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Luan X, Fan X, Li G, Li M, Li N, Yan Y, Zhao X, Liu H, Wan K. Exploring the immunogenicity of Rv2201-519: A T-cell epitope-based antigen derived from Mycobacterium tuberculosis AsnB with implications for tuberculosis infection detection and vaccine development. Int Immunopharmacol 2024; 129:111542. [PMID: 38342063 DOI: 10.1016/j.intimp.2024.111542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 01/03/2024] [Accepted: 01/11/2024] [Indexed: 02/13/2024]
Abstract
Research dedicated to diagnostic reagents and vaccine development for tuberculosis (TB) is challenging due to the paucity of immunodominant antigens that can predict disease risk and exhibit protective potential. Therefore, it is crucial to identify T-cell epitope-based Mycobacterium tuberculosis (MTB) antigens characterized by specific and prominent recognition by the immune system. In this study, we constructed a T-cell epitope-rich tripeptide-splicing fragment (nucleotide positions 131-194, 334-377, and 579-643) of Rv2201 (also known as the 72 kDa AsnB)from the MTB genome, ultimately yielding the recombinant protein Rv2201-519 in Escherichia coli BL21 (DE3). Subsequently, we gauged the recombinant protein's ability to detect tuberculosis infection through ELISpot and assessed its immunostimulatory effect on mouse models using flow cytometry and ELISA. Our results indicated that Rv2201-519 possessed promising sensitivity; however, the sensitivity was lower than that of a commercial diagnostic kit containing ESAT-6, CFP-10, and Rv3615c (80.56 % vs. 94.44 %). The Rv2201-519 group exhibited a propensity for a CD4+ Th1 cell immune response in inoculated BALB/c mice that manifested as higher levels of antigen-specific IgG production (IgG2a/IgG1 > 1). In comparison to Ag85B, Rv2201-519 induced a more robust Th1-type cellular immune response as evidenced by a notable rise in the ratio of IFN-γ/IL-4 and IL-12 cytokine production and increased CD4+ T cell activation with a higher percentage of CD4+IFN-γ+ T cells. Rv2201-519 also induced a higher level of IL-6 compared with Ag85B, a higher percentage of CD8+ T cells specific for Rv2201-519, and a lower percentage of CD8+IL-4+ T cells. Collectively, the current evidence suggests that Rv2201-519 could potentially serve as an immunodominant protein for tuberculosis infection screening, laying the groundwork for further evaluation in recombinant Bacillus Calmette-Guérin (BCG) and subunit vaccines against MTB challenges in future studies.
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Affiliation(s)
- Xiuli Luan
- Beijing Chest Hospital, Capital Medical University/Beijing Tuberculosis & Thoracic Tumor Research Institute, Beijing 101100, China; National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
| | - Xueting Fan
- National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
| | - Guilian Li
- National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
| | - Mchao Li
- National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
| | - Na Li
- National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
| | - Yuhan Yan
- National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
| | - Xiuqin Zhao
- National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
| | - Haican Liu
- National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.
| | - Kanglin Wan
- National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.
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Yu J, Fan X, Luan X, Wang R, Cao B, Qian C, Li G, Li M, Zhao X, Liu H, Wan K, Yuan X. A novel multi-component protein vaccine ECP001 containing a protein polypeptide antigen nPstS1 riching in T-cell epitopes showed good immunogenicity and protection in mice. Front Immunol 2023; 14:1138818. [PMID: 37153610 PMCID: PMC10161251 DOI: 10.3389/fimmu.2023.1138818] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 03/10/2023] [Indexed: 05/09/2023] Open
Abstract
Tuberculosis (TB) is an infectious disease that seriously affects human health. Until now, the only anti-TB vaccine approved for use is the live attenuated Mycobacterium bovis (M. bovis) vaccine - BCG vaccine, but its protective efficacy is relatively low and does not provide satisfactory protection against TB in adults. Therefore, there is an urgent need for more effective vaccines to reduce the global TB epidemic. In this study, ESAT-6, CFP-10, two antigens full-length and the T-cell epitope polypeptide antigen of PstS1, named nPstS1, were selected to form one multi-component protein antigens, named ECP001, which include two types, one is a mixed protein antigen named ECP001m, the other is a fusion expression protein antigen named ECP001f, as candidates for protein subunit vaccines. were prepared by constructing one novel subunit vaccine by mixing or fusing the three proteins and combining them with aluminum hydroxide adjuvant, and the immunogenicity and protective properties of the vaccine was evaluated in mice. The results showed that ECP001 stimulated mice to produce high titre levels of IgG, IgG1 and IgG2a antibodies; meanwhile, high levels of IFN-γ and a broad range of specific cytokines were secreted by mouse splenocytes; in addition, ECP001 inhibited the proliferation of Mycobacterium tuberculosis in vitro with a capacity comparable to that of BCG. It can be concluded that ECP001 is a novel effective multicomponent subunit vaccine candidate with potential as BCG Initial Immunisation-ECP001 Booster Immunisation or therapeutic vaccine for M. tuberculosis infection.
