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Ullah H, Shi X, Taj A, Cheng L, Yan Q, Sha S, Ahmad, Kang J, Haris M, Ma X, Ma Y. Mycobacterium tuberculosis PE_PGRS38 Enhances Intracellular Survival of Mycobacteria by Inhibiting TLR4/NF-κB-Dependent Inflammation and Apoptosis of the Host. BIOLOGY 2024; 13:313. [PMID: 38785795 PMCID: PMC11118070 DOI: 10.3390/biology13050313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 04/20/2024] [Accepted: 04/27/2024] [Indexed: 05/25/2024]
Abstract
Mycobacterium tuberculosis (Mtb) ranks as the most lethal human pathogen, able to fend off repeated attacks by the immune system or medications. PE_PGRS proteins are hallmarks of the pathogenicity of Mtb and contribute to its antigenic diversity, virulence, and persistence during infection. M. smegmatis is a nonpathogenic mycobacterium that naturally lacks PE_PGRS and is used as a model to express Mtb proteins. PE_PGRS has the capability to evade host immune responses and enhance the intracellular survival of M. smegmatis. Despite the intense investigations into PE_PGRS proteins, their role in tuberculosis remains elusive. We engineered the recombinant M. smegmatis strain Ms-PE_PGRS38. The result shows that PE_PGRS38 is expressed in the cell wall of M. smegmatis. PE_PGRS38 contributes to biofilm formation, confers permeability to the cell wall, and shows variable responses to exogenous stresses. PE_PGRS38 downregulated TLR4/NF-κB signaling in RAW264.7 macrophages and lung tissues of infected mice. In addition, PE_PGRS38 decreased NLRP3-dependent IL-1β release and limited pathogen-mediated inflammasome activity during infection. Moreover, PE_PGRS38 inhibited the apoptosis of RAW264.7 cells by downregulating the expression of apoptotic markers including Bax, cytochrome c, caspase-3, and caspase-9. In a nutshell, our findings demonstrate that PE_PGRS38 is a virulence factor for Mtb that enables recombinant M. smegmatis to survive by resisting and evading the host's immune responses during infection.
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Affiliation(s)
- Hayan Ullah
- Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian 116044, China; (H.U.); (A.T.); (L.C.); (S.S.); (J.K.); (M.H.)
- Department of Microbiology, Dalian Medical University, Dalian 116044, China;
| | - Xiaoxia Shi
- Department of Experimental Teaching Center of Public Health, Dalian Medical University, Dalian 116044, China;
| | - Ayaz Taj
- Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian 116044, China; (H.U.); (A.T.); (L.C.); (S.S.); (J.K.); (M.H.)
| | - Lin Cheng
- Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian 116044, China; (H.U.); (A.T.); (L.C.); (S.S.); (J.K.); (M.H.)
| | - Qiulong Yan
- Department of Microbiology, Dalian Medical University, Dalian 116044, China;
| | - Shanshan Sha
- Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian 116044, China; (H.U.); (A.T.); (L.C.); (S.S.); (J.K.); (M.H.)
| | - Ahmad
- Department of Immunology, Dalian Medical University, Dalian 116044, China;
| | - Jian Kang
- Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian 116044, China; (H.U.); (A.T.); (L.C.); (S.S.); (J.K.); (M.H.)
| | - Muhammad Haris
- Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian 116044, China; (H.U.); (A.T.); (L.C.); (S.S.); (J.K.); (M.H.)
| | - Xiaochi Ma
- Pharmaceutical Research Center, The Second Affiliated Hospital, Dalian Medical University, Dalian 116044, China
| | - Yufang Ma
- Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian 116044, China; (H.U.); (A.T.); (L.C.); (S.S.); (J.K.); (M.H.)
- Department of Microbiology, Dalian Medical University, Dalian 116044, China;
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2
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Gong W, Pan C, Cheng P, Wang J, Zhao G, Wu X. Peptide-Based Vaccines for Tuberculosis. Front Immunol 2022; 13:830497. [PMID: 35173740 PMCID: PMC8841753 DOI: 10.3389/fimmu.2022.830497] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 01/10/2022] [Indexed: 12/12/2022] Open
Abstract
Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis. As a result of the coronavirus disease 2019 (COVID-19) pandemic, the global TB mortality rate in 2020 is rising, making TB prevention and control more challenging. Vaccination has been considered the best approach to reduce the TB burden. Unfortunately, BCG, the only TB vaccine currently approved for use, offers some protection against childhood TB but is less effective in adults. Therefore, it is urgent to develop new TB vaccines that are more effective than BCG. Accumulating data indicated that peptides or epitopes play essential roles in bridging innate and adaptive immunity and triggering adaptive immunity. Furthermore, innovations in bioinformatics, immunoinformatics, synthetic technologies, new materials, and transgenic animal models have put wings on the research of peptide-based vaccines for TB. Hence, this review seeks to give an overview of current tools that can be used to design a peptide-based vaccine, the research status of peptide-based vaccines for TB, protein-based bacterial vaccine delivery systems, and animal models for the peptide-based vaccines. These explorations will provide approaches and strategies for developing safer and more effective peptide-based vaccines and contribute to achieving the WHO's End TB Strategy.
