51
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Senoputra MA, Shiratori B, Hasibuan FM, Koesoemadinata RC, Apriani L, Ashino Y, Ono K, Oda T, Matsumoto M, Suzuki Y, Alisjahbana B, Hattori T. Diagnostic value of antibody responses to multiple antigens from Mycobacterium tuberculosis in active and latent tuberculosis. Diagn Microbiol Infect Dis 2015; 83:278-85. [PMID: 26307672 DOI: 10.1016/j.diagmicrobio.2015.07.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 07/23/2015] [Accepted: 07/25/2015] [Indexed: 10/23/2022]
Abstract
We investigated the antibody responses to 10 prospective Mycobacterium tuberculosis (MTB) antigens and evaluated their ability to discriminate between latent (LTBI) and active pulmonary tuberculosis (TB). Our results indicate that plasma levels of anti-α-crystallin (ACR), antilipoarabinomannan, anti-trehalose 6,6'-dimycolate, and anti-tubercular-glycolipid antigen antibodies were higher in patients with active TB, compared to those in the LTBI and control subjects. No differences in the antibodies were observed between the control and LTBI subjects. Antibodies against the glycolipid antigens could not distinguish between Mycobacterium avium complex (MAC)-negative TB patients and MAC-infected LTBI individuals. The most useful serological marker was antibodies to ACR, with MAC-negative TB patients having higher titers than those observed in MAC-positive LTBI and control subjects. Our data indicate that antibody to ACR is a promising target for the serological diagnosis of patients with active TB patients. When dealing with antiglycolipid antibodies, MAC coinfection should always be considered in serological studies.
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Affiliation(s)
- Muhammad Andrian Senoputra
- Division of Emerging Infectious Diseases, Graduate School of Medicine, Tohoku University, 21 Seiryo-machi, Aoba-ku, Sendai, 980-8574 Miyagi, Japan; Public Health Science Program, Faculty of Medicine, Universitas Padjadjaran, Jl. Eicjkman 38, Bandung, 40161, West Java, Indonesia.
| | - Beata Shiratori
- Division of Emerging Infectious Diseases, Graduate School of Medicine, Tohoku University, 21 Seiryo-machi, Aoba-ku, Sendai, 980-8574 Miyagi, Japan; Division of Disaster-related Infectious Diseases, International Research Institute of Disaster Science, Tohoku University, 2-1 Seiryo-machi, Aoba-ku, Sendai, 980-8574, Miyagi, Japan; Japan International Corporation of Welfare Services, 2-3-20 Toranomon YHK Bldg. 4F, Toranomon, Minato-ku, 105-0001 Tokyo, Japan.
| | - Fakhrial Mirwan Hasibuan
- Division of Emerging Infectious Diseases, Graduate School of Medicine, Tohoku University, 21 Seiryo-machi, Aoba-ku, Sendai, 980-8574 Miyagi, Japan; Public Health Science Program, Faculty of Medicine, Universitas Padjadjaran, Jl. Eicjkman 38, Bandung, 40161, West Java, Indonesia.
| | | | - Lika Apriani
- TB-HIV Research Center, Medical faculty, Padjadjaran University, Jl. Eicjkman 38, Bandung, 40161, West Java, Indonesia.
| | - Yugo Ashino
- Division of Emerging Infectious Diseases, Graduate School of Medicine, Tohoku University, 21 Seiryo-machi, Aoba-ku, Sendai, 980-8574 Miyagi, Japan; Division of Disaster-related Infectious Diseases, International Research Institute of Disaster Science, Tohoku University, 2-1 Seiryo-machi, Aoba-ku, Sendai, 980-8574, Miyagi, Japan.
| | - Kenji Ono
- Microbiological Research Institute, Otsuka Pharmaceutical Co., Ltd., 463-10 Kagasuno, Kawauchi-cho, 771-0192 Tokushima, Japan.
| | - Tetsuya Oda
- Microbiological Research Institute, Otsuka Pharmaceutical Co., Ltd., 463-10 Kagasuno, Kawauchi-cho, 771-0192 Tokushima, Japan.
| | - Makoto Matsumoto
- Microbiological Research Institute, Otsuka Pharmaceutical Co., Ltd., 463-10 Kagasuno, Kawauchi-cho, 771-0192 Tokushima, Japan.
| | - Yasuhiko Suzuki
- Division of Global Epidemiology, Research Center for Zoonosis Control, Hokkaido University, North 20, West 10, Kita-ku, Sapporo, 001-0020 Hokkaido, Japan.
| | - Bachti Alisjahbana
- TB-HIV Research Center, Medical faculty, Padjadjaran University, Jl. Eicjkman 38, Bandung, 40161, West Java, Indonesia.
| | - Toshio Hattori
- Division of Emerging Infectious Diseases, Graduate School of Medicine, Tohoku University, 21 Seiryo-machi, Aoba-ku, Sendai, 980-8574 Miyagi, Japan; Division of Disaster-related Infectious Diseases, International Research Institute of Disaster Science, Tohoku University, 2-1 Seiryo-machi, Aoba-ku, Sendai, 980-8574, Miyagi, Japan.
