Title : Glycan modifications to the
gp120 immunogens used in the RV144 vaccine trial improve binding to broadly neutralizing antibodies
Abstract :
- To date, the RV144 HIV vaccine trial has been the only study to show that immunization can confer protection from HIV infection
- While encouraging, the modest 31.2% (P = 0.04) efficacy achieved in this study left significant room for improvement, and created an incentive to optimize the AIDSVAX B/E vaccine immunogens to increase the level of vaccine efficacy
- Since the completion of the RV144 trial, our understanding of the antigenic structure of the HIV envelope protein , gp120 , and of the specificity of broadly neutralizing monoclonal antibodies (bN-mAbs) that bind to it, has significantly improved
- In particular, we have learned that multiple families of bN-mAbs require specific oligomannose glycans for binding
- Both of the monomeric gp120 immunogens (MN- and A244-rgp120 ) in the AIDSVAX B/E vaccine used in the RV144 trial were enriched for glycans containing high levels of sialic acid, and lacked critical N-linked glycosylation sites required for binding by several families of bN-mAbs
- The absence of these epitopes may have contributed to the low level of efficacy achieved in this study
- In this report, we describe our efforts to improve the antigenic structure of the r gp120 immunogens used in the vaccine by optimizing glycan-dependent epitopes recognized by multiple bN-mAbs
- Our results demonstrated that by shifting the location of one PNGS in A244-rgp120 , and by adding two PNGS to MN-r gp120 , in conjunction with the production of both proteins in a cell line that favors the incorporation of oligomannose glycans, we could significantly improve the binding by three major families of bN-mAbs
- The immunogens described here represent a second generation of gp120-based vaccine immunogens that exhibit potential for use in RV144 follow-up studies
Output (sent_index, trigger,
protein,
sugar,
site):
- 5. glycosylation, , -, -, sites
Output(Part-Of) (sent_index,
protein,
site):
*Output_Site_Fusion* (sent_index,
protein,
sugar,
site):