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Affiliation(s)
- Wenping Gong
- Tuberculosis Prevention and Control Key Laboratory/Beijing Key Laboratory of New Techniques of Tuberculosis Diagnosis and Treatment, Senior Department of Tuberculosis, The 8th Medical Center of PLA General Hospital, Beijing, China
| | - Chao Pan
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing, China
| | - Peng Cheng
- Tuberculosis Prevention and Control Key Laboratory/Beijing Key Laboratory of New Techniques of Tuberculosis Diagnosis and Treatment, Senior Department of Tuberculosis, The 8th Medical Center of PLA General Hospital, Beijing, China
- Hebei North University, Zhangjiakou City, China
| | - Jie Wang
- Tuberculosis Prevention and Control Key Laboratory/Beijing Key Laboratory of New Techniques of Tuberculosis Diagnosis and Treatment, Senior Department of Tuberculosis, The 8th Medical Center of PLA General Hospital, Beijing, China
| | - Guangyu Zhao
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Xueqiong Wu
- Tuberculosis Prevention and Control Key Laboratory/Beijing Key Laboratory of New Techniques of Tuberculosis Diagnosis and Treatment, Senior Department of Tuberculosis, The 8th Medical Center of PLA General Hospital, Beijing, China
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3
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Padh H, Yagnik B, Sharma D, Desai P. EpiMix Based Novel Vaccine Candidate for Shigella: Evidence of Prophylactic Immunity in Balb/c Mice. Int J Pept Res Ther 2021; 27:1095-1110. [PMID: 33551691 PMCID: PMC7846920 DOI: 10.1007/s10989-020-10153-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/21/2020] [Indexed: 12/01/2022]
Abstract
Multidrug resistant Shigella is one of the leading causes of mortality in children and infants. Availability of vaccine could prevent the Shigella infection and reduce the mortality. Conventional approaches of vaccine development against shigellosis have not resulted in desirable vaccine. As shigellosis may be caused by multiple strains and serotypes, there is a need to develop a multivalent vaccine, capable of providing protection against multiple Shigella strains. To develop broad spectrum vaccine, we had previously derived a pool of conserved epitopes against Shigella by using multiple immunoinformatic tools. In this study, the identified conserved epitopes derived from the Outer Membrane Proteins A and C of Shigella were chemically synthesized, and the EpiMix made up of 5 epitopes coupled to a carrier protein, ovalbumin was developed and validated for its immunogenicity. The intramuscular immunization with EpiMix in Balb/c mice led to increase in EpiMix specific serum IgG, and significant increase in fecal IgA as well as in IL-4, IL-2and IFN-γ levels. Further, the EpiMix immunized mice showed protection when challenged against S. flexneri ATCC 12022 using the intraperitoneal route. Moreover, the analysis of cytokine profile and IFN-γ/IL4 ratio in post Shigella challenge immunized mice suggested the high levels of IFN-γ levels and possible dominance of Th1 response, playing pivotal role in the elimination of Shigella. Collectively, the results demonstrate the immunogenic potential and protective efficacy of the EpiMix in the murine shigellosis model. However, the detailed study and further optimisation of epitopes would substantiate the prospective use of EpiMix as a prophylactic candidate for vaccination.
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Affiliation(s)
- Harish Padh
- Sardar Patel University, Vallabh Vidyanagar, Gujarat 388120 India
| | - Bhrugu Yagnik
- Department of Cell and Molecular Biology, B.V. Patel Pharmaceutical Education and Research Development (PERD) Centre, Ahmedabad, Gujarat 380054 India
- BRD School of Bioscience, Sardar Patel University, Vallabh Vidyanagar, Gujarat 388120 India
| | - Drashya Sharma
- Department of Cell and Molecular Biology, B.V. Patel Pharmaceutical Education and Research Development (PERD) Centre, Ahmedabad, Gujarat 380054 India
- BRD School of Bioscience, Sardar Patel University, Vallabh Vidyanagar, Gujarat 388120 India
| | - Priti Desai
- Department of Cell and Molecular Biology, B.V. Patel Pharmaceutical Education and Research Development (PERD) Centre, Ahmedabad, Gujarat 380054 India
- Department of Biological Science and Biotechnology, Institute of Advanced Research (IAR), Institutional Area, Koba, Gandhinagar, Gujarat 382426 India
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4
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PE_PGRS33, an Important Virulence Factor of Mycobacterium tuberculosis and Potential Target of Host Humoral Immune Response. Cells 2021; 10:cells10010161. [PMID: 33467487 PMCID: PMC7830552 DOI: 10.3390/cells10010161] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 01/04/2021] [Accepted: 01/12/2021] [Indexed: 01/16/2023] Open
Abstract
PE_PGRS proteins are surface antigens of Mycobacterium tuberculosis (Mtb) and a few other pathogenic mycobacteria. The PE_PGRS33 protein is among the most studied PE_PGRSs. It is known that the PE domain of PE_PGRS33 is required for the protein translocation through the mycobacterial cell wall, where the PGRS domain remains available for interaction with host receptors. Interaction with Toll like receptor 2 (TLR2) promotes secretion of inflammatory chemokines and cytokines, which are key in the immunopathogenesis of tuberculosis (TB). In this review, we briefly address some key challenges in the development of a TB vaccine and attempt to provide a rationale for the development of new vaccines aimed at fostering a humoral response against Mtb. Using PE_PGRS33 as a model for a surface-exposed antigen, we exploit the availability of current structural data using homology modeling to gather insights on the PGRS domain features. Our study suggests that the PGRS domain of PE_PGRS33 exposes four PGII sandwiches on the outer surface, which, we propose, are directly involved through their loops in the interactions with the host receptors and, as such, are promising targets for a vaccination strategy aimed at inducing a humoral response.
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5
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Sharma T, Grover S, Arora N, P M, Ehtesham NZ, Hasnain SE. PGRS Domain of Rv0297 of Mycobacterium tuberculosis Is Involved in Modulation of Macrophage Functions to Favor Bacterial Persistence. Front Cell Infect Microbiol 2020; 10:451. [PMID: 33042856 PMCID: PMC7517703 DOI: 10.3389/fcimb.2020.00451] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Accepted: 07/23/2020] [Indexed: 01/04/2023] Open
Abstract
Mycobacterium tuberculosis (M. tb) Rv0297-encoded PE_PGRS5 has been known to be expressed at the later stages of infection and in acidified phagosomes during transcriptome and proteomic studies. The possible role of Rv0297 in the modulation of phagosomal maturation and in providing protection against a microbicidal environment has been hypothesized. We show that Rv0297PGRS is involved in modulating the calcium homeostasis of macrophages followed by impedance of the phagolysosomal acidification process. This is evident from the downregulation of the late endosomal markers (Rab7 and cathepsin D) in the macrophages infected with recombinant Mycobacterium smegmatis (rM.smeg)—M.smeg_Rv0297 and M.smeg_Rv0297PGRS—or treated with recombinant Rv0297PGRS protein. Macrophages infected with rM.smeg expressing Rv0297 produce nitric oxide and undergo apoptosis, which may aid in the dissemination of pathogen in the later stages of infection. Rv0297 was also found to be involved in rescuing the bacterium from oxidative and hypoxic stress employed by macrophages and augmented the survivability of the recombinant bacterium. These results attribute to the functional significance of this protein in M.tb virulence mechanism. The fact that this protein gets expressed at the later stages of lung granulomas during M.tb infection suggests that the bacterium possibly employs Rv0297 as its dissemination and survival strategy.