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Affiliation(s)
- Jinjie Yu
- School of Public Health, University of South China, Hengyang, China
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Xueting Fan
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Xiuli Luan
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Ruihuan Wang
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Bin Cao
- School of Public Health, University of South China, Hengyang, China
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Chengyu Qian
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
- School of Life Sciences, College of Laboratory Medicine, Wenzhou Medical University, Wenzhou, China
| | - Guilian Li
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Machao Li
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Xiuqin Zhao
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Haican Liu
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
- *Correspondence: Haican Liu, ; Kanglin Wan, ; Xiuqin Yuan,
| | - Kanglin Wan
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
- *Correspondence: Haican Liu, ; Kanglin Wan, ; Xiuqin Yuan,
| | - Xiuqin Yuan
- School of Public Health, University of South China, Hengyang, China
- *Correspondence: Haican Liu, ; Kanglin Wan, ; Xiuqin Yuan,
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Luan X, Fan X, Wang R, Deng Y, Chen Z, Li N, Yan Y, Li X, Liu H, Li G, Wan K. High Immunogenicity of a T-Cell Epitope-Rich Recombinant Protein Rv1566c-444 From Mycobacterium tuberculosis in Immunized BALB/c Mice, Despite Its Low Diagnostic Sensitivity. Front Immunol 2022; 13:824415. [PMID: 35265079 PMCID: PMC8899609 DOI: 10.3389/fimmu.2022.824415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 01/12/2022] [Indexed: 11/13/2022] Open
Abstract
The discovery of immunodominant antigens is of great significance for the development of new especially sensitive diagnostic reagents and effective vaccines in controlling tuberculosis (TB). In the present study, we targeted the T-Cell epitope-rich fragment (nucleotide position 109-552) of Rv1566c from Mycobacterium tuberculosis (MTB) and got a recombinant protein Rv1566c-444 and the full-length protein Rv1566c with Escherichia coli expression system, then compared their performances for TB diagnosis and immunogenicity in a mouse model. The results showed that Rv1566c-444 had similar sensitivity with Rv1566c (44.44% Vs 30.56%) but lower sensitivity than ESAT-6&CFP-10&Rv3615c (44.4% Vs. 94.4%) contained in a commercial kit for distinguishing TB patients from healthy donors. In immunized BALB/c mice, Rv1566c-444 elicited stronger T-helper 1 (Th1) cellular immune response over Rv1566c with higher levels of Th1 cytokine IFN-γ and IFN-γ/IL-4 expression ratio by ELISA; more importantly, with a higher proliferation of CD4+ T cells and a higher proportion of CD4+ TNF-α+ T cells with flow cytometry. Rv1566c-444 also induced a higher level of IL-6 by ELISA and a higher proportion of Rv1566c-444-specific CD8+ T cells and a lower proportion of CD8+ IL-4+ T cells by flow cytometry compared with the Rv1566c group. Moreover, the Rv1566c-444 group showed a high IgG secretion level and the same type of CD4+ Th cell immune response (both IgG1/IgG2a >1) as its parental protein group. Our results showed the potential of the recombinant protein Rv1566c-444 enriched with T-Cell epitopes from Rv1566c as a host T cell response measuring biomarker for TB diagnosis and support further evaluation of Rv1566c-444 as vaccine antigen against MTB challenge in animal models in the form of protein mixture or fusion protein.
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Affiliation(s)
- Xiuli Luan
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Xueting Fan
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Ruihuan Wang
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Yunli Deng
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,Community Health Management Service Center, Longgang District Peoples Hospital of Shenzhen, Shenzhen, China
| | - Zixin Chen
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,Department of Infection Control, Longgang District People's Hospital of Shenzhen, Shenzhen, China
| | - Na Li
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Yuhan Yan
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Xiaoyan Li
- Laboratory Animal Center, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Haican Liu
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Guilian Li
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Kanglin Wan
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
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Kumra Ahnlide V, Kumra Ahnlide J, Wrighton S, Beech JP, Nordenfelt P. Nanoscale binding site localization by molecular distance estimation on native cell surfaces using topological image averaging. eLife 2022; 11:64709. [PMID: 35200140 PMCID: PMC8871386 DOI: 10.7554/elife.64709] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 01/13/2022] [Indexed: 01/26/2023] Open
Abstract
Antibody binding to cell surface proteins plays a crucial role in immunity, and the location of an epitope can altogether determine the immunological outcome of a host-target interaction. Techniques available today for epitope identification are costly, time-consuming, and unsuited for high-throughput analysis. Fast and efficient screening of epitope location can be useful for the development of therapeutic monoclonal antibodies and vaccines. Cellular morphology typically varies, and antibodies often bind heterogeneously across a cell surface, making traditional particle-averaging strategies challenging for accurate native antibody localization. In the present work, we have developed a method, SiteLoc, for imaging-based molecular localization on cellular surface proteins. Nanometer-scale resolution is achieved through localization in one dimension, namely, the distance from a bound ligand to a reference surface. This is done by using topological image averaging. Our results show that this method is well suited for antibody binding site measurements on native cell surface morphology and that it can be applied to other molecular distance estimations as well. Antibodies play a key role in the immune system. These proteins stick to harmful substances, such as bacteria and other disease-causing pathogens, marking them for destruction or blocking their attack. Antibodies are highly selective, and this ability has been used to target particular molecules in research, diagnostics and therapies. Typically, antibodies need to stick to a particular segment, or ‘epitope’, on the surface of a cell in order to trigger an immune response. Knowing where these regions are can help explain how these immune proteins work and aid the development of more effective drugs and diagnostic tools. One way to identify these sites is to measure the nano-distance between antibodies and other features on the cell surface. To do this, researchers take multiple images of the cell the antibody is attached to using light microscopy. Various statistical methods are then applied to create an ‘average image’ that has a higher resolution and can therefore be used to measure the distance between these two points more accurately. While this approach works on fixed shapes, like a perfect circle, it cannot handle human cells and bacteria which are less uniform and have more complex surfaces. Here, Kumra Ahnlide et al. have developed a new method called SiteLoc which can overcome this barrier. The method involves two fluorescent probes: one attached to a specific site on the cell’s surface, and the other to the antibody or another molecule of interest. These two probes emit different colours when imaged with a fluorescent microscope. To cope with objects that have uneven surfaces, such as cells and bacteria, the two signals are transformed to ‘follow’ the same geometrical shape. The relative distance between them is then measured using statistical methods. Using this approach, Kumra Ahnlide et al. were able to identify epitopes on a bacterium, and measure distances on the surface of human red blood cells. The SiteLoc system could make it easier to develop antibody-based treatments and diagnostic tools. Furthermore, it could also be beneficial to the wider research community who could use it to probe other questions that require measuring nanoscale distances.
