Design of a Polytopic Construct of Lack, Tsa and Gp63 Proteins for the Diagnosis of Cutaneous Leishmaniasis: An in Silico Strategy Publisher



Arabmazar Z¹ ; Mohebali M^{1, 2} ; Ranjbar MM³ ; Tabaei SJS⁴ ; Mamaghani AJ^{5, 6} ; Taghipour N⁷ Show Affiliations
Source: Journal of Asia-Pacific Entomology Published:2022

Abstract

Cutaneous leishmaniasis (CL), which is caused by different species of the genus Leishmania, including L. major, is a significant parasitic disease worldwide. Commercial leishmaniasis diagnostic kits frequently target the entire parasite antigen, although this approach can reduce the specificity of the tests. The present study sought to increase the specificity of antigen detection tests by identifying the B-cell epitopes on the surface of the protozoa and developing an antigenic multiepitope construct to react with the system of B-cell epitopes unique to L. major. More specifically, the linear and conformational B-cell epitopes for three L. major proteins, namely, GP63, LACK, and TSA, were predicted using the ABCprd, IEDB, LBtope, CBTOPE, and DiscoTope servers. The three-dimensional structures of these proteins, as well as of the complete multiepitope, were predicted using the I-TASSER server. The multiepitope structure models were validated by means of Ramachandran plots and the Prosa and Verify3D servers. The multiepitope construct was evaluated using the ProtParam and SOLpro servers. The synthesized multiepitope was then successfully expressed into a pET28a plasmid. The expression was confirmed using SDS-PAGE and dot blot techniques. Moreover, the expressed protein was evaluated by means of Western blotting. A band of approximately 39 kDa was observed by SDS-PAGE. The rGLT-pET-28a showed a high response with the 1:1000 dilution of the anti-His-tag monoclonal antibody by Western blot. The results of this study indicated that the integrated GP63, LACK, and TSA multiepitope antigens of L. major represent a potential target for a novel diagnostic kit for CL. © 2022