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Affiliation(s)
- Tarina Sharma
- Kusuma School of Biological Sciences, Indian Institute of Technology, New Delhi, India
| | - Sonam Grover
- Institute of Molecular Medicine, Jamia Hamdard, New Delhi, India
| | - Naresh Arora
- Institute of Molecular Medicine, Jamia Hamdard, New Delhi, India
| | - Manjunath P
- ICMR-National Institute of Pathology, New Delhi, India
| | | | - Seyed Ehtesham Hasnain
- Institute of Molecular Medicine, Jamia Hamdard, New Delhi, India.,Dr. Reddy's Institute of Life Sciences, Hyderabad, India
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6
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The PGRS Domain of Mycobacterium tuberculosis PE_PGRS Protein Rv0297 Is Involved in Endoplasmic Reticulum Stress-Mediated Apoptosis through Toll-Like Receptor 4. mBio 2018; 9:mBio.01017-18. [PMID: 29921671 PMCID: PMC6016250 DOI: 10.1128/mbio.01017-18] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The genome of Mycobacterium tuberculosis, the causal organism of tuberculosis (TB), encodes a unique protein family known as the PE/PPE/PGRS family, present exclusively in the genus Mycobacterium and nowhere else in the living kingdom, with largely unexplored functions. We describe the functional significance of the PGRS domain of Rv0297, a member of this family. In silico analyses revealed the presence of intrinsically disordered stretches and putative endoplasmic reticulum (ER) localization signals in the PGRS domain of Rv0297 (Rv0297PGRS). The PGRS domain aids in ER localization, which was shown by infecting macrophage cells with M. tuberculosis and by overexpressing the protein by transfection in macrophage cells followed by activation of the unfolded protein response, as evident from increased expression of GRP78/GRP94 and CHOP/ATF4, leading to disruption of intracellular Ca2+ homeostasis and increased nitric oxide (NO) and reactive oxygen species (ROS) production. The consequent activation of the effector caspase-8 resulted in apoptosis of macrophages, which was Toll-like receptor 4 (TLR4) dependent. Administration of recombinant Rv0297PGRS (rRv0297PGRS) also exhibited similar effects. These results implicate a hitherto-unknown role of the PGRS domain of the PE_PGRS protein family in ER stress-mediated cell death through TLR4. Since this protein is already known to be present at later stages of infection in human granulomas it points to the possibility of it being employed by M. tuberculosis for its dissemination via an apoptotic mechanism. Apoptosis is generally thought to be a defense mechanism in protecting the host against Mycobacterium tuberculosis in early stages of infection. However, apoptosis during later stages in lung granulomas may favor the bacterium in disseminating the disease. ER stress has been found to induce apoptosis in TB granulomas, in zones where apoptotic macrophages accumulate in mice and humans. In this study, we report ER stress-mediated apoptosis of host cells by the Rv0297-encoded PE_PGRS5 protein of M. tuberculosis exceptionally present in the pathogenic Mycobacterium genus. The PGRS domain of Rv0297 aids the protein in localizing to the ER and induces the unfolded protein response followed by apoptosis of macrophages. The effect of the Rv0297PGRS domain was found to be TLR4 dependent. This study presents novel insights on the strategies employed by M. tuberculosis to disseminate the disease.
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7
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Mycobacterium tuberculosis PE_PGRS18 enhances the intracellular survival of M. smegmatis via altering host macrophage cytokine profiling and attenuating the cell apoptosis. Apoptosis 2018; 22:502-509. [PMID: 27987050 DOI: 10.1007/s10495-016-1336-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Mycobacterium tuberculosis PE/PPE family proteins, named after the presence of conserved PE (Pro-Glu) and PPE (Pro-Pro-Glu) domains at N-terminal, are prevalent in M. tuberculosis genome. The function of most PE/PPE family proteins remains elusive. To characterize the function of PE_PGRS18, the encoding gene was heterologously expressed in M. smegmatis, a nonpathogenic mycobacterium. The recombinant PE_PGRS18 is cell wall associated. M. smegmatis PE_PGRS18 recombinant showed differential response to stresses and altered the production of host cytokines IL-6, IL-1β, IL-12p40 and IL-10, as well as enhanced survival within macrophages largely via attenuating the apoptosis of macrophages. In summary, the study firstly unveiled the role of PE_PGRS18 in physiology and pathogenesis of mycobacterium.
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8
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Sayes F, Pawlik A, Frigui W, Gröschel MI, Crommelynck S, Fayolle C, Cia F, Bancroft GJ, Bottai D, Leclerc C, Brosch R, Majlessi L. CD4+ T Cells Recognizing PE/PPE Antigens Directly or via Cross Reactivity Are Protective against Pulmonary Mycobacterium tuberculosis Infection. PLoS Pathog 2016; 12:e1005770. [PMID: 27467705 PMCID: PMC4965174 DOI: 10.1371/journal.ppat.1005770] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 06/27/2016] [Indexed: 01/01/2023] Open
Abstract
Mycobacterium tuberculosis (Mtb), possesses at least three type VII secretion systems, ESX-1, -3 and -5 that are actively involved in pathogenesis and host-pathogen interaction. We recently showed that an attenuated Mtb vaccine candidate (Mtb Δppe25-pe19), which lacks the characteristic ESX-5-associated pe/ppe genes, but harbors all other components of the ESX-5 system, induces CD4+ T-cell immune responses against non-esx-5-associated PE/PPE protein homologs. These T cells strongly cross-recognize the missing esx-5-associated PE/PPE proteins. Here, we characterized the fine composition of the functional cross-reactive Th1 effector subsets specific to the shared PE/PPE epitopes in mice immunized with the Mtb Δppe25-pe19 vaccine candidate. We provide evidence that the Mtb Δppe25-pe19 strain, despite its significant attenuation, is comparable to the WT Mtb strain with regard to: (i) its antigenic repertoire related to the different ESX systems, (ii) the induced Th1 effector subset composition, (iii) the differentiation status of the Th1 cells induced, and (iv) its particular features at stimulating the innate immune response. Indeed, we found significant contribution of PE/PPE-specific Th1 effector cells in the protective immunity against pulmonary Mtb infection. These results offer detailed insights into the immune mechanisms underlying the remarkable protective efficacy of the live attenuated Mtb Δppe25-pe19 vaccine candidate, as well as the specific potential of PE/PPE proteins as protective immunogens. Mycobacterium tuberculosis (Mtb), the causative agent of human tuberculosis, is one of the most widely spread human pathogens, responsible for more than 9.6 million of new tuberculosis cases and 1.5 million deaths, annually. The resurgence of pulmonary tuberculosis in immuno-compromised patients, including HIV-co-infected populations, and increasing spread of drug-resistant Mtb strains are worrying. Given the estimated 2 billion cases of latent Mtb infections and the only partial efficacy of the unique, currently available tuberculosis-vaccine Mycobacterium bovis BCG (Bacille Calmette-Guerin) it is necessary to develop improved vaccines. Here, we demonstrate that the host cellular immunity, mediated by CD4+ T lymphocytes, specific to the “PE/PPE” families of mycobacterial antigens, contribute to the protection against Mtb-induced disease. We revealed the fine composition of the PE/PPE-specific T cells by characterizing their effector functions and differentiation status. We previously described a live attenuated mycobacterial strain as a vaccine candidate that is able to induce such CD4+ T cells and which displays particular properties at stimulating the cells of the innate immune system. These responses play a central role in the initiation of the host defense and in the protection against tuberculosis. Our results pave the way for further development of candidates in preclinical models of anti-tuberculosis vaccination.