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Affiliation(s)
- Vibha Kumra Ahnlide
- Division of Infection Medicine, Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
| | - Johannes Kumra Ahnlide
- Division of Infection Medicine, Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
| | - Sebastian Wrighton
- Division of Infection Medicine, Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
| | - Jason P Beech
- Division of Solid State Physics, Department of Physics, Lund University, Lund, Sweden
| | - Pontus Nordenfelt
- Division of Infection Medicine, Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
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Morgan J, Muskat K, Tippalagama R, Sette A, Burel J, Lindestam Arlehamn CS. Classical CD4 T cells as the cornerstone of antimycobacterial immunity. Immunol Rev 2021; 301:10-29. [PMID: 33751597 PMCID: PMC8252593 DOI: 10.1111/imr.12963] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 02/11/2021] [Accepted: 02/13/2021] [Indexed: 12/13/2022]
Abstract
Tuberculosis is a significant health problem without an effective vaccine to combat it. A thorough understanding of the immune response and correlates of protection is needed to develop a more efficient vaccine. The immune response against Mycobacterium tuberculosis (Mtb) is complex and involves all aspects of the immune system, however, the optimal protective, non‐pathogenic T cell response against Mtb is still elusive. This review will focus on discussing CD4 T cell immunity against mycobacteria and its importance in Mtb infection with a primary focus on human studies. We will in particular discuss the large heterogeneity of immune cell subsets that have been revealed by recent immunological investigations at an unprecedented level of detail. These studies have identified specific classical CD4 T cell subsets important for immune responses against Mtb in various states of infection. We further discuss the functional attributes that have been linked to the various subsets such as upregulation of activation markers and cytokine production. Another important topic to be considered is the antigenic targets of Mtb‐specific immune responses, and how antigen reactivity is influenced by both disease state and environmental exposure(s). These are key points for both vaccines and immune diagnostics development. Ultimately, these factors are holistically considered in the definition and investigations of what are the correlates on protection and resolution of disease.
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Affiliation(s)
- Jeffrey Morgan
- Center for Infectious Disease, La Jolla Institute for Immunology, La Jolla, CA, USA
| | - Kaylin Muskat
- Center for Infectious Disease, La Jolla Institute for Immunology, La Jolla, CA, USA
| | - Rashmi Tippalagama
- Center for Infectious Disease, La Jolla Institute for Immunology, La Jolla, CA, USA
| | - Alessandro Sette
- Center for Infectious Disease, La Jolla Institute for Immunology, La Jolla, CA, USA
| | - Julie Burel
- Center for Infectious Disease, La Jolla Institute for Immunology, La Jolla, CA, USA
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Ivanyi J. Tuberculosis vaccination needs to avoid 'decoy' immune reactions. Tuberculosis (Edinb) 2020; 126:102021. [PMID: 33254012 DOI: 10.1016/j.tube.2020.102021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 11/09/2020] [Accepted: 11/10/2020] [Indexed: 11/16/2022]
Abstract
Current search for a new effective vaccine against tuberculosis involves selected antigens, vectors and adjuvants. These are being evaluated usually by their booster inoculation following priming with Bacillus Calmette-Guerin. The purpose of this article is to point out, that despite being attenuated of virulence, priming with BCG may still involve immune mechanisms, which are not favourable for protection against active disease. It is postulated, that the responsible 'decoy' constituents selected during the evolution of pathogenic tubercle bacilli may be involved in the evasion from bactericidal host resistance and stimulate immune responses of a cytokine phenotype, which lead to the transition from latent closed granulomas to reactivation with infectious lung cavities. The decoy mechanisms appear as favourable for most infected subjects but leading in a minority of cases to pathology which can effectively transmit the infection. It is proposed that construction and development of new vaccine candidates could benefit from avoiding decoy-type immune mechanisms.
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Affiliation(s)
- Juraj Ivanyi
- Centre for Host-Microbiome Interactions, Guy's Campus of Kings College London, SE1, 1UL, United kingdom.
