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Immunogenicity of HIV-1-Based Virus-Like Particles with Increased Incorporation and Stability of Membrane-Bound Env. Vaccines (Basel) 2021; 9:vaccines9030239. [PMID: 33801906 PMCID: PMC8002006 DOI: 10.3390/vaccines9030239] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 03/04/2021] [Accepted: 03/05/2021] [Indexed: 01/04/2023] Open
Abstract
An optimal prophylactic vaccine to prevent human immunodeficiency virus (HIV-1) transmission should elicit protective antibody responses against the HIV-1 envelope glycoprotein (Env). Replication-incompetent HIV-1 virus-like particles (VLPs) offer the opportunity to present virion-associated Env with a native-like structure during vaccination that closely resembles that encountered on infectious virus. Here, we optimized the incorporation of Env into previously designed mature-form VLPs (mVLPs) and assessed their immunogenicity in mice. The incorporation of Env into mVLPs was increased by replacing the Env transmembrane and cytoplasmic tail domains with those of influenza haemagglutinin (HA-TMCT). Furthermore, Env was stabilized on the VLP surface by introducing an interchain disulfide and proline substitution (SOSIP) mutations typically employed to stabilize soluble Env trimers. The resulting mVLPs efficiently presented neutralizing antibody epitopes while minimizing exposure of non-neutralizing antibody sites. Vaccination of mice with mVLPs elicited a broader range of Env-specific antibody isotypes than Env presented on immature VLPs or extracellular vesicles. The mVLPs bearing HA-TMCT-modified Env consistently induced anti-Env antibody responses that mediated modest neutralization activity. These mVLPs are potentially useful immunogens for eliciting neutralizing antibody responses that target native Env epitopes on infectious HIV-1 virions.
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2
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Li SW, Wright M, Healey JF, Hutchinson JM, O’Rourke S, Mesa KA, Lollar P, Berman PW. Gene editing in CHO cells to prevent proteolysis and enhance glycosylation: Production of HIV envelope proteins as vaccine immunogens. PLoS One 2020; 15:e0233866. [PMID: 32470085 PMCID: PMC7259603 DOI: 10.1371/journal.pone.0233866] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 05/13/2020] [Indexed: 01/12/2023] Open
Abstract
Several candidate HIV subunit vaccines based on recombinant envelope (Env) glycoproteins have been advanced into human clinical trials. To facilitate biopharmaceutical production, it is necessary to produce these in CHO (Chinese Hamster Ovary) cells, the cellular substrate used for the manufacturing of most recombinant protein therapeutics. However, previous studies have shown that when recombinant Env proteins from clade B viruses, the major subtype represented in North America, Europe, and other parts of the world, are expressed in CHO cells, they are proteolyzed and lack important glycan-dependent epitopes present on virions. Previously, we identified C1s, a serine protease in the complement pathway, as the endogenous CHO protease responsible for the cleavage of clade B laboratory isolates of -recombinant gp120s (rgp120s) expressed in stable CHO-S cell lines. In this paper, we describe the development of two novel CHOK1 cell lines with the C1s gene inactivated by gene editing, that are suitable for the production of any protein susceptible to C1s proteolysis. One cell line, C1s-/- CHOK1 2.E7, contains a deletion in the C1s gene. The other cell line, C1s-/- MGAT1- CHOK1 1.A1, contains a deletion in both the C1s gene and the MGAT1 gene, which limits glycosylation to mannose-5 or earlier intermediates in the N-linked glycosylation pathway. In addition, we compare the substrate specificity of C1s with thrombin on the cleavage of both rgp120 and human Factor VIII, two recombinant proteins known to undergo unintended proteolysis (clipping) when expressed in CHO cells. Finally, we demonstrate the utility and practicality of the C1s-/- MGAT1- CHOK1 1.A1 cell line for the expression of clinical isolates of clade B Envs from rare individuals that possess broadly neutralizing antibodies and are able to control virus replication without anti-retroviral drugs (elite neutralizer/controller phenotypes). The Envs represent unique HIV vaccine immunogens suitable for further immunogenicity and efficacy studies.