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Affiliation(s)
- Fadel Sayes
- Institut Pasteur, Unité de Pathogénomique Mycobactérienne Intégrée, Paris, France
| | - Alexandre Pawlik
- Institut Pasteur, Unité de Pathogénomique Mycobactérienne Intégrée, Paris, France
| | - Wafa Frigui
- Institut Pasteur, Unité de Pathogénomique Mycobactérienne Intégrée, Paris, France
| | - Matthias I. Gröschel
- Institut Pasteur, Unité de Pathogénomique Mycobactérienne Intégrée, Paris, France
| | - Samuel Crommelynck
- Institut Pasteur, Unité de Pathogénomique Mycobactérienne Intégrée, Paris, France
| | - Catherine Fayolle
- Institut Pasteur, Unité de Régulation Immunitaire et Vaccinologie, Paris, France
- INSERM U1041, Paris, France
| | - Felipe Cia
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | - Daria Bottai
- University of Pisa, Ricerca Traslazionale e delle Nuove Tecnologie in Medicina e Chirurgia, Pisa, Italy
| | - Claude Leclerc
- Institut Pasteur, Unité de Régulation Immunitaire et Vaccinologie, Paris, France
- INSERM U1041, Paris, France
| | - Roland Brosch
- Institut Pasteur, Unité de Pathogénomique Mycobactérienne Intégrée, Paris, France
| | - Laleh Majlessi
- Institut Pasteur, Unité de Pathogénomique Mycobactérienne Intégrée, Paris, France
- * E-mail:
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9
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Phelan JE, Coll F, Bergval I, Anthony RM, Warren R, Sampson SL, Gey van Pittius NC, Glynn JR, Crampin AC, Alves A, Bessa TB, Campino S, Dheda K, Grandjean L, Hasan R, Hasan Z, Miranda A, Moore D, Panaiotov S, Perdigao J, Portugal I, Sheen P, de Oliveira Sousa E, Streicher EM, van Helden PD, Viveiros M, Hibberd ML, Pain A, McNerney R, Clark TG. Recombination in pe/ppe genes contributes to genetic variation in Mycobacterium tuberculosis lineages. BMC Genomics 2016; 17:151. [PMID: 26923687 PMCID: PMC4770551 DOI: 10.1186/s12864-016-2467-y] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 02/12/2016] [Indexed: 11/23/2022] Open
Abstract
Background Approximately 10 % of the Mycobacterium tuberculosis genome is made up of two families of genes that are poorly characterized due to their high GC content and highly repetitive nature. The PE and PPE families are typified by their highly conserved N-terminal domains that incorporate proline-glutamate (PE) and proline-proline-glutamate (PPE) signature motifs. They are hypothesised to be important virulence factors involved with host-pathogen interactions, but their high genetic variability and complexity of analysis means they are typically disregarded in genome studies. Results To elucidate the structure of these genes, 518 genomes from a diverse international collection of clinical isolates were de novo assembled. A further 21 reference M. tuberculosis complex genomes and long read sequence data were used to validate the approach. SNP analysis revealed that variation in the majority of the 168 pe/ppe genes studied was consistent with lineage. Several recombination hotspots were identified, notably pe_pgrs3 and pe_pgrs17. Evidence of positive selection was revealed in 65 pe/ppe genes, including epitopes potentially binding to major histocompatibility complex molecules. Conclusions This, the first comprehensive study of the pe and ppe genes, provides important insight into M. tuberculosis diversity and has significant implications for vaccine development. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2467-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jody E Phelan
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, WC1E 7HT, London, UK.
| | - Francesc Coll
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, WC1E 7HT, London, UK.
| | - Indra Bergval
- KIT Biomedical Research, Royal Tropical Institute, Amsterdam, Netherlands.
| | - Richard M Anthony
- KIT Biomedical Research, Royal Tropical Institute, Amsterdam, Netherlands.
| | - Rob Warren
- Department of Science and Technology and National Research Foundation Centre of Excellence for Biomedical Tuberculosis Research, and Medical Research Council Centre for Molecular and Cellular Biology, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa.
| | - Samantha L Sampson
- Department of Science and Technology and National Research Foundation Centre of Excellence for Biomedical Tuberculosis Research, and Medical Research Council Centre for Molecular and Cellular Biology, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa.
| | - Nicolaas C Gey van Pittius
- Department of Science and Technology and National Research Foundation Centre of Excellence for Biomedical Tuberculosis Research, and Medical Research Council Centre for Molecular and Cellular Biology, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa.
| | - Judith R Glynn
- Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, WC1E 7HT, London, UK.
| | - Amelia C Crampin
- Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, WC1E 7HT, London, UK. .,Karonga Prevention Study, Lilongwe, Malawi.
| | - Adriana Alves
- National Mycobacterium Reference Laboratory, Porto, Portugal.
| | - Theolis Barbosa Bessa
- Centro de Pesquisas Goncalo Moniz, Fundacao Oswaldo Cruz Bahia R, Salvador, Bahia, Brazil.
| | - Susana Campino
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, WC1E 7HT, London, UK.
| | - Keertan Dheda
- Department of Medicine, Lung Infection and Immunity Unit, Division of Pulmonology & UCT Lung Institute, University of Cape Town, Cape Town, Western Cape, South Africa. .,Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, Western Cape, South Africa.
| | - Louis Grandjean
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, WC1E 7HT, London, UK. .,Laboratorio de Enfermedades Infecciosas, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru.
| | - Rumina Hasan
- Department of Pathology and Laboratory Medicine, The Aga Khan University, Stadium Road, Karachi, Pakistan.
