Original Article

Design and Construction of a Fusion Peptide Containing B1, B2, B4, and EPC1 Epitopes for Diagnosis of Human Cystic Echinococcosis


Background: Cystic echinococcosis (CE), larval stage of Echinococcus granulosus, immunodiagnostics is still a challenge due to asymptomatic nature of CE during the early phase of infection and imperfection of diagnostic antigens. In silico design and assessments of hydatid cyst antigens provide preeminent information for novel and favorable diagnostic methods.

Methods: This study was performed at the Tehran University of Medical Sciences, Tehran, Iran in 2018. The sequences of B2, EPC1, B1 and B4 antigens were collected and analyzed for sequence conservancy by protein BLAST search and CLUSTALW multiple sequence alignment. The secondary and 3D structures were predicted using ab initio and threading methods. The antigens were analyzed for their B cell epitopic content using linear and conformational B cell epitope prediction tools. The final diagnostic antigen was designed by fusing the selected epitopic determinants form each antigen.

Results: Given the conservancy results and B cell epitope predictions, the whole B2 antigen along with amino acids spanning 1-50, 1-30, and 30-81 regions of EPC1, B1 and B4 antigens were selected to design the final antigen. High surface accessibility (75%), protein stability, low free energy and high number of amino acids involved in B cell epitopes were desirable properties for the final antigen to interact with antibodies against CE.

Conclusion: In silico design of such antigens is useful for better diagnosis of CE, decrease the cost and the time required for antigen design, while avoiding the ethical aspects of in vivo studies.



