RESUMO
Globally, avian influenza (AI) is a serious problem in poultry farming. Despite vaccination, the prevalence of AI in México highlights the need for new approaches to control AI and to reduce the economic losses associated with its occurrence in susceptible birds. Recombinant proteins from avian influenza virus (AIV) have been expressed in different organisms, such as plants. The present study investigated the feasibility of designing and expressing the HA protein of AIV in the transplastomic microalga Chlamydomonas reinhardtii as a novel approach for AIV control and taking advantage of culture conditions, its reproductive range, and safe use in consideration of the generally regarded as safe food ingredient regulatory classification. The results showed that the HA protein of AIV in C. reinhardtii presents antigenic activity by western blot test and through its application in chickens, demonstrating its feasibility as a recombinant antigen against AIV.
Assuntos
Chlamydomonas reinhardtii/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Vírus da Influenza A Subtipo H5N2/imunologia , Vacinas contra Influenza/imunologia , Influenza Aviária/imunologia , Doenças das Aves Domésticas/imunologia , Animais , Anticorpos Antivirais/imunologia , Galinhas , Chlamydomonas reinhardtii/metabolismo , Cloroplastos/genética , Cloroplastos/metabolismo , Avaliação Pré-Clínica de Medicamentos , Expressão Gênica , Glicoproteínas de Hemaglutininação de Vírus da Influenza/administração & dosagem , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Vírus da Influenza A Subtipo H5N2/genética , Vacinas contra Influenza/administração & dosagem , Vacinas contra Influenza/genética , Influenza Aviária/prevenção & controle , Influenza Aviária/virologia , Doenças das Aves Domésticas/prevenção & controle , Doenças das Aves Domésticas/virologiaRESUMO
Scorpion venoms are a rich source of K(+) channel-blocking peptides. For the most part, they are structurally related small disulfide-rich proteins containing a conserved pattern of six cysteines that is assumed to dictate their common three-dimensional folding. In the conventional pattern, two disulfide bridges connect an α-helical segment to the C-terminal strand of a double- or triple-stranded ß-sheet, conforming a cystine-stabilized α/ß scaffold (CSα/ß). Here we show that two K(+) channel-blocking peptides from Tityus scorpions conserve the cysteine spacing of common scorpion venom peptides but display an unconventional disulfide pattern, accompanied by a complete rearrangement of the secondary structure topology into a CS helix-loop-helix fold. Sequence and structural comparisons of the peptides adopting this novel fold suggest that it would be a new elaboration of the widespread CSα/ß scaffold, thus revealing an unexpected structural versatility of these small disulfide-rich proteins. Acknowledgment of such versatility is important to understand how venom structural complexity emerged on a limited number of molecular scaffolds.