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Mahmood MS, Bin-T-Abid D, Irshad S, Batool H. Analysis of Putative Epitope Candidates of Mycobacterium tuberculosis Against Pakistani Human Leukocyte Antigen Background: An Immunoinformatic Study for the Development of Future Vaccine. Int J Pept Res Ther 2020; 27:597-614. [PMID: 32922244 PMCID: PMC7472948 DOI: 10.1007/s10989-020-10111-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/22/2020] [Indexed: 11/25/2022]
Abstract
Tuberculosis (TB), a chronic disease caused by Mycobacterium tuberculosis (Mtb), is a global health issue across the world. Pakistan ranks fifth among the countries, which are facing, a significantly great number of mortalities and morbidities due to TB. Unfortunately, all previously reported treatments are not successful for the eradication of TB. Here in this study, we report an emerging treatment option for this disease. We have applied immunoinformatics to predict highly conserved B and T-cell epitopes from Mtb, showing significant binding affinities to the frequent HLA alleles in the Pakistani population. A total of ten highly referenced and experimentally validated epitopes were selected from the Immune Epitope Database (IEDB), followed by their conservancy analysis using weblogos. The consensus sequences and variants derived from these sequences were examined, for their binding affinities, with prevalent HLA alleles of Pakistan. Moreover, the antigenic and allergenic natures of these peptides were also evaluated via Vaxijen and AllerTOP, respectively. Consequently, all potentially allergenic and non-antigenic, peptide fragments, were excluded from the analysis. Among all putative epitopes, three CD8 + T-cell epitopes were selected, as ideal vaccine candidates and, population coverage analysis revealed that the combination of these three peptides was covering, 67.28% Pakistani Asian and 57.15% mixed Pakistani populations. Likewise, eleven linear and six conformational or discontinuous B-cell epitopes were also marked as potential vaccine candidates based on their prediction score, non-allergenic nature, and antigenic properties. These epitopes, however, need the final validation via wet-lab studies. After their approval, these epitopes would be effective candidates for the future designing of epitope-based vaccines against Mtb infections in Pakistan.
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Affiliation(s)
- Malik Siddique Mahmood
- Institute of Biochemistry and Biotechnology, University of the Punjab, P. O box No. 54590, Lahore, Pakistan
| | - Duaa Bin-T-Abid
- Institute of Biochemistry and Biotechnology, University of the Punjab, P. O box No. 54590, Lahore, Pakistan
| | - Saba Irshad
- Institute of Biochemistry and Biotechnology, University of the Punjab, P. O box No. 54590, Lahore, Pakistan
| | - Hina Batool
- Department of Life Science, School of Science, University of Management Technology, Lahore, Pakistan
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8
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TCR-like domain antibody against Mycobacterium tuberculosis (Mtb) heat shock protein antigen presented by HLA-A*11 and HLA-A*24. Int J Biol Macromol 2020; 155:305-314. [DOI: 10.1016/j.ijbiomac.2020.03.229] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 02/23/2020] [Accepted: 03/26/2020] [Indexed: 02/04/2023]
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9
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Ramaiah A, Nayak S, Rakshit S, Manson AL, Abeel T, Shanmugam S, Sahoo PN, John AJUK, Sundaramurthi JC, Narayanan S, D'Souza G, von Hoegen P, Ottenhoff THM, Swaminathan S, Earl AM, Vyakarnam A. Evidence for Highly Variable, Region-Specific Patterns of T-Cell Epitope Mutations Accumulating in Mycobacterium tuberculosis Strains. Front Immunol 2019; 10:195. [PMID: 30814998 PMCID: PMC6381025 DOI: 10.3389/fimmu.2019.00195] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 01/23/2019] [Indexed: 01/26/2023] Open
Abstract
Vaccines that confer protection through induction of adaptive T-cell immunity rely on understanding T-cell epitope (TCE) evolution induced by immune escape. This is poorly understood in tuberculosis (TB), an ancient, chronic disease, where CD4 T-cell immunity is of recognized importance. We probed 905 functionally validated, curated human CD4 T cell epitopes in 79 Mycobacterium tuberculosis (Mtb) whole genomes from India. This screen resulted in identifying 64 mutated epitopes in these strains initially using a computational pipeline and subsequently verified by single nucleotide polymorphism (SNP) analysis. SNP based phylogeny revealed the 79 Mtb strains to cluster to East African Indian (EAI), Central Asian Strain (CAS), and Beijing (BEI) lineages. Eighty-nine percent of the mutated T-cell epitopes (mTCEs) identified in the 79 Mtb strains from India has not previously been reported. These mTCEs were encoded by genes with high nucleotide diversity scores including seven mTCEs encoded by six antigens in the top 10% of rapidly divergent Mtb genes encoded by these strains. Using a T cell functional assay readout, we demonstrate 62% of mTCEs tested to significantly alter CD4 T-cell IFNγ and/or IL2 secretion with associated changes in predicted HLA-DR binding affinity: the gain of function mutations displayed higher predicted HLA-DR binding affinity and conversely mutations resulting in loss of function displayed lower predicted HLA-DR binding affinity. Most mutated antigens belonged to the cell wall/cell processes, and, intermediary metabolism and respiration families though all known Mtb proteins encoded mutations. Analysis of the mTCEs in an SNP database of 5,310 global Mtb strains identified 82% mTCEs to be significantly more prevalent in Mtb strains isolated from India, including 36 mTCEs identified exclusively in strains from India. These epitopes had a significantly higher predicted binding affinity to HLA-DR alleles that were highly prevalent in India compared to HLA-DR alleles rare in India, highlighting HLA-DR maybe an important driver of these mutations. This first evidence of region-specific TCE mutations potentially employed by Mtb to escape host immunity has important implications for TB vaccine design.
