Designing a Multi-Epitope Vaccine Against Cancer-Testis Antigens in Non-Small Cell Lung Cancer: an In Silico Approach

Leana Rich M. Herrera, and Elizabeth P. Bisa *Department Physical Sciences, College of Science, polytechnic University of the Philippines

The 5-year survival rate of non-small-cell lung cancer (NSCLC) patients has not significantly improved despite advancements in the currently applied treatments. Thus, efforts are put forth in developing novel immunotherapeutic agents targeting cancer-testis antigens (CTA) in NSCLC. This work utilized reverse vaccinology approach in designing a novel multi-epitope vaccine targeting melanoma-associated antigen 3 (MAGEA3), MAGEA4, New York esophageal squamous cell carcinoma-1 (NY-ESO-1), and Kita-Kyushu lung cancer antigen 1 (KK-LC1), being the most frequently expressed CTAs in NSCLC.

Epitopes were mapped using the sequences of CTAs. Population coverage (PC) of CD4+ and CD8+ epitopes were estimated. Selected linear B cell (BL), CD4+, and CD8+ epitopes were adjoined in a multi-epitope construct (Mvax), flagellin domain as an adjuvant. Antigenicity, and cross-reactivity of Mvax were examined. The tertiary structure of Mvax was modelled, and validated. All epitopes included in the vaccine were docked with their human leukocyte antigen (HLA) binders. The immunogenicity of epitopes in Mvax was validated through molecular dynamics analysis.

Mvax contains 22 epitopes from MAGEA3, MAGEA4, NY-ESO-1, and KK-LC1. It is classified as antigenic, non-allergen, non-toxic, and possess physicochemical stability. Epitopes have no significant hits with other human proteins, except for 2 other CTAs frequently expressed in NSCLC. The stretch of BL epitopes in Mvax confers flexibility, and accessibility emphasizing its antigenicity. The tertiary structure model used for Mvax has good structural quality. All epitopes included in the vaccine are highly immunogenic as indicated by good binding affinity, low binding energy, and acceptable root-mean-square deviation (RMSD). CD4+ and CD8+ epitopes have global PC of 81.81%, and 84.15%, respectively.

This is the first work to use reverse vaccinology approach in designing a multi-epitope vaccine targeting MAGEA3, MAGEA4, NY-ESO-1, and KK-LC1 in NSCLC. In silico assessments showed that Mvax confers antigenicity, immunogenicity, stability, and safety. In vitro and in vivo studies are anticipated.