IgE Epitopes of the House Dust Mite Allergen Der p 7 Are Mainly Discontinuous and Conformational.

Background: Several studies indicate that Der p 7 is an important and clinically relevant allergen of Dermatophagoides pteronyssinus which should be included in vaccines for treatment of house dust mite (HDM) allergy. Aim of this study was to characterize the IgE epitopes of Der p 7. Methods: Recombinant Der p 7 was expressed and purified, analyzed for fold by circular dichroism and tested for its allergenic activity by basophil activation. Seven overlapping, surface-exposed peptides (P1-P7) with a length of 27 to 37 amino acids, which spanned the Der p 7 sequence, were synthesized and tested for IgE reactivity and allergenic activity by basophil activation assay. Carrier-bound peptides were studied for their ability to induce allergen-specific IgG antibodies in rabbits. Peptide-specific antibodies were used to inhibit allergic patients` IgE binding to Der p 7 by ELISA for mapping of IgE epitopes. Results: rDer p 7 showed high allergenic activity comparable with Der p 5, Der p 21, and Der p 23. None of the seven tested peptides showed any IgE reactivity or allergenic activity when tested with HDM- allergic patients indicating lack of sequential IgE epitopes on Der p 7. IgE inhibition experiments using anti-peptide specific IgGs and molecular modeling enabled us to identify discontinuous, conformational IgE epitopes of Der p 7. Conclusion and Clinical Relevance: IgE epitopes of Der p 7 belong to the conformational and discontinuous type whereas sequential Der p 7 peptides lack IgE reactivity. It should thus be possible to construct hypoallergenic vaccines for Der p 7 based on carrier-bound allergen peptides.

Burden of allergic rhinitis and impact of MP-AzeFlu from the patient perspective: pan European patient survey.

OBJECTIVE: The aims of this survey were to (1) assess the burden of allergic rhinitis (AR) from the patient perspective, (2) investigate MP-AzeFlu use in real life and its impact on patients' lives and (3) explore factors associated with treatment satisfaction. METHODS: A cross-sectional, quantitative, online, questionnaire-based survey was conducted in seven European countries (March-June 2019). Questions explored AR burden and treatment satisfaction. Satisfaction was assessed using the Treatment Satisfaction Questionnaire for Medication 9-item (TSQM-9; max score = 100). Participants (aged ≥18 years) had a doctor/healthcare provider confirmed AR diagnosis and used MP-AzeFlu within the last year. RESULTS: Pre-MP-AzeFlu treatment, participants (n = 1004) reported an average of 3.3 (SD:3.5) doctor visits/year, 8.1 (SD:11.0) days/year absenteeism and 15.8 (SD:18.9) days/year presenteeism due to AR. Only 48% of participants used MP-AzeFlu twice/day as recommended. Post-MP-AzeFlu 57% of participants reported better QoL, 47% reported fewer doctor visits and 52% discontinued polypharmacy. Absenteeism and presenteeism were reduced by 2.5 (SD 10.0) and 7.3 (SD:16.0) days/year, respectively. 70% of participants were more/much more satisfied with MP-AzeFlu versus previous AR treatment(s), and ≥70% were satisfied/extremely satisfied with its ability to prevent/treat AR, relieve symptoms and with its onset of action. Mean global, effectiveness and convenience TSQM-9 scores were 70.0 (SD:19.8), 68.3 (SD:21.6) and 72.7 (SD:20.4), respectively. Treatment satisfaction and effectiveness were significantly improved when MP-AzeFlu was taken as recommended. CONCLUSIONS: The impact of AR on patients' lives remains high. Real-life use of MP-AzeFlu reduces that impact and is associated with a high level of effectiveness, convenience and global satisfaction.

Immunotherapy With the PreS-based Grass Pollen Allergy Vaccine BM32 Induces Antibody Responses Protecting Against Hepatitis B Infection.

BACKGROUND: We have constructed and clinically evaluated a hypoallergenic vaccine for grass pollen allergy, BM32, which is based on fusion proteins consisting of peptides from the IgE binding sites of the major grass pollen allergens fused to preS (preS1+preS2), a domain of the hepatitis B virus (HBV) large envelope protein which mediates the viral attachment and entry. Aim of this study was the characterization of the HBV-specific immune response induced by vaccination of allergic patients with BM32 and the investigation of the vaccines' potential to protect against infection with HBV. METHODS: Hepatitis B-specific antibody and T cell responses of patients vaccinated with BM32 were studied using recombinant preS and synthetic overlapping peptides spanning the preS sequence. The specificities of the antibody responses were compared with those of patients with chronic HBV infection. Furthermore, the capacity of BM32-induced antibodies, to inhibit HBV infection was investigated using HepG2-hNTCP cell-based in vitro virus neutralization assays. FINDINGS: IgG antibodies from BM32-vaccinated but not of HBV-infected individuals recognized the sequence motif implicated in NTCP (sodium-taurocholate co-transporting polypeptide)-receptor interaction of the hepatitis B virus and inhibited HBV infection. INTERPRETATION: Our study demonstrates that the recombinant hypoallergenic grass pollen allergy vaccine BM32 induces hepatitis B-specific immune responses which protect against hepatitis B virus infection in vitro.

Structural and Functional Characterization of the Major Allergen Amb a 11 from Short Ragweed Pollen.

Allergy to the short ragweed (Ambrosia artemisiifolia) pollen is a major health problem. The ragweed allergen repertoire has been recently expanded with the identification of Amb a 11, a new major allergen belonging to the cysteine protease family. To better characterize Amb a 11, a recombinant proform of the molecule with a preserved active site was produced in Escherichia coli, refolded, and processed in vitro into a mature enzyme. The enzymatic activity is revealed by maturation following an autocatalytic processing resulting in the cleavage of both N- and C-terminal propeptides. The 2.05-Å resolution crystal structure of pro-Amb a 11 shows an overall typical C1A cysteine protease fold with a network of molecular interactions between the N-terminal propeptide and the catalytic triad of the enzyme. The allergenicity of Amb a 11 was confirmed in a murine sensitization model, resulting in airway inflammation, production of serum IgEs, and induction of Th2 immune responses. Of note, inflammatory responses were higher with the mature form, demonstrating that the cysteine protease activity critically contributes to the allergenicity of the molecule. Collectively, our results clearly demonstrate that Amb a 11 is a bona fide cysteine protease exhibiting a strong allergenicity. As such, it should be considered as an important molecule for diagnosis and immunotherapy of ragweed pollen allergy.