| | - Zahra Hasan
- Department of Pathology and Laboratory Medicine, The Aga Khan University, Stadium Road, Karachi, Pakistan.
| | - Anabela Miranda
- National Mycobacterium Reference Laboratory, Porto, Portugal.
| | - David Moore
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, WC1E 7HT, London, UK.
| | - Stefan Panaiotov
- National Center of Infectious and Parasitic Diseases, 1504, Sofia, Bulgaria.
| | | | | | - Patricia Sheen
- Laboratorio de Enfermedades Infecciosas, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru.
| | | | - Elizabeth M Streicher
- Department of Science and Technology and National Research Foundation Centre of Excellence for Biomedical Tuberculosis Research, and Medical Research Council Centre for Molecular and Cellular Biology, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa.
| | - Paul D van Helden
- Department of Science and Technology and National Research Foundation Centre of Excellence for Biomedical Tuberculosis Research, and Medical Research Council Centre for Molecular and Cellular Biology, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa.
| | - Miguel Viveiros
- Grupo de Micobactérias, Unidade de Microbiologia Médica, Global Health and Tropical Medicine (GHTM), Instituto de Higiene e Medicina Tropical, Universidade NOVA de Lisboa (IHMT/UNL), Lisbon, Portugal.
| | - Martin L Hibberd
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, WC1E 7HT, London, UK.
| | - Arnab Pain
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia.
| | - Ruth McNerney
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, WC1E 7HT, London, UK.
| | - Taane G Clark
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, WC1E 7HT, London, UK. .,Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, WC1E 7HT, London, UK.
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Oyarzun P, Kobe B. Computer-aided design of T-cell epitope-based vaccines: addressing population coverage. Int J Immunogenet 2015. [PMID: 26211755 DOI: 10.1111/iji.12214] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Epitope-based vaccines (EVs) make use of short antigen-derived peptides corresponding to immune epitopes, which are administered to trigger a protective humoral and/or cellular immune response. EVs potentially allow for precise control over the immune response activation by focusing on the most relevant - immunogenic and conserved - antigen regions. Experimental screening of large sets of peptides is time-consuming and costly; therefore, in silico methods that facilitate T-cell epitope mapping of protein antigens are paramount for EV development. The prediction of T-cell epitopes focuses on the peptide presentation process by proteins encoded by the major histocompatibility complex (MHC). Because different MHCs have different specificities and T-cell epitope repertoires, individuals are likely to respond to a different set of peptides from a given pathogen in genetically heterogeneous human populations. In addition, protective immune responses are only expected if T-cell epitopes are restricted by MHC proteins expressed at high frequencies in the target population. Therefore, without careful consideration of the specificity and prevalence of the MHC proteins, EVs could fail to adequately cover the target population. This article reviews state-of-the-art algorithms and computational tools to guide EV design through all the stages of the process: epitope prediction, epitope selection and vaccine assembly, while optimizing vaccine immunogenicity and coping with genetic variation in humans and pathogens.
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Affiliation(s)
- P Oyarzun
- Biotechnology Centre, Facultad de Ingeniería y Tecnología, Universidad San Sebastián, Concepción, Chile
| | - B Kobe
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD, Australia
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Identification of Novel Potential Vaccine Candidates against Tuberculosis Based on Reverse Vaccinology. BIOMED RESEARCH INTERNATIONAL 2015; 2015:483150. [PMID: 25961021 PMCID: PMC4413515 DOI: 10.1155/2015/483150] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2014] [Accepted: 01/07/2015] [Indexed: 11/21/2022]
Abstract
Tuberculosis (TB) is a chronic infectious disease, considered as the second leading cause of death worldwide, caused by Mycobacterium tuberculosis. The limited efficacy of the bacillus Calmette-Guérin (BCG) vaccine against pulmonary TB and the emergence of multidrug-resistant TB warrants the need for more efficacious vaccines. Reverse vaccinology uses the entire proteome of a pathogen to select the best vaccine antigens by in silico approaches. M. tuberculosis H37Rv proteome was analyzed with NERVE (New Enhanced Reverse Vaccinology Environment) prediction software to identify potential vaccine targets; these 331 proteins were further analyzed with VaxiJen for the determination
of their antigenicity value. Only candidates with values ≥0.5 of antigenicity and 50% of adhesin probability and without homology with human proteins or transmembrane regions were selected, resulting in 73 antigens. These proteins were grouped by families in seven groups and analyzed by amino acid sequence alignments, selecting 16 representative proteins. For each candidate, a search of the literature and protein analysis with different bioinformatics tools, as well as a simulation of the immune response, was conducted. Finally, we selected six novel vaccine candidates, EsxL, PE26, PPE65, PE_PGRS49, PBP1, and Erp, from M. tuberculosis that can be used to improve or design new TB vaccines.
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Gastelum-Aviña P, Velazquez C, Espitia C, Lares-Villa F, Garibay-Escobar A. A PE_PGRS33 protein ofMycobacterium tuberculosis: an ideal target for future tuberculosis vaccine design. Expert Rev Vaccines 2015; 14:699-711. [DOI: 10.1586/14760584.2015.1015995] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Cohen I, Parada C, Acosta-Gío E, Espitia C. The PGRS Domain from PE_PGRS33 of Mycobacterium tuberculosis is Target of Humoral Immune Response in Mice and Humans. Front Immunol 2014; 5:236. [PMID: 24904584 PMCID: PMC4033847 DOI: 10.3389/fimmu.2014.00236] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2014] [Accepted: 05/06/2014] [Indexed: 12/05/2022] Open
Abstract
The PE_PGRS33 protein is a member of the PE family, which encompasses the PE and the PE_PGRS subfamilies. Among PE_PGRS’s, this protein is one of the most studied antigens and its immunomodulatory properties are influence by both PE and PGRS domains. However, the contribution of these domains to the host immune recognition of the PE_PGRS33 protein and their potential role in latent tuberculosis infection in humans is still unknown. In this study, the immunogenic properties of the complete PE_PGRS33 protein and each domain separately were evaluated in BALB/c mice and latent tuberculosis infected (LTBI) humans. In mice, PE_PGRS33 and its domains induced similar antibody production and secretion of IFN-γ. PE_PGRS33 and the PE domain stimulated higher CD4+ and CD8+ T-cell proliferation compared to the PGRS domain. This demonstrated that the principal difference in the immune recognition of the domains is the higher activation of T-cell subpopulations involved in the control of tuberculosis. In humans, the secretion of IFN-γ in response to PE_PGRS33 was detected in both LTBI and in non-infected vaccinated individuals. The same was observed for antibody response, which targets epitopes located in the PGRS domain but not in the PE domain. These observations suggest that T and B cell responses to PE_PGRS33 are induced by BCG vaccination and can be maintained for many years in non-infected individuals. This also indicates that the IFN-γ response detected might not be associated with latent tuberculosis infection. These results contribute to the elucidation of the role of the PE_PGRS33 protein and its PE and PGRS domains in the immune response against Mycobacterium tuberculosis.
