title: Improving sensitivity for serodiagnosis of tuberculosis using TB16.3-echA1 fusion protein.
abstract: This study aimed at developing and assessing the fusion proteins with enhanced sensitivity to detect antibodies in plasma as a diagnostic method for tuberculosis. DNA fragments encoding TB16.3 and echA1 gene regions corresponding to proteins TB16.3 and echA1 from Mycobacterium tuberculosis were amplified through PCR. Through a series of restrictions and ligations two novel fusion constructs TB16.3-echA1 and TB16.3-tnPstS1 were produced and expressed in Escherichia coli. These were screened for detection of antibodies in human plasma. The individual antigens TB16.3, echA1 and tnPstS1 and the fusion protein TB16.3-tnPstS1 and TB16.3-echA1 showed sensitivities of 29%, 25.5%, 42.8%, 40.0% and 47.2%, respectively. Lower sensitivity in case of TB16.3-tnPstS1 seems to be due to the structural arrangement between the two proteins, which is likely to mask several of their epitopes. The higher sensitivity of TB16.3-echA1 appears to be due to lesser interaction between the two proteins thus allowing free availability of epitopes for binding antibodies. 64% of TB patients were found positive for either one of the two fusion proteins TB16.3-echA1 and TB16.3-tnPstS1. This study indicates that the novel fusion protein TB16.3-echA1 has a potential in serodiagnosis of TB with improved sensitivity and reliability.
authors.affiliation: School of Biological Sciences, Quaid-e-Azam Campus, University of the Punjab, Lahore 54590, Pakistan. Electronic address: sana.sbs@pu.edu.pk.
authors.forename: Sana
authors.initials: S
authors.lastname: Khurshid
authors.affiliation: School of Biological Sciences, Quaid-e-Azam Campus, University of the Punjab, Lahore 54590, Pakistan. Electronic address: madeehaafzal85@gmail.com.
authors.forename: Madeeha
authors.initials: M
authors.lastname: Afzal
authors.affiliation: School of Biological Sciences, Quaid-e-Azam Campus, University of the Punjab, Lahore 54590, Pakistan. Electronic address: ruqyyakhalid@gmail.com.
authors.forename: Ruqyya
authors.initials: R
authors.lastname: Khalid
authors.affiliation: Center for Comparative Medicine, University of California, Davis, California 95616, USA. Electronic address: ihkhan@ucdavis.edu.
authors.forename: Imran H
authors.initials: IH
authors.lastname: Khan
authors.affiliation: School of Biological Sciences, Quaid-e-Azam Campus, University of the Punjab, Lahore 54590, Pakistan. Electronic address: mwapu@brain.net.pk.
authors.forename: M Waheed
authors.initials: MW
authors.lastname: Akhtar
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial / Q000737:chemistry / Q000235:genetics; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D003001:Cloning, Molecular; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D008958:Models, Molecular; D009169:Mycobacterium tuberculosis / Q000235:genetics / Q000276:immunology*; D011237:Predictive Value of Tests; D011487:Protein Conformation; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics; D015203:Reproducibility of Results; D012698:Serologic Tests / Q000379:methods*; D014397:Tuberculosis, Pulmonary / Q000097:blood / Q000175:diagnosis* / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D015415:Biomarkers; D011993:Recombinant Fusion Proteins; C000602432:TB16.3-echA1 fusion protein
keywords: Immunoassay; Serodiagnosis; Tuberculosis