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De Groot AS, Roberts BJ, Mattei A, Lelias S, Boyle C, Martin WD. Immunogenicity risk assessment of synthetic peptide drugs and their impurities. Drug Discov Today 2023; 28:103714. [PMID: 37467878 DOI: 10.1016/j.drudis.2023.103714] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 06/15/2023] [Accepted: 07/12/2023] [Indexed: 07/21/2023]
Abstract
Peptide drugs play an important part in medicine owing to their many therapeutic applications. Of the 80 peptide drugs approved for use in humans, at least five are now off-patent and are consequently being developed as generic alternatives to the originator products. To accelerate access to generic products, the FDA has proposed new regulatory pathways that do not require direct comparisons of generics to originators in clinical trials. The 'Abbreviated New Drug Application' (ANDA) pathway recommends that sponsors provide information on any new impurities in the generic drug, compared with the originator product, because the impurities can have potential to elicit unwanted immune responses owing to the introduction of T-cell epitopes. This review describes how peptide drug impurities can elicit unexpected immunogenicity and describes a framework for performing immunogenicity risk assessment of all types of bioactive peptide products. Although this report primarily focuses on generic peptides and their impurities, the approach might also be of interest for developers of novel peptide drugs who are preparing their products for an initial regulatory review.
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Affiliation(s)
- Anne S De Groot
- EpiVax, 188 Valley Street, Suite 424, Providence, RI, USA; University of Georgia, Center for Vaccines and Immunology, Athens, GA USA.
| | | | - Aimee Mattei
- EpiVax, 188 Valley Street, Suite 424, Providence, RI, USA
| | - Sandra Lelias
- EpiVax, 188 Valley Street, Suite 424, Providence, RI, USA
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2
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Jesus-Oliveira P, Silva-Couto L, Pinho N, Da Silva-Ferreira AT, Saboia-Vahia L, Cuervo P, Da-Cruz AM, Gomes-Silva A, Pinto EF. Identification of Immunodominant Proteins of the Leishmania (Viannia) naiffi SubProteome as Pan-Specific Vaccine Targets against Leishmaniasis. Vaccines (Basel) 2023; 11:1129. [PMID: 37514945 PMCID: PMC10386316 DOI: 10.3390/vaccines11071129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/22/2023] [Accepted: 04/10/2023] [Indexed: 07/30/2023] Open
Abstract
Leishmaniasis is a wide-spectrum disease caused by parasites from Leishmania genus. A well-modulated immune response that is established after the long-lasting clinical cure of leishmaniasis can represent a standard requirement for a vaccine. Previous studies demonstrated that Leishmania (Viannia) naiffi causes benign disease and its antigens induce well-modulated immune responses in vitro. In this work we aimed to identify the immunodominant proteins present in the soluble extract of L. naiffi (sLnAg) as candidates for composing a pan-specific anti-leishmaniasis vaccine. After immunoblotting using cured patients of cutaneous leishmaniasis sera and proteomics approaches, we identified a group of antigenic proteins from the sLnAg. In silico analyses allowed us to select mildly similar proteins to the host; in addition, we evaluated the binding potential and degree of promiscuity of the protein epitopes to HLA molecules and to B-cell receptors. We selected 24 immunodominant proteins from a sub-proteome with 328 proteins. Homology analysis allowed the identification of 13 proteins with the most orthologues among seven Leishmania species. This work demonstrated the potential of these proteins as promising vaccine targets capable of inducing humoral and cellular pan-specific immune responses in humans, which may in the future contribute to the control of leishmaniasis.
