title: Altered peptidase and viral-specific T cell response in LMP2 mutant mice.
abstract: MHC class I molecules present peptides generated by processing of endogenously synthesized proteins to CD8+ T lymphocytes. Recently, large proteolytic complexes, termed proteasomes, were implicated in antigen processing. Two proteasomal subunits, LMP2 and LMP7, are encoded within the MHC class II region, but their precise role in antigen processing is unknown. We have generated mice that harbor a disruption in their LMP2 gene. Proteasomes purified from spleen and liver of these mutant mice exhibit altered peptidase activities, and antigen-presenting cells showed reduced capacity to stimulate a T cell hybridoma specific for H-2Db plus a nucleoprotein epitope of an influenza A virus. The mutant mice have reduced (60%-70% of wild type) levels of CD8+ T lymphocytes and generate 5- to 6-fold fewer influenza nucleoprotein-specific cytotoxic T lymphocyte precursors. These findings indicate that LMP2 influences antigen processing.
authors.affiliation: Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge 02139, USA.
authors.forename: L
authors.initials: L
authors.lastname: Van Kaer
authors.forename: P G
authors.initials: PG
authors.lastname: Ashton-Rickardt
authors.forename: M
authors.initials: M
authors.lastname: Eichelberger
authors.forename: M
authors.initials: M
authors.lastname: Gaczynska
authors.forename: K
authors.initials: K
authors.lastname: Nagashima
authors.forename: K L
authors.initials: KL
authors.lastname: Rock
authors.forename: A L
authors.initials: AL
authors.lastname: Goldberg
authors.forename: P C
authors.initials: PC
authors.lastname: Doherty
authors.forename: S
authors.initials: S
authors.lastname: Tonegawa
mesh_terms: D000818:Animals; D017951:Antigen Presentation; D000938:Antigen-Presenting Cells / Q000276:immunology; D000956:Antigens, Viral; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000378:metabolism; D003546:Cysteine Endopeptidases; D005802:Genes, MHC Class II; D015395:Histocompatibility Antigens Class I / Q000096:biosynthesis; D008099:Liver / Q000737:chemistry; D051379:Mice; D018345:Mice, Knockout; D009975:Orthomyxoviridae / Q000276:immunology; D010222:Parainfluenza Virus 1, Human / Q000276:immunology; D010447:Peptide Hydrolases / Q000378:metabolism*; D011506:Proteins / Q000235:genetics / Q000502:physiology*; D013154:Spleen / Q000737:chemistry; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000166:cytology / Q000378:metabolism
chemical_list: D000956:Antigens, Viral; D015395:Histocompatibility Antigens Class I; D011506:Proteins; C071313:LMP-2 protein; D010447:Peptide Hydrolases; D003546:Cysteine Endopeptidases