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1.
Int J Mol Sci ; 25(12)2024 Jun 13.
Article in English | MEDLINE | ID: mdl-38928218

ABSTRACT

Pollen from common ragweed is an important allergen source worldwide and especially in western and southern Romania. More than 100 million patients suffer from symptoms of respiratory allergy (e.g., rhinitis, asthma) to ragweed pollen. Among the eleven characterized allergens, Amb a 6 is a non-specific lipid transfer protein (nsLTP). nsLTPs are structurally stable proteins in pollen and food from different unrelated plants capable of inducing severe reactions. The goal of this study was to produce Amb a 6 as a recombinant and structurally folded protein (rAmb a 6) and to characterize its physicochemical and immunological features. rAmb a 6 was expressed in Spodoptera frugiperda Sf9 cells as a secreted protein and characterized by mass spectrometry and circular dichroism (CD) spectroscopy regarding molecular mass and fold, respectively. The IgE-binding frequency towards the purified protein was evaluated using sera from 150 clinically well-characterized ragweed-allergic patients. The allergenic activities of rAmb a 6 and the nsLTP from the weed Parietaria judaica (Par j 2) were evaluated in basophil activation assays. rAmb a 6-specific IgE reactivity was associated with clinical features. Pure rAmb a 6 was obtained by insect cell expression. Its deduced molecular weight corresponded to that determined by mass spectrometry (i.e., 10,963 Da). rAmb a 6 formed oligomers as determined by SDS-PAGE under non-reducing conditions. According to multiple sequence comparisons, Amb a 6 was a distinct nsLTP with less than 40% sequence identity to currently known plant nsLTP allergens, except for nsLTP from Helianthus (i.e., 52%). rAmb a 6 is an important ragweed allergen recognized by 30% of ragweed pollen allergic patients. For certain patients, rAmb a 6-specific IgE levels were higher than those specific for the major ragweed allergen Amb a 1 and analysis also showed a higher allergenic activity in the basophil activation test. rAmb a 6-positive patients suffered mainly from respiratory symptoms. The assumption that Amb a 6 is a source-specific ragweed allergen is supported by the finding that none of the patients showing rAmb a 6-induced basophil activation reacted with Par j 2 and only one rAmb a 6-sensitized patient had a history of plant food allergy. Immunization of rabbits with rAmb a 6 induced IgG antibodies which strongly inhibited IgE binding to rAmb a 6. Our results demonstrate that Amb a 6 is an important source-specific ragweed pollen allergen that should be considered for diagnosis and allergen-specific immunotherapy of ragweed pollen allergy.


Subject(s)
Allergens , Antigens, Plant , Carrier Proteins , Immunoglobulin E , Humans , Allergens/immunology , Immunoglobulin E/immunology , Antigens, Plant/immunology , Antigens, Plant/chemistry , Animals , Carrier Proteins/immunology , Carrier Proteins/metabolism , Plant Proteins/immunology , Plant Proteins/chemistry , Female , Rhinitis, Allergic, Seasonal/immunology , Male , Adult , Ambrosia/immunology , Spodoptera/immunology , Recombinant Proteins/immunology , Amino Acid Sequence , Sf9 Cells , Middle Aged , Plant Extracts
2.
Int J Mol Sci ; 25(10)2024 May 09.
Article in English | MEDLINE | ID: mdl-38791214

ABSTRACT

Common ragweed pollen allergy has become a health burden worldwide. One of the major allergens in ragweed allergy is Amb a 1, which is responsible for over 90% of the IgE response in ragweed-allergic patients. The major allergen isoform Amb a 1.01 is the most allergenic isoform in ragweed pollen. So far, no recombinant Amb a 1.01 with similar allergenic properties to its natural counterpart (nAmb a 1.01) has been produced. Hence, this study aimed to produce a recombinant Amb a 1.01 with similar properties to the natural isoform for improved ragweed allergy management. Amb a 1.01 was expressed in insect cells using a codon-optimized DNA construct with a removable N-terminal His-Tag (rAmb a 1.01). The recombinant protein was purified by affinity chromatography and physicochemically characterized. The rAmb a 1.01 was compared to nAmb a 1.01 in terms of the IgE binding (enzyme-linked immunosorbent assay (ELISA), immunoblot) and allergenic activity (mediator release assay) in well-characterized ragweed-allergic patients. The rAmb a 1.01 exhibited similar IgE reactivity to nAmb a 1.01 in different IgE-binding assays (i.e., IgE immunoblot, ELISA, quantitative ImmunoCAP inhibition measurements). Furthermore, the rAmb a 1.01 showed comparable dose-dependent allergenic activity to nAmb a 1.01 regarding basophil activation. Overall, the results showed the successful expression of an rAmb a 1.01 with comparable characteristics to the corresponding natural isoform. Our findings provide the basis for an improvement in ragweed allergy research, diagnosis, and immunotherapy.