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Affiliation(s)
- Prisciliana Jesus-Oliveira
- Laboratório Interdisciplinar de Pesquisas Médicas, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro 21040-360, Brazil
| | - Luzinei Silva-Couto
- Laboratório Interdisciplinar de Pesquisas Médicas, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro 21040-360, Brazil
| | - Nathalia Pinho
- Laboratório de Pesquisa em Leishmanioses, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro 21040-360, Brazil
- Rede de Pesquisas de Neuroinflamação do Rio de Janeiro, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro 21040-360, Brazil
| | | | - Leonardo Saboia-Vahia
- Laboratório de Vírus Respiratórios e Sarampo, Laboratório de Referência para COVID-19 (World Health Organization), Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro 21040-360, Brazil
| | - Patricia Cuervo
- Laboratório de Pesquisa em Leishmanioses, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro 21040-360, Brazil
- Rede de Pesquisas de Neuroinflamação do Rio de Janeiro, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro 21040-360, Brazil
| | - Alda Maria Da-Cruz
- Laboratório Interdisciplinar de Pesquisas Médicas, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro 21040-360, Brazil
- Rede de Pesquisas em Saúde, Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro, Rio de Janeiro 20020-000, Brazil
- Disciplina de Parasitologia, Departamento de Microbiologia, Imunologia e Parasitologia, Faculdade de Ciências Médicas, Universidade Estadual do Rio de Janeiro, Rio de Janeiro 20550-170, Brazil
- Instituto Nacional de Ciência e Tecnologia em Neuroimunomodulação (INCT-NIM), Rio de Janeiro 21040-900, Brazil
| | - Adriano Gomes-Silva
- Laboratório Interdisciplinar de Pesquisas Médicas, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro 21040-360, Brazil
- Laboratório de Pesquisa Clínica em Micobacterioses, Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Rio de Janeiro 21040-360, Brazil
| | - Eduardo Fonseca Pinto
- Laboratório Interdisciplinar de Pesquisas Médicas, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro 21040-360, Brazil
- Rede de Pesquisas em Saúde, Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro, Rio de Janeiro 20020-000, Brazil
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Martin PJ, Levine DM, Storer BE, Zheng X, Jain D, Heavner B, Norris BM, Geraghty DE, Spellman SR, Sather CL, Wu F, Hansen JA. A Model of Minor Histocompatibility Antigens in Allogeneic Hematopoietic Cell Transplantation. Front Immunol 2021; 12:782152. [PMID: 34868058 PMCID: PMC8636906 DOI: 10.3389/fimmu.2021.782152] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 10/29/2021] [Indexed: 12/02/2022] Open
Abstract
Minor histocompatibility antigens (mHAg) composed of peptides presented by HLA molecules can cause immune responses involved in graft-versus-host disease (GVHD) and graft-versus-leukemia effects after allogeneic hematopoietic cell transplantation (HCT). The current study was designed to identify individual graft-versus-host genomic mismatches associated with altered risks of acute or chronic GVHD or relapse after HCT between HLA-genotypically identical siblings. Our results demonstrate that in allogeneic HCT between a pair of HLA-identical siblings, a mHAg manifests as a set of peptides originating from annotated proteins and non-annotated open reading frames, which i) are encoded by a group of highly associated recipient genomic mismatches, ii) bind to HLA allotypes in the recipient, and iii) evoke a donor immune response. Attribution of the immune response and consequent clinical outcomes to individual peptide components within this set will likely differ from patient to patient according to their HLA types.