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Affiliation(s)
- Arunachalam Ramaiah
- Centre for Infectious Disease Research, Indian Institute of Science, Bangalore, India
| | - Soumya Nayak
- Centre for Infectious Disease Research, Indian Institute of Science, Bangalore, India
| | - Srabanti Rakshit
- Centre for Infectious Disease Research, Indian Institute of Science, Bangalore, India
| | - Abigail L Manson
- Broad Institute of MIT and Harvard, Cambridge, MA, United States
| | - Thomas Abeel
- Broad Institute of MIT and Harvard, Cambridge, MA, United States
| | | | - Pravat Nalini Sahoo
- Centre for Infectious Disease Research, Indian Institute of Science, Bangalore, India
| | | | | | - Sujatha Narayanan
- National Institute for Research in Tuberculosis (ICMR), Chennai, India
| | - George D'Souza
- Department of Pulmonary Medicine, St. John's Research Institute, Bangalore, India
| | | | - Tom H M Ottenhoff
- Department of Infectious Diseases, Leiden University Medical Center, Leiden, Netherlands
| | | | - Ashlee M Earl
- Broad Institute of MIT and Harvard, Cambridge, MA, United States
| | - Annapurna Vyakarnam
- Centre for Infectious Disease Research, Indian Institute of Science, Bangalore, India.,Department of Infectious Diseases, Faculty of Life Sciences & Medicine, School of Immunology and Microbial Sciences, King's College London, London, United Kingdom
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10
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Dewi DNSS, Soedarsono, Mertaniasih NM. T CELL EPITOPES OF THE ESXA FULL GENE OF MYCOBACTERIUM TUBERCULOSIS FROM SPUTUM OF MDR-TB PATIENTS. Afr J Infect Dis 2018; 12:66-70. [PMID: 30109288 PMCID: PMC6085733 DOI: 10.21010/ajid.v12i2.10] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2017] [Revised: 04/01/2018] [Accepted: 04/03/2018] [Indexed: 02/02/2023] Open
Abstract
Background: In 2015, World Health Organization (WHO) discovered 10.4 million tuberculosis (TB) cases around the world. Multidrug-resistant tuberculosis (MDR-TB) became a threat because it has high mortality number. There were 480,000 new MDR-TB cases in 2015. Based on those problems, diagnostic development to detect M. tuberculosis rapidly and accurately is needed. The importance of detecting epitope expression of esxA full gene because there was a potential of complexity over the protein structure and might affect the protein concentration. By knowing epitope prediction, there’s an expectation that it can help the development of TB diagnostic. This research was aimed to determine the T cell epitope prediction of esxA full gene from MDR-TB patients Material and Methods: Total of 24 MDR-TB sputum isolate from TB patients at Dr. Soetomo Hospital were collected from September to December 2016. Samples were confirmed as MDR-TB using GeneXpert and Bactec MGIT 960. Those samples tested using PCR targeted 580 bp of esxA gene and sequencing. Gene sequence was aligned against wild type using Bioedit program version 7.2.5 and NCBI BLAST. T cell epitope prediction was analyzed by GENETYX version 10. Results: Epitope predictions that could be obtained were IEAAAS, ASAIQG, VTSIHS, TKLAAA, VTGMFA based IAd Pattern Position and EAAAS based Rothbard/Taylor Pattern Position. Those prediction epitopes can determine the severity of disease, therefore full gene of esxA could be used as diagnostic target. Conclusion: This research discovered five specific T cell epitope prediction based on IAd Pattern Position and one epitope prediction according to Rothbard/Taylor Pattern Position.
