An in silico approach for prediction of B cell and T cell epitope candidates against Chikungunya virus.

Several outbreaks of Chikungunya virus (CHIKV) had been reported since 1952 when mankind had his first encounter against the virus in Tanzania. Although these reports designate the CHIKV to be rarely fatal, cases of outbreaks in the last decade accompanied by severe complications and death poses a challenge to the development of effective treatment methods. Several attempts to vaccine development against CHIKV still remains unsuccessful. In this study, we aimed at the prediction of B-cell and T cell epitopes against CHIKV by using immunoinformatics. This, in turn, can contribute to development of an epitope based vaccine against CHIKV. Both linear and discontinuous B-cell epitopes, as well as Cytotoxic T-lymphocyte epitopes, were predicted for the CHIKV Envelope (E1 and E2) glycoproteins and (NS2). The antigenic CTL epitopes with highest binding affinities with type-1 MHC were selected and the peptides were docked to them. Docking followed by molecular dynamics simulations were performed to assess the stability of the docked complexes.

Lipid peroxidation, DNA damage, and apoptosis in dengue fever.

Interplay between the apoptosis, DNA damage, and oxidative stress as a host response to dengue viral infections remains unclear. Peripheral blood mononuclear cells (PBMCs) were isolated from 60 dengue infected patients, 20 patients with febrile illness other than dengue (OFI) and 10 non-febrile illness (NFI) patients. DNA damage in the PBMCs was assessed using single cell gel electrophoresis and stages of apoptosis underwent by the PBMCs were studied by Annexin-PI staining using flow cytometry. Plasma levels of malondialdehyde levels were estimated using thiobarbituric acid assay. Dengue infected individuals had showed increased DNA damage than NFI and OFI controls at the time of admission. Annexin-PI staining revealed increased frequency of apoptotic cells in dengue infected PBMCs than controls during the admission time. Similar pattern was observed in samples collected around defervescence. Within the dengue cases, percentage of live cells was higher in non-severe dengue than severe dengue at both the time points. Follow-up samples in dengue showed less number of live cells and higher percentage of apoptotic cells with respect to their baseline and this was reversed in case of OFI. Plasma malondialdehyde levels were found to be relatively higher in dengue cases than controls at admission and around defervescence. Significant positive correlation between DNA damage, apoptosis, and plasma malondialdehyde levels might pave a way for understanding the complex interactions between virus and hosts response thereby aids in identifying plausible immunopathological links contributing to disease pathogenesis. © 2018 IUBMB Life, 70(11):1133-1143, 2018.