Subject(s)
Allergens , Ambrosia , Antigens, Plant , Immunoglobulin E , Recombinant Proteins , Humans , Antigens, Plant/immunology , Antigens, Plant/genetics , Antigens, Plant/chemistry , Immunoglobulin E/immunology , Animals , Allergens/immunology , Allergens/genetics , Ambrosia/immunology , Recombinant Proteins/immunology , Recombinant Proteins/genetics , Female , Adult , Plant Proteins/immunology , Plant Proteins/genetics , Plant Proteins/chemistry , Rhinitis, Allergic, Seasonal/immunology , Male , Middle Aged , Plant Extracts/chemistry
3.
Int J Biol Macromol ; 258(Pt 1): 128856, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38143053

ABSTRACT

Allergen component products, such as recombinant proteins and epitope peptides of allergic components, are used as an adjunct to allergen-specific immunotherapy. We characterized a novel allergen, Tyr p 31, from Tyrophagus putrescentiae, a common allergenic mite. T. putrescentiae total RNA was amplified to Tyr p 31-encoding cDNA, which was inserted into pET28a(+). pET28a(+)-Tyr p 31 was then transformed into Rosetta 2 (DE3) pLysS cells and expressed under isopropyl ß-D-thiogalactoside induction. Next, we visualized Tyr p 31 through sodium dodecyl sulfate polyacrylamide gel electrophoresis and Western blotting based on its theoretical molecular weight. Recombinant Tyr p 31 (rTyr p 31) was purified, and its secondary structure was noted to comprise α-helices, antiparallel coils, ß-turns, parallel coils, and random coils. Our enzyme-linked immunosorbent assay and Western blotting results for T. putrescentiae-positive sera from children with allergic disorders demonstrated rTyr p 31-specific IgE-positivity rates of 72.41 % and 85.7 %, respectively. In BEAS-2B cells, rTyr p 31 increased IL-6 and IL-8 expression; furthermore, BEAS-2B cells treated with 30 µg/mL rTyr p 31 demonstrated 100 upregulated and 12 downregulated genes. In summary, we identified Tyr p 31, a novel T. putrescentiae allergen component, and noted rTyr p 31 to have a high IgE-binding rate and strong immunogenicity.


Subject(s)
Allergens , Hypersensitivity , Child , Humans , Allergens/chemistry , Immunoglobulin E , Recombinant Proteins/genetics , Monophenol Monooxygenase , Tyrosine
4.
Khirurgiia (Mosk) ; (7): 12-19, 2023.
Article in Russian | MEDLINE | ID: mdl-37379401

ABSTRACT

OBJECTIVE: To evaluate the effectiveness of surgical treatment of patients with malignancies of lungs, pleura and chest wall in early and long-term follow-up period in anti-tuberculosis hospital. MATERIAL AND METHODS: There were 2139 patients between 2016 and 2020. Chest tumors were diagnosed in 290 (13.6%) patients and 210 (94.2%) ones underwent surgery. RESULTS: Surgical interventions are rare in patients with lung cancer and active tuberculosis (0.7%, n=15). Lobectomies prevailed (73.3%). All sublobar resections were performed in elderly patients with severe comorbidities and low functional reserves. Postoperative complications occurred in 9% of cases. Overall 3-year survival rate was 84.8%, overall 5-year survival rate - 70.8%. Overall survival of patients with lung cancer and tuberculosis does not depend on activity of specific process. CONCLUSION: The TRA test used in differential diagnostics of tuberculosis and lung cancer has a mediating value. Lung cancer surgery in patients with active tuberculosis has no negative effect on effectiveness of tuberculosis treatment. Surgical treatment of malignancies in anti-tuberculosis hospital can be performed in accordance with standards of specialized medical care in oncology.


Subject(s)
Lung Neoplasms , Pneumonectomy , Humans , Aged , Treatment Outcome , Neoplasm Staging , Pneumonectomy/adverse effects , Lung Neoplasms/diagnosis , Lung Neoplasms/surgery , Hospitals , Retrospective Studies
5.
J Biotechnol ; 369: 1-13, 2023 Jun 10.
Article in English | MEDLINE | ID: mdl-37164269

ABSTRACT

Shellfish are a leading cause of allergies worldwide, affecting about one-tenth of the general population. The sarcoplasmic calcium-binding protein, also known as allergen Pen m 4, is an important factor in shrimp allergies. Our objective was to assess the most effective techniques for producing a recombinant Pen m 4 protein as a potential tool for diagnosing shrimp allergies. In this study, for the first time, we produced a functional recombinant Pen m 4 protein in a eukaryotic system, Pichia pastoris, and analyzed it against Escherichia coli-produced equivalents in enzyme-linked immunosorbent and reverse-phase protein microarray assays. A dual tag system based on the maltose-binding protein was successfully used to increase the yield of Pen m 4 by 1.3-2.3-fold in both bacteria and yeast, respectively. Immunological characterization showed that N-glycosylation is neither crucial for the folding of Pen m 4 nor its recognition by specific IgE. However, the Ca2+-depletion assay indicated a dependence on calcium ion presence in blood samples. Results demonstrate how a comparative analysis can elucidate essential allergen manufacturing points. In conclusion, E. coli-produced Pen m 4 protein fused with the maltose-binding protein should be the preferred option for further studies in Penaeus monodon allergy diagnostics.