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Affiliation(s)
- Sophia W. Li
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, California, United States of America
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Meredith Wright
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - John F. Healey
- Department of Pediatrics, Emory University, Atlanta, Georgia, United States of America
| | - Jennie M. Hutchinson
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Sara O’Rourke
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Kathryn A. Mesa
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Pete Lollar
- Department of Pediatrics, Emory University, Atlanta, Georgia, United States of America
| | - Phillip W. Berman
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, United States of America
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3
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Li SW, Yu B, Byrne G, Wright M, O'Rourke S, Mesa K, Berman PW. Identification and CRISPR/Cas9 Inactivation of the C1s Protease Responsible for Proteolysis of Recombinant Proteins Produced in CHO Cells. Biotechnol Bioeng 2019; 116:2130-2145. [PMID: 31087560 DOI: 10.1002/bit.27016] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 04/12/2019] [Accepted: 05/09/2019] [Indexed: 12/14/2022]
Abstract
Proteolysis associated with recombinant protein expression in Chinese Hamster Ovary (CHO) cells has hindered the development of biologics including HIV vaccines. When expressed in CHO cells, the recombinant HIV envelope protein, gp120, undergoes proteolytic clipping by a serine protease at a key epitope recognized by neutralizing antibodies. The problem is particularly acute for envelope proteins from clade B viruses that represent the major genetic subtype circulating in much of the developed world, including the US and Europe. In this paper, we have identified complement Component 1's (C1s), a serine protease from the complement cascade, as the protease responsible for the proteolysis of gp120 in CHO cells. CRISPR/Cas9 knockout of the C1s protease in a CHO cell line was shown to eliminate the proteolytic activity against the recombinantly expressed gp120. In addition, the C1s-/- MGAT1- CHO cell line, with the C1s protease and the MGAT1 glycosyltransferase knocked out, enabled the production of unclipped gp120 from a clade B isolate (BaL-rgp120) and enriched for mannose-5 glycans on gp120 that are required for the binding of multiple broadly neutralizing monoclonal antibodies (bN-mAbs). The availability of this technology will allow for the scale-up and testing of multiple vaccine concepts in regions of the world where clade B viruses are in circulation. Furthermore, the proteolysis issues caused by the C1s protease suggests a broader need for a C1s-deficient CHO cell line to express other recombinant proteins that are susceptible to serine protease activity in CHO cells. Similarly, the workflow described here to identify and knockout C1s in a CHO cell line can be applied to remedy the proteolysis of biologics by other CHO proteases.
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Affiliation(s)
- Sophia W Li
- Department of Chemistry, University of California Santa Cruz, California
| | - Bin Yu
- Department of Biomolecular Engineering, University of California Santa Cruz, California
| | - Gabriel Byrne
- Department of Biomolecular Engineering, University of California Santa Cruz, California
| | - Meredith Wright
- Department of Biomolecular Engineering, University of California Santa Cruz, California
| | - Sara O'Rourke
- Department of Biomolecular Engineering, University of California Santa Cruz, California
| | - Kathryn Mesa
- Department of Biomolecular Engineering, University of California Santa Cruz, California
| | - Phillip W Berman
- Department of Biomolecular Engineering, University of California Santa Cruz, California
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4
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Wen Y, Trinh HV, Linton CE, Tani C, Norais N, Martinez-Guzman D, Ramesh P, Sun Y, Situ F, Karaca-Griffin S, Hamlin C, Onkar S, Tian S, Hilt S, Malyala P, Lodaya R, Li N, Otten G, Palladino G, Friedrich K, Aggarwal Y, LaBranche C, Duffy R, Shen X, Tomaras GD, Montefiori DC, Fulp W, Gottardo R, Burke B, Ulmer JB, Zolla-Pazner S, Liao HX, Haynes BF, Michael NL, Kim JH, Rao M, O’Connell RJ, Carfi A, Barnett SW. Generation and characterization of a bivalent protein boost for future clinical trials: HIV-1 subtypes CR01_AE and B gp120 antigens with a potent adjuvant. PLoS One 2018; 13:e0194266. [PMID: 29698406 PMCID: PMC5919662 DOI: 10.1371/journal.pone.0194266] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 02/28/2018] [Indexed: 01/23/2023] Open
