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Principal Investigator: ELLIS L REINHERZ
Organization: DANA-FARBER CANCER INST
Fiscal Year: 2019
Award: $1,289,810
Funding agency: National Institute of Allergy and Infectious Diseases
ABSTRACT
There are only a handful of sites on the HIV-1 envelope protein that represent regions of vulnerability for
elicitation of broadly neutralizing antibody (BNAbs). Four are associated with the gp120 subunit while one of
the sites resides in the membrane proximal external region (MPER) of gp41. We previously showed that the
MPER is a conserved structural element consisting of two helices separated by a hinge with tandem joints that
facilitates viral hemifusion and fusion. MPER-specific BNAbs exert their anti-viral effect by disturbing gp41
conformational change required for viral entry into host cells. These BNAbs manifest extraordinary HIV-1 strain
and clade neutralization breadth as exemplified by the mAb 10E8. Until recently, it was not known how to elicit
anti-MPER specific Abs. The MPER is poorly immunogenic either as a component of the intact gp160 trimeric
spike or in the context of an isolated gp41 subunit immunogen. Hence, anti-MPER Abs are not the most
frequent specificity elicited during natural infections. This subdominance is not surprising given the fact that the
MPER is lipid immersed to a significant degree. However, very recently, stealth liposomes arraying the isolated
MPER and cargoing conjoint CD4 T cell epitope and TLR ligands were found to effectively foster MPER-
specific bone marrow (BM) plasma cell development in the mouse, including those producing Abs with somatic
hypermutation and lengthy CDRH3 as shown by microengraving and single-cell PCR analysis. Immunogenicity
of this segment is dominated by residue accessibility and modulated by stereochemistry. The consequence of
the latter is that unwanted specificities can be engendered during fabricated insertion of the MPER segment
into a lipid membrane. Here, by appending transmembrane (TM) segments with relevant membrane tilt angles
guided by computational predictions and structural/biophysical verification as well as removal of exposed
misguiding chemical adducts, we shall program the desired nanovaccine immunogenicity for B cell memory
and plasma cell development. In Aim I, we shall use native HIV-1 or variant TM sequences to insert the MPER
into nanodiscs and liposomes. Orientation and depth of MPER residues will be assessed by NMR and EPR
methods and iteratively adjusted and refined in conjunction with molecular electron microscopy and X-ray
crystallographic studies using anti-MPER Abs. In Aim II, using conventional mice as well as the KyMouse with
complete humanization of the mouse Ig loci, we shall establish both immunogens and vaccine schedules to
engender BNAb elicitation, comparing them with those arising from natural HIV-1 infection. Existing liposome
formulations, novel nanodiscs and evolving biomaterial arrays will be used for immunization and then MPER
residue specificity, extraction activity, native spike binding and HIV-1 neutralizing activity of elicited antibodies
will be assessed by examining bulk IgG and single BM plasma cell Abs. Optimization of several MPER
sequences for induction of highly potent BNAbs against M subgroup clades will be performed in preparation for
future clinical nanovaccine trials.
Terms: <7S Gamma Globulin><ATGN><Ab response><Abscission><Affinity><Antibodies><Antibody Formation><Antibody Production><Antigen Variation><Antigenic Determinants><Antigenic Variability><Antigenic Variation><Antigens><Antiviral Agents><Antiviral Drugs><Antivirals><B blood cells><B cell><B cells><B-Cells><B-Lymphocytes><B-cell><Binding><Binding Determinants><Biocompatible Materials><Biomaterials><Biophysics><Blood Plasma Cell><Bone Marrow><Bone Marrow Reticuloendothelial System><C-terminal><CD4 Cells><CD4 Positive T Lymphocytes><CD4 T cells><CD4 helper T cell><CD4 lymphocyte><CD4+ T-Lymphocyte><CD4-Positive Lymphocytes><Cell Attachment><Cell Body><Cell Maturation><Cell Membrane Lipids><Cell-Matrix Adhesions><Cell-Matrix Junction><Cells><Characteristics><Chemicals><Chronic><Clinical><Clinical Treatment Moab><Conserved Sequence><Cryo-electron Microscopy><Cryoelectron Microscopy><Development><Dimensions><Electron Cryomicroscopy><Electron Microscopy><Elements><Envelope Protein><Epitopes><Excision><Extirpation><Formulation><Fostering><Frequencies><Future><Genetic Alteration><Genetic Change><Genetic defect><Glycans><HIV Envelope Glycoprotein gp120><HIV Envelope Protein gp120><HIV env Protein gp120><HIV-1><HIV-I><HIV1><HTLV-III gp120><Human><Human Immunodeficiency Virus Type 1><Human immunodeficiency virus 1><Ig Somatic Hypermutation><IgG><Immune Globulins><Immunization><Immunization Schedule><Immunoglobulin G><Immunoglobulin Somatic Hypermutation><Immunoglobulins><Immunologic Sensitization><Immunologic Stimulation><Immunological Sensitization><Immunological Stimulation><Immunostimulation><Individual><Infection><Joints><Knowledge><Ligands><Lipid Binding><Lipids><Liposomal><Liposomes><Masks><Membrane><Membrane Lipids><Memory B Cell><Memory B-Lymphocyte><Methods><Mice><Mice Mammals><Modern Man><Molecular><Molecular Configuration><Molecular Conformation><Molecular Interaction><Molecular Stereochemistry><Monoclonal Antibodies><Murine><Mus><Mutation><Plasma Cells><Plasmacytes><Polysaccharides><Preparation><Production><Recombinants><Removal><Roentgen Rays><Schedule><Side><Site><Specificity><Structure><Subgroup><Surgical Removal><T-Cell Epitopes><T-Lymphocyte Epitopes><T4 Cells><T4 Lymphocytes><TM Domain><Time><Transmembrane Domain><Transmembrane Region><Vaccination><Vaccine Design><Vaccines><Variant><Variation><Viral><X-Radiation><X-Rays><X-Rays Radiation><Xrays><adduct><alpha helix><anti-viral agents><anti-viral drugs><anti-virals><antibody biosynthesis><biological material><biophysical foundation><biophysical principles><biophysical sciences><conformation><conformational state><cryo-EM><cryoEM><design><designing><developmental><env Antigens><env Gene Products><env Polyproteins><env Protein><genome mutation><gp120><gp120 ENV Glycoprotein><gp120(HIV)><gp160><immunogen><immunogenic><immunogenicity><immunoglobulin biosynthesis><improved><lipid bound><mAbs><membrane structure><nano disk><nano vaccine><nanodisk><nanovaccine><neutralizing antibody><novel><particle><plasma cell development><plasmocyte><programs><resection><somatic hypermutation><stereochemistry><α-helix>