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Principal Investigator: S. Munir ALAM
Organization: DUKE UNIVERSITY
Fiscal Year: 2023
Award: $325,000
Funding agency: National Institute of Allergy and Infectious Diseases
Induction of broadly neutralizing antibodies (bnAbs) is a critical unmet goal of HIV vaccine development.
BnAb DH511 is of high interest as a vaccine lead due to its very high breadth and the high in vivo protective
potency of MPER bNAbs. Key challenges for inducing DH511-like bnAbs are: (a) the low affinity of DH511-
like precursors for HIV peptides and proteins, (b) the restriction on bnAb angle of approach imposed by the
recessed, membrane-proximal epitope environment and (c) the absence of the DH511 epitope from most
soluble, native-like trimers.
A promising strategy to initiate DH511-like bnAb induction is germline targeting, in which suitable
DH511-class precursors are specifically activated using engineered immunogens, thus selecting BCRs with
the potential to develop broad neutralization in the absence of autoreactivity. This approach will also help
circumvent steric problems associated with the recessed location of the epitope, by priming precursors with
known genetic and structural potential to mature into bnAbs compatible with MPER steric restraints. In this
project, which is Project 1 of a multi-project collaborative proposal, we will engineer epitope-scaffold
immunogens that bind with high affinity to and activate DH511-like precursors, using computational design
and directed evolution.
As known bnAbs are highly mutated, vaccine induction of bnAbs following a germline-targeting prime
will likely require sequential immunization with other immunogens designed to shepherd affinity maturation
of the B-cell receptor. We will develop different classes of boosting immunogens, including epitope-
scaffolds with more native epitopes, membrane-protein scaffolds and membrane-bound Env variants
stabilized in a conformation to which DH511 binds strongly. Structural studies of soluble and membrane-
bound immunogens in complex with DH511 lineage members will guide immunogen development.
The Animal Core of this collaborative proposal will generate knock-in mice that express DH511-like
precursors, and Project 2 will use those mice to test B cell priming and boosting in vivo. Project 2 will
conduct sequential prime/boost immunization experiments in knock-in mice and use ELISA, cytometry,
single B cell sorting and sequencing and neutralization assays to track and optimize affinity maturation,
providing experimental feedback to Project 1 to allow for iterative improvement of immunogens.
In summary, these studies seek to develop novel HIV vaccine candidates and also to shift HIV vaccine
research towards a reductionist approach based on state-of-the-art protein engineering to develop
germline-targeting and boosting immunogens, development of human Ig knock-in mouse models to enable
testing of human-repertoire-specific vaccines, and in-depth analysis of vaccine-induced affinity maturation
pathways in vivo to guide iterative vaccine optimization.
Terms: <AIDS Virus><Acquired Immune Deficiency Syndrome Virus><Acquired Immunodeficiency Syndrome Virus><Affinity><Animal Model><Animal Models and Related Studies><Animals><Antibodies><Antibody Response><Antigenic Determinants><Antigens><Assay><Avidity><B blood cells><B cell><B cell receptor><B cells><B-Cell Activation><B-Cell Antigen Receptor><B-Cells><B-Lymphocytes><B-cell><Binding><Binding Determinants><Bioassay><Biologic Assays><Biological Assay><Cell Isolation><Cell Segregation><Cell Separation><Cell Separation Technology><Complement><Complement Proteins><Complex><Cryo-electron Microscopy><Cryoelectron Microscopy><Cytometry><Development><Directed Molecular Evolution><Distal><ELISA><Electron Cryomicroscopy><Engineering><Envelope Protein><Environment><Enzyme-Linked Immunosorbent Assay><Epitopes><Feedback><Genetic><Genetic Alteration><Genetic Change><Genetic defect><Germ-Line Mutation><Germline Mutation><Glycans><Glycoproteins><Goals><HIV><HIV vaccine><HIV-1><HIV-I><HIV/AIDS Vaccines><HIV1><Health Priorities><Hereditary Mutation><Human><Human Immunodeficiency Virus Type 1><Human Immunodeficiency Viruses><Human immunodeficiency virus 1><Immunity><Immunization><In Vitro><KI mice><Knock-in Mouse><LAV-HTLV-III><Lead><Length><Lipid Binding><Lipids><Liposomal><Liposomes><Location><Lymphadenopathy-Associated Virus><Membrane><Membrane Protein Gene><Membrane Proteins><Membrane-Associated Proteins><Methods><Mice><Mice Mammals><Modern Man><Molecular Configuration><Molecular Conformation><Molecular Interaction><Molecular Stereochemistry><Murine><Mus><Mutate><Mutation><NGS Method><NGS system><Passive Immunization><Pathway interactions><Pb element><Peptides><Polysaccharides><Protein Engineering><Proteins><Regimen><Resolution><SHIV><Scaffolding Protein><Single Crystal Diffraction><Specificity><Structure><Surface Proteins><Techniques><Testing><Vaccination><Vaccine Research><Vaccines><Variant><Variation><Viral><Virus><Virus-HIV><X Ray Crystallographies><X-Ray Crystallography><X-Ray Diffraction Crystallography><X-Ray/Neutron Crystallography><Xray Crystallography><Yeasts><activated B cells><autoreactivity><cell sorting><conformation><conformational><conformational state><conformationally><conformations><cross reactivity><cryo-EM><cryoEM><cryogenic electron microscopy><design><designing><develop a vaccine><develop vaccines><development of a vaccine><developmental><directed evolution><env Antigens><env Gene Products><env Polyproteins><env Protein><enzyme linked immunoassay><experiment><experimental research><experimental study><experiments><genetic protein engineering><genome mutation><germline variant><global health><heavy metal Pb><heavy metal lead><human immunodeficiency virus vaccine><immunogen><immunogenicity><improved><in vivo><interest><knockin mice><lipid bound><member><membrane structure><model of animal><mouse model><murine model><nano particle><nano-sized particle><nanodisk><nanoparticle><nanosized particle><neutralizing antibody><next gen sequencing><next generation sequencing><nextgen sequencing><novel><pathway><protein design><reconstitute><reconstitution><resolutions><response><restraint><scaffold><scaffolding><simian HIV><simian human immunodeficiency virus><vaccine candidate><vaccine development><vaccine-related research>