M Waheed Akhtar
University of the Punjab, Pakistan
Title: Designing antigens for reliable serodiagnosis of tuberculosis
Biography
Biography: M Waheed Akhtar
Abstract
Antigens of Mycobacterium tuberculosis produce highly variable response in different tuberculosis patients. Thus detection of multiple antibodies is necessary to ensure reliability in serodiagnosis of tuberculosis. Fusion molecules consisting of fragments having epitopes from two or more antigens showing high sensitivity against all the corresponding antibodies would be helpful in achieving this objective. In silico analysis to examine positioning of the epitopes in the fusion molecules can be of great advantage in designing such constructs successfully. We have produced a series of truncated antigens and constructed fusion molecules from epitope regions of several M. tuberculosis antigens like PstS1, TB16.3, echA, HSPX, PE35 and FbpC1. Data obtained on the basis of antibody detection in hundreds of plasma samples of both the smear positive and smear negative tuberculosis patients showed that sensitivity of some of the antigens after truncation increased significantly. Some of the fusion molecules constructed showed sensitivities very similar to the expected combined sensitivity of the contributing antigens. The heat shock protein HSPX of M. tuberculosis not only exhibited full sensitivity but also resulted in soluble expression in E. coli in fusion with some other antigens. Construction of the fusion molecules, their expression at high levels, some in a soluble form and showing high sensitivity in detecting multiple antibodies seem promising for developing a reliable and cost-effective serodiagnosis of tuberculosis.