Antigen processing for amateurs and professionals.
The initiation and propagation of immune responses is dependent on the ability of antigen-presenting cells (APCs) to convert proteins into peptides, to load them intracellularly onto major histocompatibility complex (MHC) products and then to deliver the peptide-MHC complexes to the plasma membrane. Perhaps the most effective or 'professional' of all APCs are dendritic cells (DCs). DCs express high levels of MHC molecules together with a variety of 'accessory molecules' that help render DCs more effective at stimulating T cells than any other cell type. However, much of the capacity of a DC for T-cell stimulation reflects a remarkable ability to regulate the organization and function of its endocytic and secretory pathways during its development. This review describes recent insights into the cell-biological specializations responsible for the 'professional' status of the DC in antigen processing and presentation.
Mellman
I
I
Dept of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA. ira.mellman@yale.edu
Turley
S J
SJ
Steinman
R M
RM
D000818:Animals; D017951:Antigen Presentation / Q000276:immunology*; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology*; D006801:Humans; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*