Immunology of Experimental Synthetic Carbohydrate-Protein Conjugate Vaccines against Streptococcus pneumoniae Serotypes

摘要

The design and development of synthetic routes for the preparation of oligosaccharide fragments of capsular polysaccharides of Streptococcus pneumoniae serotypes took 25 years of intensive research at the Bijvoet Center. During that time sets of oligosaccharides of type 3, 6A, 6B, 14, and 23F were synthesized. Meanwhile, the Eijkman-Winkler Institute performed immunological studies on the effects of these carbohydrates in mice and rabbits. Different carriers (including liposomes), dosages, and adjuvants were tested in order to obtain high antibody titers with opsonic activity. Opsonization promoted the uptake and killing of bacteria by phagocytes, resulting in protective immunity to a lethal challenge with the corresponding virulent S. pneumoniae strain. The immunogenicity of synthetic oligosaccharide-protein conjugates was compared with that of polysaccharide-protein conjugates for the same serotypes of S. pneumoniae.