title: The ability of B cells and dendritic cells to present antigen increases during ontogeny.
abstract: The immune response to polysaccharide (PS) Ags in mice is delayed during ontogeny even when administered in a thymus-dependent (TD) form. In this study, Neisseria meningitidis group C PS-tetanus toxoid conjugate (MCPS-TT) vaccine was used to examine whether the delay in the development of Ab responses to TD PS conjugate vaccines in neonatal mice is due to defective Ag presentation. The results show that B cells and dendritic cells (DC) from 3- and 7-day-old mice were severely defective in presenting TT and MCPS-TT to Ag-specific T cell clones. The ability of these cells to present Ag reaches adult levels by 4 wk. The development of anti-MCPS and anti-TT Abs in neonatal mice parallels the functional ability of their APC to present Ag. DC from neonatal mice expressed very low levels of MHC class II, costimulatory molecules B7.1, B7.2, and CD11c but high levels of monocyte-specific markers F4/80 and CD11b and granulocyte marker, Ly6G. Significant changes in the expression of these markers were observed as the age of the mice increased. MHC class II, B7.1 and B7.2, and CD11c all increased with age, reaching adult levels between 3 and 4 wk, concurrent with the function of APC. These results demonstrate that one reason neonates fail to produce high titers of anti-PS Abs even when immunized in a TD form is that their B cells and DC are not fully functional.
authors.affiliation: Division of Monoclonal Antibodies, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892, USA.
authors.forename: S
authors.initials: S
authors.lastname: Muthukkumar
authors.forename: J
authors.initials: J
authors.lastname: Goldstein
authors.forename: K E
authors.initials: KE
authors.lastname: Stein
mesh_terms: D000375:Aging / Q000276:immunology; D000818:Animals; D000831:Animals, Newborn / Q000254:growth & development* / Q000276:immunology*; D000907:Antibodies, Bacterial / Q000096:biosynthesis; D017951:Antigen Presentation / Q000502:physiology* / Q000528:radiation effects; D000942:Antigens, Bacterial / Q000276:immunology; D015703:Antigens, CD / Q000096:biosynthesis; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism* / Q000528:radiation effects; D018122:B7-1 Antigen / Q000096:biosynthesis; D051940:B7-2 Antigen; D002454:Cell Differentiation / Q000276:immunology; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology* / Q000378:metabolism* / Q000382:microbiology; D005260:Female; D000949:Histocompatibility Antigens Class II / Q000096:biosynthesis; D016130:Immunophenotyping; D008213:Lymphocyte Activation / Q000528:radiation effects; D007959:Lymphocyte Culture Test, Mixed; D008562:Membrane Glycoproteins / Q000096:biosynthesis; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009345:Neisseria meningitidis / Q000276:immunology; D011135:Polysaccharides, Bacterial / Q000276:immunology; D011247:Pregnancy; D013154:Spleen / Q000276:immunology / Q000378:metabolism; D013745:Tetanus Toxoid / Q000008:administration & dosage / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D015703:Antigens, CD; D018122:B7-1 Antigen; D051940:B7-2 Antigen; C497965:Cd86 protein, mouse; D000949:Histocompatibility Antigens Class II; D008562:Membrane Glycoproteins; D011135:Polysaccharides, Bacterial; D013745:Tetanus Toxoid; C037676:meningococcal group C polysaccharide