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Heydarchi B, Center RJ, Bebbington J, Cuthbertson J, Gonelli C, Khoury G, Mackenzie C, Lichtfuss M, Rawlin G, Muller B, Purcell D. Trimeric gp120-specific bovine monoclonal antibodies require cysteine and aromatic residues in CDRH3 for high affinity binding to HIV Env. MAbs 2016; 9:550-566. [PMID: 27996375 PMCID: PMC5384801 DOI: 10.1080/19420862.2016.1270491] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/29/2022] Open
Abstract
We isolated HIV-1 Envelope (Env)-specific memory B cells from a cow that had developed high titer polyclonal immunoglobulin G (IgG) with broad neutralizing activity after a long duration vaccination with HIV-1AD8 Env gp140 trimers. We cloned the bovine IgG matched heavy (H) and light (L) chain variable (V) genes from these memory B cells and constructed IgG monoclonal antibodies (mAbs) with either a human constant (C)-region/bovine V-region chimeric or fully bovine C and V regions. Among 42 selected Ig+ memory B cells, two mAbs (6A and 8C) showed high affinity binding to gp140 Env. Characterization of both the fully bovine and human chimeric isoforms of these two mAbs revealed them as highly type-specific and capable of binding only to soluble AD8 uncleaved gp140 trimers and covalently stabilized AD8 SOSIP gp140 cleaved trimers, but not monomeric gp120. Genomic sequence analysis of the V genes showed the third heavy complementarity-determining region (CDRH3) of 6A mAb was 21 amino acids in length while 8C CDRH3 was 14 amino acids long. The entire V heavy (VH) region was 27% and 25% diverged for 6A and 8C, respectively, from the best matched germline V genes available, and the CDRH3 regions of 6A and 8C were 47.62% and 78.57% somatically mutated, respectively, suggesting a high level of somatic hypermutation compared with CDRH3 of other species. Alanine mutagenesis of the VH genes of 6A and 8C, showed that CDRH3 cysteine and tryptophan amino acids were crucial for antigen binding. Therefore, these bovine vaccine-induced anti-HIV antibodies shared some of the notable structural features of elite human broadly neutralizing antibodies, such as CDRH3 size and somatic mutation during affinity-maturation. However, while the 6A and 8C mAbs inhibited soluble CD4 binding to gp140 Env, they did not recapitulate the neutralizing activity of the polyclonal antibodies against HIV infection.
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Affiliation(s)
- Behnaz Heydarchi
- a Department of Microbiology and Immunology , The University of Melbourne at The Peter Doherty Institute for Infection & Immunity , Melbourne , VIC , Australia
| | - Rob J Center
- a Department of Microbiology and Immunology , The University of Melbourne at The Peter Doherty Institute for Infection & Immunity , Melbourne , VIC , Australia
| | - Jonathan Bebbington
- a Department of Microbiology and Immunology , The University of Melbourne at The Peter Doherty Institute for Infection & Immunity , Melbourne , VIC , Australia
| | - Jack Cuthbertson
- a Department of Microbiology and Immunology , The University of Melbourne at The Peter Doherty Institute for Infection & Immunity , Melbourne , VIC , Australia
| | - Christopher Gonelli
- a Department of Microbiology and Immunology , The University of Melbourne at The Peter Doherty Institute for Infection & Immunity , Melbourne , VIC , Australia
| | - Georges Khoury
- a Department of Microbiology and Immunology , The University of Melbourne at The Peter Doherty Institute for Infection & Immunity , Melbourne , VIC , Australia
| | - Charlene Mackenzie
- a Department of Microbiology and Immunology , The University of Melbourne at The Peter Doherty Institute for Infection & Immunity , Melbourne , VIC , Australia
| | - Marit Lichtfuss
- a Department of Microbiology and Immunology , The University of Melbourne at The Peter Doherty Institute for Infection & Immunity , Melbourne , VIC , Australia
| | - Grant Rawlin
- a Department of Microbiology and Immunology , The University of Melbourne at The Peter Doherty Institute for Infection & Immunity , Melbourne , VIC , Australia
| | - Brian Muller
- a Department of Microbiology and Immunology , The University of Melbourne at The Peter Doherty Institute for Infection & Immunity , Melbourne , VIC , Australia