1. Eckert J, Deplazes P (2004). Biological, Epi-demiological, and clinical aspects of echi-nococcosis, a zoonosis of increasing concern. Clin Microbiol Rev, 17:107-35.
2. Zhang W, Zhang Z, Wu W et al (2015). Ep-idemiology and control of echinococ-cosis in central Asia, with particular refer-ence to the People's Republic of China. Acta Trop, 141:235-43.
3. Craig PS, McManus DP, Lightowlers MW et al (2007). Prevention and control of cystic echinococcosis. Lancet Infect Dis, 7:385-94.
4. Junghanss T, da Silva AM, Horton J et al (2008). Clinical management of cystic echinococcosis: state of the art, prob-lems, and perspectives. Am J Trop Med Hyg, 79:301-11.
5. Belhassen-García M, Romero-Alegria A, Ve-lasco-Tirado V et al (2014). Study of hy-datidosis-attributed mortality in endemic area. PLoS One, 9(3):e91342.
6. Caremani M, Maestrini R, Occhini U et al (1993). Echographic epidemiology of cystic hydatid disease in Italy. Eur J Epi-demiol, 9:401-4.
7. Perdomo R, Alvarez C, Monti J et al (1997). Principles of the surgical approach in human liver cystic echinococcosis. Acta Trop, 64:109-22.
8. Taheri MS, Pourghorban R, Faghihi Langroudi T et al (2013). Not-to-tap cyst-ic lesions: spectrum of hydatid disease. Emerg Radiol, 20(6):553-61.
9. Brunetti E, Kern P, Vuitton DA (2010). Writing Panel for the WHO-IWGE. Ex-pert consensus for the diagnosis and treatment of cystic and alveolar echino-coccosis in humans. Acta Trop, 114(1):1-16.
10. Barnes TS, Deplazes P, Gottstein B et al (2012). Challenges for diagnosis and con-trol of cystic hydatid disease. Acta Trop, 123(1):1-7.
11. Virginio VG, Hernández A, Root MB et al (2003). A set of recombinant antigens from Echinococcus granulosus with potential for use in the immunodiagnosis of hu-man cystic hydatid disease. Clin Exp Im-munol, 132(2):309–315.
12. Fernández V, Ferreira HB, Fernández C et al (1996). Molecular characterisation of a novel 8-kDa subunit of Echinococcus granu-losus antigen B. Mol Biochem Parasitol, 77(2):247-50.
13. Haag KL, Alves-Junior L, Zaha A et al (2004). Contingent, non-neutral evolution in a multicellular parasite: natural selection and gene conversion in the Echinococcus granulosus antigen B gene family. Gene, 333:157-67.
14. Rott MB, Fernández V, Farias S et al (2000). Comparative analysis of two different subunits of antigen B from Echinococcus granulosus: gene sequences, expression in Escherichia coli and serological evalua-tion. Acta Trop, 31; 75(3):331-40.
15. Li J, Zhang W-B, McManus DP (2004). Re-combinant antigens for immunodiagno-sis of cystic echinococcosis. Biological Pro-cedures Online, 6:67–77.
16. Khalili S, Rasaee MJ, Bamdad T (2017). 3D structure of DKK1 indicates its Involve-men in both canonical and non-canonical Wnt pathways. Mol Biol (Mosk), 51(1):180-192.
17. Jahangiri A, Rasooli I, Owlia P et al (2018). An integrative in silico approach to the structure of Omp33-36 in Acinetobacter baumannii. Comput Biol Chem, 72:77-86.
18. Torgerson P (2003). Economic effects of echinococcosis. Acta Trop, 85: 113-118
19. Nepalia S, Joshi A, Shende A, Sharma S (2006). Management of echinococcosis. J Assoc Physicians India, 54: 458-462.
20. Manzano-Román R, Sánchez-Ovejero C, Hernández-González A et al (2015). Sero-logical diagnosis and follow-up of human cystic echinococcosis: a new hope for the future? Biomed Res Int, 428205.
21. Zhang W, McManus DP (2006). Recent ad-vances in the immunology and diagnosis of echinococcosis. FEMS Immunol and Med Microbiol, 47: 24-41.
22. Carmena D, Benito A, Eraso E (2006). An-tigens for the immunodiagnosis of Echi-nococcus granulosus infection. An up-date. Acta Trop, 98 (1):74-86.
23. Monteiro KM, Zaha A, Ferreira HB (2008). Recombinant subunits as tools for the Structural and functional characterization of Echinococcus granulosus antigen B. Exp Parasitol, 119(4):490-8.
24. Muzulin P. M, Kamenetzky L, Gutierrez AM (2008).Echinococcus granulosus antigen B gene family: further studies of strain polymor-phism at the genomic and transcriptional levels. Exp parasitol, 118: 156-164.
25. Chemale G, Haag KL, Ferreira HB, Zaha A (2001). Echinococcus granulosus antigen B is encoded by a gene family. Mol Biochem Parasitol, 116(2):233-7.
26. Jiang L, Zhang YG, Liu MX et al (2012). Analysis on the reactivity of five subunits of antigen B family in serodiagnosis of echinococcosis. Exp Parasitol, 131(1):85-91.
27. Shepherd JC, McManus DP (1987). Specific and cross-reactive antigens of Echinococcus granulosus hydatid cyst fluid. Mol Biochem Parasitol, 25(2):143-54.
28. Fathi S, Jalousian F, Hosseini SH (2018). Design and construction of a new re-combinant fusion protein (2b2t+EPC1) and its assessment for serodiagnosis of cystic echinococcosis. APMIS, 126(5):428-439.
IssueVol 48 No 9 (2019) QRcode
SectionOriginal Article(s)
DOI https://doi.org/10.18502/ijph.v48i9.3027
Cystic echinococcosis Diagnosis Insilico B cell epitope Fusion epitope Antigen B

Rights and permissions
Creative Commons License This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
How to Cite
DARABI E, MOTEVASELI E, KHORRAMIZADEH MR, MOHEBALI M, ROKNI MB, ZAHABIUN F, KIA EB. Design and Construction of a Fusion Peptide Containing B1, B2, B4, and EPC1 Epitopes for Diagnosis of Human Cystic Echinococcosis. Iran J Public Health. 2019;48(9):1671-1680.