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Affiliation(s)
- Ingrid Cohen
- Departamento de Inmunología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México , Mexico City , Mexico
| | - Cristina Parada
- Departamento de Inmunología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México , Mexico City , Mexico
| | - Enrique Acosta-Gío
- Facultad de Odontología, Universidad Nacional Autónoma de México , Mexico City , Mexico
| | - Clara Espitia
- Departamento de Inmunología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México , Mexico City , Mexico
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Vani J, Shaila MS, Trinath J, Balaji KN, Kaveri SV, Bayry J. Mycobacterium tuberculosis Cell Wall–Associated Rv3812 Protein Induces Strong Dendritic Cell–Mediated Interferon γ Responses and Exhibits Vaccine Potential. J Infect Dis 2013; 208:1034-6. [DOI: 10.1093/infdis/jit281] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
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15
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Sundaramurthi JC, Brindha S, Shobitha SR, Swathi A, Ramanandan P, Hanna LE. In silico identification of potential antigenic proteins and promiscuous CTL epitopes in Mycobacterium tuberculosis. INFECTION GENETICS AND EVOLUTION 2012; 12:1312-8. [PMID: 22484107 DOI: 10.1016/j.meegid.2012.03.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Revised: 03/23/2012] [Accepted: 03/28/2012] [Indexed: 01/11/2023]
Abstract
Cell-mediated immunity is critical for the control of Mycobacterium tuberculosis infection. We hypothesized that those proteins of M. tuberculosis (MTB) that do not have homologs in humans as well as human gut flora, would mount a good antigenic response in man, and employed a bioinformatics approach to identify MTB antigens capable of inducing a robust cell-mediated immune response in humans. In the first step we identified 624 MTB proteins that had no homologs in humans. Comparison of this set of proteins with the proteome of 77 different microbes that comprise the human gut flora narrowed down the list to 180 proteins unique to MTB. Twenty nine of the 180 proteins are known to be associated with dormancy. Since dormancy associated proteins are known to harbor CTL epitopes, we selected four representative unique proteins and subjected them to epitope analysis using ProPred1. Nineteen novel promiscuous epitopes were identified in the four proteins. Population coverage for 7 of the 19 shortlisted epitopes including Rv3852 (58-KPAEAPVSL, 112-VPLIVAVTL, 118-VTLSLLALL and 123-LALLLIRQL), Rv2706c (66-RPLSGVSFL) Rv3466 (8- RIVEVFDAL and 38-RSLERLECL) was >74%. These novel promiscuous epitopes are conserved in other virulent MTB strains, and can therefore be further investigated for their immunological relevance and usefulness as vaccine candidates.
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Affiliation(s)
- Jagadish Chandrabose Sundaramurthi
- ICMR-Biomedical Informatics Centre, Department of Clinical Research, National Institute for Research in Tuberculosis (Formerly Tuberculosis Research Centre), Indian Council of Medical Research, Chennai 600 031, Tamil Nadu, India
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Mohareer K, Tundup S, Hasnain SE. Transcriptional regulation of Mycobacterium tuberculosis PE/PPE genes: a molecular switch to virulence? J Mol Microbiol Biotechnol 2012; 21:97-109. [PMID: 22286037 DOI: 10.1159/000329489] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The PE/PPE family of proteins, which constitute 10% of the coding capacity of the mycobacterial genome, comprises a unique set of genes which have no known homologs and have expanded throughout their evolution. Their association with virulence has been implicated by several researchers in tuberculosis, but the molecular basis of their virulence is yet to be completely explored. PE/PPE genes are mostly associated with the pathogenic strains of mycobacteria as many of them are known to be deleted in non-pathogenic ones. The non-essentiality of these genes for their in vitro growth but essentiality during infection highlights their active role in the host-pathogen interaction and consequently virulence. Even within the different strains of pathogenic mycobacteria and clinical isolates, many of the PE/PPE genes show sequence variation, pointing to their importance in providing antigenic variations, and have also been speculated to perform varied roles by differential expression during host-pathogen interaction. The transcriptional regulators of these genes could therefore act as a molecular switch for the pathogenesis of Mycobacterium tuberculosis. This review focuses on the expression and regulation of PE/PPE genes in the context of infection and pathogenicity and discusses the potential of these proteins as drug targets.
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Affiliation(s)
- Krishnaveni Mohareer
- Institute of Life Sciences, Hyderabad, Indian Institute of Technology Delhi, New Delhi, India
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Integrative analysis of transcriptome and genome indicates two potential genomic islands are associated with pathogenesis of Mycobacterium tuberculosis. Gene 2011; 489:21-9. [PMID: 21924330 DOI: 10.1016/j.gene.2011.08.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Revised: 07/20/2011] [Accepted: 08/26/2011] [Indexed: 11/20/2022]
Abstract
Mycobacterium tuberculosis (M.tb) is a successful human pathogen and widely prevalent throughout the world. Genomic islands (GIs) are thought to be related to pathogenicity. In this study, we predicted two potential genomic islands in M.tb genome, respectively named as GI-1 and GI-2. It is indicated that the genes belong to PE_PGRS family in GI-1 and genes involved in sulfolipid-1 (SL-1) synthesis in GI-2 are strongly associated with M.tb pathogenesis. Sequence analysis revealed that the five PGRS genes are more polymorphic than other PGRS members in full virulence M.tb complex strains at significance level 0.01 but not in attenuated strains. Expression analysis of microarrays collected from literatures displayed that GI-1 genes, especially Rv3508 might be correlated with the response to the inhibition of aerobic respiration. Microarray analysis also showed that SL-1 cluster genes are drastically down-expressed in attenuated strains relative to full virulence strains. We speculated that the effect of SL-1 on M.tb pathogenicity could be associated with long-term survival and persistence establishment during infection. Additionally, the gene Rv3508 in GI-1 was under positive selection. Rv3508 may involve the response of M.tb to the inhibition of aerobic respiration by low oxygen or drug PA-824, and it may be a common feature of genes in GI-1. These findings may provide some novel insights into M.tb physiology and pathogenesis.
