Antigen recognition and presentation by dendritic cells.
In this article we review the following important points in the antigen-presenting system: (1) the regulation of the expression of major histocompatibility complex (MHC) molecules, (2) the mechanism of cross-presentation, and (3) the interaction of antigen-presenting cells (APC) and T-cells. 1. The expression of MHC class I or class II molecules is regulated by the interaction of the MHC enhanceosome and the class II transactivator (CIITA). CIITA also regulates the gene expression of plexna-1, which encodes a semaphorin receptor, plexin-A1, that might be involved in the interaction with T-cells through an unknown ligand for plexin-A1. 2. Two pathways, a proteasome/TAP-independent pathway and a proteasome/TAP-dependent pathway, have now been identified in the cross-presentation. In the proteasome/TAP-dependent pathway, the translocon/Sec61 protein channel is an important element for the transport of antigenic peptides in phagosomes to the cytoplasm. 3. The integration of adhesion/costimulatory molecules and peptide-MHC complexes at the surface of APC creates the "immunological synapse" region, which potentiates the efficiency of APC-T-cell interactions. The peptide-MHC complexes preferentially reside in the "raft" structure or associate with tetraspanin family molecules.
Inaba
Kayo
K
Laboratory of Immunobiology, Department of Animal Development and Physiology, Division of Systemic Life Science, Kyoto University, Japan. kayo@zoo.zool.kyoto-u.ac.jp
Inaba
Muneo
M
D000818:Animals; D017951:Antigen Presentation / Q000276:immunology*; D002450:Cell Communication / Q000276:immunology*; D003713:Dendritic Cells / Q000276:immunology*; D006649:Histocompatibility Antigens / Q000276:immunology*; D006801:Humans; D013601:T-Lymphocytes / Q000276:immunology*
D006649:Histocompatibility Antigens