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Affiliation(s)
- Desak Nyoman Surya Suameitria Dewi
- Student of Doctoral Program of Medical Science, Faculty of Medicine, Universitas Airlangga, Jl. Mayjen. Prof. Dr. Moestopo No. 47, Surabaya 60131, Indonesia.,Laboratory of Tuberculosis, Institute of Tropical Disease, Universitas Airlangga, Kampus C Jl. Mulyorejo Universitas Airlangga, Surabaya 60115, Indonesia
| | - Soedarsono
- Department of Pulmonology, Faculty of Medicine, Universitas Airlangga -Dr. Soetomo Hospital, Jl. Mayjen. Prof. Dr. Moestopo No. 47, Surabaya 60131, Indonesia
| | - Ni Made Mertaniasih
- Department of Clinical Microbiology, Faculty of Medicine, Universitas Airlangga -Dr. Soetomo Hospital, Jl. Mayjen. Prof. Dr. Moestopo No. 47, Surabaya 60131, Indonesia
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11
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Ganda IS, Zhong Q, Hali M, Albuquerque RLC, Padilha FF, da Rocha SRP, Whittum-Hudson JA. Dendrimer-conjugated peptide vaccine enhances clearance of Chlamydia trachomatis genital infection. Int J Pharm 2017; 527:79-91. [PMID: 28546072 PMCID: PMC5522616 DOI: 10.1016/j.ijpharm.2017.05.045] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 05/07/2017] [Accepted: 05/21/2017] [Indexed: 12/12/2022]
Abstract
Peptide-based vaccines have emerged in recent years as promising candidates in the prevention of infectious diseases. However, there are many challenges to maintaining in vivo peptide stability and enhancement of peptide immunogenicity to generate protective immunity which enhances clearance of infections. Here, a dendrimer-based carrier system is proposed for peptide-based vaccine delivery, and shows its anti-microbial feasibility in a mouse model of Chlamydia trachomatis. Chlamydiae are the most prevalent sexually transmitted bacteria worldwide, and also the causal agent of trachoma, the leading cause of preventable infectious blindness. In spite of the prevalence of this infectious agent and the many previous vaccine-related studies, there is no vaccine commercially available. The carrier system proposed consists of generation 4, hydroxyl-terminated, polyamidoamine (PAMAM) dendrimers (G4OH), to which a peptide mimic of a chlamydial glycolipid antigen-Peptide 4 (Pep4, AFPQFRSATLLL) was conjugated through an ester bond. The ester bond between G4OH and Pep4 is expected to break down mainly in the intracellular environment for antigen presentation. Pep4 conjugated to dendrimer induced Chlamydia-specific serum antibodies after subcutaneous immunizations. Further, this new vaccine formulation significantly protected immunized animals from vaginal challenge with infectious Chlamydia trachomatis, and it reduced infectious loads and tissue (genital tract) damage. Pep4 conjugated to G4OH or only mixed with peptide provided enhanced protection compared to Pep4 and adjuvant (i.e. alum), suggesting a potential adjuvant effect of the PAMAM dendrimer. Combined, these results demonstrate that hydroxyl-terminated PAMAM dendrimer is a promising polymeric nanocarrier platform for the delivery of peptide vaccines and this approach has potential to be expanded to other infectious intracellular bacteria and viruses of public health significance.
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Affiliation(s)
- Ingrid S Ganda
- Biomaterials Laboratory, Technology and Research Institute, Tiradentes University, Aracaju, SE, 49032-490, Brazil; Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, MI 48202, USA; Departments of Immunology and Microbiology, Internal Medicine (Rheumatology), and Ophthalmology, School of Medicine, Wayne State University, Detroit, MI 48201, USA.
| | - Qian Zhong
- Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, MI 48202, USA.
| | - Mirabela Hali
- Departments of Immunology and Microbiology, Internal Medicine (Rheumatology), and Ophthalmology, School of Medicine, Wayne State University, Detroit, MI 48201, USA.
| | - Ricardo L C Albuquerque
- Laboratory of Morphology and Structural Biology, Technology and Research Institute, Tiradentes University, Aracaju, SE, 49032-490, Brazil.
| | - Francine F Padilha
- Biomaterials Laboratory, Technology and Research Institute, Tiradentes University, Aracaju, SE, 49032-490, Brazil.
| | - Sandro R P da Rocha
- Biomaterials Laboratory, Technology and Research Institute, Tiradentes University, Aracaju, SE, 49032-490, Brazil; Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, MI 48202, USA.
| | - Judith A Whittum-Hudson
- Departments of Immunology and Microbiology, Internal Medicine (Rheumatology), and Ophthalmology, School of Medicine, Wayne State University, Detroit, MI 48201, USA.
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12
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Yruela I, Contreras-Moreira B, Magalhães C, Osório NS, Gonzalo-Asensio J. Mycobacterium tuberculosis Complex Exhibits Lineage-Specific Variations Affecting Protein Ductility and Epitope Recognition. Genome Biol Evol 2017; 8:3751-3764. [PMID: 28062754 PMCID: PMC5521731 DOI: 10.1093/gbe/evw279] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/18/2016] [Indexed: 12/19/2022] Open
Abstract
The advent of whole-genome sequencing has provided an unprecedented detail about the evolution and genetic significance of species-specific variations across the whole Mycobacterium tuberculosis Complex. However, little attention has been focused on understanding the functional roles of these variations in the protein coding sequences. In this work, we compare the coding sequences from 74 sequenced mycobacterial species including M. africanum, M. bovis, M. canettii, M. caprae, M. orygis, and M. tuberculosis. Results show that albeit protein variations affect all functional classes, those proteins involved in lipid and intermediary metabolism and respiration have accumulated mutations during evolution. To understand the impact of these mutations on protein functionality, we explored their implications on protein ductility/disorder, a yet unexplored feature of mycobacterial proteomes. In agreement with previous studies, we found that a Gly71Ile substitution in the PhoPR virulence system severely affects the ductility of its nearby region in M. africanum and animal-adapted species. In the same line of evidence, the SmtB transcriptional regulator shows amino acid variations specific to the Beijing lineage, which affects the flexibility of the N-terminal trans-activation domain. Furthermore, despite the fact that MTBC epitopes are evolutionary hyperconserved, we identify strain- and lineage-specific amino acid mutations affecting previously known T-cell epitopes such as EsxH and FbpA (Ag85A). Interestingly, in silico studies reveal that these variations result in differential interaction of epitopes with the main HLA haplogroups.
