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Abstract Background Persistent infection with high-risk Human papillomavirus (HPV), specifically HPV-16, is the leading cause of cervical cancer. Although preventative vaccines have shown significant efficacy in preventing HPV infection, cervical cancer is a significant public health issue that affects millions of women worldwide. Modern therapeutic approaches, such as peptide vaccines, could be promising and have potential for the treatment of the HPV-infected population. Methods A HPV16-E7 multi-epitopic vaccine (MEVE7) was designed to comprise potent CD4 + and CD8 + T cell epitopes and optimally expressed in a prokaryotic expression system. Polyclonal antibodies were generated, and their reactivity with immunizing antigen and native protein in E7 expressing cells (TC-1) was assessed by ELISA and immunofluorescent staining, respectively. The efficacy of the vaccine was assessed in a therapeutic animal model of HPV-induced cancer. Results Our study revealed that the final construct was successfully expressed in E. coli BL21 (DE3)-gold within 4 h of induction as inclusion bodies. Among the tested solubilization buffers, the buffer with a pH of 12 and containing 2 M urea showed the highest solubilization effect. Polyclonal antibodies directed against the E7 multi-epitope vaccine were able to react strongly with the immunizing antigen and E7-bearing cells (TC-1). Immunization of TC-1 tumor-bearing mice with HPV16-E7, markedly delayed tumor growth and propagation. Conclusion The poly-epitope vaccine for HPV16-E7, as expressed and purified in this research, is highly immunogenic and capable of triggering E7-specific antibodies, making it a potential therapeutic HPV vaccine. Further research is needed to optimize the vaccination schedule and assess the E7-specific immune cell profile.

Abstract Antibiotics become less effective in treating infectious diseases as resistance increases. Staphylococcus aureus is a global problem due to its ability to form biofilms and resistance mechanisms. Phage endolysin is one of the most promising methods for combating antibiotic resistance. ZAM-MSC chimeric endolysin has three domains derived from SAL1 and lysostaphin, which target the peptide bridge of peptidoglycan. In this study purified ZAM-MSC (with yield of 30 mg/lit) had bactericidal activity against methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) at low concentrations (2.38 μg/ml and 1.88 μg/ml, respectively). The antibacterial spectrum revealed that ZAM-MSC was active against diverse Staphylococci. it has maintained 100% stability after 24 h incubation in pH 5 to 10 against S. aureus, as well as demonstrated significant thermostability and maintained nearly its full activity at different temperatures (4–42 °C) up to 1 day of incubation. The anti-biofilm activity of various concentrations of ZAM-MSC against MSSA and MRSA biofilms was not dose-dependent, and antibiofilm activity was observed even at low concentrations (14 μg/ml). Further, the molecular dynamics simulations demonstrated that the ZAM-MSC chimer and its parent proteins remained dynamically stable, showing similar flexibility despite the size and hydrogen bond number differences. In conclusion, the study reveals that chimeric ZAM-MSC is a distinctive enzyme with exceptional biochemical properties and rapid lytic activity against Staphylococci.

Background: The potential of plants, as a safe and eukaryotic system, is considered in the production of recombinant therapeutic human protein today; but the expression level of heterologous proteins is limited by the post-transcriptional gene silencing (PTGS) response in this new technology. The use of viral suppressors of gene silencing can prevent PTGS and improve transient expression level of foreign proteins. In this study, we investigated the effect of p19 silencing suppressor on recombinant human nerve growth factor expression in Nicotiana benthamiana. Materials and Methods: The p19 coding region was inserted in the pCAMBIA using NcoI and BstEII recognition sites. Also, the cloned synthesized recombinant human NGF (rhNGF) fragment was cloned directly into PVX vector by ClaI and SalI restriction enzymes. The co-agroinfiltration of rhNGF with p19 viral suppressor of gene silencing was evaluated by dot-blot and SDS-PAGE. The amount of expressed rhNGF protein was calculated by AlphaEaseFC software. Results: Co-agroinfiltration of hNGF with P19 suppressor showed about forty-fold increase (8% total soluble protein (TSP)) when compared to the absence of P19 suppressor (0.2%TSP). Conclusion: The results presented here confirmed that the use of P19 gene silencing suppressor derived from tomato bushy stunt virus (TBSV) could efficiently increase the transient expression of recombinant proteins in Nicotiana benthamiana manifold.