Peptides of a novel Mycobacterium tuberculosis-specific cell wall protein for immunodiagnosis of tuberculosis.
The sequencing of the Mycobacterium tuberculosis genome revealed the existence of several genes encoding novel proteins with unknown functions, one of which is the proline-threonine repetitive protein (PTRP; Rv0538). Genomic studies of various mycobacterial species and M. tuberculosis clinical isolates demonstrate that ptrp is specific to the M. tuberculosis complex and ubiquitous in clinical isolates. Enzyme-linked immunosorbent assay, Western blot analysis, and electron microscopic evaluation of M. tuberculosis subcellular fractions and intact bacteria confirm that PTRP is a cell wall protein. Antibodies to PTRP are present in serum specimens from human immunodeficiency virus (HIV)-negative, tuberculosis (TB)-positive and HIV-positive, TB-positive patients but not purified protein derivative (PPD)-negative or PPD-positive healthy control subjects, demonstrating its diagnostic potential. Epitope mapping of PTRP delineated 4 peptides that can identify >80% of sputum smear-positive and >50% of smear-negative, HIV-negative, TB-positive patients and >80% of HIV-positive, TB-positive patients. These results demonstrate that immunodominant epitopes of carefully selected M. tuberculosis-specific proteins can be used to devise a simple peptide-based serodiagnostic test for TB.
Singh
Krishna K
KK
Department of Pathology, New York University School of Medicine, New York, NY 10010, USA.
Sharma
Naresh
N
Vargas
Diana
D
Liu
Zhentong
Z
Belisle
John T
JT
Potharaju
Visalakshi
V
Wanchu
Ajay
A
Behera
Digambar
D
Laal
Suman
S
D000595:Amino Acid Sequence; D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial; D001426:Bacterial Proteins / Q000378:metabolism*; D002473:Cell Wall / Q000737:chemistry*; D003001:Cloning, Molecular; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D016680:Genome, Bacterial; D006801:Humans; D016056:Immunodominant Epitopes / Q000737:chemistry; D007159:Immunologic Tests / Q000379:methods*; D008969:Molecular Sequence Data; D009169:Mycobacterium tuberculosis / Q000378:metabolism*; D014376:Tuberculosis / Q000097:blood / Q000175:diagnosis* / Q000276:immunology
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D016056:Immunodominant Epitopes