Phagocytic processing of bacterial antigens for class I MHC presentation to T cells

• Published in: Nature (London) Vol. 361; no. 6410; pp. 359 - 362
• Main Authors: Pfeifer, John D, Wick, Mary Jo, Roberts, Richard L, Findlay, Kirk, Normark, Staffan J, Harding, Clifford V
• Format: Journal Article
• Language: English
• Published: London Nature Publishing 28-01-1993; Nature Publishing Group
• Subjects: Amino Acid Sequence; Analysis of the immune response. Humoral and cellular immunity; Animals; Antigens, Bacterial - genetics; Antigens, Bacterial - immunology; Antigens, Bacterial - metabolism; Bacteria; Bacterial Proteins - genetics; Bacterial Proteins - immunology; Bacterial Proteins - metabolism; Biological and medical sciences; CD8 Antigens - immunology; Cell interactions; Epitopes; Escherichia coli - genetics; Escherichia coli Proteins; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Histocompatibility Antigens Class I - physiology; Immunobiology; Macrophages - physiology; Macrophages - ultrastructure; Mice; Mice, Inbred C57BL; Mice, Inbred CBA; Microscopy, Electron; Molecular Sequence Data; Ovalbumin - genetics; Ovalbumin - immunology; Ovalbumin - metabolism; Pathology; Phagocytosis; Recombinant Fusion Proteins - metabolism; Salmonella typhimurium - genetics; T-Lymphocyte Subsets - immunology; T-Lymphocytes - immunology; Vacuoles - physiology; Vacuoles - ultrastructure; Antigen presentation; Molecular processing; Major histocompatibility system; Rodentia; Cell cell interaction; Molecular interaction; Activation; Antigen; Vertebrata; Mammalia; Mouse; T-Lymphocyte; Bacteria; Class I histocompatibility antigen; Phagocytosis
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/361359a0

Class I major histocompatibility complex (MHC) molecules present antigens that are produced within the presenting cell or penetrate from the vacuolar system into the cytosol for processing. Most studies of exogenous antigen processing have used soluble antigens, which are not efficiently presented by class I MHC molecules and do not elicit CD8 T-cell responses in vivo. But particulate antigen preparations with no known mechanism for cytosolic penetration can also elicit CD8 T-cell responses in vivo. We report here that phagocytosis of bacteria with no mechanism for cytosolic penetration also results in presentation of bacterial antigens by class I MHC molecules. Moreover, this mechanism is resistant to cycloheximide and Brefeldin A, which block the classical class I processing pathway. These results suggest a novel vacuolar class I processing pathway for exogenous phagocytic antigens.