Subject(s)
Escherichia coli , Hypersensitivity , Humans , Escherichia coli/genetics , Escherichia coli/metabolism , Maltose-Binding Proteins/metabolism , Immunoglobulin E , Recombinant Proteins/chemistry , Allergens/genetics , Allergens/chemistry , Pichia/genetics , Pichia/metabolism
6.
Mol Immunol ; 158: 54-67, 2023 06.
Article in English | MEDLINE | ID: mdl-37119758

ABSTRACT

House dust mite (HDM) allergy belongs to the most important allergies and affects approximately 65-130 million people worldwide. Additionally, untreated HDM allergy may lead to the development of severe disease manifestations such as atopic dermatitis or asthma. Diagnosis and immunotherapy of HDM allergic patients are well established but are often hampered by the use of mite extracts that are of bad quality and lack important allergens. The use of individual allergens seems to be a promising alternative to natural allergen extracts, since they represent well-defined components that can easily be produced and quantified. However, a thorough characterization of the individual allergens is required to determine their clinical relevance and to identify those allergens that are required for correct diagnosis of HDM allergy and for successful immunotherapy. This review gives an update on the individual HDM allergens and their benefits for diagnosis and immunotherapy of HDM allergic patients.


Subject(s)
Dust Mite Allergy , Hypersensitivity , Humans , Animals , Hypersensitivity/diagnosis , Hypersensitivity/therapy , Allergens , Immunotherapy , Antigens, Dermatophagoides , Pyroglyphidae
7.
Int J Mol Sci ; 24(2)2023 Jan 07.
Article in English | MEDLINE | ID: mdl-36674705

ABSTRACT

Exposure to the Mus m 1 aeroallergen is a significant risk factor for laboratory animal allergy. This allergen, primarily expressed in mouse urine where it is characterized by a marked and dynamic polymorphism, is also present in epithelium and dander. Considering the relevance of sequence/structure assessment in protein antigenic reactivity, we compared the sequence of the variant Mus m 1.0102 to other members of the Mus m 1 allergen, and used Discotope 2.0 to predict conformational epitopes based on its 3D-structure. Conventional diagnosis of mouse allergy is based on serum IgE testing, using an epithelial extract as the antigen source. Given the heterogeneous and variable composition of extracts, we developed an indirect ELISA assay based on the recombinant component Mus m 1.0102. The assay performed with adequate precision and reasonable diagnostic accuracy (AUC = 0.87) compared to a routine clinical diagnostic test that exploits the native allergen. Recombinant Mus m 1.0102 turned out to be a valuable tool to study the fine epitope mapping of specific IgE reactivity to the major allergen responsible for mouse allergy. We believe that advancing in its functional characterization will lead to the standardization of murine lipocalins and to the development of allergen-specific immunotherapy.


Subject(s)
Allergens , Food Hypersensitivity , Animals , Mice , Lipocalins/genetics , Enzyme-Linked Immunosorbent Assay , Immunoglobulin E , Recombinant Proteins/genetics
8.
Protein Expr Purif ; 203: 106211, 2023 03.
Article in English | MEDLINE | ID: mdl-36462715

ABSTRACT

Structural and functional information about food allergens is essential for understanding the allergenicity of food proteins. All allergens belong to a small number of protein families. Various allergens from different families have been successfully produced recombinantly in E. coli for their characterization and applications in allergy diagnosis and treatment. However, recombinant hexameric 11S seed storage protein has not been reported, although numerous 11S legumins are known to be food allergens, including the recently identified macadamia nut allergen Mac i 2. Here we report the production of a macadamia nut legumin by expressing it in E. coli with a substrate site of HRV 3C protease and cleaving the purified protein with HRV 3C protease. The protease divided the protein into two chains and left a native terminus for the C-terminal chain, resulting in a recombinant hexameric 11S allergen for the first time after the residues upstream to the cleavage site flipped out of the way of the trimer-trimer interaction. The 11S allergens are known to have multiple isoforms in many species. The present study removed an obstacle in obtaining homogeneous allergens needed for studying allergens and mitigating allergenicity. Immunoreactivity of the protein with serum IgE confirmed it to be a new isoform of Mac i 2.


