Lentiviral display to screen for improved Env immunogens

Funding: Bill & Melinda Gates Foundation
Duration: 1.7.2006 – 30.6.2013

HI-viral particles are ideal vehicles to present combinatorial libraries of gp41 and gp140 derivatives in a membrane environment. Thus, we are generating lentiviral libraries displaying many variants of stable trimeric derivatives generated by various 'molecular evolution' approaches. Iterative rounds of panning with available and new NMabs at increasing stringency will select high affinity binders. Selected and re-amplified particles displaying Env variants will be further assayed for (i) affinity to different NMabs (Biacore), (ii) trimerization state and (iii) stability. Selected Env antigens will be produced as immunogens as VLPs, proteoliposomes or recombinant proteins. The correlation between binding affinity and breadth of neutralization (antibody responses in rabbits) will be determined.
In addition a FACS-based screening system for epitope identification of anti-Env-antibodies will be developed. High troughput FACS analysis of an Env-library comprising individual alanine mutations at any position will identify critical amino acids for the binding of antibodies of interest.

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