Dendritic Cells Regulate Exposure of MHC Class II at Their Plasma Membrane by Oligoubiquitination
2006; Cell Press; Volume: 25; Issue: 6 Linguagem: Inglês
10.1016/j.immuni.2006.11.001
ISSN1097-4180
AutoresGuillaume van Niel, Richard Wubbolts, Toine ten Broeke, Sonja I. Buschow, Ferry Ossendorp, Cornelis J.M. Melief, Graça Raposo, Bas W. van Balkom, Willem Stoorvogel,
Tópico(s)Immune Cell Function and Interaction
ResumoSummaryDendritic cells (DCs) initiate adaptive immune responses by activating T cells via cognate interactions between MHC-peptide complexes and T cell receptors. In immature DCs, MHC class II is predominantly stored in late endocytic compartments, where it has a short half-life because of degradation. In contrast, mature DCs recruit MHC class II to the plasma membrane. We here demonstrate that in immature DCs, the β-chain of MHC class II was oligoubiquitinated after proteolytic processing of the associated invariant chain in endosomes and that this modification was required for efficient endocytosis and sorting into luminal vesicles of multivesicular bodies. Ubiquitination of MHC class II was suppressed in lipopolysaccharide-activated DCs. Mutated MHC class II lacking its ubiquitination site was expressed at the plasma membrane, irrespective of DC maturation. Together, these data provide a molecular basis for the regulation of MHC class II-mediated antigen presentation by DCs.
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