Immunological depiction of synthetic B-cell epitopes of Mycobacterium tuberculosis

Abstract

Background: To combat the tuberculosis (TB) epidemic, the development of a better and faster diagnosis or more effective vaccine is essential. Pulmonary TB (PTB) is one of the major causes of morbidity and mortality. Early diagnosis of TB is difficult. Serological assays have been performed with several antigens of laboratory strains such as Mycobacterium tuberculosis H37Rv which have not been found to be highly sensitive. In the present study, various peptides were synthesized which were predicted on the basis of immunoreactivity and differential expression in clinical isolates of M. tuberculosis compared to their expression in a laboratory strain of M. tuberculosis. Therefore, the aim of this study was to compare the antibody levels in PTB and healthy controls against these peptides.

Methods: An effort was made to evaluate antibody response to peptides derived from proteins Rv2588c, Rv0512, Rv0148, Rv0896, and Rv0635 of M. tuberculosis in PTB patients and healthy individuals through enzyme-linked immunosorbent assay. Five milliliters of venous blood samples was collected from each participant, and serum was separated and stored until use.

Results: Antibody levels against these peptides, Rv2588c, Rv0512, Rv0148, Rv0896. and Rv0635 in 139 PTB patients and 52 healthy controls were evaluated. Higher immune response was observed in PTB patients when compared with healthy individuals. Strong immunoglobulin G responses with high percentage, considerable difference among patients and healthy controls was observed with P < 0.0001.

Conclusion: In our study, we found significant statistical differences in antibody levels in PTB patients and healthy individuals against these peptides. These peptides are suggestive of being a potential new candidate (s) for early diagnosis of TB.

Keywords: B-cell epitopes; Mycobacterium tuberculosis; peptides; pulmonary tuberculosis.