Alérgenos recombinantes de Blomia tropicalis e Dermatophagoides pteronyssinus como possíveis marcadores de gravidade para doenças alérgicas

Abstract

Introduction: Allergies to house dust mites, such as Blomia tropicalis and Dermatophagoides pteronyssinus, represent a major public health problem. Molecular and immunological characterization of allergens from these two species is crucial for clinical applications. Objectives: Express and purify the allergens Blo t 41 and Der p 20 and compare the IgE reactivity of these two allergens in cohorts of allergic individuals. Materials and Methods: The Blo t 41 and Der p 20 gene sequences were cloned into pET21a(+) vectors and expressed in E. coli BL21(DE3). After solubility testing, purification was performed by ion exchange and size exclusion chromatography. The functionality of Blo t 41 was confirmed by binding to chitin. rBlo t 41 and rDer p 20 underwent a stability test at room temperature and 4°C with periodic samples collected, and IgE reactivity was determined by indirect ELISA using 222 sera from allergic asthmatic patients. Results and Conclusion: The expression of rBlo t 41 (13 kDa) and rDer p 20 (40 kDa) was successful and confirmed. In the allergen stability test, rDer p 20 was shown to be thermally stable at room temperature and at 4ºC, while rBlo t 41 was shown to be more resistant at room temperature. The chitin binding assay confirmed that rBlo t 41 is a functional chitin-binding protein. In the serological analysis, rBlo t 41 showed greater reactivity (59% in allergic subjects; 18% in allergic asthmatics) than Der p 20 (37% and 12%, respectively), identified as a major allergen of B. tropicalis. Der p 20 showed a strong positive correlation with the D. pteronyssinus extract in patients with mild allergic asthma. E. coli BL21 (DE3) can be used as an effective expression vector to produce rBlo t 41 and rDer p 20, with high expression yields. Considering that they showed IgE reactivity in sera from patients allergic to HDMs, these recombinant allergens could, therefore, be used in future diagnostic applications and further explored as potential markers for disease severity.