Vaccine Design from the Ensemble of Surface Glycoprotein Epitopes of SARS-CoV-2: An Immunoinformatics Approach.

The present study aimed to work out a peptide-based multi-epitope vaccine against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We predicted different B-cell and T-cell epitopes by using the Immune Epitopes Database (IEDB). Homology modeling of the construct was done using SWISS-MODEL and then docked with different toll-like-receptors (TLR4, TLR7, and TLR8) using PatchDock, HADDOCK, and FireDock, respectively. From the overlapped epitopes, we designed five vaccine constructs C1-C5. Based on antigenicity, allergenicity, solubility, different physiochemical properties, and molecular docking scores, we selected the vaccine construct 1 (C1) for further processing. Docking of C1 with TLR4, TLR7, and TLR8 showed striking interactions with global binding energy of -43.48, -65.88, and -60.24 Kcal/mol, respectively. The docked complex was further simulated, which revealed that both molecules remain stable with minimum RMSF. Activation of TLRs induces downstream pathways to produce pro-inflammatory cytokines against viruses and immune system simulation shows enhanced antibody production after the booster dose. In conclusion, C1 was the best vaccine candidate among all designed constructs to elicit an immune response SARS-CoV-2 and combat the coronavirus disease (COVID-19).

Stable Huh-7 cell lines expressing non-structural proteins of genotype 1a of hepatitis C virus.

Hepatitis C virus (HCV) infection has infected approximately 3% of the world population. HCV genotype 1a is distributed throughout the world, and along with genotype 1b, is relatively resistant to current standards of therapy compared to other HCV genotypes. The present study was designed to produce stable Huh-7 cell lines expressing non-structural proteins of HCV genotype la, representing an in vitro system to facilitate the development of new antiviral drugs against chronic HCV infection. The non-structural genes of HCV genotype 1a were amplified and cloned in a mammalian expression vector pCR 3.1/FIagTag. Huh-7 cells were transfected with one of two expression plasmids, the first containing the NS2, NS3, and NS4a cassette, and second containing the NS5a and NS5b genes. Stable cell lines were produced under the selection of gentamycin (G418). mRNA and protein expression analysis was performed by RT-PCR and Western blotting. The RT-PCR and Western blot results confirmed the stable expression of each of the gene products. Stable Huh-7 cell lines with HCV la non-structural proteins may be helpful for evaluating the role of HCV proteins in molecular pathogenesis, and could facilitate the development of new therapeutic drugs.

Development of persistent HCV genotype 3a infection cell culture model in huh-7 cell.

BACKGROUND: Hepatitis C virus (HCV) is one of the major health concerns globally, with genotype 3a as the most prevalent in Pakistan. Lack of efficient HCV genotype 3a small animal models as well as genomic replicons has hampered the complete understanding of its life cycle, pathogenesis and therapeutic options. In this study we aimed to develop a persistent HCV genotype 3a infectious cell culture model. METHODS: We inoculated Huh-7 cells with HCV genotype 3a serum. Cells and media supernatant were collected at different time periods up to 40th day post infection. Culture media supernatant was also collected to find out its ability to infect naive Huh-7 cells. RESULTS: HCV replication was confirmed at both RNA and protein level through Real Time RCR and western blot using HCV core as marker. In order to validate the persistence of our model for HCV genotype 3a replication we inhibited the HCV replication through core specific siRNAs. The HCV RNA was detected intracellularly from the day one post infection up till 40th day, while HCV core protein was detected from the second day up to 40th day consistently. In culture media supernatant HCV RNA was also actively detected conferring its ability to infect the naive Huh-7 cells. Furthermore, core specific siRNA showed significant inhibition at 24th hour post transfection both at RNA and protein level with progressive increase in the expression of core gene after 3rd day. It clearly depicts that the Huh-7 successfully retained the HCV replication after degradation of siRNA. CONCLUSION: Finally, we report that our persistent infection cell culture model consistently replicate HCV genotype 3a for more than 1 month.

Resistance of polio to its eradication in Pakistan.

BACKGROUND: This study is based on EPI (Expanded Program on Immunization) immunization surveys and surveillance of polio, its challenges in immunization and the way forward to overcome these challenges. METHODS: Several Government documents, survey reports and unpublished program documents were studied and online search was made to find information on EPI Pakistan. SPSS 16 and Microsoft Excel 2007 were used for the statistical analysis. RESULTS: Immunization against polio is higher in urban areas as compared to rural areas. Marked variation in vaccination has been observed in different provinces of Pakistan in the last decade. Secondly 10-20% of the children who have received their first dose of trivalent polio vaccine were deprived of their 2nd and 3rd dose because of poor performance of EPI and Lack of information about immunization. CONCLUSION: In spite of numerous successes, such as the addition of new vaccines and raising immunization to over 100% in some areas, EPI is still struggling to reach its polio eradication goals. Inadequate service delivery, lack of information about immunization and limited number of vaccinators were found to be the key reason for poor performance of immunization and for large number of cases reported each year due to the deficiency of second and third booster dose.