title: H2-M3 restricted presentation of a Listeria-derived leader peptide.
abstract: Protective immunity to infection by many intracellular pathogens requires recognition by cytotoxic T lymphocytes (CTLs) of antigens presented on major histocompatibility complex (MHC) class I molecules. To be presented for recognition by pathogen-specific CTLs, these antigens must gain access to the host cell class I processing pathway. In the case of intracellular bacterial pathogens, the majority of bacterial proteins are retained within the bacterial membrane and therefore remain inaccessible to the host cell for antigen processing. We have isolated a CTL clone from a C57BL/6 mouse infected with the intracellular gram-positive bacterium Listeria monocytogenes (LM) and have identified the source of the antigen. Using a genomic expression library, we determined that the clone recognizes an antigenic N-formyl peptide presented by the nonpolymorphic murine MHC class Ib molecule, H2-M3. Several lengths of this peptide were able to sensitize cells for lysis by this CTL clone. The source of this antigenic peptide is a 23-amino acid polypeptide encoded at the start of a polycistronic region. Analysis of mRNA secondary structure of this region suggests that this polypeptide may be a leader peptide encoded by a transcriptional attenuator.
authors.affiliation: National Jewish Medical and Research Center, University of Colorado Health Sciences Center, Denver, Colorado 80206, USA.
authors.forename: M F
authors.initials: MF
authors.lastname: Princiotta
authors.forename: L L
authors.initials: LL
authors.lastname: Lenz
authors.forename: M J
authors.initials: MJ
authors.lastname: Bevan
authors.forename: U D
authors.initials: UD
authors.lastname: Staerz
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017951:Antigen Presentation; D000942:Antigens, Bacterial / Q000276:immunology*; D001483:Base Sequence; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D008089:Listeria monocytogenes / Q000276:immunology*; D008088:Listeriosis / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D008969:Molecular Sequence Data; D010455:Peptides / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology* / Q000382:microbiology
chemical_list: D000942:Antigens, Bacterial; D015395:Histocompatibility Antigens Class I; D010455:Peptides