[Way to the peptide vaccine against hepatitis C]

Synthesis and Analysis of Properties of an Immunogenic Fragment from NS4A Polypeptide of Hepatitis C Virus

Abstract—

The work is aimed at the synthesis and analysis from NS4A of hepatitis C virus (HCV) antigen peptide fragment that contains a conserved B-cell and T-helper epitopes. The 24-mer peptide VIVGRIILSGRPAVIPDREVLYRK-NH2, which contains the main immunogenic site 24–46 of HCV NS4A antigen (corresponding to the 1681–1703 amino acid residues of the HCV polypeptide), subtype 1b, has been prepared via solid-phase synthesis according to the Fmoc-protocol. Particles with diameters of 73 ± 10 nm (30%) and 236 ± 5 nm (70%) have been detected in the water solution of the highly purified peptide (0.5 mg/mL) by dynamic light scattering. The polydispersity index of 0.377 ± 0.012 implies the existence of heterogeneity because of the aggregation of the peptide molecules. The ζ-potential of the peptide aggregates has been determined as 7.0 ± 0.5 mV by means of electrophoretic light scattering. These data confirm the possibility for the development of a nanoscale liposome form of the peptide preparation. Immunoreactivity of the synthesized highly purified peptide has been studied with the use of blood sera of patients with chronic hepatitis C. Antipeptide immunoglobulins G have been detected in 41.7% of serum samples. Thus, this peptide has been shown to reproduce at least one B-epitope, to which antibodies are raised during natural HCV infection. The synthesized 24-mer peptide is a promising candidate for further research and for use as a potential immunogen for the design of a nanoscale therapeutic immunogenic liposomal peptide composition with synthetic lipids as an adjuvant.

Advanced In Silico Tools for Designing of Antigenic Epitope as Potential Vaccine Candidates Against Coronavirus

Vaccines are the most economical and potent substitute of available medicines to cure various bacterial and viral diseases. Earlier, killed or attenuated pathogens were employed for vaccine development. But in present era, the peptide vaccines are in much trend and are favoured over whole vaccines because of their superiority over conventional vaccines. These vaccines are either based on single proteins or on synthetic peptides including several B-cell and T-cell epitopes. However, the overall mechanism of action remains the same and works by prompting the immune system to activate the specific B-cell- and T-cell-mediated responses against the pathogen. Rino Rappuoli and others have contributed in this field by plotting the design of the most potent and fully computational approach for discovery of potential vaccine candidates which is popular as reverse vaccinology. This is quite an unambiguous advance for vaccine evolution where one begins with the genome information of the pathogen and ends up with the list of certain epitopes after application of multiple bioinformatics tools. This book chapter is an effort to bring this approach of reverse vaccinology into notice of readers using example of coronavirus.