Rational Design and In-Silico Evaluation of a Multi-Epitope Vaccine Targeting Human Glypican-3 (GPC3) for Hepatocellular Carcinoma Immunotherapy

Abstract

Hepatocellular carcinoma (HCC) is among the most common and lethal cancers in the world, with more than 900,000 new cases diagnosed every year and remains one of the leading death factors of cancer. The lack of efficacy with currently available treatments has created a need for new immunotherapeutic approaches. The cancer-testis antigen, glypican-3 (GPC3), is an oncofetal protein overexpressed in > 70% of HCC but not expressed in normal adult liver and was chosen as the objective for the rational vaccine design. B-cell, cytotoxic T-lymphocyte (CTL), and helper T-lymphocyte (HTL) epitopes were predicted with an integrated immunoinformatic pipeline, filtered for antigenicity, non-allergenicity, and non-toxicity from available databases, constructed as a stable multi-epitope structure along with appropriate linkers and adjuvants. The stability and accuracy of the construct were verified by structural modeling and validation, and its binding affinity to TLR4 was demonstrated by docking with strong hydrogen bonding interactions in combination with hydrophobic contacts. Molecular dynamics (500 ns) simulations showed conformational stability, chain compaction of the vaccine as well as thermodynamically favorable interactions. CAI for codon optimized ampC was 0.87 and optimal GC content for expression in E. coli. Simulation of the immune response predicted strong activations of both B and T cells, antibody production and memory. The results above clearly indicate that the GPC3-derived multi-epitope vaccine may be a good candidate for HCC immunotherapy and it deserves experimental verification.