title: Long antibody HCDR3s from HIV-naïve donors presented on a PG9 neutralizing antibody background mediate HIV neutralization.
abstract: Development of broadly neutralizing antibodies (bnAbs) against HIV-1 usually requires prolonged infection and induction of Abs with unusual features, such as long heavy-chain complementarity-determining region 3 (HCDR3) loops. Here we sought to determine whether the repertoires of HIV-1-naïve individuals contain Abs with long HCDR3 loops that could mediate HIV-1 neutralization. We interrogated at massive scale the structural properties of long Ab HCDR3 loops in HIV-1-naïve donors, searching for structured HCDR3s similar to those of the HIV-1 bnAb PG9. We determined the nucleotide sequences encoding 2.3 × 10(7)unique HCDR3 amino acid regions from 70 different HIV-1-naïve donors. Of the 26,917 HCDR3 loops with 30-amino acid length identified, we tested 30 for further study that were predicted to have PG9-like structure when chimerized onto PG9. Three of these 30 PG9 chimeras bound to the HIV-1 gp120 monomer, and two were neutralizing. In addition, we found 14 naturally occurring HCDR3 sequences that acquired the ability to bind to the HIV-1 gp120 monomer when adding 2- to 7-amino acid mutations via computational design. Of those 14 designed Abs, 8 neutralized HIV-1, with IC50values ranging from 0.7 to 98 µg/mL. These data suggest that the repertoire of HIV-1-naïve individuals contains rare B cells that encode HCDR3 loops that bind or neutralize HIV-1 when presented on a PG9 background with relatively few or no additional mutations. Long HCDR3 sequences are present in the HIV-naïve B-cell repertoire, suggesting that this class of bnAbs is a favorable target for rationally designed preventative vaccine efforts.
authors.affiliation: Chemical and Physical Biology Program, Vanderbilt University, Nashville, TN 37232; Center for Structural Biology, Vanderbilt University, Nashville, TN 37232; Vanderbilt Vaccine Center, Vanderbilt University, Nashville, TN 37232;
authors.forename: Jordan R
authors.initials: JR
authors.lastname: Willis
authors.affiliation: Center for Structural Biology, Vanderbilt University, Nashville, TN 37232; Vanderbilt Vaccine Center, Vanderbilt University, Nashville, TN 37232; Department of Pathology, Microbiology, and Immunology, Vanderbilt University, Nashville, TN 37232;
authors.forename: Jessica A
authors.initials: JA
authors.lastname: Finn
authors.affiliation: Vanderbilt Vaccine Center, Vanderbilt University, Nashville, TN 37232; Department of Pathology, Microbiology, and Immunology, Vanderbilt University, Nashville, TN 37232;
authors.forename: Bryan
authors.initials: B
authors.lastname: Briney
authors.affiliation: Vanderbilt Vaccine Center, Vanderbilt University, Nashville, TN 37232; Department of Pediatrics, Vanderbilt University, Nashville, TN 37232;
authors.forename: Gopal
authors.initials: G
authors.lastname: Sapparapu
authors.affiliation: Vanderbilt Vaccine Center, Vanderbilt University, Nashville, TN 37232;
authors.forename: Vidisha
authors.initials: V
authors.lastname: Singh
authors.affiliation: Vanderbilt Vaccine Center, Vanderbilt University, Nashville, TN 37232;
authors.forename: Hannah
authors.initials: H
authors.lastname: King
authors.affiliation: Department of Surgery, Duke University Medical Center, Durham, NC 27710;
authors.forename: Celia C
authors.initials: CC
authors.lastname: LaBranche
authors.affiliation: Department of Surgery, Duke University Medical Center, Durham, NC 27710;
authors.forename: David C
authors.initials: DC
authors.lastname: Montefiori
authors.affiliation: Chemical and Physical Biology Program, Vanderbilt University, Nashville, TN 37232; Center for Structural Biology, Vanderbilt University, Nashville, TN 37232; Department of Chemistry, Vanderbilt University, Nashville, TN 37232; Institute for Chemical Biology, Vanderbilt University, Nashville, TN 37232 jens.meiler@vanderbilt.edu james.crowe@vanderbilt.edu.
authors.forename: Jens
authors.initials: J
authors.lastname: Meiler
authors.affiliation: Chemical and Physical Biology Program, Vanderbilt University, Nashville, TN 37232; Vanderbilt Vaccine Center, Vanderbilt University, Nashville, TN 37232; Department of Pathology, Microbiology, and Immunology, Vanderbilt University, Nashville, TN 37232; Department of Pediatrics, Vanderbilt University, Nashville, TN 37232; jens.meiler@vanderbilt.edu james.crowe@vanderbilt.edu.
authors.forename: James E
authors.initials: JE
authors.lastname: Crowe
mesh_terms: D019943:Amino Acid Substitution; D057134:Antibodies, Neutralizing / Q000235:genetics / Q000276:immunology; D001782:Blood Donors; D022801:Complementarity Determining Regions; D005260:Female; D015483:HIV Antibodies / Q000235:genetics / Q000276:immunology; D015699:HIV Envelope Protein gp120 / Q000235:genetics / Q000276:immunology*; D015497:HIV-1 / Q000235:genetics / Q000276:immunology*; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000235:genetics / Q000276:immunology; D008297:Male; D020125:Mutation, Missense
chemical_list: D057134:Antibodies, Neutralizing; D022801:Complementarity Determining Regions; D015483:HIV Antibodies; D015699:HIV Envelope Protein gp120; D007143:Immunoglobulin Heavy Chains; C514793:gp120 protein, Human immunodeficiency virus 1
keywords: HIV; molecular conformation; neutralizing antibodies; protein design