latrunculin-b and hen-egg-lysozyme-peptide-(46-61)

Major histocompatibility complex class II (MHC II) molecules capture peptides within the endocytic pathway to generate T cell receptor (TCR) ligands. Immature dendritic cells (DCs) sequester intact antigens in lysosomes, processing and converting antigens into peptide-MHC II complexes upon induction of DC maturation. The complexes then accumulate in distinctive, nonlysosomal MHC II+ vesicles that appear to migrate to the cell surface. Although the vesicles exclude soluble lysosomal contents and antigen-processing machinery, many contain MHC I and B7 costimulatory molecules. After arrival at the cell surface, the MHC and costimulatory molecules remain clustered. Thus, transport of peptide-MHC II complexes by DCs not only accomplishes transfer from late endocytic compartments to the plasma membrane, but does so in a manner that selectively concentrates TCR ligands and costimulatory molecules for T cell contact.

Topics: Animals; Antibodies, Monoclonal; Antigen Presentation; Antigens, CD; B-Lymphocytes; B7-2 Antigen; Biological Transport; Bridged Bicyclo Compounds, Heterocyclic; Cell Membrane; Cells, Cultured; Dendritic Cells; Endocytosis; Endosomes; Histocompatibility Antigens Class I; Histocompatibility Antigens Class II; Kinetics; Ligands; Lipopolysaccharides; Lysosomes; Membrane Glycoproteins; Mice; Mice, Inbred C3H; Muramidase; Peptide Fragments; Receptors, Antigen, T-Cell; Thiazoles; Thiazolidines