Glycotranscriptome study reveals an enzymatic switch modulating glycosaminoglycan synthesis during B-cell development
Sophie Duchez1, Virginie Pascal, Nadine Cogné
1Université de Limoges, CNRS UMR6101, Contrôle des Réponses Immunes B et Lymphoproliférations, Limoges, France.
European Journal of Immunology
|November 15, 2011
Summary
Glycosaminoglycans (GAGs) regulate B-cell physiology. Heparan sulfate synthesis, regulated by EXTL1, impacts B-cell differentiation and activation, suggesting GAGs are key B-cell regulators.
Area of Science:
- Immunology
- Glycobiology
- Cell Biology
Background:
- B-cell responses are modulated by cell surface glycans.
- Glycan architecture depends on the expression of multiple enzymes.
- Distinct B-cell populations exhibit varying glycosylation patterns.
Purpose of the Study:
- To investigate the role of glycosaminoglycans (GAGs) in B-cell differentiation and function.
- To determine the impact of specific GAG-modulating enzymes on B-cell physiology.
- To explore the developmental regulation of chondroitin sulfate and heparan sulfate synthesis in B cells.
Main Methods:
- Analyzed glycosylation-related gene expression in B-cell populations.
- Overexpressed EXTL1 in the B-cell lineage of transgenic mice.
- Assessed B-cell differentiation, peripheral B-cell compartments, serum immunoglobulin levels, and in vitro responses to polyclonal activation.
Main Results:
- CSGalNAcT-1 and EXTL1 showed inverse fluctuations during B-cell development, suggesting a switch between chondroitin and heparan sulfate synthesis.
- Overexpression of EXTL1 caused a partial blockade in B-cell differentiation at the pro-B to pre-B transition.
- Peripheral B-cell compartments and immunoglobulin levels were normal in EXTL1 transgenic mice, but in vitro proliferation upon polyclonal activation was reduced.
Conclusions:
- Heparan sulfate chains, despite low abundance in lymphocytes, act as regulators of B-cell physiology.
- A developmentally regulated switch between chondroitin and heparan sulfate synthesis influences B-cell differentiation and function.
- The study highlights the critical role of GAGs in modulating B-cell responses.
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