Subject(s)
Allergens , Antigens, Plant , Nut Hypersensitivity , Humans , Allergens/chemistry , Antigens, Plant/chemistry , Antigens, Plant/genetics , Escherichia coli/genetics , Immunoglobulin E/chemistry , Macadamia/genetics , Nut Hypersensitivity/diagnosis , Nut Hypersensitivity/metabolism , Plant Proteins/genetics , Plant Proteins/chemistry , Protein Isoforms , Legumins
9.
Iran J Allergy Asthma Immunol ; 21(5): 494-511, 2022 Oct 26.
Article in English | MEDLINE | ID: mdl-36341559

ABSTRACT

Allergen-specific immunotherapy (AIT) involves administering allergen extracts. It is used to desensitize allergic patients. Herbal allergen extracts that are optimum in efficacy and fewest in side effects are still challenging to produce. To overcome these limitations, oral immunotherapy, epicutaneous immunotherapy, intralymphatic immunotherapy, and artificial recombinant allergen preparations have been evaluated. Recombinant allergens have become more popular with the development of molecular diagnostics and therapeutics. Besides food and drug allergens, pollen, fungal spores, and other allergens have been studied. Based on related clinical studies, this comprehensive overview will present the latest perspectives on AIT methods and available allergenic products, as well as discuss the challenges and opportunities for treating allergic disorders.


Subject(s)
Allergens , Hypersensitivity , Humans , Desensitization, Immunologic/methods , Hypersensitivity/therapy , Hypersensitivity/drug therapy , Pollen , Plant Extracts
10.
Pediatr Allergy Immunol ; 33(8): e13835, 2022 08.
Article in English | MEDLINE | ID: mdl-36003049

ABSTRACT

BACKGROUND: Dust mite extract contains multiple components that, while useful in clinical allergy diagnosis and treatment, can cause serious side effects. Defining components of dust mite extract is important their contributions to allergic disease. This study aimed to characterize a novel dust mite allergen, Der p 22. METHODS: We amplified the cDNA encoding Der p 22 from total RNA of the mite Dermatophagoides pteronyssinus, and inserted it into an expression construct for transformation to competent cells. Purified recombinant (r) Der p 22 was tested for IgE-binding reactivity in sera obtained from children with allergic asthma by the Affiliated Wuxi Children's Hospital of Nanjing Medical University (Jiangsu, China). rDer p 22 also was used to challenge BALB/c mice to assess effects on T helper cells and cytokine levels and applied to cultured lung epithelial cells to evaluate apoptosis and cytokine secretion. RESULTS: rDer p 22 bound to IgE in 93.75% of sera from pediatric allergic asthma patients. Mice challenged with rDer p 22 had altered Th1/Th2 ratios in spleen and lymph, and lower levels of cytokines IFN-γ but higher levels of IL-4 and IL-10 in alveolar lavage fluid compared with controls (p < .05). Cultured lung epithelial cells had greater apoptosis rates and exhibited higher levels of IL-6, IL-8, and GM-CSF when treated with rDer p 22 compared with control treatment (p < .05). CONCLUSIONS: Recombinant Der p 22 exhibited high IgE-binding rates in allergic children, indicating the activity of the recombinant protein and suggesting this novel allergen may be appropriate for inclusion in an allergy diagnostic workup. This finding is supported by in vitro and mouse in vivo studies showing rDer p 22 induced strong allergenic reactivity and apoptosis.


Subject(s)
Antigens, Dermatophagoides , Arthropod Proteins , Asthma , Hypersensitivity , Allergens , Animals , Antigens, Dermatophagoides/genetics , Antigens, Dermatophagoides/immunology , Arthropod Proteins/genetics , Arthropod Proteins/immunology , Asthma/metabolism , Asthma/microbiology , Cloning, Molecular , Cytokines/metabolism , Dermatophagoides pteronyssinus , Dust , Humans , Immunoglobulin E/chemistry , Immunoglobulin E/metabolism , Mice , Pyroglyphidae
11.
Foods ; 11(3)2022 Jan 30.
Article in English | MEDLINE | ID: mdl-35159555

