The comings and goings of MHC class I molecules herald a new dawn in cross-presentation.
Immunol Rev
; 272(1): 65-79, 2016 07.
Article
em En
| MEDLINE
| ID: mdl-27319343
ABSTRACT
MHC class I (MHC-I) molecules are the centerpieces of cross-presentation. They are loaded with peptides derived from exogenous sources and displayed on the plasma membrane to communicate with CD8 T cells, relaying a message of tolerance or attack. The study of cross-presentation has been focused on the relative contributions of the vacuolar versus cytosolic pathways of antigen processing and the location where MHC-I molecules are loaded. While vacuolar processing generates peptides loaded onto vacuolar MHC-I molecules, how and where exogenous peptides generated by the proteasome and transported by TAP meet MHC-I molecules for loading has been a matter of debate. The source and trafficking of MHC-I molecules in dendritic cells have largely been ignored under the expectation that these molecules came from the Endoplasmic reticulum (ER) or the plasma membrane. New studies reveal a concentrated pool of MHC-I molecules in the endocytic recycling compartment (ERC). These pools are rapidly mobilized to phagosomes carrying microbial antigens, and in a signal-dependent manner under the control of Toll-like receptors. The phagosome becomes a dynamic hub receiving traffic from multiple sources, the ER-Golgi intermediate compartment for delivering the peptide-loading machinery and the ERC for deploying MHC-I molecules that alert CD8 T cells of infection.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Células Dendríticas
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Fagossomos
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Linfócitos T CD8-Positivos
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Apresentação Cruzada
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Complexo de Endopeptidases do Proteassoma
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Retículo Endoplasmático
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Infecções
Limite:
Animals
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Humans
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article