Abstract
The RV144 Phase III clinical trial with ALVAC-HIV prime and AIDSVAX B/E subtypes CRF01_AE (A244) and B (MN) gp120 boost vaccine regime in Thailand provided a foundation for the future development of improved vaccine strategies that may afford protection against the human immunodeficiency virus type 1 (HIV-1). Results from this trial showed that immune responses directed against specific regions V1V2 of the viral envelope (Env) glycoprotein gp120 of HIV-1, were inversely correlated to the risk of HIV-1 infection. Due to the low production of gp120 proteins in CHO cells (2–20 mg/L), cleavage sites in V1V2 loops (A244) and V3 loop (MN) causing heterogeneous antigen products, it was an urgent need to generate CHO cells harboring A244 gp120 with high production yields and an additional, homogenous and uncleaved subtype B gp120 protein to replace MN used in RV144 for the future clinical trials. Here we describe the generation of Chinese Hamster Ovary (CHO) cell lines stably expressing vaccine HIV-1 Env antigens for these purposes: one expressing an HIV-1 subtype CRF01_AE A244 Env gp120 protein (A244.AE) and one expressing an HIV-1 subtype B 6240 Env gp120 protein (6240.B) suitable for possible future manufacturing of Phase I clinical trial materials with cell culture expression levels of over 100 mg/L. The antigenic profiles of the molecules were elucidated by comprehensive approaches including analysis with a panel of well-characterized monoclonal antibodies recognizing critical epitopes using Biacore and ELISA, and glycosylation analysis by mass spectrometry, which confirmed previously identified glycosylation sites and revealed unknown sites of O-linked and N-linked glycosylations at non-consensus motifs. Overall, the vaccines given with MF59 adjuvant induced higher and more rapid antibody (Ab) responses as well as higher Ab avidity than groups given with aluminum hydroxide. Also, bivalent proteins (A244.AE and 6240.B) formulated with MF59 elicited distinct V2-specific Abs to the epitope previously shown to correlate with decreased risk of HIV-1 infection in the RV144 trial. All together, these results provide critical information allowing the consideration of these candidate gp120 proteins for future clinical evaluations in combination with a potent adjuvant.
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Affiliation(s)
- Yingxia Wen
- Novartis Vaccines and Diagnostics, Cambridge, MA, United States of America
| | - Hung V. Trinh
- US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
- Henry Jackson Foundation for the Advancement of Military Medicine, Silver Spring, MD, United States of America
| | | | | | | | | | - Priyanka Ramesh
- Novartis Vaccines and Diagnostics, Cambridge, MA, United States of America
| | - Yide Sun
- Novartis Vaccines and Diagnostics, Cambridge, MA, United States of America
| | - Frank Situ
- Novartis Vaccines and Diagnostics, Cambridge, MA, United States of America
| | | | - Christopher Hamlin
- US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
- Henry Jackson Foundation for the Advancement of Military Medicine, Silver Spring, MD, United States of America
| | - Sayali Onkar
- US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
- Henry Jackson Foundation for the Advancement of Military Medicine, Silver Spring, MD, United States of America
| | - Sai Tian
- GSK, Rockville, MD, United States of America
| | - Susan Hilt
- Novartis Vaccines and Diagnostics, Cambridge, MA, United States of America
| | - Padma Malyala
- Novartis Vaccines and Diagnostics, Cambridge, MA, United States of America
| | - Rushit Lodaya
- Novartis Vaccines and Diagnostics, Cambridge, MA, United States of America
| | - Ning Li
- GSK, Rockville, MD, United States of America
| | - Gillis Otten
- Novartis Vaccines and Diagnostics, Cambridge, MA, United States of America
| | - Giuseppe Palladino
- Novartis Vaccines and Diagnostics, Cambridge, MA, United States of America
| | | | - Yukti Aggarwal
- Novartis Vaccines and Diagnostics, Cambridge, MA, United States of America
| | - Celia LaBranche
- Department of Surgery, Duke University Medical Center, Durham, NC, United States of America
| | - Ryan Duffy
- Duke Human Vaccine Institute, Duke University, Durham, NC, United States of America
| | - Xiaoying Shen
