An Effective CTL Peptide Vaccine for Ebola Zaire Based on Survivors’ CD8+ Targeting of a Particular Nucleocapsid Protein Epitope with Potential Implications for COVID-19 Vaccine Design

CV Herst; S Burkholz; J Sidney; A Sette; PE Harris; S Massey; T Brasel; E Cunha-Neto; DS Rosa; WCH Chao; R Carback; T Hodge; L Wang; S Ciotlos; P Lloyd; R Rubsamen

We fabricated adjuvanted microspheres for this study as a room temperature stable dry powder using the Flow Focusing process to be 11µM in diameter so as to prevent more than one microsphere from being phagocytosed by any given antigen presenting cell (APC) at the same time [37] . By loading only one peptide 55 sequence per microsphere, we maximized the peptide payload and mitigated the possibility of multiple, different peptide sequences being delivered to the APC simultaneously, which could possibly result in competitive inhibition at the motif which could interfere with antigen presentation and subsequent T-cell expansion (Supplementary Material Section 1). 60 We also set out to see if a similar approach to a CTL vaccine design for SARS-CoV-2 would be feasible based on an analysis of the HLA binding characteristics of peptide sequences on SARS-CoV-2 nucleocapsid.