| | - Damian Purcell
- a Department of Microbiology and Immunology , The University of Melbourne at The Peter Doherty Institute for Infection & Immunity , Melbourne , VIC , Australia
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Heydarchi B, Center RJ, Gonelli C, Muller B, Mackenzie C, Khoury G, Lichtfuss M, Rawlin G, Purcell DFJ. Repeated Vaccination of Cows with HIV Env gp140 during Subsequent Pregnancies Elicits and Sustains an Enduring Strong Env-Binding and Neutralising Antibody Response. PLoS One 2016; 11:e0157353. [PMID: 27300145 PMCID: PMC4907510 DOI: 10.1371/journal.pone.0157353] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 05/28/2016] [Indexed: 11/18/2022] Open
Abstract
An important feature of a potential vaccine against HIV is the production of broadly neutralising antibodies (BrNAbs) capable of potentially blocking infectivity of a diverse array of HIV strains. BrNAbs naturally arise in some HIV infected individuals after several years of infection and their serum IgG can neutralise various HIV strains across different subtypes. We previously showed that vaccination of cows with HIV gp140 AD8 trimers resulted in a high titre of serum IgG against HIV envelope (Env) that had strong BrNAb activity. These polyclonal BrNAbs concentrated into the colostrum during the late stage of pregnancy and can be harvested in vast quantities immediately after calving. In this study, we investigated the effect of prolonged HIV gp140 vaccination on bovine colostrum IgG HIV Env-binding and BrNAb activity over subsequent pregnancies. Repeated immunisation led to a maintained high titre of HIV Env specific IgG in the colostrum batches, but this did not increase through repeated cycles. Colostrum IgG from all batches also strongly competed with sCD4 binding to gp140 Env trimer and with human-derived monoclonal VRC01 and b12 BrNAbs that bind the CD4 binding site (CD4bs). Furthermore, competition neutralisation assays using RSC3 Env gp120 protein core and a derivative CD4bs mutant, RSC3 Δ371I/P363N, showed that CD4bs neutralising antibodies contribute to the neutralising activity of all batches of purified bovine colostrum IgG. This result indicates that the high IgG titre/avidity of anti-CD4bs antibodies with BrNAb activity was achieved during the first year of vaccination and was sustained throughout the years of repeated vaccinations in the cow tested. Although IgG of subsequent colostrum batches may have a higher avidity towards the CD4bs, the overall breadth in neutralisation was not enhanced. This implies that the boosting vaccinations over 4 years elicited a polyclonal antibody response that maintained the proportion of both neutralising and non-neutralising CD4bs antibodies.
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Affiliation(s)
- Behnaz Heydarchi
- Department of Microbiology and Immunology, at The Peter Doherty Institute for Infection & Immunity, The University of Melbourne, Melbourne, Victoria, Australia
| | - Rob J. Center
- Department of Microbiology and Immunology, at The Peter Doherty Institute for Infection & Immunity, The University of Melbourne, Melbourne, Victoria, Australia
| | - Christopher Gonelli
- Department of Microbiology and Immunology, at The Peter Doherty Institute for Infection & Immunity, The University of Melbourne, Melbourne, Victoria, Australia
| | - Brian Muller
- Department of Microbiology and Immunology, at The Peter Doherty Institute for Infection & Immunity, The University of Melbourne, Melbourne, Victoria, Australia
| | - Charlene Mackenzie
- Department of Microbiology and Immunology, at The Peter Doherty Institute for Infection & Immunity, The University of Melbourne, Melbourne, Victoria, Australia
| | - Georges Khoury
- Department of Microbiology and Immunology, at The Peter Doherty Institute for Infection & Immunity, The University of Melbourne, Melbourne, Victoria, Australia
| | - Marit Lichtfuss
- Department of Microbiology and Immunology, at The Peter Doherty Institute for Infection & Immunity, The University of Melbourne, Melbourne, Victoria, Australia
| | - Grant Rawlin
- Department of Microbiology and Immunology, at The Peter Doherty Institute for Infection & Immunity, The University of Melbourne, Melbourne, Victoria, Australia