- Duke Human Vaccine Institute, Duke University, Durham, NC, United States of America
| | - Georgia D. Tomaras
- Department of Surgery, Duke University Medical Center, Durham, NC, United States of America
- Duke Human Vaccine Institute, Duke University, Durham, NC, United States of America
| | - David C. Montefiori
- Department of Surgery, Duke University Medical Center, Durham, NC, United States of America
| | - William Fulp
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States of America
| | - Raphael Gottardo
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States of America
| | - Brian Burke
- Novartis Vaccines and Diagnostics, Cambridge, MA, United States of America
| | - Jeffrey B. Ulmer
- GSK, Rockville, MD, United States of America
- * E-mail: (SWB); (AC); (JBU)
| | - Susan Zolla-Pazner
- Icahn School of Medicine at Mount Sinai, New York, NY, United States of America
| | - Hua-Xin Liao
- Duke Human Vaccine Institute, Duke University, Durham, NC, United States of America
- Biomedine Institute, College of Life Science, Jinan University, Guangzhou, China
| | - Barton F. Haynes
- Duke Human Vaccine Institute, Duke University, Durham, NC, United States of America
| | - Nelson L. Michael
- US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
| | - Jerome H. Kim
- US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
| | - Mangala Rao
- US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
| | - Robert J. O’Connell
- US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
- Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Andrea Carfi
- GSK, Rockville, MD, United States of America
- * E-mail: (SWB); (AC); (JBU)
| | - Susan W. Barnett
- GSK, Rockville, MD, United States of America
- * E-mail: (SWB); (AC); (JBU)
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5
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Abstract
We describe the development and potential use of various designs of recombinant HIV-1 envelope glycoprotein trimers that mimic the structure of the virion-associated spike, which is the target for neutralizing antibodies. The goal of trimer development programs is to induce broadly neutralizing antibodies with the potential to intervene against multiple circulating HIV-1 strains. Among the topics we address are the designs of various constructs; how native-like trimers can be produced and purified; the properties of such trimers in vitro and their immunogenicity in various animals; and the immunization strategies that may lead to the eventual elicitation of broadly neutralizing antibodies. In summary, native-like trimers are a now a platform for structure- and immunology-based design improvements that could eventually yield immunogens of practical value for solving the long-standing HIV-1 vaccine problem.
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Affiliation(s)
- Rogier W. Sanders
- Department of Microbiology and ImmunologyWeill Medical College of Cornell UniversityNew YorkNYUSA
- Department of Medical MicrobiologyAcademic Medical CenterUniversity of AmsterdamAmsterdamThe Netherlands
| | - John P. Moore
- Department of Microbiology and ImmunologyWeill Medical College of Cornell UniversityNew YorkNYUSA
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6
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Immunogenicity of a Prefusion HIV-1 Envelope Trimer in Complex with a Quaternary-Structure-Specific Antibody. J Virol 2015; 90:2740-55. [PMID: 26719262 DOI: 10.1128/jvi.02380-15] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 12/10/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The HIV-1 envelope trimer (Env) is the target of broadly neutralizing antibodies and is being explored as a vaccine candidate to elicit protective antibodies. One of the most promising antigenic and structural mimics of HIV-1 Env is the SOSIP.664-stabilized soluble trimer from the clade A strain BG505, which is preferentially recognized by broadly neutralizing antibodies. Trimer immunization elicits high-titer neutralization of the autologous tier 2 BG505 strain; however, breadth is limited, and substantial interest has focused on understanding and improving trimer immunogenicity. We sought to improve the antigenic specificity of BG505 SOSIP.664 by reducing recognition of the variable loop 3 (V3) region, which elicits only weakly neutralizing antibodies. To stabilize the trimer in its prefusion closed conformation, we complexed trimeric BG505 SOSIP.664 with the antigen-binding fragment (Fab) of PGT145, a broadly neutralizing quaternary-structure-specific