ABSTRACT

The Pacific oyster is a commercially important mollusc and, in contrast to most other shellfish species, frequently consumed without prior heat treatment. Oysters are rich in many nutrients but can also cause food allergy. Knowledge of their allergens and cross-reactivity remains very limited. These limitations make an optimal diagnosis of oyster allergy difficult, in particular to the Pacific oyster (Crassostrea gigas), the most cultivated and consumed oyster species worldwide. This study aimed to characterise IgE sensitisation profiles of 21 oyster-sensitised patients to raw and heated Pacific oyster extract using immunoblotting and advanced mass spectrometry, and to assess the relevance of recombinant oyster allergen for improved diagnosis. Tropomyosin was identified as the major allergen recognised by IgE from 18 of 21 oyster-sensitised patients and has been registered with the WHO/IUIS as the first oyster allergen (Cra g 1). The IgE-binding capacity of oyster-sensitised patients' IgE to purified natural and recombinant tropomyosin from oyster, prawn, and dust mite was compared using enzyme-linked immunosorbent assay. The degree of IgE binding varied between patients, indicating partial cross-sensitisation and/or co-sensitisation. Amino acid sequence alignment of tropomyosin from these three species revealed five regions that contain predicted IgE-binding epitopes, which are most likely responsible for this cross-reactivity. This study fully biochemically characterises the first and major oyster allergen Cra g 1 and demonstrates that the corresponding recombinant tropomyosin should be implemented in improved component-resolved diagnostics and guide future immunotherapy.

12.
J Allergy Clin Immunol ; 149(3): 1031-1043, 2022 03.
Article in English | MEDLINE | ID: mdl-34419535

ABSTRACT

BACKGROUND: House dust mite (HDM) allergens are major elicitors of allergic reactions worldwide. OBJECTIVE: Identification, characterization, and evaluation of diagnostic utility of a new important HDM allergen was performed. METHODS: A cDNA coding for a new Dermatophagoides pteronyssinus (Dp) allergen, Der p 37, was isolated from a Dp expression library with allergic patients' IgE antibodies. Recombinant Der p 37 (rDer p 37) expressed in Escherichia coli was purified, then characterized by mass spectrometry, circular dichroism, and IgE reactivity by ImmunoCAP ISAC technology with sera from 111 clinically defined HDM-allergic patients. The allergenic activity of rDer p 37 was studied by basophil activation and CD4+ T-cell responses by carboxyfluorescein diacetate succinimidyl ester dilution assays. Specific antibodies raised against rDer p 37 were used for the ultrastructural localization of Der p 37 in mites by immunogold transmission electron microscopy. RESULTS: Der p 37, a 26 kDa allergen with homology to chitin-binding proteins, is immunologically distinct from Der p 15, 18, and 23. It is located in the peritrophic membrane of fecal pellets. Der p 37 reacted with IgE antibodies from a third of HDM-allergic patients and induced specific basophil- and CD4+ T-cell activation. Der p 37 IgE-positive patients had significantly higher IgE levels to major HDM allergens, reacted with more HDM allergens, and had a higher risk (odds ratio = 3.1) of asthma compared to Der p 37-negative patients. CONCLUSIONS: Der p 37, a new Dp allergen recognized by a third of HDM-allergic patients, may serve as a surrogate marker for severe HDM sensitization and asthma.


Subject(s)
Asthma , Hypersensitivity , Allergens , Animals , Antigens, Dermatophagoides , Arthropod Proteins , Asthma/diagnosis , Dust , Escherichia coli/genetics , Humans , Immunoglobulin E , Pyroglyphidae
13.
Mol Immunol ; 137: 42-51, 2021 09.
Article in English | MEDLINE | ID: mdl-34214828

ABSTRACT

Papaya is reported to trigger food and respiratory allergy. Here, we identified chymopapain Cari p 2 as an allergen that can sensitize atopic individuals through fruit consumption followed by respiratory hazards through pollen exposure. Recombinant Cari p 2 displayed IgE-reactivity with 78% of papaya allergic sera. rCari p 2 also displayed allergenic activity through basophil degranulation. rCari p 2 is correctly folded and showed irreversible denaturation in the melting curve. rCari p 2 displayed IgE-cross-reactivity with homologous cysteine proteases from kiwi and pineapple. Cari p 2 transcript was also detected in papaya pulps. rCari p 2 was resistant to pepsin digestion and retained IgE-reactivity after 60 minutes of pepsin digestion. In mouse model, rCari p 2 was found to elicit inflammatory responses in the lung and gastrointestinal epithelium. Hence, Cari p 2 is a newly characterized allergen with diagnostic and immunotherapeutic potential for managing allergic disorders in papaya sensitized individuals.


Subject(s)
Allergens/immunology , Chymopapain/immunology , Cross Reactions/immunology , Fruit/immunology , Pollen/immunology , Recombinant Proteins/immunology , Adult , Animals , Cloning, Molecular/methods , Cysteine Proteases/immunology , Female , Food Hypersensitivity/immunology , Humans , Immunoglobulin E/immunology , Male , Mice , Middle Aged , Young Adult
14.
Allergy Asthma Immunol Res ; 13(1): 154-163, 2021 Jan.
Article in English | MEDLINE | ID: mdl-33191683