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Zhang Y, Zhang H, Zhou T, Zhong Y, Jin Q. Genes under positive selection in Mycobacterium tuberculosis. Comput Biol Chem 2011; 35:319-22. [PMID: 22000803 DOI: 10.1016/j.compbiolchem.2011.08.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Revised: 07/20/2011] [Accepted: 08/11/2011] [Indexed: 12/29/2022]
Abstract
We employed an evolutionary genomics approach to detect genes under lineage-specific positive selection for the two closely related Mycobacterium tuberculosis strains, the virulent H37Rv and the avirulent H37Ra, with the clinical isolate CDC1551 as the outgroup. We found six H37Rv-specific and six H37Ra-specific positively selected genes, among which the former comprised a flavoprotein, a RNA polymerase sigma factor SigM, two PPE family proteins, as well as two hypothetical proteins, while the latter consisted of a dehydrogenase, a (3R)-hydroxyacyl-ACP dehydratase subunit HadA, a PPE family protein, and three PE-PGRS family proteins. Obviously, the PE/PPE/PE-PGRS family proteins were the main targets of positive selection. The functional discussion of our findings implied that those positively selected genes were highly involved in antigen variations and immune evasions of Mycobacterium tuberculosis.
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Affiliation(s)
- Yuan Zhang
- State Key Laboratory for Molecular Virology and Genetic Engineering, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100176, China.
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Lv Y, Yan B, Yang H, Liu J, Zhong W, Li K, Chen Z, Xu C. LMP2/LMP7 gene variant: a risk factor for intestinal Mycobacterium tuberculosis infection in the Chinese population. J Gastroenterol Hepatol 2011; 26:1145-50. [PMID: 21303409 DOI: 10.1111/j.1440-1746.2011.06693.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
BACKGROUND AND AIMS Low molecular mass protein-2 (LMP2) and low molecular mass protein-7 (LMP7) genes play a critical role in foreign antigen processing on the major histocompatibility complex-I CD8(+) cytotoxic T-lymphocyte pathway. This study was designed to investigate whether the sequence variants in the LMP2/LMP7 coding region were associated with intestinal Mycobacterium tuberculosis (M. tuberculosis) infection or with the co-infection of pulmonary tuberculosis. METHODS A total of 168 patients with intestinal tuberculosis and 235 normal controls were recruited for this study. Two polymorphisms of LMP2 (Arg60-His) and LMP7 (Gln145-Lys) were identified by polymerase chain reaction-restriction fragment length polymorphism method. The associations of the LMP2/LMP7 genotype and haplotype with intestinal M. tuberculosis infection were assessed by using logistic regression analysis. RESULTS The results revealed that LMP7 position codon 145 Lys/Lys and Gln/Lys alleles in the coding region were associated with the infection of intestinal M. tuberculosis (P=0.003, odds ratio [OR]= 3.86 and P < 0.001, OR = 2.28, respectively). Meanwhile, the Arg-Lys and Cys-Lys haplotypes exhibited significant relation to the intestinal M. tuberculosis infection (P= 0.006, OR=1.87; P=0.021, OR=1.83, respectively). No significant associations were observed for any of the single-nucleotide polymorphism genotypes or haplotypes with the co-infection of pulmonary tuberculosis (P > 0.05). CONCLUSIONS The results indicated that the genetic variant within the LMP2/LMP7 gene would increase the risk of intestinal M. tuberculosis infection.
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Affiliation(s)
- Yuan Lv
- Department of Anti-Infection and Institute of Clinical Pharmacology, Peking University First Hospital, Beijing, China
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20
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Wang J, Huang Y, Zhang A, Zhu C, Yang Z, Xu H. DNA polymorphism of Mycobacterium tuberculosis PE_PGRS33 gene among clinical isolates of pediatric TB patients and its associations with clinical presentation. Tuberculosis (Edinb) 2011; 91:287-92. [PMID: 21664871 DOI: 10.1016/j.tube.2011.05.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Revised: 04/26/2011] [Accepted: 05/09/2011] [Indexed: 11/16/2022]
Abstract
In vitro and in animal studies have suggested an important role for the Mycobacterium tuberculosis PE_PGRS33 protein in the pathogenesis of TB. A significant level of PE_PGRS33 gene DNA polymorphism among clinical isolates from adult tuberculosis (TB) patients and its association with clinical and epidemiological phenotypes of the disease has been found. To better understand the role of PE_PGRS33 protein in the pathogenesis pediatric TB, we investigated DNA polymorphism of the PE_PGRS33 gene among 101 of pediatric TB patients' isolates and assessed the relationship between the PE_PGRS33 sequence variation and clinical characteristics of TB. Twelve different PE_PGRS33 sequence variations representing 12 different alleles were observed among the 101 M. tuberculosis clinical isolates investigated. Of these 101 isolates, 62(59.41%) had PE_PGRS33 alleles that would result in a change in the amino acid sequence of the PE_PGRS33 protein. The degree of DNA polymorphism within individual M. tuberculosis isolates from pediatric TB patients was remarkably lower than that previously found in M. tuberculosis isolates from adults TB patients. The frequency distribution of isolates having PE_PGRS33 gene sequence variations was similar between Beijing and non-Beijing families of the pathogen. Patients having TB meningitis and negative PPD skin test results appeared to be more likely to be infected by isolates having a mutant type of the PE_PGRS33 gene than patients who had no TB meningitis (OR 2.54, 95% CI [1.11-5.84]) and patients who had positive PPD-skin test results (OR 4.26, 95% CI [1.14-12.86]), respectively. This study provides new insight into the molecular pathogenesis of pediatric TB.