antibody. Compared to the ligand-free trimer, the PGT145 Fab-BG505 SOSIP.664 complex displayed increased melting temperature stability and reduced V3 recognition. In guinea pigs, immunization with the PGT145 Fab-BG505 SOSIP.664 complex elicited ∼100-fold lower V3-directed binding and neutralization titers than those obtained with ligand-free BG505 SOSIP.664. Both complexed and ligand-free BG505 SOSIP.664 elicited comparable neutralization of the autologous BG505 virus, and in both cases, BG505 neutralization mapped to the outer domain of gp120 for some guinea pigs. Our results indicate that it is possible to reduce immune recognition of the V3 region of the trimer while maintaining the antigenic profile needed to induce autologous neutralizing antibodies. These data suggest that appropriate modifications of trimer immunogens could further focus the immune response on key neutralization epitopes. IMPORTANCE HIV-1 Env trimers have been proposed as preferred HIV-1 vaccine immunogens. One version, BG505 SOSIP.664, a soluble stabilized trimer, was recently shown to elicit high-titer autologous neutralizing antibodies (NAbs) in rabbits. Here we compared two immunogens: the ligand-free BG505 SOSIP.664 trimer and the same trimer bound to the antigen-binding fragment (Fab) of the PGT145 antibody, a broadly neutralizing antibody which recognizes the trimer at its membrane-distal apex. We hypothesized that the Fab-bound complex would stabilize BG505 SOSIP.664 in its prefusion closed conformation and limit reactivity to weakly neutralizing antibodies targeting the variable loop 3 (V3) region. In guinea pigs, the Fab-complexed trimer induced 100-fold lower responses to the V3 region, while both ligand-free and Fab-complexed trimers elicited similar levels of autologous NAbs. Our findings demonstrate the potential to reduce "off-target" immunogenicity while maintaining the capacity to generate autologous NAbs.
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7
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Rimbon J, Sánchez-Kopper A, Wahl A, Takors R. Monitoring intracellular protein degradation in antibody-producing Chinese hamster ovary cells. Eng Life Sci 2015. [DOI: 10.1002/elsc.201400103] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Jérémy Rimbon
- Institute of Biochemical Engineering; University of Stuttgart; Stuttgart Germany
| | | | - Andreas Wahl
- Institute of Biochemical Engineering; University of Stuttgart; Stuttgart Germany
| | - Ralf Takors
- Institute of Biochemical Engineering; University of Stuttgart; Stuttgart Germany
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8
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Nakane S, Iwamoto A, Matsuda Z. The V4 and V5 Variable Loops of HIV-1 Envelope Glycoprotein Are Tolerant to Insertion of Green Fluorescent Protein and Are Useful Targets for Labeling. J Biol Chem 2015; 290:15279-91. [PMID: 25911103 DOI: 10.1074/jbc.m114.628610] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Indexed: 12/19/2022] Open
Abstract
The mature human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env) comprises the non-covalently associated gp120 and gp41 subunits generated from the gp160 precursor. Recent structural analyses have provided quaternary structural models for gp120/gp41 trimers, including the variable loops (V1-V5) of gp120. In these models, the V3 loop is located under V1/V2 at the apical center of the Env trimer, and the V4 and V5 loops project outward from the trimeric protomers. In addition, the V4 and V5 loops are predicted to have less movement upon receptor binding during membrane fusion events. We performed insertional mutagenesis using a GFP variant, GFPOPT, placed into the variable loops of HXB2 gp120. This allowed us to evaluate the current structural models and to simultaneously generate a GFP-tagged HIV-1 Env, which was useful for image analyses. All GFP-inserted mutants showed similar levels of whole-cell expression, although certain mutants, particularly V3 mutants, showed lower levels of cell surface expression. Functional evaluation of their fusogenicities in cell-cell and virus-like particle-cell fusion assays revealed that V3 was the most sensitive to the insertion and that the V1/V2 loops were less sensitive than V3. The V4 and V5 loops were the most tolerant to insertion, and certain tag proteins other than GFPOPT could also be inserted without functional consequences. Our results support the current structural models and provide a GFPOPT-tagged Env construct for imaging studies.