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Affiliation(s)
- Paul J Martin
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States.,Department of Medicine, University of Washington School of Medicine, Seattle, WA, United States
| | - David M Levine
- Department of Biostatistics, University of Washington, Seattle, WA, United States
| | - Barry E Storer
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States
| | - Xiuwen Zheng
- Department of Biostatistics, University of Washington, Seattle, WA, United States
| | - Deepti Jain
- Department of Biostatistics, University of Washington, Seattle, WA, United States
| | - Ben Heavner
- Department of Biostatistics, University of Washington, Seattle, WA, United States
| | - Brandon M Norris
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States
| | - Daniel E Geraghty
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States
| | - Stephen R Spellman
- Center for International Blood and Marrow Transplant Research, National Marrow Donor Program, Minneapolis, MN, United States
| | - Cassie L Sather
- Genomics & Bioinformatics Shared Resource, Fred Hutchinson Cancer Research Center, Seattle, WA, United States
| | - Feinan Wu
- Genomics & Bioinformatics Shared Resource, Fred Hutchinson Cancer Research Center, Seattle, WA, United States
| | - John A Hansen
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States.,Department of Medicine, University of Washington School of Medicine, Seattle, WA, United States
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The pockets guide to HLA class I molecules. Biochem Soc Trans 2021; 49:2319-2331. [PMID: 34581761 PMCID: PMC8589423 DOI: 10.1042/bst20210410] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Revised: 09/03/2021] [Accepted: 09/06/2021] [Indexed: 01/11/2023]
Abstract
Human leukocyte antigens (HLA) are cell-surface proteins that present peptides to T cells. These peptides are bound within the peptide binding cleft of HLA, and together as a complex, are recognised by T cells using their specialised T cell receptors. Within the cleft, the peptide residue side chains bind into distinct pockets. These pockets ultimately determine the specificity of peptide binding. As HLAs are the most polymorphic molecules in humans, amino acid variants in each binding pocket influences the peptide repertoire that can be presented on the cell surface. Here, we review each of the 6 HLA binding pockets of HLA class I (HLA-I) molecules. The binding specificity of pockets B and F are strong determinants of peptide binding and have been used to classify HLA into supertypes, a useful tool to predict peptide binding to a given HLA. Over the years, peptide binding prediction has also become more reliable by using binding affinity and mass spectrometry data. Crystal structures of peptide-bound HLA molecules provide a means to interrogate the interactions between binding pockets and peptide residue side chains. We find that most of the bound peptides from these structures conform to binding motifs determined from prediction software and examine outliers to learn how these HLAs are stabilised from a structural perspective.
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Maharaj L, Adeleke VT, Fatoba AJ, Adeniyi AA, Tshilwane SI, Adeleke MA, Maharaj R, Okpeku M. Immunoinformatics approach for multi-epitope vaccine design against P. falciparum malaria. INFECTION GENETICS AND EVOLUTION 2021; 92:104875. [PMID: 33905890 DOI: 10.1016/j.meegid.2021.104875] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 04/07/2021] [Accepted: 04/20/2021] [Indexed: 12/13/2022]
Abstract
Plasmodium falciparum (P. falciparum) is a leading causative agent of malaria, an infectious disease that can be fatal. Unfortunately, control measures are becoming less effective over time. A vaccine is needed to effectively control malaria and lead towards the total elimination of the disease. There have been multiple attempts to develop a vaccine, but to date, none have been certified as appropriate for wide-scale use. In this study, an immunoinformatics method is presented to design a multi-epitope vaccine construct predicted to be effective against P. falciparum malaria. This was done through the prediction of 12 CD4+ T-cell, 10 CD8+ T-cell epitopes and, 1 B-cell epitope which were assessed for predicted high antigenicity, immunogenicity, and non-allergenicity through in silico methods. The Human Leukocyte Antigen (HLA) population coverage showed that the alleles associated with the epitopes accounted for 78.48% of the global population. The CD4+ and CD8+ T-cell epitopes were docked to HLA-DRB1*07:01 and HLA-A*32:01 successfully. Therefore, the epitopes were deemed to be suitable as components of a multi-epitope vaccine construct. Adjuvant RS09 was added to the construct to generate a stronger immune response, as confirmed by an immune system simulation. Finally, the structural stability of the predicted multi-epitope vaccine was assessed using molecular dynamics simulations. The results show a promising vaccine design that should be further synthesised and assessed for its efficacy in an experimental laboratory setting.
