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1.
J Neuroimmunol ; 320: 19-24, 2018 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-29759137

RESUMO

Immunoglobulin G (IgG) harbors a conserved N-glycosylation site which is important for its effector functions. Changes in glycosylation of IgG occur in many autoimmune diseases but also in physiological conditions. Therefore, the glycosylation pattern of serum IgG is well characterized. However, limited data is available on the glycosylation pattern of IgG in cerebrospinal fluid (CSF) compared to serum. Here, we report significantly reduced levels of bisected glycans in CSF IgG. Galactosylation and sialylation of IgG4 also differed significantly. Therefore, we propose a common mechanism mediating glycosylation changes of IgG at the transition from serum to CSF in steady state conditions.


Assuntos
Imunoglobulina G/sangue , Imunoglobulina G/líquido cefalorraquidiano , Imunoglobulina G/química , Idoso , Idoso de 80 Anos ou mais , Feminino , Glicosilação , Humanos , Masculino , Pessoa de Meia-Idade , Polissacarídeos/análise , Polissacarídeos/química
2.
Nat Immunol ; 18(1): 104-113, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27820809

RESUMO

The checkpoints and mechanisms that contribute to autoantibody-driven disease are as yet incompletely understood. Here we identified the axis of interleukin 23 (IL-23) and the TH17 subset of helper T cells as a decisive factor that controlled the intrinsic inflammatory activity of autoantibodies and triggered the clinical onset of autoimmune arthritis. By instructing B cells in an IL-22- and IL-21-dependent manner, TH17 cells regulated the expression of ß-galactoside α2,6-sialyltransferase 1 in newly differentiating antibody-producing cells and determined the glycosylation profile and activity of immunoglobulin G (IgG) produced by the plasma cells that subsequently emerged. Asymptomatic humans with rheumatoid arthritis (RA)-specific autoantibodies showed identical changes in the activity and glycosylation of autoreactive IgG antibodies before shifting to the inflammatory phase of RA; thus, our results identify an IL-23-TH17 cell-dependent pathway that controls autoantibody activity and unmasks a preexisting breach in immunotolerance.


Assuntos
Artrite Reumatoide/imunologia , Autoanticorpos/metabolismo , Linfócitos B/imunologia , Tolerância Imunológica , Imunoglobulina G/metabolismo , Interleucina-23/metabolismo , Células Th17/imunologia , Animais , Diferenciação Celular , Células Cultivadas , Modelos Animais de Doenças , Glicosilação , Humanos , Interleucinas/metabolismo , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos C57BL , Sialiltransferases/genética , Sialiltransferases/metabolismo , Transdução de Sinais , beta-D-Galactosídeo alfa 2-6-Sialiltransferase , Interleucina 22
3.
J Immunol Res ; 2015: 638129, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26185769

RESUMO

To analyze the glycosylation of anti-ß2GP1, we investigated purified IgG from healthy children, patients with APS, and asymptomatic adult carriers of antiphospholipid antibodies. We observed that in the sera of healthy children and of patients with APS, IgG3 and IgG2 were predominant, respectively. The potentially protective anti-ß2GP1-IgM was lower in the sera of healthy children. Although anti-ß2GP1-associated C1q did not differ between children and patients with antiphospholipid syndrome, the associated C3c was significantly higher in the sera of healthy children. This indicates a more efficient clearance of anti-ß2GP1 immune complexes in the healthy children. This clearance is not accompanied by inflammation or coagulatory events. It is likely that the most important pathogenic factor of the anti-ß2GP1-IgG is related to the different glycosylation observed in healthy and diseased individuals. We detected a significantly higher sialylation of anti-ß2GP1-IgG isolated from the sera of healthy children and asymptomatic adults when compared with that of patients with clinically apparent antiphospholipid syndrome. Low sialylated IgG reportedly ameliorates inflammation and inflammation promotes hyposialylation. Thus, both reactions create a vicious circle that precipitates the pathology of the antiphospholipid syndrome including thrombus-formation. We conclude that the increased sialylation of anti-ß2GP1-IgG of sera of healthy individuals limits their pathogenicity.


Assuntos
Autoanticorpos/imunologia , Autoanticorpos/metabolismo , Fragmentos Fc das Imunoglobulinas/metabolismo , Imunoglobulina G/imunologia , Imunoglobulina G/metabolismo , beta 2-Glicoproteína I/imunologia , Adolescente , Anticorpos Antifosfolipídeos/imunologia , Síndrome Antifosfolipídica/imunologia , Síndrome Antifosfolipídica/metabolismo , Estudos de Casos e Controles , Criança , Pré-Escolar , Complemento C1q/imunologia , Complemento C1q/metabolismo , Complemento C3c/imunologia , Complemento C3c/metabolismo , Ensaio de Imunoadsorção Enzimática , Feminino , Glicosilação , Humanos , Imunoglobulina M/imunologia , Lactente , Recém-Nascido , Masculino , beta 2-Glicoproteína I/antagonistas & inibidores
4.
Biomed Chromatogr ; 29(5): 783-7, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25339319

RESUMO

Immobilization of polysaccharides (yeast mannan and gum arabic) on the macroporous poly(glycidyl methacrylate) monodisperse microspheres coated with silica (SiO2 )-containing amino groups on the surface was used to prepare affinity sorbents for lectin purification. The efficiency of isolating mannose specific Pisum sativum lectin was demonstrated on sorbent with immobilized yeast mannan and that of galactose specific Glycine hispida lectin on sorbent with immobilized gum arabic. The microspheres with immobilized polysaccharides can be used for selecting an affinity sorbent for purification of other mannose- and galactose-specific lectins. In contrast to yeast mannan, the gum arabic immobilized on the microspheres possesses much narrower specificity and is suitable for purification of only those galactose specific lectins which interact well with l-rhamnose or l-arabinose. The synthesized macroporous particles are capable of immobilizing 50 mg of polysaccharide per 1 g of the matrix, which is 10 times higher than the capacity of epoxy-activated Sepharose 6B. That makes it possible to obtain the same lectin quantity using a column of 10 times smaller volume. Another advantage of novel affinity sorbents comparing corresponding Sepharose gels is the possibility of sorbent drying after use.


Assuntos
Cromatografia de Afinidade/métodos , Pisum sativum/química , Extratos Vegetais/isolamento & purificação , Lectinas de Plantas/isolamento & purificação , Ácidos Polimetacrílicos/química , Polissacarídeos/química , Dióxido de Silício/química , Cromatografia de Afinidade/instrumentação
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