BIOL 230 Lecture Guide - Cros-Presentation ofExogenous Antigens to MHC-I Molecules

Fig. 12: Cross-Presentation of Exogenous Antigens to MHC-I Molecules
by a Dendritic Cell: Transfer of Peptides from Phagolysosome to Vesicles Containing MHC-I Molecules

Exogenous antigens can be cross-presented to MHC-I molecules by certain dendritic cells. One proposed mechanism is via the direct transfer of peptides from the phagolysosome into the vesicles containing the MHC-I molecules in the dendritic cell.

1. An exogenous antigen is engulfed and placed in a phagosome.
2. After a lysosome fuses with the phagosome forming a phagolysosome.
3. Proteins from the exogenous antigen are degraded by lysosomal proteases into peptides.
4. The peptides are directly transfered from the phagolysosome to the vesicles containing the MHC-I molecules.
5 . The MHC-I molecules with bound peptides are then transported to the surface of the dendritic cell where they can be presented to naive T8-lymphocytes.

Illustration of Cross-Presentation of Exogenous Antigens to MHC-I Molecules by a Dendritic Cell: Transfer of Peptides from Phagolysosome to Vesicles Containing MHC-I Molecules .jpg by Gary E. Kaiser, Ph.D.
Professor of Microbiology, The Community College of Baltimore County, Catonsville Campus
This work is licensed under a Creative Commons Attribution 4.0 International License.
Based on a work at https://cwoer.ccbcmd.edu/science/microbiology/index_gos.html.

Last updated: August, 2019
Please send comments and inquiries to Dr. Gary Kaiser

Fig. 12: Cross-Presentation of Exogenous Antigens to MHC-I Molecules by a Dendritic Cell: Transfer of Peptides from Phagolysosome to Vesicles Containing MHC-I Molecules

Fig. 12: Cross-Presentation of Exogenous Antigens to MHC-I Molecules
by a Dendritic Cell: Transfer of Peptides from Phagolysosome to Vesicles Containing MHC-I Molecules