Topological journey of parasite-derived antigens for presentation by MHC class I molecules.
Within cells of their host, many bacteria and parasites inhabit specialized compartments, such as a modified phagosome for Mycobacterium tuberculosis or a parasitophorous vacuole for Toxoplasma gondii. These locations could exclude microbial material from entry into the MHC class I surveillance pathway. Remarkably, however, under these circumstances, cells can still signal the presence of invading pathogens to circulating CD8(+) T cells, which typically play a key role in protection against such intracellular organisms. Here, we review MHC I presentation pathways in various contexts, ranging from model antigens in non-infectious settings to pathogen-infected cells. We suggest that presentation of intracellular pathogens can be described as not just one, but several distinct pathways; perhaps because diverse pathogens have evolved different strategies to interact with host cells.
Blanchard
Nicolas
N
Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3200, USA. nicolas.blanchard@inserm.fr
Shastri
Nilabh
N
D000818:Animals; D017951:Antigen Presentation; D000938:Antigen-Presenting Cells / Q000276:immunology; D000941:Antigens / Q000276:immunology*; D003593:Cytoplasm / Q000276:immunology; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D006801:Humans
D000941:Antigens; D015395:Histocompatibility Antigens Class I