title: Immune response of neonates to pneumococcal polysaccharide-protein conjugate.
abstract: Immune responses were studied in adult and young mice exposed to pneumococcal 6A and 19F polysaccharides (PSs), as well as 19F PS conjugated to proteins, e.g. human immunoglobulin G (HIgG), pneumococcal R61 cell wall polypeptide, and bovine serum albumin (BSA). Significantly higher IgM and IgG2 antibody titres were induced in mice receiving 19F PS-protein conjugates than in the control group receiving 19F PS alone. Maternal immunization with 19F PS-HIgG conjugate elicited a low immune response in the offspring. However, when young mice from immunized mothers were given and additional dose of polysaccharide-protein conjugate, they gave an antibody response greater than that of mice not given additional immunogen. Similarly, young mice exposed to 14-valent pneumococcal vaccine during gestation produced higher antibody response to 6A and 19F PSs. Secondary immunization of 19F PS or PS-protein conjugate at 1 or 2 weeks after primary immunization did not enhance antibody formation but rather suppressed the immune response to that polysaccharide.
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000276:immunology*; D000917:Antibody Formation; D005260:Female; D007112:Immunity, Maternally-Acquired; D007117:Immunization, Secondary; D007074:Immunoglobulin G / Q000096:biosynthesis; D007075:Immunoglobulin M / Q000096:biosynthesis; D008431:Maternal-Fetal Exchange; D051379:Mice; D008807:Mice, Inbred BALB C; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D011247:Pregnancy; D011506:Proteins / Q000276:immunology*; D013296:Streptococcus pneumoniae / Q000276:immunology*
chemical_list: D007074:Immunoglobulin G; D007075:Immunoglobulin M; D011135:Polysaccharides, Bacterial; D011506:Proteins