TY - JOUR T1 - Enhancing glycan occupancy of soluble HIV-1 envelope trimers to mimic the native viral spike JF - bioRxiv DO - 10.1101/2020.07.02.184135 SP - 2020.07.02.184135 AU - Ronald Derking AU - Joel D. Allen AU - Christopher A. Cottrell AU - Kwinten Sliepen AU - Gemma E. Seabright AU - Wen-Hsin Lee AU - Kimmo Rantalainen AU - Aleksandar Antanasijevic AU - Jeffrey Copps AU - Anila Yasmeen AU - Patricia van der Woude AU - Steven W. de Taeye AU - Tom L.G.M. van den Kerkhof AU - P.J. Klasse AU - Gabriel Ozorowski AU - Marit J. van Gils AU - John P. Moore AU - Andrew B. Ward AU - Max Crispin AU - Rogier W. Sanders Y1 - 2020/01/01 UR - http://biorxiv.org/content/early/2020/07/02/2020.07.02.184135.abstract N2 - The HIV-1 envelope glycoprotein (Env) trimer is decorated with N-linked glycans, which are attached to asparagine residues in the amino acid sequon NxT/S by oligosaccharyltransferases (OST). Artificial glycan “holes” exist when a PNGS is under-occupied on recombinant Env-based vaccines, but not on their viral counterpart. Native-like SOSIP trimers, including clinical candidates, have these artificial holes in the glycan shield that induce strain-specific neutralizing antibodies (NAbs) or non-NAbs. To increase PNGS occupancy, eliminate artificial glycan holes, and mimic the glycosylation of native BG505 Env, we replaced all 12 NxS sequons on the BG505 SOSIP trimer with NxT, thereby increasing the affinity of the sequons for OST. All PNGS, except N133 and N160, were nearly fully occupied on the modified trimer. Occupancy of the N133 site could be increased by changing N133 to NxS, while occupancy of the N160 site could be restored by reverting the nearby N156 sequon to NxS. Hence, OST affinity can influence glycan occupancy when two PNGS are in close proximity. Increasing glycan occupancy should reduce off-target immune responses to artificial glycan holes on vaccine antigens.Competing Interest StatementR. W. S. and J. P. M. are listed on patents concerning stabilized Env trimers. ER -