title: Deficient TACI expression on B lymphocytes of newborn mice leads to defective Ig secretion in response to BAFF or APRIL.
abstract: Capsular polysaccharides of encapsulated bacteria do not induce immune response in newborns and the mechanism for this unresponsiveness is not clear. In adults, transmembrane activator and calcium-modulator and cyclophilin [corrected] ligand interactor (TACI) is a TNFR family member molecule with a pivotal role in Ab responses against polysaccharide vaccines. We investigated the expression and the functions of the TNF family cytokines, B cell-activating factor of the TNF family (BAFF) and a proliferation-inducing ligand (APRIL), and their receptors in newborn mice and found that TACI expression on B lymphocytes was dramatically reduced (p < 0.0001) in newborns as compared with adults. More importantly, TACI ligands BAFF or APRIL were unable to induce IgA/IgG/IgM secretion from newborn B lymphocytes. Additionally, TACI expression seems to be important in plasma cell development. Indeed, in contrast to adults, stimulation of newborn B lymphocytes with BAFF or APRIL did not result in up-regulation of CD138 expression. In vitro or in vivo exposure of newborn B lymphocytes to oligodeoxynucleotides (CpG ODN) led to up-regulation of TACI expression on newly formed, follicular, and marginal zone as well as B1 B lymphocyte populations, and rendered them responsive to BAFF- or APRIL-mediated CD138 expression and IgA/IgG secretion. Finally, immunization of newborn BALB/c mice but not TACI knockout mice with CpG ODN containing (4-hydroxy-3-nitrophenyl)acetyl-Ficoll led to development of IgG Abs against (4-hydroxy-3-nitrophenyl)acetyl. These findings demonstrate that low TACI expression may be a critical factor that determines the susceptibility of newborns to infections with encapsulated bacteria and the impaired immunogenicity of polysaccharide vaccines. Finally, CpG ODNs may correct deficient newborn response to polysaccharide vaccines by up-regulating TACI.
authors.affiliation: Laboratory of Bacterial Polysaccharides, Division of Bacterial, Parasitic, and Allergenic Products, Center for Biologics Evaluation and Research, Rockville, MD 20852, USA.
authors.forename: Sunita
authors.initials: S
authors.lastname: Kanswal
authors.forename: Nora
authors.initials: N
authors.lastname: Katsenelson
authors.forename: Angamuthu
authors.initials: A
authors.lastname: Selvapandiyan
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Bram
authors.forename: Mustafa
authors.initials: M
authors.lastname: Akkoyunlu
mesh_terms: D000276:Adjuvants, Immunologic; D000818:Animals; D000831:Animals, Newborn; D053264:B-Cell Activating Factor / Q000276:immunology / Q000378:metabolism*; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D001428:Bacterial Vaccines / Q000276:immunology; D004247:DNA / Q000276:immunology / Q000378:metabolism; D005362:Ficoll / Q000031:analogs & derivatives / Q000276:immunology; D007136:Immunoglobulins / Q000096:biosynthesis / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D009838:Oligodeoxyribonucleotides / Q000276:immunology; D010950:Plasma Cells / Q000276:immunology* / Q000378:metabolism; D053668:Syndecan-1 / Q000276:immunology / Q000378:metabolism; D053303:Transmembrane Activator and CAML Interactor Protein / Q000276:immunology / Q000378:metabolism*; D053300:Tumor Necrosis Factor Ligand Superfamily Member 13 / Q000276:immunology / Q000378:metabolism*
chemical_list: C516150:(4-hydroxy-3-nitrophenyl)acetyl-Ficoll; D000276:Adjuvants, Immunologic; D053264:B-Cell Activating Factor; D001428:Bacterial Vaccines; C408982:CPG-oligonucleotide; D007136:Immunoglobulins; D009838:Oligodeoxyribonucleotides; D053668:Syndecan-1; C486361:Tnfrsf13b protein, mouse; C491959:Tnfsf13 protein, mouse; C505720:Tnfsf13b protein, mouse; D053303:Transmembrane Activator and CAML Interactor Protein; D053300:Tumor Necrosis Factor Ligand Superfamily Member 13; D005362:Ficoll; D004247:DNA