title: Characteristics of immune responses to native and protein conjugated pneumococcal polysaccharide type 14.
abstract: The immune response to pneumococcal polysaccharide type 14 (PPS-14), induced by native PPS-14 was compared with the response induced by PPS-14 conjugated with CRM197 (PPS-14-CRM197). In our animal model, immunization with PPS-14-CRM197 gave a significant enhancement of anti-PPS-14 serum titres for IgM and IgG, but not for IgA. Also an increase in total number of anti-PPS-14 antibody-secreting cells was found. Using immunohistochemical techniques, a different distribution pattern of specific antibody-containing cells in spleen section after immunization with PPS-14-CRM197 was observed. Furthermore, a higher number of IFN-gamma producing cells was found after immunization with PPS-14-CRM197, as compared with immunization with PPS-14. This enhanced IFN-gamma production may be the cause for enhanced IgG response observed after immunization with PPS-14-CRM197. The specific immune response was less affected by splenectomy in animals immunized with PPS-14-CRM197 than with PPS-14. However, an age-related response to the native as well as the conjugated form of the PPS-14 was observed, since no effect of conjugation with CRM197 was seen in the onset of the immune response to PPS-14 in young animals. In conclusion, our results affirm the hypothesis that conjugation of polysaccharides changes the characteristics of the antigen towards a thymus-dependent antigen.
authors.affiliation: Department of Cell Biology and Immunology, Medical Faculty, Vrije Universiteit, Amsterdam, The Netherlands.
authors.forename: G P
authors.initials: GP
authors.lastname: van den Dobbelsteen
authors.forename: H
authors.initials: H
authors.lastname: Kroes
authors.forename: E P
authors.initials: EP
authors.lastname: van Rees
mesh_terms: D000375:Aging / Q000276:immunology; D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis*; D000942:Antigens, Bacterial / Q000276:immunology*; D016667:Bacterial Capsules; D001426:Bacterial Proteins / Q000276:immunology*; D016207:Cytokines / Q000096:biosynthesis*; D008198:Lymph Nodes / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010581:Peyer's Patches / Q000276:immunology; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D051381:Rats; D017208:Rats, Wistar; D013154:Spleen / Q000276:immunology; D013156:Splenectomy; D013296:Streptococcus pneumoniae / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D016207:Cytokines; D011135:Polysaccharides, Bacterial; C092298:pneumococcal polysaccharide 14 - CRM 197; C056696:pneumococcal polysaccharide, type 14