Produção de alérgeno Blo t 5 recombinante (rBlo t 5) de Blomia tropicalis e reatividade de anticorpos IgE a alérgenos Blo t 5 nativo e recombinante em pacientes atópicos

Abstract

Allergies are caused by immunological reactions to allergens, which are substances capable of triggering specific IgE responses in genetically predisposed subjects. In tropical and subtropical regions, allergens derived from B. tropicalis are important causes of IgE-mediated sensitization among patients with asthma and allergic rhinitis. The aim of this study was to produce the recombinant Blo t 5 allergen and to evaluate its reactivity to IgE in sera from atopic patients compared to its native counterpart and B. tropicalis crude extract using immunoenzymatic assays. A full-length cDNA encoding was Blo t 5 was cloned from a mRNA Bt using a transcriptase reverse and PCR. The cDNA was PCR-amplifed, sequenced and subcloned into E.coli expression vector and recombinant protein rBlo t 5 was purified. Immunoglobulin E (IgE) reactivity of the nBlo t 5 and rBlo t 5 allergens was determined by enzyme-linked immunosorbent assay (ELISA). rBlo t 5 was capable of binding to IgE revealing the preservation of additional unique IgE epitopes in rBlo t 5 BT+ group (36%) and BT- (31,2%). This comparative study confirmed production and purification the recombinant Blo t 5. The recombinant protein showed great, when patients sera was used, presenting moderate correlation of human IgE reactivity between rBlo t and crude Bt extract, rBlo t 5 and nBlo t 5 in these sera in patients in Brazil.