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Affiliation(s)
- Leah Maharaj
- Discipline of Genetics, School of Life Sciences, University of KwaZulu-Natal, Westville, South Africa
| | - Victoria T Adeleke
- Discipline of Chemical Engineering, University of KwaZulu-Natal, Howard Campus, Durban 4041, South Africa
| | - Abiodun J Fatoba
- Discipline of Genetics, School of Life Sciences, University of KwaZulu-Natal, Westville, South Africa
| | - Adebayo A Adeniyi
- Department of Chemistry, Faculty of Natural and Agricultural Sciences, University of the Free State, Bloemfontein, South Africa; Department of Industrial Chemistry, Federal University Oye Ekiti, Nigeria
| | - Selaelo I Tshilwane
- School of Life Sciences, University of KwaZulu-Natal, Westville, South Africa
| | - Matthew A Adeleke
- Discipline of Genetics, School of Life Sciences, University of KwaZulu-Natal, Westville, South Africa
| | - Rajendra Maharaj
- Office of Malaria Research, Medical Research Council, South Africa
| | - Moses Okpeku
- Discipline of Genetics, School of Life Sciences, University of KwaZulu-Natal, Westville, South Africa.
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Zhang S, Chen J, Hong P, Li J, Tian Y, Wu Y, Wang S. PromPDD, a web-based tool for the prediction, deciphering and design of promiscuous peptides that bind to HLA class I molecules. J Immunol Methods 2019; 476:112685. [PMID: 31678214 DOI: 10.1016/j.jim.2019.112685] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Revised: 10/07/2019] [Accepted: 10/10/2019] [Indexed: 12/30/2022]
Abstract
Promiscuous peptides that can be presented by multiple human leukocyte antigens (HLAs) have great potential for the development of vaccines with wide population coverage. However, the current available methods for the prediction of peptides that bind to major histocompatibility complex (MHC) are mainly aimed at the rapid or mass screening of potential T cell epitopes from pathogen antigens or proteomics. The current approaches do not allow deciphering the contribution of the residue at each peptide position to the promiscuous binding ability of the peptide or obtaining guidelines for the design of promiscuous peptides. In this study, we re-evaluated and characterized four matrix-based prediction models that have been extensively used for the prediction of HLA-binding peptides and found that the prediction models generated based on the average relative binding (ARB) matrix shared a consistent and conservative threshold for all well-studied HLA class I alleles. Evaluations performed using datasets of HLA supertype-specific peptides with various cross-binding abilities and peptide mutant analogues indicated that the ARB-based binding matrices could be used to decipher and design promiscuous peptides that bind to multiple HLA molecules. A web-based tool called PromPDD was developed using ARB matrix-based models, and this tool enables the prediction, deciphering and design of promiscuous peptides that bind to multiple HLA molecules within or across HLA supertypes in a simpler and more direct manner. Furthermore, we expanded the application of PromPDD to HLA class I alleles with limited experimentally verified data by generating pan-specific matrices using a derived modular method, and 2641 HLA molecules encoded by HLA-A and HLA-B genes are available in PromPDD. PromPDD, which is freely available at http://www.immunoinformatics.net/PromPDD/, is the first tool for the deciphering and design of promiscuous peptides that bind to HLA class I molecules.
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Affiliation(s)
- Songlin Zhang
- Institute of Immunology, PLA, College of Basic Medical Sciences, Third Military Medical University (Army Medical University), Chongqing 400038, China
| | - Jian Chen
- Institute of Immunology, PLA, College of Basic Medical Sciences, Third Military Medical University (Army Medical University), Chongqing 400038, China
| | - Peijian Hong
- Institute of Immunology, PLA, College of Basic Medical Sciences, Third Military Medical University (Army Medical University), Chongqing 400038, China
| | - Jinru Li
- Institute of Immunology, PLA, College of Basic Medical Sciences, Third Military Medical University (Army Medical University), Chongqing 400038, China
| | - Yi Tian
- Institute of Immunology, PLA, College of Basic Medical Sciences, Third Military Medical University (Army Medical University), Chongqing 400038, China
| | - Yuzhang Wu
- Institute of Immunology, PLA, College of Basic Medical Sciences, Third Military Medical University (Army Medical University), Chongqing 400038, China.
| | - Shufeng Wang
- Institute of Immunology, PLA, College of Basic Medical Sciences, Third Military Medical University (Army Medical University), Chongqing 400038, China.