ABSTRACT

Arginine kinase (AK) was first identified as an allergen in the Indian-meal moth and subsequently shown to occur as allergen in various invertebrates and shellfish. The cDNA coding for AK from the house dust mite (HDM) species Dermatophagoides pteronyssinus, Der p 20, has been isolated, but no recombinant Der p 20 (rDer p 20) allergen has been produced and characterized so far. We report the expression of Der p 20 as recombinant protein in Escherichia coli. rDer p 20 was purified and shown to be a monomeric, folded protein by size exclusion chromatography and circular dichroism spectroscopy, respectively. Using AK-specific antibodies, Der p 20 was found to occur mainly in HDM bodies, but not in fecal particles. Thirty percent of clinically well-characterized HDM allergic patients (n = 98) whose immunoglobulin E (IgE) reactivity profiles had been determined with an extensive panel of purified HDM allergens (Der f 1, 2; Der p 1, 2, 4, 5, 7, 10, 11, 14, 15, 18, 21, 23 and 37) showed IgE reactivity to Der p 20. IgE reactivity to Der p 20 was more frequently associated with lung symptoms. AKs were detected in several invertebrates with specific antibodies and Der p 20 showed IgE cross-reactivity with AK from shrimp (Litopenaeus vannamei). Thus, Der p 20 is a cross-reactive HDM allergen and may serve as a diagnostic marker for HDM-induced lung symptoms such as asthma.

15.
Exp Ther Med ; 20(5): 21, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32934686

ABSTRACT

Storage mites, such as Tyrophagus putrescentiae, are an important source of allergens that cause allergic diseases in humans. It has previously been indicated that T. putrescentiae has a high sensitization rate as an allergen in some Asian and European countries. Identifying and cloning the allergens in this species may enable improved diagnostic and therapeutic approaches. The aim of the present study was to clone and sequence the T. putrescentiae group 13 allergen (Tyr p 13) isolated from storage mites in China, to use bioinformatics tools to model its biophysical characteristics and to induce protein expression to test its IgE-binding activity. The full-length cDNA comprised 486 bp and was predicted to include a signal peptide of 22 amino acids. Its secondary structure was shown to comprise an α-helix (10.79%), extended strand (33.81%) and random coils (55.40%). Using homology modeling, the present study constructed a reasonable tertiary structure of Tyr p 13. Linear Bcell epitopes at amino acids 47-53, 70-76, 81-86, 101-105 and 112120 were predicted. Three discontinuous B-cell epitopes were also predicted: i) 47, 48, 49, 50, 51, 52, 53, 70, 71, 72 and 73; ii) 91, 92, 93, 94, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121 and 138; and iii) 74, 76, 79, 81, 82, 83, 84, 86, 101, 102, 103, 104 and 105. SDS-PAGE identified a specific band at the predicted molecular weight of the recombinant Tyr p 13 (rTyr p 13), demonstrating its successful expression. The rTyr p 13 bound to IgE in the serum of 13.2% (5/38) of patients allergic to T. putrescentiae, according to ELISA. The successful cloning of Tyr p 13 and basic bioinformatics analysis of the protein provided a foundation for the further study of this allergen with regards to the diagnosis and treatment of patients allergic to storage mites. These results provided a theoretical basis for the design of rTyr p 13 with modified B-cell epitopes.

16.
Clin Exp Allergy ; 50(8): 964-972, 2020 08.
Article in English | MEDLINE | ID: mdl-32506709

ABSTRACT

BACKGROUND: Severe allergy to fruits mediated by a 7 kDa allergen belonging to the gibberellin-regulated protein (GRP) family is known to be associated with Cupressaceae pollinosis. OBJECTIVE: To identify and characterize Cupressaceae pollen allergens involved in GRP-related fruit allergy. METHODS: Pru p 7-related proteins from pollen of Cupressus sempervirens, Juniperus ashei and Cryptomeria japonica were identified using a rabbit anti-Pru p 7 antiserum, purified chromatographically and sequenced by mass spectrometry and bioinformatic comparisons. The C sempervirens protein was produced as a recombinant allergen in Pichia pastoris. IgE antibody binding to pollen GRP proteins was analysed in a peach allergic (n = 54) and a cypress pollen allergic (n = 88) patient population from southern France using ImmunoCAP. RESULTS: In each of the three Cupressaceae species studied, a 7 kDa pollen protein related to Pru p 7 was identified and found to comprise an amino acid sequence of 63 residues in length, 92%-98% identical to each other and 67%-68% identical to Pru p 7. The C sempervirens, J ashei and C japonica GRP allergens have been officially recognized by the WHO/IUIS Allergen Nomenclature Sub-Committee and named Cup s 7, Jun a 7 and Cry j 7, respectively. Recombinant Cup s 7 showed IgE antibody binding capacity comparable to that of the purified natural allergen. Among 51 peach allergic subjects sensitized to Pru p 7, substantially higher levels of IgE to Cup s 7 than to Pru p 7 were found. Further, the pollen protein was able to completely outcompete IgE binding to Pru p 7, while the reverse competition effect was modest, consistent with primary sensitization by the pollen allergen. CONCLUSION AND CLINICAL RELEVANCE: Pru p 7-related pollen allergens from three Cupressaceae species have been characterized and may become useful for the identification of pollinosis patients at risk of developing severe fruit allergy.