| | - Damian F. J. Purcell
- Department of Microbiology and Immunology, at The Peter Doherty Institute for Infection & Immunity, The University of Melbourne, Melbourne, Victoria, Australia
- * E-mail:
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Lloyd SB, Lichtfuss M, Amarasena TH, Alcantara S, De Rose R, Tachedjian G, Alinejad-Rokny H, Venturi V, Davenport MP, Winnall WR, Kent SJ. High fidelity simian immunodeficiency virus reverse transcriptase mutants have impaired replication in vitro and in vivo. Virology 2016; 492:1-10. [PMID: 26896929 DOI: 10.1016/j.virol.2016.02.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 02/09/2016] [Accepted: 02/11/2016] [Indexed: 11/15/2022]
Abstract
The low fidelity of HIV replication facilitates immune and drug escape. Some reverse transcriptase (RT) inhibitor drug-resistance mutations increase RT fidelity in biochemical assays but their effect during viral replication is unclear. We investigated the effect of RT mutations K65R, Q151N and V148I on SIV replication and fidelity in vitro, along with SIV replication in pigtailed macaques. SIVmac239-K65R and SIVmac239-V148I viruses had reduced replication capacity compared to wild-type SIVmac239. Direct virus competition assays demonstrated a rank order of wild-type>K65R>V148I mutants in terms of viral fitness. In single round in vitro-replication assays, SIVmac239-K65R demonstrated significantly higher fidelity than wild-type, and rapidly reverted to wild-type following infection of macaques. In contrast, SIVmac239-Q151N was replication incompetent in vitro and in pigtailed macaques. Thus, we showed that RT mutants, and specifically the common K65R drug-resistance mutation, had impaired replication capacity and higher fidelity. These results have implications for the pathogenesis of drug-resistant HIV.
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Affiliation(s)
- Sarah B Lloyd
- Department of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Victoria 3010, Australia
| | - Marit Lichtfuss
- Department of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Victoria 3010, Australia
| | - Thakshila H Amarasena
- Department of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Victoria 3010, Australia
| | - Sheilajen Alcantara
- Department of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Victoria 3010, Australia
| | - Robert De Rose
- Department of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Victoria 3010, Australia
| | - Gilda Tachedjian
- Department of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Victoria 3010, Australia; Centre for Biomedical Research, Burnet Institute, Melbourne, Victoria 3004, Australia; Department of Microbiology, Monash University, Clayton, Victoria 3168, Australia
| | | | - Vanessa Venturi
- Kirby Institute, University of New South Wales, Sydney, NSW 2052, Australia
| | - Miles P Davenport
- Kirby Institute, University of New South Wales, Sydney, NSW 2052, Australia
| | - Wendy R Winnall
- Department of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Victoria 3010, Australia
| | - Stephen J Kent
- Department of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Victoria 3010, Australia; Melbourne Sexual Health Centre and Department of Infectious Diseases, Alfred Health, Central Clinical School, Monash University, Melbourne, Australia; ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, University of Melbourne, Parkville, Australia.
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Lee WS, Parsons MS, Kent SJ, Lichtfuss M. Can HIV-1-Specific ADCC Assist the Clearance of Reactivated Latently Infected Cells? Front Immunol 2015; 6:265. [PMID: 26074924 PMCID: PMC4445400 DOI: 10.3389/fimmu.2015.00265] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 05/13/2015] [Indexed: 02/05/2023] Open
Affiliation(s)
- Wen Shi Lee
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne , Melbourne, VIC , Australia
| | - Matthew Sidney Parsons
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne , Melbourne, VIC , Australia
| | - Stephen John Kent
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne , Melbourne, VIC , Australia
| | - Marit Lichtfuss
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne , Melbourne, VIC , Australia
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