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Immunological MHC supertypes and allelic expression: how low is the functional MHC diversity in free-ranging Namibian cheetahs? CONSERV GENET 2019. [DOI: 10.1007/s10592-019-01143-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Usmani SS, Kumar R, Bhalla S, Kumar V, Raghava GPS. In Silico Tools and Databases for Designing Peptide-Based Vaccine and Drugs. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2018; 112:221-263. [PMID: 29680238 DOI: 10.1016/bs.apcsb.2018.01.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The prolonged conventional approaches of drug screening and vaccine designing prerequisite patience, vigorous effort, outrageous cost as well as additional manpower. Screening and experimentally validating thousands of molecules for a specific therapeutic property never proved to be an easy task. Similarly, traditional way of vaccination includes administration of either whole or attenuated pathogen, which raises toxicity and safety issues. Emergence of sequencing and recombinant DNA technology led to the epitope-based advanced vaccination concept, i.e., small peptides (epitope) can stimulate specific immune response. Advent of bioinformatics proved to be an adjunct in vaccine and drug designing. Genomic study of pathogens aid to identify and analyze the protective epitope. A number of in silico tools have been developed to design immunotherapy as well as peptide-based drugs in the last two decades. These tools proved to be a catalyst in drug and vaccine designing. This review solicits therapeutic peptide databases as well as in silico tools developed for designing peptide-based vaccine and drugs.
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Affiliation(s)
- Salman Sadullah Usmani
- Center for Computational Biology, Indraprastha Institute of Information Technology, New Delhi, India; Bioinformatics Centre, CSIR-Institute of Microbial Technology, Chandigarh, India
| | - Rajesh Kumar
- Center for Computational Biology, Indraprastha Institute of Information Technology, New Delhi, India; Bioinformatics Centre, CSIR-Institute of Microbial Technology, Chandigarh, India
| | - Sherry Bhalla
- Center for Computational Biology, Indraprastha Institute of Information Technology, New Delhi, India
| | - Vinod Kumar
- Center for Computational Biology, Indraprastha Institute of Information Technology, New Delhi, India; Bioinformatics Centre, CSIR-Institute of Microbial Technology, Chandigarh, India
| | - Gajendra P S Raghava
- Center for Computational Biology, Indraprastha Institute of Information Technology, New Delhi, India; Bioinformatics Centre, CSIR-Institute of Microbial Technology, Chandigarh, India.
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Sankar S, Ramamurthy M, Nandagopal B, Sridharan G. Short peptide epitope design from hantaviruses causing HFRS. Bioinformation 2017; 13:231-236. [PMID: 28943728 PMCID: PMC5602290 DOI: 10.6026/97320630013231] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 07/03/2017] [Accepted: 07/05/2017] [Indexed: 12/15/2022] Open
Abstract
Several genotypes of the hantavirus cause hemorrhagic fever with renal syndrome (HFRS) and is an important public health problem
worldwide. There is now growing interest to develop subunit vaccines especially focused to elicit cytotoxic T lymphocyte responses
which are important against viral infection. We identified candidate T-cell epitopes that bind to Class I HLA supertypes towards
identifying potential subunit vaccine entity. These epitopes are conserved in all 5 hantavirus genotypes of HFRS (Hantaan, Dobrava-
Belgrade, Seoul, Gou virus and Amur). The epitopes identified from S and M segment genomes were analyzed for human proteasome
cleavage, transporter associated antigen processing (TAP) efficiency and antigenicity using bioinformatic approaches. The epitope
MRNTIMASK which had the two characteristics of high proteasomal cleavage score and TAP score, also had high antigenicity score.
Our results indicate that this epitope from the nucleocapsid protein may be considered the most favorable moiety for the development
of subunit peptide vaccine.
