5v7j
From Proteopedia
Crystal Structure at 3.7 A Resolution of Glycosylated HIV-1 Clade A BG505 SOSIP.664 Prefusion Env Trimer with Four Glycans (N197, N276, N362, and N462) removed in Complex with Neutralizing Antibodies 3H+109L and 35O22.
Structural highlights
Function[Q2N0S6_9HIV1] The envelope glyprotein gp160 precursor down-modulates cell surface CD4 antigen by interacting with it in the endoplasmic reticulum and blocking its transport to the cell surface (By similarity).[RuleBase:RU004292][SAAS:SAAS000328_004_020447] The gp120-gp41 heterodimer allows rapid transcytosis of the virus through CD4 negative cells such as simple epithelial monolayers of the intestinal, rectal and endocervical epithelial barriers. Both gp120 and gp41 specifically recognize glycosphingolipids galactosyl-ceramide (GalCer) or 3' sulfo-galactosyl-ceramide (GalS) present in the lipid rafts structures of epithelial cells. Binding to these alternative receptors allows the rapid transcytosis of the virus through the epithelial cells. This transcytotic vesicle-mediated transport of virions from the apical side to the basolateral side of the epithelial cells does not involve infection of the cells themselves (By similarity).[SAAS:SAAS000328_004_240990] Publication Abstract from PubMedWhile the HIV-1-glycan shield is known to shelter Env from the humoral immune response, its quantitative impact on antibody elicitation has been unclear. Here, we use targeted deglycosylation to measure the impact of the glycan shield on elicitation of antibodies against the CD4 supersite. We engineered diverse Env trimers with select glycans removed proximal to the CD4 supersite, characterized their structures and glycosylation, and immunized guinea pigs and rhesus macaques. Immunizations yielded little neutralization against wild-type viruses but potent CD4-supersite neutralization (titers 1: >1,000,000 against four-glycan-deleted autologous viruses with over 90% breadth against four-glycan-deleted heterologous strains exhibiting tier 2 neutralization character). To a first approximation, the immunogenicity of the glycan-shielded protein surface was negligible, with Env-elicited neutralization (ID50) proportional to the exponential of the protein-surface area accessible to antibody. Based on these high titers and exponential relationship, we propose site-selective deglycosylated trimers as priming immunogens to increase the frequency of site-targeting antibodies. Quantification of the Impact of the HIV-1-Glycan Shield on Antibody Elicitation.,Zhou T, Doria-Rose NA, Cheng C, Stewart-Jones GBE, Chuang GY, Chambers M, Druz A, Geng H, McKee K, Kwon YD, O'Dell S, Sastry M, Schmidt SD, Xu K, Chen L, Chen RE, Louder MK, Pancera M, Wanninger TG, Zhang B, Zheng A, Farney SK, Foulds KE, Georgiev IS, Joyce MG, Lemmin T, Narpala S, Rawi R, Soto C, Todd JP, Shen CH, Tsybovsky Y, Yang Y, Zhao P, Haynes BF, Stamatatos L, Tiemeyer M, Wells L, Scorpio DG, Shapiro L, McDermott AB, Mascola JR, Kwong PD Cell Rep. 2017 Apr 25;19(4):719-732. doi: 10.1016/j.celrep.2017.04.013. PMID:28445724[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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