INVESTIGADORES
CUESTAS Maria Lujan
congresos y reuniones científicas
Título:
Expression of HBsAg from different genotypes to improve the efficacy of the current anti-hepatitis B vaccine
Autor/es:
EGUIBAR N; PERAZZO P; SORDELLI A; RODRIGUEZ DEL VALLE N; GALLEGO M; MOLINA R; SAQUIN J; NUDEL C; GONZALEZ R; NUSBLAT A; CUESTAS ML
Reunión:
Congreso; LI Reunión SAIB; 2015
Resumen:
Introduction: Phylogenetic analysis based on thecomparison of complete HBV genomes has defined at least 8 genotypes (A-H) andseveral subgenotypes that display a characteristic geographic distribution andshow differences in biological properties. Genotypes E and F are the most divergent amongall genotypes within the adeterminant (aminoacids 107-147 of HBsAg) and within the S gene, respectively.These features, together with the emergence of S-escape mutants, have raisedconcerns about the efficacy of the current genotype A-based vaccines on theAfrican and American continent, where genotypes E and F are prevalent,respectively. Aims: To analyze the effect of the most divergent genotypes(E, F1b and F4) and their interaction with anti-HBs antibodies derived fromvaccination with genotype A2.Methods: Genes for each genotype were cloned into the expression vector pPICZa andtransformed into Pichia pastoris X-33. For detection of HBsAg, commercial ELISAassays were performed. VLPs were characterized and reactivity was assayed invitro (TEM and DLS) and in silico.Results: High expression levels were obtained, and the resulting VLPs had asize of about 20 nm. Reactivity with anti-HBs antibodies was variable.Conclusions: Our results point out the pressing need to assess the incorporation ofgenotypes E/F-derived HBsAg vaccine in those endemic areas where such genotypesare prevalent.