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Affiliation(s)
- Sathish Sankar
- Sri Sakthi Amma Institute of Biomedical Research, Sri Narayani Hospital and Research Centre, Sripuram, Vellore 632 055, Tamil Nadu, India
| | - Mageshbabu Ramamurthy
- Sri Sakthi Amma Institute of Biomedical Research, Sri Narayani Hospital and Research Centre, Sripuram, Vellore 632 055, Tamil Nadu, India
| | - Balaji Nandagopal
- Sri Sakthi Amma Institute of Biomedical Research, Sri Narayani Hospital and Research Centre, Sripuram, Vellore 632 055, Tamil Nadu, India
| | - Gopalan Sridharan
- Sri Sakthi Amma Institute of Biomedical Research, Sri Narayani Hospital and Research Centre, Sripuram, Vellore 632 055, Tamil Nadu, India
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Lu G, Villa JA, Donlin MJ, Edwards TC, Cheng X, Heier RF, Meyers MJ, Tavis JE. Hepatitis B virus genetic diversity has minimal impact on sensitivity of the viral ribonuclease H to inhibitors. Antiviral Res 2016; 135:24-30. [PMID: 27693161 DOI: 10.1016/j.antiviral.2016.09.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Revised: 09/12/2016] [Accepted: 09/19/2016] [Indexed: 02/07/2023]
Abstract
Hepatitis B virus (HBV) causes hepatitis, cirrhosis, liver failure, and liver cancer, but the current therapies that employ either nucelos(t)ide analogs or (pegylated)interferon α do not clear the infection in the large majority of patients. Inhibitors of the HBV ribonuclease H (RNaseH) that are being developed with the goal of producing anti-HBV drugs are promising candidates for use in combination with the nucleos(t)ide analogs to improve therapeutic efficacy. HBV is genetically very diverse, with at least 8 genotypes that differ by ≥8% at the sequence level. This diversity is reflected in the viral RNaseH enzyme, raising the possibility that divergent HBV genotypes or isolates may have varying sensitivity to RNaseH inhibitors. To evaluate this possibility, we expressed and purified 18 patient-derived RNaseHs from genotypes B, C, and D. Basal RNaseH activity and sensitivity to three novel RNaseH inhibitors from three different chemotypes were assessed. We also evaluated four consensus HBV RNaseHs to determine if such sequences would be suitable for use in antiviral drug screening. The patient-derived enzymes varied by over 10-fold in their basal RNaseH activities, but they were equivalently sensitive to each of the three inhibitors. Similarly, all four consensus HBV RNaseH enzymes were active and were equally sensitive to an RNaseH inhibitor. These data indicate that a wide range of RNaseH sequences would be suitable for use in antiviral drug screening, and that genotype- or isolate-specific genetic variations are unlikely to present a barrier during antiviral drug development against the HBV RNaseH.
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Affiliation(s)
- Gaofeng Lu
- Department of Molecular Microbiology and Immunology and Saint Louis University Liver Center, Saint Louis University School of Medicine, St. Louis, MO, USA; Department of Gastroenterology, The Second Affiliated Hospital, Zhengzhou University, Zhengzhou, Henan, People's Republic of China
| | - Juan Antonio Villa
- Department of Molecular Microbiology and Immunology and Saint Louis University Liver Center, Saint Louis University School of Medicine, St. Louis, MO, USA
| | - Maureen J Donlin
- Department of Molecular Microbiology and Immunology and Saint Louis University Liver Center, Saint Louis University School of Medicine, St. Louis, MO, USA
| | - Tiffany C Edwards
- Department of Molecular Microbiology and Immunology and Saint Louis University Liver Center, Saint Louis University School of Medicine, St. Louis, MO, USA
| | - Xiaohong Cheng
- Department of Molecular Microbiology and Immunology and Saint Louis University Liver Center, Saint Louis University School of Medicine, St. Louis, MO, USA
| | - Richard F Heier
- Center for World Health and Medicine, Saint Louis University School of Medicine, St. Louis, MO, USA
| | - Marvin J Meyers
- Center for World Health and Medicine, Saint Louis University School of Medicine, St. Louis, MO, USA
| | - John E Tavis
- Department of Molecular Microbiology and Immunology and Saint Louis University Liver Center, Saint Louis University School of Medicine, St. Louis, MO, USA.
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