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Affiliation(s)
- Inmaculada Yruela
- Estación Experimental de Aula Dei-Consejo Superior de Investigaciones Científicas (EEAD-CSIC), Zaragoza, Spain.,Grupo de Bioquímica, Biofísica y Biología Computacional (BIFI, UNIZAR), Unidad Asociada I+D+i al CSIC, Zaragoza, Spain
| | - Bruno Contreras-Moreira
- Estación Experimental de Aula Dei-Consejo Superior de Investigaciones Científicas (EEAD-CSIC), Zaragoza, Spain.,Grupo de Bioquímica, Biofísica y Biología Computacional (BIFI, UNIZAR), Unidad Asociada I+D+i al CSIC, Zaragoza, Spain.,Fundación ARAID, Aragón, Spain
| | - Carlos Magalhães
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Nuno S Osório
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Jesús Gonzalo-Asensio
- Grupo de Genética de Micobacterias, Departamento de Microbiología y Medicina Preventiva, Facultad de Medicina, Universidad de Zaragoza, Zaragoza, Spain.,CIBER Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain.,Instituto de Biocomputación y Física de Sistemas Complejos (BIFI-UNIZAR), Zaragoza, Spain.,Servicio de Microbiología Hospital Universitario Miguel Servet, ISS Aragón, Zaragoza, Spain
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13
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Wang L, Deng X, Liu H, Zhao L, You X, Dai P, Wan K, Zeng Y. The mimic epitopes ofMycobacterium tuberculosisscreened by phage display peptide library have serodiagnostic potential for tuberculosis. Pathog Dis 2016; 74:ftw091. [DOI: 10.1093/femspd/ftw091] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/29/2016] [Indexed: 11/12/2022] Open
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14
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Duan Z, Li D, Jia Q, Xu J, Chen X, Xu Z, Liu H, Chen B, Wen J. The diagnostic potential of MPT63-derived HLA-A*0201-restricted CD8+ T-cell epitopes for active pulmonary tuberculosis. Microbiol Immunol 2015; 59:705-15. [PMID: 26577013 DOI: 10.1111/1348-0421.12339] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 11/10/2015] [Accepted: 11/11/2015] [Indexed: 12/23/2022]
Abstract
MPT63 protein is found only in Mycobacterium tuberculosis complex, including M. tuberculosis and M. bovis. Detection of MPT63-specific IFN-γ-secreting T cells could be useful for the diagnosis of tuberculosis (TB) diseases. In the present study, the HLA-A*0201 restriction of ten predicted MPT63-derived CD8(+) T-cell epitopes was assessed on the basis of T2 cell line and HLA-A*0201 transgenic mice. The diagnostic potential of immunogenic peptides in active pulmonary TB patients was evaluated using an IFN-γ enzyme-linked immunospot assay. It was found that five peptides bound to HLA-A*0201 with high affinity, whereas the remaining peptides exhibited low affinity for HLA-A*0201. Five immunogenic peptides (MPT6318-26 , MPT6329-37 , MPT6320-28 , MPT635-14 and MPT6310-19 ) elicited large numbers of cytotoxic IFN-γ-secreting T cells in HLA-A*0201 transgenic mice. Each of the five immunogenic peptides was recognized by peripheral blood mononuclear cells from 45% to 73% of 40 HLA-A*0201 positive TB patients. The total diagnostic sensitivity of the five immunogenic peptides was higher than that of a T-SPOT.TB assay (based on ESAT-6 and CFP-10) (93% versus 90%). It is noticeable that the diagnostic sensitivity of the combination of five immunogenic peptides and T-SPOT.TB assay reached 100%. These MPT63-derived HLA-A*0201-restricted CD8(+) T-cell epitopes would likely contribute to the immunological diagnosis of M. tuberculosis infection and may provide the components for designing an effective TB vaccine.
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Affiliation(s)
- Zhiliang Duan
- Department of Clinical Laboratory, Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Xueyuan West Road
| | - Dezhou Li
- Institute of Arboviruses, School of Basic Medical Sciences, Wenzhou Medical University, Chashan, Wenzhou 325000.,Department of Liver Disease, Second People's Hospital of Ningbo, Ningbo 315010
| | - Qingjun Jia
- Institute of Arboviruses, School of Basic Medical Sciences, Wenzhou Medical University, Chashan, Wenzhou 325000.,Department of Microbiology and Immunology, School of Basic Medical Sciences, Wenzhou Medical University, Chashan, Wenzhou 325000, China
| | - Juanjuan Xu
- Institute of Arboviruses, School of Basic Medical Sciences, Wenzhou Medical University, Chashan, Wenzhou 325000.,Department of Microbiology and Immunology, School of Basic Medical Sciences, Wenzhou Medical University, Chashan, Wenzhou 325000, China
| | - Xinyu Chen
- Department of Clinical Laboratory, Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Xueyuan West Road.,Institute of Arboviruses, School of Basic Medical Sciences, Wenzhou Medical University, Chashan, Wenzhou 325000
| | - Zhigang Xu
- Institute of Arboviruses, School of Basic Medical Sciences, Wenzhou Medical University, Chashan, Wenzhou 325000.,Department of Microbiology and Immunology, School of Basic Medical Sciences, Wenzhou Medical University, Chashan, Wenzhou 325000, China
| | - Huifang Liu
- Institute of Arboviruses, School of Basic Medical Sciences, Wenzhou Medical University, Chashan, Wenzhou 325000.,Department of Microbiology and Immunology, School of Basic Medical Sciences, Wenzhou Medical University, Chashan, Wenzhou 325000, China
| | - Bokun Chen
- Institute of Arboviruses, School of Basic Medical Sciences, Wenzhou Medical University, Chashan, Wenzhou 325000
