Towards an Ensemble Vaccine against the Pegivirus Using Computational Modelling Approaches and Its Validation through In Silico Cloning and Immune Simulation

Pegivirus, HPgV, which was earlier known as Gb virus and hepatitis G virus, is an enveloped, positive-stranded RNA and lymphotropic virus classified into the Flaviviridae family. The transmission routes primarily involve blood products, and infections are worldwide, leading up to 25% of persistent infections. To date, no effective therapeutic means are available to clear Pegivirus infections. Effective vaccine therapeutics is the best alternative to manage this disease and any associated potential pandemic. Thus, whole proteome-based mining of immunogenic peptides, i.e., CTL (cytotoxic T lymphocytes), HTL (helper T lymphocytes), and B cell epitopes, was mapped to design a vaccine ensemble. Our investigation revealed that 29 different epitopes impart a critical role in immune response induction, which was also validated by exploring its physiochemical properties and experimental feasibility. In silico expression and host immune simulation were examined using an agent-based modeling approach and confirmed the induction of both primary and secondary immune factors such as IL, cytokines, and antibodies. The current study warrants further lab experiments to demonstrate its efficacy and safety.

Multi-epitope peptide sequence in-silico construction from HGV genome

In this study I have approached through in-silico method or reverse vaccinology taking advantage of the genome sequence of hepatitis G virus. It serves its benefit of identifying antigens seen by both conventional as well as discovering any novel antigen. This peptide candidate can serve a triple purpose of hepatitis C vaccine, hepatitis G vaccine and HIV management addition. 89.2% of the residues were in the favoured region of Ramachandran plot. These points make it favourable for in-vitro trials and further refinement. Because of the high similarity of hepatitis C genome to hepatitis G genome, it is highly probable that this peptide sequence might act as both hepatitis C and hepatitis G vaccine. Patients with past or current HGV infection have higher CD4+ lymphocyte counts and better AIDS-free survival rates. This peptide sequence might cause a breakthrough in the treatment of HIV without exposing them to develop hepatitis.

Hepatitis viruses (excluding hepatitis C virus)

Viral hepatitis is an ancient disease which remains a major health problem worldwide. The group of hepatitis viruses includes five unrelated human viruses (A to E), which differ in their genome organization, biology, and epidemiology, while being united by their hepatotropism. About 10–15% of cases of viral hepatitis are considered as non-A to E hepatitis, whose aetiology is still unknown, but the search for which has led to the identification of several new viruses (e.g. hepatitis G virus or GB virus-C, TT, and SEN viruses) of uncertain pathogenic significance. Thus, the search for new hepatitis agents responsible for the small proportion of cases with cryptogenic hepatitis continues.

PREVALENCE OF HEPATITIS G VIRUS AMONG PATIENTS WITH CHRONIC LIVER DISEASE AND HEALTHY INDIVIDUALS, SANA'A CITY-YEMEN

Hepatitis G virus (HGV) is a newly discovered and enveloped RNA positive-stranded flavivirus-like particle, which has not yet been proven to have major negative effects on liver. Therefore, it is important to estimate the prevalence and risk factors of hepatitis G virus infection in Yemeni viral hepatitis patients and general population to design standard prevention and treatment plans. Screening HGV antibodies among 60 chronic HBV and 144 chronic HCV patients comparing with it's prevalence in 218 healthy controls were carried out. Serum samples were collected and tested for human HGV IgG by commercially available ELISA technique. Demographic data such as gender, age, and risk factors of contracting HGV virus were recorded in predesigned questionnaire. The crude prevalence rate of HGV was 2.8%, female specific rate was 0% and male specific rate was 3.5%. The prevalence of HGV among HBV patients was 0%; HCV was 1.4% while in healthy individuals it was 4.6%. When age groups considered, the prevalence of HGV among age groups 20-29 years and 30-39 years was 3.5%, while in older age groups the rate of HGV was 0%. There was a trend towards increased levels of HGV infection with the second and third decades of life (3.5%). There was no significant association between HGV infection and risk factors of hepatitis viruses. It can be concluded from this study that HGV virus is circulating in the risk groups and in the community in general Yemen, and there is a possibility that this virus may at some time become epidemic if preventive measures are not applied. The risk of community among healthy people more than in risk groups as HBV and HCV patients. Additionally HGV increases with young male adults.

Divergent Pro-Inflammatory Cytokine Response Induced by GB Virus C/ Hepatitis G virus (GBV-C/HGV) and Torque Teno Virus (TTV) Co-Infections in Hepatitis C Virus (HCV) Infected Thalassemia Patients

Despite common incidence of GB virus C/Hepatitis G virus (GBV-C/HGV) and Torque Teno Virus (TTV) co-infections in subjects with Hepatitis C virus (HCV) infection, pathogenic role of these co-infections in HCV infected subjects has not been clear since studies have mostly been based on liver enzyme profile yielding variable results. Pro-inflammatory cytokines that participate in host immune response against viruses are generated as a consequence of triggering of related genes by Nuclear Factor Kappa B (NF-kB) that is a member of transcription family. Study of three pro-inflammatory cytokines e.g. interleukin 1 beta (IL-1β), Interleukin-6 (IL-6), interleukin-8 (IL-8) in a group of multi-transfused thalassemic subjects in relation to positivity for HCV, HGV and TTV infections showed elevated levels of these cytokines in serum as well as in supernatant of peripheral blood mononuclear cell (PBMCs) cultures in HCV-GBV-C/HGV co-infected subgroup compared to HCV mono-infected subgroup (p <0.05 for comparison of all three cytokines) while HCV-TTV co-infected subgroup showed lowering of these levels compared to HCV mono-infected subgroup (p <0.05 for comparison of all three cytokines). Levels of p65 component of NF-kB i.e.NF-kB p65 in nuclear extracts of lipopolysaccharide stimulated PBMCs correlated positively with the levels of pro-inflammatory cytokines in serum as well as that in supernatants of PBMC cultures in both HCV- GBV-C/HGV co-infected and HCV-TTV co-infected subgroups (p values ranging from <0.001 to 0.004). Levels of NF-kB p65 in nuclear extracts and levels of pro-inflammatory cytokines in serum as well as in supernatants of PBMC culture did not show any alteration compared to thalassemic subjects with HGV or TTV infections alone and healthy non-transfused subjects. Based on the inhibitory role of TTV on activation of NF-kB in TTV-HCV co-infected cases observed in the present study and the reported contribution of NF-kB towards development of hepatocellular carcinoma (HCC) due to establishment of chronicity, it may be worth evaluating if TTV or any component of TTV can be utilized as therapeutic vaccine against development of HCC in HCV infected subjects.