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52
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Mendum TA, Wu H, Kierzek AM, Stewart GR. Lipid metabolism and Type VII secretion systems dominate the genome scale virulence profile of Mycobacterium tuberculosis in human dendritic cells. BMC Genomics 2015; 16:372. [PMID: 25956932 PMCID: PMC4425887 DOI: 10.1186/s12864-015-1569-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 04/23/2015] [Indexed: 12/20/2022] Open
Abstract
Background Mycobacterium tuberculosis continues to kill more people than any other bacterium. Although its archetypal host cell is the macrophage, it also enters, and survives within, dendritic cells (DCs). By modulating the behaviour of the DC, M. tuberculosis is able to manipulate the host’s immune response and establish an infection. To identify the M. tuberculosis genes required for survival within DCs we infected primary human DCs with an M. tuberculosis transposon library and identified mutations with a reduced ability to survive. Results Parallel sequencing of the transposon inserts of the surviving mutants identified a large number of genes as being required for optimal intracellular fitness in DCs. Loci whose mutation attenuated intracellular survival included those involved in synthesising cell wall lipids, not only the well-established virulence factors, pDIM and cord factor, but also sulfolipids and PGL, which have not previously been identified as having a direct virulence role in cells. Other attenuated loci included the secretion systems ESX-1, ESX-2 and ESX-4, alongside many PPE genes, implicating a role for ESX-5. In contrast the canonical ESAT-6 family of ESX substrates did not have intra-DC fitness costs suggesting an alternative ESX-1 associated virulence mechanism. With the aid of a gene-nutrient interaction model, metabolic processes such as cholesterol side chain catabolism, nitrate reductase and cysteine-methionine metabolism were also identified as important for survival in DCs. Conclusion We conclude that many of the virulence factors required for survival in DC are shared with macrophages, but that survival in DCs also requires several additional functions, such as cysteine-methionine metabolism, PGLs, sulfolipids, ESX systems and PPE genes. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1569-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Tom A Mendum
- Department of Microbial and Cellular Sciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford, GU2 7XH, UK.
| | - Huihai Wu
- Department of Microbial and Cellular Sciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford, GU2 7XH, UK.
| | - Andrzej M Kierzek
- Department of Microbial and Cellular Sciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford, GU2 7XH, UK.
| | - Graham R Stewart
- Department of Microbial and Cellular Sciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford, GU2 7XH, UK.
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53
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Jiang Y, Liu H, Li M, Li G, Pang H, Dou X, Zhao X, Wan K. Single nucleotide polymorphism in Ag85 genes of Mycobacterium tuberculosis complex: analysis of 178 clinical isolates from China and 13 BCG strains. Int J Med Sci 2015; 12:126-34. [PMID: 25589888 PMCID: PMC4293177 DOI: 10.7150/ijms.9951] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Accepted: 12/01/2014] [Indexed: 11/05/2022] Open
Abstract
Host immune pressure and associated immune evasion of pathogenic bacteria are key features of host-pathogen co-evolution. Human T-cell epitopes of Mycobacterium tuberculosis (M. tuberculosis) were evolutionarily hyperconserved and thus it was deduced that M. tuberculosis lacks antigenic variation and immune evasion. However, in our previous studies, proteins MPT64, PstS1, Rv0309 and Rv2945c all harbored higher numbers of amino acid substitutions in their T cell epitopes, which suggests their roles in ongoing immune evasion. Here, we used the same set of 180 clinical M. tuberculosis complex (MTBC) isolates from China, amplified the genes encoding Ag85 complex, and compared the sequences. The results showed that Ag85 were hyperconserved in T/B cell epitopes and the genes were more likely to be under purifying selection. The divergence of host immune selection on different proteins may result from different function of the proteins. In addition, A312G of Ag85A and T418C of Ag85B may represent special mutations in BCG strains, which may be used to differentiate M.bovis and BCG strains from MTB strains. Also, C714A in Ag85B seems to be a valuable phylogenetic marker for Beijing strains.
