Expanding the Scope of Ugi Multicomponent Bioconjugation to Produce Pneumococcal Multivalent Glycoconjugates as Vaccine Candidates

Bioconjug Chem. 2020 Sep 16;31(9):2231-2240. doi: 10.1021/acs.bioconjchem.0c00423. Epub 2020 Sep 2.

Abstract

Conjugate vaccines against encapsulated pathogens like Streptococcus pneumoniae face many challenges, including the existence of multiple serotypes with a diverse global distribution that constantly requires new formulations and higher coverage. Multivalency is usually achieved by combining capsular polysaccharide-protein conjugates from invasive serotypes, and for S. pneumoniae, this has evolved from 7- up to 20-valent vaccines. These glycoconjugate formulations often contain high concentrations of carrier proteins, which may negatively affect glycoconjugate immune response. This work broadens the scope of an efficient multicomponent strategy, leading to multivalent pneumococcal glycoconjugates assembled in a single synthetic operation. The bioconjugation method, based on the Ugi four-component reaction, enables the one-pot incorporation of two different polysaccharide antigens to a tetanus toxoid carrier, thus representing the fastest approach to achieve multivalency. The reported glycoconjugates incorporate three combinations of capsular polysaccharides 1, 6B, 14, and 18C from S. pneumoniae. The glycoconjugates were able to elicit functional specific antibodies against pneumococcal strains comparable to those shown by mixtures of the two monovalent glycoconjugates.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chemistry Techniques, Synthetic
  • Glycoconjugates / chemical synthesis
  • Glycoconjugates / chemistry*
  • Glycoconjugates / immunology
  • Glycoconjugates / therapeutic use
  • Humans
  • Mice
  • Models, Molecular
  • Pneumococcal Infections / immunology
  • Pneumococcal Infections / prevention & control
  • Pneumococcal Vaccines / chemical synthesis
  • Pneumococcal Vaccines / chemistry*
  • Pneumococcal Vaccines / immunology
  • Pneumococcal Vaccines / therapeutic use
  • Rabbits
  • Streptococcus pneumoniae / immunology
  • Vaccines, Conjugate / chemistry*
  • Vaccines, Conjugate / immunology
  • Vaccines, Conjugate / therapeutic use

Substances

  • Glycoconjugates
  • Pneumococcal Vaccines
  • Vaccines, Conjugate