Ponente
Descripción
Cross-reactive material 197 (CRM 197) is a non-toxic mutant of diphtheria toxin, in which glycine 52 was replaced with glutamic acid. This protein has been used as a carrier in different vaccines like antineumoccoccal Prevnar 13®. The protein was first obtained from the supernatant of a Corynebacterium diphtheriae mutant strain that is characterized by a slow growth rate and a relatively low yield of mutant toxin, resulting in high production costs. As an alternative, different heterologous systems have been used for its expression, such as Bacillus subtilis, Escherichia coli, and Pichia pastoris. The characteristics of recombinant CRM 197, in terms of structure, post-translational modifications, solubility and antigenicity, are similar to the protein expressed in C. diphtheriae. Finlay Vaccines Institute has been working for several years in tetanus toxoid conjugate vaccines against different infection diseases. In this scenario, it is pivotal the diversification of carrier proteins candidates. Due the challenges of CRM197 production, the aim of this work is to obtain high yields of CRM 197 in the periplasm of E. coli. B834(DE3) strain, in order to use it for conjugating polysaccharide antigens and being able to use it as a carrier protein in new vaccines.
