Abstract
As the sole target of broadly neutralizing antibodies (bnAbs) to HIV, the envelope glycoprotein (Env) trimer is the focus of vaccination strategies designed to elicit protective bnAbs in humans. Because HIV Env is densely glycosylated with 75–90 N-glycans per trimer, most bnAbs use or accommodate them in their binding epitope, making the glycosylation of recombinant Env a key aspect of HIV vaccine design. Upon analysis of three HIV strains, we here find that site-specific glycosylation of Env from infectious virus closely matches Envs from corresponding recombinant membrane-bound trimers. However, viral Envs differ significantly from recombinant soluble, cleaved (SOSIP) Env trimers, strongly impacting antigenicity. These results provide a benchmark for virus Env glycosylation needed for the design of soluble Env trimers as part of an overall HIV vaccine strategy.
Highlights
As the sole target of broadly neutralizing antibodies to human immunodeficiency virus (HIV), the envelope glycoprotein (Env) trimer is the focus of vaccination strategies designed to elicit protective bnAbs in humans
We found that sitespecific glycan processing of Env from infectious virus produced in peripheral blood mononuclear cells (PBMCs) is similar to that of the recombinant membrane-bound trimers produced in human embryonic kidney (HEK) 293 F cells
HIV Env trimers from three HIV strains, JR-FL, BG505 N332, and B41, were produced as recombinant soluble SOSIP.[664] (SOSIP) trimers, membrane-bound ΔCt trimers, pseudovirus and/or infectious virus
Summary
As the sole target of broadly neutralizing antibodies (bnAbs) to HIV, the envelope glycoprotein (Env) trimer is the focus of vaccination strategies designed to elicit protective bnAbs in humans. A major advance towards engineering an HIV Env-based vaccine was the development of stabilized soluble trimers[7,8,9] These stable constructs contain the conformational and quaternary epitopes for many bnAbs that are not found on recombinant gp[120] monomers, while shielding epitopes of many nonneutralizing antibodies that reside in the interface between monomers[3,7]. Analysis of soluble HIV Env trimers reveals that N-glycans have predominately high mannose-type glycans at some sites, and predominately complex glycans at other sites, reflecting minimal and extensive processing at the different glycosites, respectively[14,15,16] Such differences are highly relevant to the specificity and antigenicity of bnAbs that include either high mannose or complex-type glycans into their epitopes[3,17]. The abundance of each glycoform was not determined, 14 out of 24 glycosites contained mostly high mannose glycoforms, while others contained mainly complex-type or a mixture of complex, hybrid and high mannose-type glycoforms[16]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
