Abstract: Disclosed herein are methods of producing glyco-modified viral antigens that provide a shift of the glycosylation profile of recombinant produced viral antigens (e.g. glycoproteins) towards the naturally occurring viral antigens (e.g. glycoproteins). Disclosed are methods of producing a modified viral antigen comprising expressing a viral antigen in a recombinant mammalian cell line having one or more of the endogenous genes Mgat2, Mgat4A, Mgat4B, Mgat5, St3Gal3, St3Gal4, B4galt1, B4galt2, B4galt3, B4galt4, B4galt5, B3gnt2, St3Gal6, SPPL3, and/or FUT8 inactivated and/or downregulated; and optionally a gene ST6Gall inserted. Disclosed are glyco-modified viral antigens produced by the method of using a recombinant mammalian cell line. Disclosed are methods of treating a subject in need thereof comprising administering a composition comprising a therapeutically effective amount of one or more of the glyco-modified viral antigens.

Abstract: Disclosed are modified hepatitis C virus (HCV) E1E2 glycoproteins. Disclosed are Disclosed are modified HCV E1E2 glycoproteins comprising a HCV E1 polypeptide; a first scaffold element; a HCV E2 polypeptide; and a second scaffold element, wherein the HCV E1 polypeptide does not comprise a transmembrane domain, and wherein the HCV E2 polypeptide does not comprise a transmembrane domain.