A nonamer peptide derived from Listeria monocytogenes metalloprotease is presented to cytolytic T lymphocytes.
Listeria monocytogenes is an intracellular bacterium that secretes proteins into the cytosol of infected macrophages. Major histocompatibility complex (MHC) class I molecules bind peptides that are generated by the degradation of bacterial proteins and present them to cytolytic T lymphocytes (CTL). In this study we have investigated CTL responses in L. monocytogenes-immunized mice to peptides that (i) derive from the L. monocytogenes proteins phosphatidylinositol-specific phospholipase C, lecithinase (most active on phosphatidylcholine), metalloprotease (Mpl), PrfA, and the ORF-A product and (ii) conform to the binding motif of the H2-Kd MHC class I molecule. We identified a nonamer peptide, Mpl 84-92, that is presented to L. monocytogenes-specific CTL by H2-Kd MHC class I molecules. Unlike other motif-conforming peptides derived from the secreted Mpl of L. monocytogenes, Mpl 84-92 is bound with high affinity by H2-Kd. Mpl 84-92 is the fourth L. monocytogenes-derived peptide found to be presented to CTL by the H2-Kd molecule during infection and demonstrates the importance of high-affinity interactions between antigenic peptides and MHC class I molecules for CTL priming.
Busch
D H
DH
Section of Infectious Diseases, Yale University School of Medicine, New Haven, Connecticut 06520, USA.
Bouwer
H G
HG
Hinrichs
D
D
Pamer
E G
EG
D000818:Animals; D017951:Antigen Presentation; D000942:Antigens, Bacterial / Q000276:immunology*; D001426:Bacterial Proteins / Q000276:immunology*; D008088:Listeriosis / Q000276:immunology*; D008666:Metalloendopeptidases / Q000737:chemistry / Q000276:immunology*; D051379:Mice; D010455:Peptides / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D010455:Peptides; D008666:Metalloendopeptidases