Well-ordered trimeric HIV-1 subtype B and C soluble spike mimetics generated by negative selection display native-like properties.

TitleWell-ordered trimeric HIV-1 subtype B and C soluble spike mimetics generated by negative selection display native-like properties.
Publication TypeJournal Article
Year of Publication2015
AuthorsGuenaga J, de Val N, Tran K, Feng Y, Satchwell K, Ward AB, Wyatt RT
JournalPLoS Pathog
Volume11
Issue1
Paginatione1004570
Date Published01/08/2015
ISSN1553-7374
Abstract

The structure of BG505 gp140 SOSIP, a soluble mimic of the native HIV-1 envelope glycoprotein (Env), marks the beginning of new era in Env structure-based immunogen design. Displaying a well-ordered quaternary structure, these subtype A-derived trimers display an excellent antigenic profile, discriminating recognition by broadly neutralizing antibodies (bNAbs) from non-broadly neutralizing antibodies (non-bNAbs), and provide a solid Env-based immunogenic platform starting point. Even with this important advance, obtaining homogeneous well-ordered soluble SOSIP trimers derived from other subtypes remains challenging. Here, we report the "rescue" of homogeneous well-ordered subtype B and C SOSIP trimers from a heterogeneous Env mixture using CD4 binding site-directed (CD4bs) non-bNAbs in a negative-selection purification process. These non-bNAbs recognize the primary receptor CD4bs only on disordered trimers but not on the native Env spike or well-ordered soluble trimers due to steric hindrance. Following negative selection to remove disordered oligomers, we demonstrated recovery of well-ordered, homogeneous trimers by electron microscopy (EM). We obtained 3D EM reconstructions of unliganded trimers, as well as in complex with sCD4, a panel of CD4bs-directed bNAbs, and the cleavage-dependent, trimer-specific bNAb, PGT151. Using bio-layer light interferometry (BLI) we demonstrated that the well-ordered trimers were efficiently recognized by bNAbs and poorly recognized by non-bNAbs, representing soluble mimics of the native viral spike. Biophysical characterization was consistent with the thermostability of a homogeneous species that could be further stabilized by specific bNAbs. This study revealed that Env trimers generate different frequencies of well-ordered versus disordered aberrant trimers even when they are genetically identical. By negatively selecting the native-like well-ordered trimers, we establish a new means to obtain soluble Env mimetics derived from subtypes B and C for expanded use as candidate vaccine immunogens.

DOI10.1371/journal.ppat.1004570
Alternate JournalPLoS Pathog.
PubMed ID25569572
PubMed Central IDPMC4287557
Grant ListP41 GM103310 / GM / NIGMS NIH HHS / United States
RR017573 / RR / NCRR NIH HHS / United States
UM1 AI100663 / AI / NIAID NIH HHS / United States
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