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Affiliation(s)
- Shuhei Nakane
- From the Research Center for Asian Infectious Diseases and China-Japan Joint Laboratory of Structural Virology and Immunology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Aikichi Iwamoto
- From the Research Center for Asian Infectious Diseases and Advanced Clinical Research Center, Division of Infectious Diseases, Institute of Medical Science The University of Tokyo, Tokyo 108-8639, Japan and
| | - Zene Matsuda
- From the Research Center for Asian Infectious Diseases and China-Japan Joint Laboratory of Structural Virology and Immunology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
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9
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Abstract
UNLABELLED Recombinant trimeric mimics of the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env) spike should expose as many epitopes as possible for broadly neutralizing antibodies (bNAbs) but few, if any, for nonneutralizing antibodies (non-NAbs). Soluble, cleaved SOSIP.664 gp140 trimers based on the subtype A strain BG505 approach this ideal and are therefore plausible vaccine candidates. Here, we report on the production and in vitro properties of a new SOSIP.664 trimer derived from a subtype B env gene, B41, including how to make this protein in low-serum media without proteolytic damage (clipping) to the V3 region. We also show that nonclipped trimers can be purified successfully via a positive-selection affinity column using the bNAb PGT145, which recognizes a quaternary structure-dependent epitope at the trimer apex. Negative-stain electron microscopy imaging shows that the purified, nonclipped, native-like B41 SOSIP.664 trimers contain two subpopulations, which we propose represent an equilibrium between the fully closed and a more open conformation. The latter is different from the fully open, CD4 receptor-bound conformation and may represent an intermediate state of the trimer. This new subtype B trimer adds to the repertoire of native-like Env proteins that are suitable for immunogenicity and structural studies. IMPORTANCE The cleaved, trimeric envelope protein complex is the only neutralizing antibody target on the HIV-1 surface. Many vaccine strategies are based on inducing neutralizing antibodies. For HIV-1, one approach involves using recombinant, soluble protein mimics of the native trimer. At present, the only reliable way to make native-like, soluble trimers in practical amounts is via the introduction of specific sequence changes that confer stability on the cleaved form of Env. The resulting proteins are known as SOSIP.664 gp140 trimers, and the current paradigm is based on the BG505 subtype A env gene. Here, we describe the production and characterization of a SOSIP.664 protein derived from a subtype B gene (B41), together with a simple, one-step method to purify native-like trimers by affinity chromatography with a trimer-specific bNAb, PGT145. The resulting trimers will be useful for structural and immunogenicity experiments aimed at devising ways to make an effective HIV-1 vaccine.
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10
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Purification of recombinant vaccinia virus-expressed monomeric HIV-1 gp120 to apparent homogeneity. Protein Expr Purif 2013; 90:34-9. [PMID: 23665667 DOI: 10.1016/j.pep.2013.04.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 04/27/2013] [Accepted: 04/29/2013] [Indexed: 11/22/2022]
Abstract
Vaccinia virus (VV) has been used to express a variety of heterologous proteins, including HIV envelope (Env) glycoproteins. The Env protein is synthesized as a precursor molecule, gp160, which is cleaved into the surface antigen gp120 and the transmembrane protein gp41. Even though production of gp160 by the VV expression system has been described, its use for gp120 production is not well documented. Here we report a new procedure for the purification of gp120 from serum-containing culture supernatant of VV-infected cells. The gp120 protein was enriched to a purity better than 60% on a snowdrop (Galanthus nivalis) lectin affinity column in the presence of 0.25% zwitterionic detergent Empigen BB. After additional DEAE anion exchange and Superdex size exclusion chromatography steps, the gp120 monomer was purified free of contamination as determined by SDS-PAGE. The retention of structural integrity was confirmed by determining the affinity constant of purified gp120s to soluble CD4 and a monoclonal antibody IgG1b12, using surface plasmon resonance analysis. The purification procedure is robust and reproducible, and may find general use for glycoprotein purifications from sources where the presence of serum is desirable.
