Development of a hypoallergenic chimeric molecule against house dust mite

• Grant number: 25/20355-5
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: October 01, 2025
• End date: February 28, 2027
• Field of knowledge: Health Sciences - Medicine - Medical Clinics
• Principal Investigator: Keity Souza Santos
• Grantee: Flávia Lopes Adami
• Host Institution: Faculdade de Medicina (FM). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 25/07392-9 - Development of a Chimeric Molecule for Sublingual Allergen-Specific Immunotherapy to Treat House Dust Mite Allergy, AP.R

Abstract

Introduction: Allergic diseases constitute a growing public health challenge,currently affecting approximately 20% of the world's population, with projections indicating thatthis number could reach 50% by 2030. Allergen-specific immunotherapy is, to date, the only approach capable of modifying the course of the disease. However,conventional allergen extracts have several limitations, such as the presence ofproteins not relevant to the patient, which can result in the emergence of newsensitizations, and the absence or loss of clinically important allergens, such asDer p 23, during the extraction process. On the other hand, the use of isolatedrecombinant proteins requires the combination of multiple molecules to address thevariety of sensitization profiles, increasing costs and maintaining the risk ofadverse reactions. Objectives: The project aims to develop a single chimeric moleculecontaining specific T-cell epitopes of the main allergens of the dust miteDermatophagoides pteronyssinus (Der p 1, Der p 2, and Der p 23), with a focus on achievinga safer, more precise, and economically viable immunotherapeutic platform.Methods: The strategy involves in silico selection of T-cell epitopes usingbioinformatics tools, avoiding IgE epitopes. The molecule constructionwill utilize optimized linkers (GPGPG and KK) and cysteine ¿¿substitutions for stability.Expression will be performed by testing different parameters such as temperature,inducer concentration, time, and E. coli strains (BL21-DE3, ClearColi, C41 pLyss, StarpLyss), followed by chromatographic purification. Characterization will include circular dichroism, mass spectrometry, and endolysosomal degradation assays.BALB/c mice will be immunized to assess humoral (blocking IgG) and cellular (ELISPOT) responses. Expected Results:We expect to obtain a stable chimeric protein capable of inducing protective antibodies and robust regulatory responses for subsequent allergenicity testing in murine models of allergic asthma.Conclusion:The proposed approach represents an innovative solution that overcomes the limitations of conventional extracts and isolated recombinant proteins, with the potential to transform allergen-specific immunotherapy and be expanded to other clinically relevant allergies.