicted Antigenic Peptides system and the BepiPred 1.0 server. In addition, the T cell epitopes were predicted by the SYFPEITHI database and the NetMHCII­2.2 server. As a result, two B cell epitopes (35­45 and 81­86) and four potential T cell epitopes including 2­15, 45­50, 55­61 and 67­73 were predicted in the present study. The current results can be used to contribute to allergen immunotherapies and useful in peptide­based vaccine designs of pollen allergy.

Tryptase inhibitors: a patent review.

INTRODUCTION: Tryptase is one of the main serine-proteinases located in the secretory granules of mast cells, and is released through degranulation, which is involved in the pathogenesis of allergic inflammatory disease, cardiovascular diseases, lung fibrosis and tumor. Therefore, inhibitors targeting tryptase may represent a new direction for the treatment of allergic inflammatory disease and other diseases. Areas covered: In this article, we discussed the history and development of tryptase inhibitors and described a variety of tryptase inhibitors via their structures and biological importance in clinical studies and drug development for tryptase-related diseases. Expert opinion: Initial tryptase inhibitors based on indole structure as the hydrophobic substituent on a benzylamine-piperidine template have low specificity and poor bioavailability. Therefore, designing new and specific inhibitors targeting tryptase should be involved in future clinical studies. Modifications toward indoles with varying N-substitution, introducing an amide bond, and growing the chain length contribute to an increase in the specific selectivity and potency of tryptase inhibitors. Tryptase has become the research hotspot to explore many related diseases. Therefore, there has been growing appreciation for the potential importance of the tryptase inhibitors as a target for treating these diseases.