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11
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Narayan KM, Agrawal N, Du SX, Muranaka JE, Bauer K, Leaman DP, Phung P, Limoli K, Chen H, Boenig RI, Wrin T, Zwick MB, Whalen RG. Prime-boost immunization of rabbits with HIV-1 gp120 elicits potent neutralization activity against a primary viral isolate. PLoS One 2013; 8:e52732. [PMID: 23326351 PMCID: PMC3541383 DOI: 10.1371/journal.pone.0052732] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Accepted: 11/20/2012] [Indexed: 11/19/2022] Open
Abstract
Development of a vaccine for HIV-1 requires a detailed understanding of the neutralizing antibody responses that can be experimentally elicited to difficult-to-neutralize primary isolates. Rabbits were immunized with the gp120 subunit of HIV-1 JR-CSF envelope (Env) using a DNA-prime protein-boost regimen. We analyzed five sera that showed potent autologous neutralizing activity (IC50s at ∼10(3) to 10(4) serum dilution) against pseudoviruses containing Env from the primary isolate JR-CSF but not from the related isolate JR-FL. Pseudoviruses were created by exchanging each variable and constant domain of JR-CSF gp120 with that of JR-FL or with mutations in putative N-glycosylation sites. The sera contained different neutralizing activities dependent on C3 and V5, C3 and V4, or V4 regions located on the glycan-rich outer domain of gp120. All sera showed enhanced neutralizing activity toward an Env variant that lacked a glycosylation site in V4. The JR-CSF gp120 epitopes recognized by the sera are generally distinct from those of several well characterized mAbs (targeting conserved sites on Env) or other type-specific responses (targeting V1, V2, or V3 variable regions). The activity of one serum requires specific glycans that are also important for 2G12 neutralization and this serum blocked the binding of 2G12 to gp120. Our findings show that different fine specificities can achieve potent neutralization of HIV-1, yet this strong activity does not result in improved breadth.
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Affiliation(s)
- Kristin M. Narayan
- Department of Infectious Diseases, Maxygen, Inc., Redwood City, California, United States of America
- Altravax, Inc., Sunnyvale, California, United States of America
| | - Nitish Agrawal
- Department of Immunology and Microbial Sciences, The Scripps Research Institute, La Jolla, California, United States of America
| | - Sean X. Du
- Department of Infectious Diseases, Maxygen, Inc., Redwood City, California, United States of America
- Altravax, Inc., Sunnyvale, California, United States of America
| | - Janelle E. Muranaka
- Department of Infectious Diseases, Maxygen, Inc., Redwood City, California, United States of America
- Altravax, Inc., Sunnyvale, California, United States of America
| | - Katherine Bauer
- Department of Immunology and Microbial Sciences, The Scripps Research Institute, La Jolla, California, United States of America
| | - Daniel P. Leaman
- Department of Immunology and Microbial Sciences, The Scripps Research Institute, La Jolla, California, United States of America
| | - Pham Phung
- Monogram Biosciences, Inc., San Francisco, California, United States of America
| | - Kay Limoli
- Monogram Biosciences, Inc., San Francisco, California, United States of America
| | - Helen Chen
- Department of Infectious Diseases, Maxygen, Inc., Redwood City, California, United States of America
| | - Rebecca I. Boenig
- Department of Infectious Diseases, Maxygen, Inc., Redwood City, California, United States of America
- Altravax, Inc., Sunnyvale, California, United States of America
| | - Terri Wrin
- Monogram Biosciences, Inc., San Francisco, California, United States of America
| | - Michael B. Zwick
- Department of Immunology and Microbial Sciences, The Scripps Research Institute, La Jolla, California, United States of America
| | - Robert G. Whalen
- Department of Infectious Diseases, Maxygen, Inc., Redwood City, California, United States of America
- Altravax, Inc., Sunnyvale, California, United States of America
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Du SX, Xu L, Zhang W, Tang S, Boenig RI, Chen H, Mariano EB, Zwick MB, Parren PWHI, Burton DR, Wrin T, Petropoulos CJ, Ballantyne JA, Chambers M, Whalen RG. A directed molecular evolution approach to improved immunogenicity of the HIV-1 envelope glycoprotein. PLoS One 2011; 6:e20927. [PMID: 21738594 PMCID: PMC3126809 DOI: 10.1371/journal.pone.0020927] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Accepted: 05/12/2011] [Indexed: 12/14/2022] Open
Abstract
A prophylactic vaccine is needed to slow the spread of HIV-1 infection. Optimization of the wild-type envelope glycoproteins to create immunogens that can elicit effective neutralizing antibodies is a high priority. Starting with ten genes encoding subtype B HIV-1 gp120 envelope glycoproteins and using in vitro homologous DNA recombination, we created chimeric gp120 variants that were screened for their ability to bind neutralizing monoclonal antibodies. Hundreds of variants were identified with novel antigenic phenotypes that exhibit considerable sequence diversity. Immunization of rabbits with these gp120 variants demonstrated that the majority can induce neutralizing antibodies to HIV-1. One novel variant, called ST-008, induced significantly improved neutralizing antibody responses when assayed against a large panel of primary HIV-1 isolates. Further study of various deletion constructs of ST-008 showed that the enhanced immunogenicity results from a combination of effective DNA priming, an enhanced V3-based response, and an improved response to the constant backbone sequences.
