title: Characterization of the nucleotide sequence of the groE operon encoding heat shock proteins chaperone-60 and -10 of Francisella tularensis and determination of the T-cell response to the proteins in individuals vaccinated with F. tularensis.
abstract: The groE operon of Francisella tularensis LVS, encoding the heat shock proteins chaperone-10 (Cpn10) and Cpn60, was sequenced and characterized, and the T-cell response of LVS-vaccinated individuals to the two proteins and the third major chaperone, Ft-DnaK, was assayed. The cpn10 and cpn60 genes were amplified by PCR with degenerate oligonucleotides derived from the N-terminal sequence of the two proteins. The sequence analysis revealed the expected two open reading frames, encoding proteins with estimated Mrs of 10,300 and 57,400. The deduced amino acid sequences closely resembled Cpn10 and Cpn60 proteins of other prokaryotes. The genes constituted a bicistronic operon, the cpn10 gene preceding the cpn60 gene. Upstream of the cpn10 gene, an inverted repeat and motifs similar to -35 and -10 sequences of sigma70-dependent but not of sigma32-dependent promoters of Escherichia coli were found. The inverted repeat of the operon resembled so-called hairpin loops identified in other characterized prokaryotic groE operons lacking sigma32-dependent promoters. Primer extension analysis disclosed one and the same transcription start, irrespective of the presence or absence of heat or oxidative stress. After separation of lysates of the F. tularensis LVS organism by two-dimensional gel electrophoresis, DnaK, Cpn60, and Cpn10 were extracted and used as antigens in T-cell tests. When compared to those from nonvaccinated individuals, T cells from individuals previously vaccinated with live F. tularensis LVS showed an increased proliferative response to DnaK and Cpn60 but not to Cpn10. The present data will facilitate further studies of the involvement of the heat shock proteins in protective immunity to tularemia.
authors.affiliation: Department of Infectious Diseases, Umeå University, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Ericsson
authors.forename: I
authors.initials: I
authors.lastname: Golovliov
authors.forename: G
authors.initials: G
authors.lastname: Sandström
authors.forename: A
authors.initials: A
authors.lastname: Tärnvik
authors.forename: A
authors.initials: A
authors.lastname: Sjöstedt
mesh_terms: D000907:Antibodies, Bacterial / Q000032:analysis; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D015152:Blotting, Northern; D015153:Blotting, Western; D002455:Cell Division / Q000276:immunology; D018835:Chaperonin 10 / Q000235:genetics* / Q000276:immunology*; D018834:Chaperonin 60 / Q000235:genetics* / Q000276:immunology*; D018833:Chaperonins; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D015180:Electrophoresis, Gel, Two-Dimensional; D004926:Escherichia coli / Q000235:genetics; D029968:Escherichia coli Proteins; D005604:Francisella tularensis / Q000235:genetics* / Q000276:immunology*; D018840:HSP70 Heat-Shock Proteins / Q000276:immunology; D018882:Heat Stress Disorders; D006360:Heat-Shock Proteins / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D009876:Operon; D018384:Oxidative Stress; D010957:Plasmids; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D012091:Repetitive Sequences, Nucleic Acid; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D014158:Transcription, Genetic; D014406:Tularemia / Q000235:genetics* / Q000276:immunology*; D014611:Vaccination
chemical_list: D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D018835:Chaperonin 10; D018834:Chaperonin 60; D029968:Escherichia coli Proteins; C028715:GroE protein, E coli; D018840:HSP70 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D018833:Chaperonins; C063842:dnaK protein, E coli