Subject(s)
Allergens/immunology , Antigens, Plant/immunology , Cupressaceae/immunology , Food Hypersensitivity/immunology , Pollen/immunology , Rhinitis, Allergic, Seasonal/immunology , Adolescent , Adult , Aged , Biomarkers/blood , Child , Child, Preschool , Female , Food Hypersensitivity/blood , Food Hypersensitivity/diagnosis , Humans , Immunoglobulin E/blood , Male , Middle Aged , Molecular Weight , Plant Proteins/immunology , Prunus persica/immunology , Rhinitis, Allergic, Seasonal/blood , Rhinitis, Allergic, Seasonal/diagnosis , Young Adult
17.
J Allergy Clin Immunol ; 146(1): 169-179.e5, 2020 07.
Article in English | MEDLINE | ID: mdl-32194042

ABSTRACT

BACKGROUND: Poultry meat can induce severe allergic reactions. So far, the molecules causing poultry meat allergy are largely unknown. OBJECTIVE: Our aim was to identify and characterize poultry meat allergens. METHODS: Profiles of patients' IgE reactivity to chicken muscle were analyzed in immunoblots, and proteins recognized by the majority of patients were subjected to peptide mass fingerprinting. A 23-kDa IgE-reactive protein was identified as myosin light chain 1, designated Gallus domesticus 7 (Gal d 7). Recombinant Gal d 7 was produced in Escherichia coli. The protein's IgE reactivity was analyzed in ELISA experiments, and cross-reactivity with allergens of other poultry species was assessed in inhibition immunoblots. Fold and thermal stability were evaluated by circular dichroism analysis, and enzymatic stability was investigated using in vitro gastrointestinal digestion assays. RESULTS: Recombinant Gal d 7 represents a properly folded, predominantly α-helical protein and displays IgE-binding activity comparable to that of its natural counterpart. IgE reactivity analysis in 28 patients allergic to chicken meat revealed that Gal d 7 is a major allergen for patients primarily sensitized to chicken meat. Furthermore, Gal d 7-cross-reactive allergens were also detected in other poultry species, suggesting that recombinant Gal d 7 can be used as a diagnostic marker allergen for poultry meat allergy. The high thermal stability, refolding capacity, and resistance to gastrointestinal enzymes might explain why Gal d 7 can act as a potent sensitizing agent. CONCLUSION: Gal d 7 represents a novel major chicken meat allergen. Recombinant Gal d 7 could be used for diagnosis of genuine poultry meat sensitization.


Subject(s)
Allergens/immunology , Avian Proteins/immunology , Food Hypersensitivity/immunology , Immunoglobulin E/immunology , Poultry , Adolescent , Adult , Aged , Allergens/chemistry , Allergens/genetics , Animals , Avian Proteins/chemistry , Avian Proteins/genetics , Chickens , Child , Child, Preschool , Female , Food Hypersensitivity/diagnosis , Humans , Male , Middle Aged , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/immunology
18.
Molecules ; 25(2)2020 Jan 16.
Article in English | MEDLINE | ID: mdl-31963206

ABSTRACT

Four recombinant (r) allergens (rAmb a 8.0101, rArt v 4.0101, rBet v 2.0101, and rPhl p 12.0101) were successfully produced and used for sensitization studies. The allergens belong to the profilin family which is one of the most numerous allergen families. These four proteins represent allergens originating from pollen of weeds (rAmb a 8.0101 and rArt v 4.0101), tree (rBet v 2.0101) and grass (rPhl p 12.0101). The recombinant allergens were characterized using various biochemical and biophysical methods and tested for their ability to bind patient-derived antibodies. One hundred patients aged 2 to 50 years sensitized to pollen and plant-derived food allergens (IgE > 0.35 kU/L) were included. Sensitization to individual allergen sources and components of birch and timothy pollens was evaluated using multiparameter immunoblots. The presence of IgE to pollen-derived recombinant profilins rAmb a 8.0101, rArt v 4.0101, rBet v 2.0101, and rPhl p 12.0101 in serum was evaluated using ELISA method. The presence of IgE against pollen profilins was detected in 20 out of 100 studied patients. High correlation was seen between IgE ELISA results with individual pollen profilins. In summary, it was shown that the recombinant versions of the four allergenic profilins can be used for sensitization studies and for component-resolved allergy diagnostics.


