| خلاصه مقاله | Background: Cystic Echinococcosis (CE) is one of the most
important zoonosis parasite diseases which caused by the larval
stage of Echinococcus granulosus (Eg). The Eg14-3-3 protein is a
vaccine candidate antigen which exists in different development
stages of E. granulosus. The basement of vaccine design strategies is identification the most efficacious epitopes of the antigen.
This study presents linear and conformational B cell epitopes of the
Eg14-3-3 antigen via computational tools.
Methods & Materials: The protoscoleces (PSC) of E. granulosus was aspirated from infected lungs and livers of slaughtered
sheep (Tabriz, Iran) and then DNA samples were extracted. The
polymerase chain reaction (PCR) was performed using specific
primers (forward: ATGTCTTCTCTCAGTAAGCGCGA and reverse:
ATCGGCTTTCGGCGGTTCAG) and basing on the sequence in GenBank (Access No. AY942149). After sequencing the PCR products,
our regional Eg14-3-3 sequence was utilized (the sequence of our
local Eg14-3-3 shall be published soon). The linear B-cell epitopes
were predicted by Bepipred Linear Epitope Prediction algorithm
with threshold 0.35. The conformational B-cell epitopes were predicted using a sequence-based server named CBTOPE which uses
the support vector machine (SVM) threshold -0.3, and also the
three dimensional (3D) properties of the antigen such as, Relative Solvent Accessibility, Number of Transmembrane Domains and
protein tertiary structure prediction. The structural details of Eg14-
3-3 which are usable in the epitope-based vaccine design evaluated
via SCRATCH Protein Predictor.
Results: The Best linear B-cell epitopes were selected based
on their length (<9 amino acids) and score (highest), so that
the high scales consist of ATEVAEGDMQTT, DTLPEESYK, EQKHDGDAK and TGDERKQASDN. Based on CBTOPE algorithm five high
17th International Congress on Infectious Diseases / International Journal of Infectious Diseases 45S (2016) 1–477 423
score sequence were found as followed; YVAEFCTGDERKQASDN,
ELARKAFDDAVAELDTLPEESYKDA, SDAGDTDAAEPPKAD, YMAKLCEQCERYDEMVKA and LSVAYKNVVGAR, so that the bold and
underlined amino acids are conformational predicted epitopes.
Therefore using the 3D structural parameters the most prominent conformational epitopes were YVAEFCTGDERKQASDN and
ELARKAFDDAVAELDTLPEESYKDA.
Conclusion: Generally, in current study the many different
aspects of Eg14-3-3 B-cell epitopes were analyzed so that achieved
data will give crucial details of Eg14-3-3 antigen for designing
the new generation of epitope-based vaccines against Echinococcus
granulosus. |