| | - Jinsheng Wen
- Institute of Arboviruses, School of Basic Medical Sciences, Wenzhou Medical University, Chashan, Wenzhou 325000.,Department of Microbiology and Immunology, School of Basic Medical Sciences, Wenzhou Medical University, Chashan, Wenzhou 325000, China
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15
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Zhai MX, Chen F, Zhao YY, Wu YH, Li GD, Gao YF, Qi YM. Novel epitopes identified from efflux pumps of Mycobacterium tuberculosis could induce cytotoxic T lymphocyte response. PeerJ 2015; 3:e1229. [PMID: 26417538 PMCID: PMC4582945 DOI: 10.7717/peerj.1229] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 08/14/2015] [Indexed: 12/05/2022] Open
Abstract
Overcoming drug-resistance is one of the major challenges to control tuberculosis (TB). The up-regulation of efflux pumps is one common mechanism that leads to drug-resistance. Therefore, immunotherapy targeting these efflux pump antigens could be promising strategy to be combined with current chemotherapy. Considering that CD8+ cytotoxic T lymphocytes (CTLs) induced by antigenic peptides (epitopes) could elicit HLA-restricted anti-TB immune response, efflux pumps from classical ABC family (Mycobacterium tuberculosis, Mtb) were chosen as target antigens to identify CTL epitopes. HLA-A2 restricted candidate peptides from Rv2937, Rv2686c and Rv2687c of Mycobacterium tuberculosis were predicted, synthesized and tested. Five peptides could induce IFN-γ release and cytotoxic activity in PBMCs from HLA-A2+ PPD+ donors. Results from HLA-A2/Kb transgenic mice immunization assay suggested that four peptides Rv2937-p168, Rv2937-p266, Rv2686c-p151, and Rv2686c-p181 could induce significant CTL response in vivo. These results suggested that these novel epitopes could be used as immunotherapy candidates to TB drug-resistance.
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Affiliation(s)
- Ming-Xia Zhai
- School of Life Sciences, Zhengzhou University , Zhengzhou , China
| | - Fei Chen
- School of Life Sciences, Zhengzhou University , Zhengzhou , China
| | - Yuan-Yuan Zhao
- School of Life Sciences, Zhengzhou University , Zhengzhou , China
| | - Ya-Hong Wu
- School of Life Sciences, Zhengzhou University , Zhengzhou , China
| | - Guo-Dong Li
- School of Life Sciences, Zhengzhou University , Zhengzhou , China
| | - Yan-Feng Gao
- School of Life Sciences, Zhengzhou University , Zhengzhou , China
| | - Yuan-Ming Qi
- School of Life Sciences, Zhengzhou University , Zhengzhou , China
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16
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Immunological consequences of intragenus conservation of Mycobacterium tuberculosis T-cell epitopes. Proc Natl Acad Sci U S A 2014; 112:E147-55. [PMID: 25548174 DOI: 10.1073/pnas.1416537112] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
A previous unbiased genome-wide analysis of CD4 Mycobacterium tuberculosis (MTB) recognition using peripheral blood mononuclear cells from individuals with latent MTB infection (LTBI) or nonexposed healthy controls (HCs) revealed that certain MTB sequences were unexpectedly recognized by HCs. In the present study, it was found that, based on their pattern of reactivity, epitopes could be divided into LTBI-specific, mixed reactivity, and HC-specific categories. This pattern corresponded to sequence conservation in nontuberculous mycobacteria (NTMs), suggesting environmental exposure as an underlying cause of differential reactivity. LTBI-specific epitopes were found to be hyperconserved, as previously reported, whereas the opposite was true for NTM conserved epitopes, suggesting that intragenus conservation also influences host pathogen adaptation. The biological relevance of this observation was demonstrated further by several observations. First, the T cells elicited by MTB/NTM cross-reactive epitopes in HCs were found mainly in a CCR6(+)CXCR3(+) memory subset, similar to findings in LTBI individuals. Thus, both MTB and NTM appear to elicit a phenotypically similar T-cell response. Second, T cells reactive to MTB/NTM-conserved epitopes responded to naturally processed epitopes from MTB and NTMs, whereas T cells reactive to MTB-specific epitopes responded only to MTB. Third, cross-reactivity could be translated to antigen recognition. Several MTB candidate vaccine antigens were cross-reactive, but others were MTB-specific. Finally, NTM-specific epitopes that elicit T cells that recognize NTMs but not MTB were identified. These epitopes can be used to characterize T-cell responses to NTMs, eliminating the confounding factor of MTB cross-recognition and providing insights into vaccine design and evaluation.
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17
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Ivanyi J, Ottenhoff THM. Significance of antigen and epitope specificity in tuberculosis. Front Immunol 2014; 5:524. [PMID: 25379038 PMCID: PMC4206936 DOI: 10.3389/fimmu.2014.00524] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Accepted: 10/06/2014] [Indexed: 11/13/2022] Open
Affiliation(s)
- Juraj Ivanyi
- Guy's Hospital Campus of Kings College London , London , UK
| | - Tom H M Ottenhoff
- Department of Infectious Diseases, Leiden University Medical Center , Leiden , Netherlands
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