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Affiliation(s)
- Sean X. Du
- Department of Infectious Diseases, Maxygen, Inc., Redwood City, California, United States of America
| | - Li Xu
- Department of Infectious Diseases, Maxygen, Inc., Redwood City, California, United States of America
| | - Wenge Zhang
- Department of Infectious Diseases, Maxygen, Inc., Redwood City, California, United States of America
| | - Susan Tang
- Department of Infectious Diseases, Maxygen, Inc., Redwood City, California, United States of America
| | - Rebecca I. Boenig
- Department of Infectious Diseases, Maxygen, Inc., Redwood City, California, United States of America
| | - Helen Chen
- Department of Infectious Diseases, Maxygen, Inc., Redwood City, California, United States of America
| | - Ellaine B. Mariano
- Department of Infectious Diseases, Maxygen, Inc., Redwood City, California, United States of America
| | - Michael B. Zwick
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California, United States of America
| | - Paul W. H. I. Parren
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California, United States of America
| | - Dennis R. Burton
- Department of Immunology and Microbial Science, and IAVI Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, California, United States of America
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard, Boston, Massachusetts, United States of America
| | - Terri Wrin
- Monogram Biosciences, San Francisco, California, United States of America
| | | | | | | | - Robert G. Whalen
- Department of Infectious Diseases, Maxygen, Inc., Redwood City, California, United States of America
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13
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Du SX, Idiart RJ, Mariano EB, Chen H, Jiang P, Xu L, Ostrow KM, Wrin T, Phung P, Binley JM, Petropoulos CJ, Ballantyne JA, Whalen RG. Effect of trimerization motifs on quaternary structure, antigenicity, and immunogenicity of a noncleavable HIV-1 gp140 envelope glycoprotein. Virology 2009; 395:33-44. [PMID: 19815247 DOI: 10.1016/j.virol.2009.07.042] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2009] [Revised: 06/01/2009] [Accepted: 07/31/2009] [Indexed: 10/20/2022]
Abstract
The external domains of the HIV-1 envelope glycoprotein (gp120 and the gp41 ectodomain, collectively known as gp140) contain all known viral neutralization epitopes. Various strategies have been used to create soluble trimers of the envelope to mimic the structure of the native viral protein, including mutation of the gp120-gp41 cleavage site, introduction of disulfide bonds, and fusion to heterologous trimerization motifs. We compared the effects on quaternary structure, antigenicity, and immunogenicity of three such motifs: T4 fibritin, a GCN4 variant, and the Escherichia coli aspartate transcarbamoylase catalytic subunit. Fusion of each motif to the C-terminus of a noncleavable JRCSF gp140(-) envelope protein led to enhanced trimerization but had limited effects on the antigenic profile and CD4-binding ability of the trimers. Immunization of rabbits provided no evidence that the trimerized gp140(-) constructs induced significantly improved neutralizing antibodies to several HIV-1 pseudoviruses, compared to gp140 lacking a trimerization motif. However, modest differences in both binding specificity and neutralizing antibody responses were observed among the various immunogens.
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Affiliation(s)
- Sean X Du
- Maxygen, Inc., 515 Galveston Drive, Redwood City, CA 94063, USA
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