Subject(s)
Allergens/immunology , Antigens, Plant/immunology , Hypersensitivity/immunology , Profilins/immunology , Recombinant Proteins/immunology , Allergens/chemistry , Amino Acid Sequence , Antigens, Plant/chemistry , Immunization , Models, Molecular , Profilins/chemistry , Protein Conformation , Protein Stability , Recombinant Proteins/chemistry , Spectrum Analysis , Structure-Activity Relationship , Thermodynamics
19.
J Investig Allergol Clin Immunol ; 30(5): 340-345, 2020.
Article in English | MEDLINE | ID: mdl-31530508

ABSTRACT

BACKGROUND AND OBJECTIVES: The prevalence of fish allergy has increased in recent years. The parvalbumin Gad c 1 is a major cod allergen that is used as a follow-up marker in patients with fish allergy. Objectives: To determine the clinical and laboratory characteristics of a population of patients with fish allergy. To analyze the role of the specific IgE (sIgE) of recombinant Gad c 1 (rGad c 1) and skin prick tests (SPTs) in confirming the acquisition of tolerance to fish. METHODS: We performed a retrospective study of patients with fish allergy from July 1, 2005 to December 31, 2016. The population was characterized according to demographic data, species of fish associated with allergic reactions, and symptoms. The SPT wheal diameter and sIgE for fish and rGad c 1 were evaluated before acquisition of tolerance (T0) and afterwards (T1). RESULTS: The study population comprised 81 patients (68% male). Most reactions were triggered by hake (51%), mackerel (30%), and cod (26%). The most frequent manifestations were urticaria/angioedema (72%), gastrointestinal symptoms (35%), and eczema (33%); 42% of patients experienced anaphylaxis. At T0, the average sIgE values were as follows: cod, 32.2 kUA/L; sardine, 18.4 kUA/L; hake, 17.5 kUA/L; salmon, 13.9 kUA/L; tuna, 4.5 kUA/L; and rGad c 1, 22.9 kUA/L. In patients who acquired tolerance to at least 1 fish species (n=60; 74%), the mean value of rGad c 1 at T1 (5.1 kUA/L) was significantly lower than at T0 (16.8 kUA/L) (P=.001). Significant values were also recorded for the average diameter of the SPT wheal and the evaluations at T0 and T1 for hake (9.42 mm/3.79 mm) and salmon (7.8 mm/2.8 mm) (P=.002 and P=.026, respectively). CONCLUSION: The decrease in sIgE to rGad c 1 and the mean wheal diameter of SPT for hake and salmon can be used as markers of prognosis in the acquisition of tolerance by fish-allergic patients.


Subject(s)
Allergens/immunology , Fishes/immunology , Food Hypersensitivity/diagnosis , Food Hypersensitivity/immunology , Parvalbumins/immunology , Recombinant Proteins/immunology , Adolescent , Adult , Animals , Female , Humans , Immunoglobulin E/immunology , Male , Prognosis , Retrospective Studies , Skin Tests , Young Adult
20.
Clin Rev Allergy Immunol ; 58(3): 326-341, 2020 Jun.
Article in English | MEDLINE | ID: mdl-31240545

ABSTRACT

Bee venom immunotherapy is the main treatment option for bee sting allergy. Its major limitations are the high percentage of allergic side effects and long duration, which are driving the development of novel therapeutic modalities. Three general approaches have been evaluated including the use of hypoallergenic allergen derivatives, adjunctive therapy, and alternative delivery routes. This article reviews preclinical and clinical evidence on the therapeutic potential of these new therapies. Among hypoallergenic derivatives, hybrid allergens showed a markedly reduced IgE reactivity in mouse models. Whether they will offer therapeutic benefit over extract, it is still not known since clinical trials have not been carried out yet. T cell epitope peptides have proven effective in small clinical trials. Major histocompatibility complex class II restriction was circumvented by using long overlapping or promiscuous T cell epitope peptides. However, the T cell-mediated late-phase adverse events have been reported with both short and longer peptides. Application of mimotopes could potentially overcome both T cell- and IgE-mediated adverse events. During this evolution of vaccine, there has been a gain in safety. The efficacy was further improved with the use of Toll-like receptor-activating adjuvants and delivery systems. In murine models, the association of allergen Api m 1 with cytosine-guanosine rich oligonucleotides stimulated strong T-helper type-1 response, whereas its encapsulation into microbubbles protected mice against allergen challenge. An intralymphatic administration of low-dose vaccine has shown the potential to decrease treatment from 5 years to only 12 weeks. Bigger clinical trials are needed to follow up on these results.


Subject(s)
Allergens/immunology , Bee Venoms/immunology , Desensitization, Immunologic/methods , Epitopes/immunology , Hypersensitivity/therapy , Recombinant Proteins/immunology , T-Lymphocytes/immunology , Animals , Bees , Desensitization, Immunologic/trends , Humans , Hypersensitivity/immunology , Hypersensitivity, Immediate , Mice
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