VII Simposio Internacional de Química 2019
SIQ 2019
Streptococcus pneumoniae is one of the fundamental causes of pneumonia, meningitis, otitis and sepsis worldwide. The main strategy to prevent these diseases is based on immunization with conjugate vaccines, where the capsular polysaccharide (CPs) is covalently linked to a carrier, usually a protein. These vaccines manage to induce powerful immune responses and generate immunological memory against the bacteria. Nowadays, the main aim is to improve the pharmacological properties of the conjugates and avoid the so-called "epitope overload effect" by replacing the carrier protein with molecules with adjuvant activity in the structure of the vaccine antigen. Alpha galactosylceramide (α-GalCer) is a glycolipid with adjuvant properties, capable of generating a powerful immune response by activating the iNKT cells. In this work, we describe the conjugation of capsular polysaccharides of S. pneumoniae to novel synthetic α-GalCer analogues as carriers; using reported conjugation methodologies, such as reductive amination, peptide coupling and multicomponent reactions such as Passerini 3-component reaction and Ugi 4-component reaction. The obtained conjugates were characterized by high-performance liquid chromatography and colorimetric methods. The identity and antigenicity of the obtained conjugates were determined by techniques such as quantitative 1H-RMN and DotBlot. The conjugates type CPs-α-GalCer-TT are immunogenic, and are able to induce an immune response type IgG similar to that generated by the conjugates containing TT. This work constitutes the first report of the employment of novel α-GalCer analogs conjugated to both PsCs of S. pneumoniae and a carrier protein as TT.
Streptococcus pneumoniae is one of the fundamental causes of pneumonia, meningitis, otitis and sepsis worldwide. The main strategy to prevent these diseases is based on immunization with conjugate vaccines, where the capsular polysaccharide (CPs) is covalently linked to a carrier, usually a protein. These vaccines manage to induce powerful immune responses and generate immunological memory against the bacteria. Nowadays, the main aim is to improve the pharmacological properties of the conjugates and avoid the so-called "epitope overload effect" by replacing the carrier protein with molecules with adjuvant activity in the structure of the vaccine antigen. Alpha galactosylceramide (α-GalCer) is a glycolipid with adjuvant properties, capable of generating a powerful immune response by activating the iNKT cells. In this work, we describe the conjugation of capsular polysaccharides of S. pneumoniae to novel synthetic α-GalCer analogues as carriers; using reported conjugation methodologies, such as reductive amination, peptide coupling and multicomponent reactions such as Passerini 3-component reaction and Ugi 4-component reaction. The obtained conjugates were characterized by high-performance liquid chromatography and colorimetric methods. The identity and antigenicity of the obtained conjugates were determined by techniques such as quantitative 1H-RMN and DotBlot. The conjugates type CPs-α-GalCer-TT are immunogenic, and are able to induce an immune response type IgG similar to that generated by the conjugates containing TT. This work constitutes the first report of the employment of novel α-GalCer analogs conjugated to both PsCs of S. pneumoniae and a carrier protein as TT.
Sobre el ponente
Lic. Dayan Viera Barredo