Characterization of novel immunodominant antigens of Mycobacterium tuberculosis.
Seven novel antigens of Mycobacterium tuberculosis, which had previously been identified based on reactivity to sera from patients with tuberculosis, were characterized. Nucleotide sequence analysis of the genes encoding these seven antigens identified one of them as the FtsH and a second as the aminoimidazole ribotide synthase of M. tuberculosis. Antisera raised to the recombinant forms of each of these seven antigens were used to study the distribution of these proteins within mycobacterial species as well as to determine their subcellular localization and hydrophobicity. Four of the seven antigens were conserved only among pathogenic strains of mycobacteria. Of the seven proteins studied, FtsH and a second protein of unknown identity were localized in membranes. Two were cytosolic, while two others, which had a high proline contents, were tightly associated with the cell wall. One protein was secreted. This secreted protein could be identified by serum from a majority of tuberculosis patients but not BCG-vaccinated individuals, suggesting its potential use in the immunodiagnosis of tuberculosis.
Amara
Rama Rao
RR
Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India.
Shanti
S
S
Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India.
Satchidanandam
Vijaya
V
Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India.
D000942:Antigens, Bacterial / Q000032:analysis* / Q000235:genetics / Q000276:immunology*; D001426:Bacterial Proteins / Q000032:analysis / Q000235:genetics / Q000276:immunology; D015139:Blotting, Southern; D015153:Blotting, Western; D002458:Cell Fractionation; D004591:Electrophoresis, Polyacrylamide Gel; D005798:Genes, Bacterial; D006801:Humans; D016056:Immunodominant Epitopes; D008565:Membrane Proteins / Q000032:analysis / Q000235:genetics / Q000276:immunology; D009169:Mycobacterium tuberculosis / Q000737:chemistry / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification; D017830:Octoxynol; D011092:Polyethylene Glycols; D011994:Recombinant Proteins / Q000276:immunology; D014397:Tuberculosis, Pulmonary / Q000276:immunology
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D016056:Immunodominant Epitopes; D008565:Membrane Proteins; D011994:Recombinant Proteins; D011092:Polyethylene Glycols; D017830:Octoxynol; C010615:Nonidet P-40