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Affiliation(s)
- Jun Wang
- Department of Infection and Digestion, Children's Hospital of Chongqing Medical University, No. 136 Zhongshan Er Road, Yuzhong District, Chongqing 400014, PR China
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Uveitis in a Patient Treated with Bacille-Calmette-Guérin. Ophthalmology 2009; 116:2457-62.e1-2. [DOI: 10.1016/j.ophtha.2009.05.021] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2009] [Revised: 05/11/2009] [Accepted: 05/12/2009] [Indexed: 11/20/2022] Open
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Chaitra MG, Shaila MS, Nayak R. Characterization of T-cell immunogenicity of two PE/PPE proteins of Mycobacterium tuberculosis. J Med Microbiol 2008; 57:1079-1086. [PMID: 18719176 DOI: 10.1099/jmm.0.47565-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The PE and PPE proteins of Mycobacterium tuberculosis form a source of antigenic variation among different strains of this bacterium. Two of the PE_PGRS protein-encoding genes, rv3812 and rv3018c, are expressed in pathogenic mycobacteria and are implicated, respectively, in the persistence of the organism in macrophages and in virulence. Peptides derived from these proteins have been predicted to bind major histocompatibility complex (MHC) class I with high affinity on the basis of immunoinformatics analysis, suggesting a possible role for these proteins in antimycobacterial immunity. In the present work, using DNA constructs containing the rv3812 and rv3018c genes of M. tuberculosis, the immunogenicity of these proteins was demonstrated in BALB/c mice. Immunization with either DNA construct induced a significant number of CD8+-type T cells and a strong Th1-type response, with high gamma interferon (IFN-gamma) and low interleukin-4 responses. Three nonameric peptides of Rv3812 and two of Rv3018c elicited a strong T-cell response in an MHC-restricted manner. An epitope-specific response was demonstrated by the lysis of peptide-pulsed antigen-presenting cells, release of perforin and IFN-gamma production. Experimentally, these peptides bound with high affinity to MHC H-2Kd and showed low dissociation rates of peptide-MHC complexes. This study suggests that the identified T-cell epitopes may contribute to immunity against tuberculosis if included in a vaccine.
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Affiliation(s)
- M G Chaitra
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India
| | - M S Shaila
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India
| | - R Nayak
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India
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Vivona S, Gardy JL, Ramachandran S, Brinkman FSL, Raghava GPS, Flower DR, Filippini F. Computer-aided biotechnology: from immuno-informatics to reverse vaccinology. Trends Biotechnol 2008; 26:190-200. [PMID: 18291542 DOI: 10.1016/j.tibtech.2007.12.006] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2007] [Revised: 12/06/2007] [Accepted: 12/19/2007] [Indexed: 11/18/2022]
Abstract
Genome sequences from many organisms, including humans, have been completed, and high-throughput analyses have produced burgeoning volumes of 'omics' data. Bioinformatics is crucial for the management and analysis of such data and is increasingly used to accelerate progress in a wide variety of large-scale and object-specific functional analyses. Refined algorithms enable biotechnologists to follow 'computer-aided strategies' based on experiments driven by high-confidence predictions. In order to address compound problems, current efforts in immuno-informatics and reverse vaccinology are aimed at developing and tuning integrative approaches and user-friendly, automated bioinformatics environments. This will herald a move to 'computer-aided biotechnology': smart projects in which time-consuming and expensive large-scale experimental approaches are progressively replaced by prediction-driven investigations.
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Affiliation(s)
- Sandro Vivona
- Molecular Biology and Bioinformatics Unit, Department of Biology, University of Padua, Padua, Italy
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Chaitra MG, Shaila MS, Chandra NR, Nayak R. HLA-A*0201-restricted cytotoxic T-cell epitopes in three PE/PPE family proteins of Mycobacterium tuberculosis. Scand J Immunol 2008; 67:411-7. [PMID: 18248530 DOI: 10.1111/j.1365-3083.2008.02078.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
CD8+ T cells are thought to play an important role in protective immunity against tuberculosis. We report the identification of three peptides derived from Rv1818c, Rv3812 and Rv3018c proteins of Mycobacterium tuberculosis that bound to HLA-A*0201 molecules and their ability to induce in vitro T-cell response in peripheral blood lymphocytes from HLA-A*0201-positive healthy individuals (PPD+) and patients with TB. The peptide-specific cytotoxic T lymphocytes (CTL) generated were capable of recognizing peptide pulsed targets. Three 9-mer peptides bound with high affinity to HLA-A*0201 and displayed low dissociation rates of the bound peptide from HLA. Epitope-specific recognition was demonstrated by the release of perforin and gamma-interferon. Overall, our results demonstrate the presence of HLA class I-restricted CD8+ CTL against proteins from PE and PPE proteins of M. tuberculosis and identify epitopes that are strongly recognized by HLA-A*0201-restricted CD8+ T cells in humans. These epitopes thus represent potential subunit components for the design of vaccines against tuberculosis.
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Affiliation(s)
- M G Chaitra
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India
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Roles of SigB and SigF in the Mycobacterium tuberculosis sigma factor network. J Bacteriol 2007; 190:699-707. [PMID: 17993538 DOI: 10.1128/jb.01273-07] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To characterize the roles of SigB and SigF in sigma factor regulation in Mycobacterium tuberculosis, we used chemically inducible recombinant strains to conditionally overexpress sigB and sigF. Using whole genomic microarray analysis and quantitative reverse transcription-PCR, we investigated the resulting global transcriptional changes after sigB induction, and we specifically tested the relative expression of other sigma factor genes after knock-in expression of sigB and sigF. Overexpression of sigB resulted in significant upregulation of genes encoding several early culture filtrate antigens (ESAT-6-like proteins), ribosomal proteins, PE-PGRS proteins, the keto-acyl synthase, KasA, and the regulatory proteins WhiB2 and IdeR. Of note, the induction of sigB did not alter the expression of other sigma factor genes, indicating that SigB is likely to serve as an end regulator for at least one branch of the M. tuberculosis sigma factor regulatory cascade. Analysis of the 5'-untranslated region (UTR) of SigB-dependent transcripts revealed a putative consensus sequence of NGTGG-N(14-18)-NNGNNG. This sequence appeared upstream of both sigB (Rv2710) and the gene following it, ideR (Rv2711), and in vitro transcription analysis with recombinant SigB-reconstituted RNA polymerase confirmed SigB-dependent transcription from each of these promoters. Knock-in expression of sigF revealed that only the sigC gene was significantly upregulated 6 and 12 h after sigF induction. The previously identified SigF promoter consensus sequence AGTTTG-N(15)-GGGTTT was identified in the 5' UTR of the sigC gene, and SigF-dependent in vitro transcription of the promoter upstream of sigC was confirmed by using recombinant SigF-reconstituted RNA polymerase. These two knock-in recombinant strains were tested in a macrophage model of infection which showed that overexpression of sigB and sigF resulted in reduced rates of M. tuberculosis intracellular growth. These results define the SigB promoter consensus recognition sequence and members of the SigB regulon. Moreover, the data suggest that, in addition to serving as an end regulator in a sigma factor cascade, SigB may auto-amplify its own expression under certain conditions.
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