The exogenous pathway for antigen presentation on major histocompatibility complex class II and CD1 molecules

2004 ◽  
Vol 5 (7) ◽  
pp. 685-692 ◽  
Author(s):  
Colin Watts
Keyword(s):  
Major Histocompatibility Complex ◽  
Major Histocompatibility Complex Class ◽  
Antigen Presentation ◽  
Class Ii ◽  
Complex Class ◽  
Major Histocompatibility ◽  
Histocompatibility Complex

scholarly journals Antigen Presentation by Dendritic Cells after Immunization with DNA Encoding a Major Histocompatibility Complex Class II–restricted Viral Epitope

1997 ◽  
Vol 186 (9) ◽  
pp. 1481-1486 ◽  
Author(s):  
Sofia Casares ◽  
Kayo Inaba ◽  
Teodor-Doru Brumeanu ◽  
Ralph M. Steinman ◽  
Constantin A. Bona
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Major Histocompatibility Complex ◽  
Major Histocompatibility Complex Class ◽  
Antigen Presentation ◽  
Class Ii ◽  
Complex Class ◽  
Major Histocompatibility ◽  
Dna Encoding ◽  
Histocompatibility Complex

Intramuscular and intracutaneous immunization with naked DNA can vaccinate animals to the encoded proteins, but the underlying mechanisms of antigen presentation are unclear. We used DNA that encodes an A/PR/8/34 influenza peptide for CD4 T cells and that elicits protective antiviral immunity. DNA-transfected, cultured muscle cells released the influenza polypeptide, which then could be presented on the major histocompatibility complex class II molecules of dendritic cells. When DNA was injected into muscles or skin, and antigen-presenting cells were isolated from either the draining lymph nodes or the skin, dendritic, but not B, cells presented antigen to T cells and carried plasmid DNA. We suggest that the uptake of DNA and/or the protein expressed by dendritic cells triggers immune responses to DNA vaccines.

scholarly journals Modulation of the Major Histocompatibility Complex Class II–Associated Peptide Repertoire by Human Histocompatibility Leukocyte Antigen (Hla)-Do

2000 ◽  
Vol 191 (7) ◽  
pp. 1127-1136 ◽  
Author(s):  
Marieke van Ham ◽  
Marcel van Lith ◽  
Björn Lillemeier ◽  
Esther Tjin ◽  
Ulrike Grüneberg ◽  
...  
Keyword(s):  
Major Histocompatibility Complex ◽  
B Cells ◽  
Major Histocompatibility Complex Class ◽  
Antigen Presentation ◽  
Cell Activation ◽  
Peptide Binding ◽  
Class Ii ◽  
Complex Class ◽  
Major Histocompatibility ◽  
Histocompatibility Complex

Antigen presentation by major histocompatibility complex class II molecules is essential for antibody production and T cell activation. For most class II alleles, peptide binding depends on the catalytic action of human histocompatibility leukocyte antigens (HLA)-DM. HLA-DO is selectively expressed in B cells and impedes the activity of DM, yet its physiological role remains unclear. Cell surface iodination assays and mass spectrometry of major histocompatibility complex class II–eluted peptides show that DO affects the antigenic peptide repertoire of class II. DO generates both quantitative and qualitative differences, and inhibits presentation of large-sized peptides. DO function was investigated under various pH conditions in in vitro peptide exchange assays and in antigen presentation assays using DO− and DO+ transfectant cell lines as antigen-presenting cells, in which effective acidification of the endocytic pathway was prevented with bafilomycin A1, an inhibitor of vacuolar ATPases. DO effectively inhibits antigen presentation of peptides that are loaded onto class II in endosomal compartments that are not very acidic. Thus, DO appears to be a unique, cell type–specific modulator mastering the class II–mediated immune response induced by B cells. DO may serve to increase the threshold for nonspecific B cell activation, restricting class II–peptide binding to late endosomal compartments, thereby affecting the peptide repertoire.

scholarly journals The Dendritic Cell Receptor for Endocytosis, Dec-205, Can Recycle and Enhance Antigen Presentation via Major Histocompatibility Complex Class II–Positive Lysosomal Compartments

2000 ◽  
Vol 151 (3) ◽  
pp. 673-684 ◽  
Author(s):  
Karsten Mahnke ◽  
Ming Guo ◽  
Sena Lee ◽  
Homero Sepulveda ◽  
Suzy L. Swain ◽  
...  
Keyword(s):  
Major Histocompatibility Complex ◽  
Major Histocompatibility Complex Class ◽  
Antigen Presentation ◽  
Class Ii ◽  
Complex Class ◽  
Major Histocompatibility ◽  
Mhc Ii ◽  
Histocompatibility Complex ◽  
Late Endosomes ◽  
Early Endosomes

Many receptors for endocytosis recycle into and out of cells through early endosomes. We now find in dendritic cells that the DEC-205 multilectin receptor targets late endosomes or lysosomes rich in major histocompatibility complex class II (MHC II) products, whereas the homologous macrophage mannose receptor (MMR), as expected, is found in more peripheral endosomes. To analyze this finding, the cytosolic tails of DEC-205 and MMR were fused to the external domain of the CD16 Fcγ receptor and studied in stable L cell transfectants. The two cytosolic domains each mediated rapid uptake of human immunoglobulin (Ig)G followed by recycling of intact CD16 to the cell surface. However, the DEC-205 tail recycled the CD16 through MHC II–positive late endosomal/lysosomal vacuoles and also mediated a 100-fold increase in antigen presentation. The mechanism of late endosomal targeting, which occurred in the absence of human IgG, involved two functional regions: a membrane-proximal region with a coated pit sequence for uptake, and a distal region with an EDE triad for the unusual deeper targeting. Therefore, the DEC-205 cytosolic domain mediates a new pathway of receptor-mediated endocytosis that entails efficient recycling through late endosomes and a greatly enhanced efficiency of antigen presentation to CD4+ T cells.

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