Drug Resistance in Hepatitis C Virus: Future Prospects and Strategies to Combat It.

Induction of highly pathogenic hepatitis C virus (HCV) causes chronic hepatitis round the world. This virus is easily prone to developing resistance against antiviral drugs because of two viral polymerases that do not possess the proofreading and overlapping reading frame abilities. There is more than one explanation for how this virus builds up resistance against antiviral drug treatments. Assays are now available to detect HCV-resistant variants, based on phenotypic and genotypic assays, and next generation sequencing. But these assays are of a little value at baseline, because they are not influential enough for making therapeutic decisions in HCV patients. Moreover, HCV monitoring is now an essential part of clinical practice. Special patients, such as those with thalassemia, renal transplant due to renal failure, and the patients undergoing hemodialysis, are at higher risk for acquiring this infection. Management of HCV infection in these patient groups is complicated by multiple side effects, including flu-like symptoms, neutropenia, fever, and neuropsychiatric disorders, thus limiting the use of ribavirin and coexisting iron overload. In HCV patients suffering from depression, the treatment may be discontinued because of some defects in neurochemical pathways caused by interferon, which can enhance the level of depression in these patients. In addition, obesity has been found to be a marker of failure of HCV treatment. There will be many resistance tolerant HCV treatment options available in the near future.

Computational prediction and analysis of envelop glycoprotein epitopes of DENV-2 and DENV-3 Pakistani isolates: a first step towards Dengue vaccine development.

Dengue fever of tropics is a mosquito transmitted devastating disease caused by dengue virus (DENV). There is no effective vaccine available, so far, against any of its four serotypes (DENV-1, DENV-2, DENV-3, and DENV-4). There is a need for the development of preventive and therapeutic vaccines against DENV to decrease the prevalence of dengue fever, especially in Pakistan. In this research, linear and conformational B-cell epitopes of envelope glycoprotein of DENV-2 and DENV-3 (the most prevalent serotypes in Pakistan) were predicted. We used Kolaskar and Tongaonkar method for linear epitope prediction, Emini's method for surface accessibility prediction and Karplus and Schulz's algorithm for flexibility determination. To propose three dimensional epitopes, the E proteins for both serotypes were homology modeled by using Phyre2 V 2.0 server, and ElliPro was used for the prediction of surface epitopes on their globular structure. Total 21 and 19 linear epitopes were predicted for DENV-2 and DENV-3 Pakistani isolates respectively. Whereas, 5 and 4 discontinuous epitopes were proposed for DENV-2 and DENV-3 Pakistani isolates respectively. Moreover, the values of surface accessibility, flexibility and solvent-accessibility can be helpful in analyzing vaccines against DENV-2 and DENV-3. In conclusion, the proposed continuous and discontinuous antigenic peptides can be valuable candidates for diagnostic and therapeutics of DENV.