B‐cell epitopes of antigenic proteins in Leishmania infantum: an in silico analysis

Abstract

Serodiagnosis of visceral leishmaniasis is often hindered by cross-reactions to other parasitic diseases. Identifying specific B-cell epitopes in proteins is therefore important for immunodiagnostics, as well as for disease control by vaccines. This study aimed to identify linear and conformational B-cell epitopes and to evaluate the secondary structure of antigen proteins in Leishmania infantum using in silico analysis. Linear epitopes were predicted using the Immune Epitope Database and Analysis Resource (IEDB), BepiPred and BcePred programs. The conformational B-cell epitopes were identified using the CBTOPE server. The combination of the predictions using IEDB, BepiPred and BcePred generated 148 linear epitopes from the calpain-like cysteine peptidase (CP), thiol-dependent reductase 1 (TDR1) and HSP70 proteins. In total, 164 conformational epitopes were predicted, mostly located in the linear epitope region. The predicted epitopes are located in α helix and random coil regions in the thiol-dependent reductase 1 and HSP70 proteins. New linear and conformational B-cell epitopes of L. infantum proteins were identified in silico, and the prediction using various programs ensures greater accuracy of the results, as suggested by confirmation of previously identified HSP70 epitopes.

An Introduction to B-Cell Epitope Mapping and In Silico Epitope Prediction

“…Unfortunately, existing prediction methods are not accurate enough and annotate general immunogenic/epitope-like regions on the antigen [69, 72]. It was demonstrated that consensus of various B-cell epitope prediction methods ensures greater accuracy of the results [73]. Here we offer a short overview of publicly available methods and servers for prediction of continuous as well as discontinuous B-cell epitopes (summarized in Tables 2 and 3).…”

Protein expression of Myt272-3 recombinant clone and in silico prediction of a possible vaccine candidate against <i>Mycobacterium tuberculosis</i>

“…The results show that all the epitopes from position 36 to 69 satisfied the threshold value requirement for antigenicity. The highest antigenicity scores were recorded in three peptides -SRDAVVL, RDAVVLS and DAVVLSG with score of 1.119 [24].…”

Peripheral T-Cell Reactivity to Heat Shock Protein 70 and Its Cofactor GrpE from Tropheryma whipplei Is Reduced in Patients with Classical Whipple's Disease

“…Hsp70 was established as a common antigen of Leishmania infantum (25) and Helicobacter pylori (26), and the Th2 response to Hsp70 of Salmonella typhi protects mice from lethal Salmonella infection (30). Tumor vaccination strategies for human papillomavirus 16 benefit from the adjuvant-type capacity of Hsp70 by fusing it to mesothelin or the oncoprotein E7 (27,28), and the complexing of potential antigens with Hsp70 or GroEL provides immunogens for CD8 ϩ T-cell activation (29).…”

“…Highly conserved Hsp70 itself is important in the defense against infectious agents, since early immune responses specific to heat shock proteins have been observed upon infections by bacteria, protozoa, fungi, or nematodes (24). An in silico analysis of known genes from Leishmania infantum uncovered potentially antigenic regions within the Hsp70 protein (25). Differential proteomics also established Hsp70 as a common antigen of Helicobacter pylori (26).…”