Immunogenicity of differentially glycosylated Marburg virus glycoproteins expressed in mammalian and insect cells

Marburg virus (MARV) infection can cause severe disease, and there is no available vaccine or therapeutic method. Research into potential vaccine design is focused on the glycoprotein (GP), which mediates the adherence and invasion process of the virus. However, it is unclear whether the degree of GP glycosylation is associated with vaccine efficacy. Here we constructed two versions of the GP expressed using insect and mammalian cell systems, respectively, either containing the mucin-like domain (MARV GPΔTM including residues 1-637) or deleting residues 264-425 to remove the part of mucin-like domain (MARV GPΔTM ΔMuc). Physicochemical properties, antigenicity, and immunogenicity were compared for soluble GPs produced in different cell expression systems. The GPΔTM ΔMuc produced in mammalian cells was more immunogenic, as evidenced by the induction of higher titers of binding antibodies and more antibodies targeting the protective epitope. Our results may offer a better understanding of glycosylation for the development of vaccines.