title: Cleavage-independent HIV-1 Env trimers engineered as soluble native spike mimetics for vaccine design.
abstract: Viral glycoproteins mediate entry by pH-activated or receptor-engaged activation and exist in metastable pre-fusogenic states that may be stabilized by directed rational design. As recently reported, the conformationally fixed HIV-1 envelope glycoprotein (Env) trimers in the pre-fusion state (SOSIP) display molecular homogeneity and structural integrity at relatively high levels of resolution. However, the SOSIPs necessitate full Env precursor cleavage, which requires endogenous furin overexpression. Here, we developed an alternative strategy using flexible peptide covalent linkage of Env subdomains to produce soluble, homogeneous, and cleavage-independent Env mimics, called native flexibly linked (NFL) trimers, as vaccine candidates. This simplified design avoids the need for furin co-expression and, in one case, antibody affinity purification to accelerate trimer scale-up for preclinical and clinical applications. We have successfully translated the NFL design to multiple HIV-1 subtypes, establishing the potential to become a general method of producing native-like, well-ordered Env trimers for HIV-1 or other viruses.
authors.affiliation: IAVI Neutralizing Antibody Center at the Scripps Research Institute, The Scripps Research Institute, La Jolla, CA 92037, USA.
authors.forename: Shailendra Kumar
authors.initials: SK
authors.lastname: Sharma
authors.affiliation: Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
authors.forename: Natalia
authors.initials: N
authors.lastname: de Val
authors.affiliation: Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037, USA.
authors.forename: Shridhar
authors.initials: S
authors.lastname: Bale
authors.affiliation: IAVI Neutralizing Antibody Center at the Scripps Research Institute, The Scripps Research Institute, La Jolla, CA 92037, USA.
authors.forename: Javier
authors.initials: J
authors.lastname: Guenaga
authors.affiliation: IAVI Neutralizing Antibody Center at the Scripps Research Institute, The Scripps Research Institute, La Jolla, CA 92037, USA.
authors.forename: Karen
authors.initials: K
authors.lastname: Tran
authors.affiliation: IAVI Neutralizing Antibody Center at the Scripps Research Institute, The Scripps Research Institute, La Jolla, CA 92037, USA.
authors.forename: Yu
authors.initials: Y
authors.lastname: Feng
authors.affiliation: Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037, USA.
authors.forename: Viktoriya
authors.initials: V
authors.lastname: Dubrovskaya
authors.affiliation: IAVI Neutralizing Antibody Center at the Scripps Research Institute, The Scripps Research Institute, La Jolla, CA 92037, USA; Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA; Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, CA 92037, USA.
authors.forename: Andrew B
authors.initials: AB
authors.lastname: Ward
authors.affiliation: IAVI Neutralizing Antibody Center at the Scripps Research Institute, The Scripps Research Institute, La Jolla, CA 92037, USA; Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037, USA; Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, CA 92037, USA. Electronic address: wyatt@scripps.edu.
authors.forename: Richard T
authors.initials: RT
authors.lastname: Wyatt
mesh_terms: D016915:AIDS Vaccines / Q000276:immunology; D000595:Amino Acid Sequence; D057809:HEK293 Cells; D015497:HIV-1 / Q000235:genetics / Q000276:immunology; D006801:Humans; D008969:Molecular Sequence Data; D059748:Proteolysis; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D054299:env Gene Products, Human Immunodeficiency Virus / Q000737:chemistry* / Q000235:genetics / Q000276:immunology
chemical_list: D016915:AIDS Vaccines; D011993:Recombinant Fusion Proteins; D054299:env Gene Products, Human Immunodeficiency Virus