A combined application of molecular docking technology and indirect ELISA for the serodiagnosis of bovine tuberculosis

Abstract

Background There is an urgent need to find reliable and rapid bovine tuberculosis (bTB) diagnostics in response to the rising prevalence of bTB worldwide. Toll-like receptor 2 (TLR2) recognizes components of bTB and initiates antigen-presenting cells to mediate humoral immunity. Evaluating the affinity of antigens with TLR2 can form the basis of a new method for the diagnosis of bTB based on humoral immunity. Objectives To develop a reliable and rapid strategy to improve diagnostic tools for bTB. Methods In this study, we expressed and purified the sixteen bTB-specific recombinant proteins in Escherichia coli . The two antigenic proteins, MPT70 and MPT83, which were most valuable for serological diagnosis of bTB were screened. Molecular docking technology was used to analyze the affinity of MPT70, MPT83, dominant epitope peptide of MPT70 (M1), and dominant epitope peptide MPT83 (M2) with TLR2, combined with the detection results of enzyme-linked immunosorbent assay to evaluate the molecular docking effect. Results The results showed that interaction surface Cα-atom root mean square deviation of proteins (M1, M2, MPT70, MPT83)-TLR2 protein are less than 2.5 A, showing a high affinity. It is verified by clinical serum samples that MPT70, MPT83, MPT70-MPT83 showed good diagnostic potential for the detection of anti-bTB IgG and M1, M2 can replace the whole protein as the detection antigen. Conclusions Molecular docking to evaluate the affinity of bTB protein and TLR2 combined with ELISA provides new insights for the diagnosis of bTB.

Identification of New Mycobacterium bovis antigens and development of a multiplexed serological bead-immunoassay for the diagnosis of bovine tuberculosis in cattle

“…MPB70, MPB83 and the MPB70/83 fusion protein were included in the Luminex-bTB immunoassay to improve its global detection sensitivity. As observed in the studies of Song et al [62] and Lyashchenko et al [63], some M. bovisinfected animals responded positively with MPB70/83 or with MPB70 and/or MPB83 only, in antibody tests, suggesting that fusion and recombinant proteins might detect overlapping, but not identical, populations of antibodies. The highly immunogenic secreted proteins ESAT6 and CFP10, which naturally form a complex involved in disease pathogenesis and virulence, have also been reported to induce antibody and CMI responses in animals of several species with M. bovis infection [10,19,32,58,64].…”