Author Proof
1 10.2217/FVL.12.95 © 2012 Future Medicine Ltd ISSN 1746-0794
Future Virology
part of
Future Virol. (2012) 7(10), 1–14
Chikungunya virus (CHIKV) is an arthropod-
borne virus. CHIKV transmission in humans
is reported to be carried out by Aedes spp. (e.g. ,
Aedes albopictus) mosquitoes [1–3] . Clinical symp-
toms of chikungunya infection are fever, rash,
headache, joint pain or arthralgia, and muscle
pain or myalgia [4–6] . The symptoms usually last
between 1 and 10 days [4] . Several outbreaks in
Africa, India and South-East Asia have been
reported previously [7–9] .
Recently, from 2004 until now, there have
been reports of a reemerged CHIKV infec-
tion in several geographic regions [10–14] . The
first of its outbreaks was recorded in Kenya in
2004. Similar outbreaks in different islands
(e.g., Comoros Islands, southwest Indian
Ocean) were also filed in early 2005 [7,15–18] .
In 2005–06 it broke out in a massive propor-
tion of India. Molecular analysis of the strains
isolated on islands in the Indian Ocean and in
India revealed that the epidemic was caused
by a central/east African genotypic variant of
CHIKV [11,12,19–21] . Soon, a large number of
travelers from industrialized countries became
infected with CHIKV. Hence what started as a
mere endemic spark became the equivalent of a
global forest fire without much ado [22,23] .
CHIKV is an alphavirus and belongs to the
Togaviridae family [24] . It possesses a single-
strand positive-sense RNA genome. Two of the
proteins in CHIKV have been sequenced in
abundance to characterize the envelope pro-
teins CHIKV- E1 and E2 [24–26] . E1-targeted
antibodies are more likely to cross-react with
other alphaviruses and thus are nonspecific
compared with E2-targeted antibodies [26,27] .
Monoclonal antibody-associated competi-
tive binding assays identified approximately
seven epitopes on the E1 glycoproteins of
Sindbis virus (SINV), Simian foamy virus
(SFV), Western equine encephalitis virus, and
Venezuelan equine encephalitis virus (VEEV).
Epitopes for E1 proteins are mostly present on
the surface of infected cells instead of the virion
surface. In vitro analysis of antibody reactions
to E1 include HI, neutralization of virus infec-
tivity, and inhibition of fusion. The presence
of different functionally distinct domains has
been suggested based on this analysis [28–30] .
Mapping monoclonal antibody binding sites
to specific E1 sequences is always a challenge.
One acid-exposed epitope involves E1–157 of
SFV [31] . A neutralizing mAb distinguishes
strains of SINV differing only at residues 72
A computational assay to design
an epitope-based peptide
vaccine against chikungunya virus
Md Rezaul Islam
1
, M Sadman Sakib
1
& Aubhishek Zaman*
2
1
Department of Biochemistry & Molecular Biology, University of Dhaka, Dhaka, Bangladesh
2
Department of Genetic Engineering & Biotechnology, University of Dhaka, Dhaka, Bangladesh
*Author for correspondence: aubhishek@gmail.com
Aim: Chikungunya virus, an arthropod-borne alphavirus, belongs to the Togavirus
family. Despite severe epidemic outbreaks on several occasions, not much
progress has been made with regard to epitope-based drug design for
chikungunya virus. In this study we performed a proteome-wide search to look
for a conserved region among the available viral proteins, one which has the
capacity to trigger a significant immune response. Materials & methods: The
conserved region was analyzed by performing an alignment of sequences
collected from sources from varied geographic locations and time periods.
Subsequently, the immune parameters for the peptide sequences were
determined using several in silico tools and immune databases. Results: Both
T-cell immunity and B-cell immunity were checked for the peptides to ensure
that they had the capacity to induce both humoral and cell-based immunity.
Our study reveals a stretch of conserved region in glycoprotein E2; yet this peptide
sequence could interact with as many as seven HLAs and showed population
coverage as high as 73.46%. The epitope was further tested for binding against
the HLA structure using in silico docking techniques to validate the binding cleft
epitope interaction in detail. Conclusion: Although the study requires further
in vivo screening, keeping in mind the consistency and reproducibility of the
immune system at selecting and reacting to peptide epitopes, this study allows
us to claim a novel peptide antigen target in E2 protein with good confidence.
Keywords
n chikungunya virus n CHIKV n
E2 envelope protein
n epitope-based drug design
Preliminary Communication