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Affiliation(s)
- Yi Jiang
- 1. 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 102206, P. R. China ; 2. Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou 310003, China
| | - Haican Liu
- 1. 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 102206, P. R. China ; 2. Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou 310003, China
| | - Machao Li
- 1. 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 102206, P. R. China ; 2. Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou 310003, China
| | - Guilian Li
- 1. 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 102206, P. R. China ; 2. Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou 310003, China
| | - Hui Pang
- 3. Immunology Department, Changzhi Medical College, Shanxi, China
| | - Xiangfeng Dou
- 4. Beijing Center for Diseases Prevention and Control, Beijing 100013, China
| | - Xiuqin Zhao
- 1. 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 102206, P. R. China ; 2. Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou 310003, China
| | - Kanglin Wan
- 1. 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 102206, P. R. China ; 2. Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou 310003, China
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Aghababa H, Mohabati Mobarez A, Khoramabadi N, Behmanesh M, Mahdavi M, Tebianian M, Nejati M. A comparative approach to strategies for cloning, expression, and purification of Mycobacterium tuberculosis mycolyl transferase 85B and evaluation of immune responses in BALB/c mice. Mol Biotechnol 2014; 56:487-97. [PMID: 24619477 DOI: 10.1007/s12033-013-9696-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Protein antigens have drawn a lot of attention from investigators working on tuberculosis vaccines. These proteins can be used to improve the immunogenicity of the new generation BCG vaccines or even replace them completely. Recombinant technology is used to insure the production of pure mycobacterial antigens in high quantities. Mycolyl transferase 85B (Ag85B) is a potent, mycobacterial antigen that significantly stimulates immune responses. Since Ag85B is an apolar protein, production of the water-soluble antigen is of interest. In this work, we report a systematic optimization strategy concerning cloning systems and purification methods, aiming at increasing the yield of recombinant Ag85B. Our optimized method resulted in a yield of 8 mg of recombinant Ag85B from 1 liter of induced culture (400 μg/ml) by using pET32a(+), Escherichia coli Rosseta-gami™(DE3) pLysS and a Ni-NTA agarose-based procedure and on-column re-solubilization. The purified recombinant Ag85B showed strong immunostimulating properties by inducing high levels of TNF-α, IFN-γ, IL-12, and IgG2a in immunized mice, therefore it can effectively be applied in TB vaccine researches.
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Affiliation(s)
- Haniyeh Aghababa
- Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
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55
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Welsh KJ, Hunter RL, Actor JK. Trehalose 6,6'-dimycolate--a coat to regulate tuberculosis immunopathogenesis. Tuberculosis (Edinb) 2014; 93 Suppl:S3-9. [PMID: 24388646 DOI: 10.1016/s1472-9792(13)70003-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Tuberculosis (TB) remains a significant public health burden worldwide. Treatment of this disease requires a minimum of six months and there is no vaccine available for the most common form of the disease. Increasing evidence suggests that the mycobacterial glycolipid trehalose 6,6' dimycolate (TDM; cord factor) plays a key role in the pathogenesis of TB disease. TDM protects the TB bacilli from macrophage-mediated killing, inhibits effective antigen presentation, and reduces the formation of protective T-cell responses. TDM promotes initiation of granuloma formation and likely plays a role in caseation. Furthermore, TDM may contribute to the development of post primary disease. Receptors for TDM were recently described and are expected to contribute to our knowledge of the molecular pathogenesis of TB disease. In this manner, understanding TDM may prove promising towards development of targeted TB therapeutics to limit clinical pathologies.
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Affiliation(s)
- Kerry J Welsh
- Department of Pathology, Medical School, University of Texas-Houston Medical School, Houston, Texas, USA
| | - Robert L Hunter
- Department of Pathology, Medical School, University of Texas-Houston Medical School, Houston, Texas, USA
| | - Jeffrey K Actor
- Department of Pathology, Medical School, University of Texas-Houston Medical School, Houston, Texas, USA.
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56
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Angala SK, Belardinelli JM, Huc-Claustre E, Wheat WH, Jackson M. The cell envelope glycoconjugates of Mycobacterium tuberculosis. Crit Rev Biochem Mol Biol 2014; 49:361-99. [PMID: 24915502 PMCID: PMC4436706 DOI: 10.3109/10409238.2014.925420] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Tuberculosis (TB) remains the second most common cause of death due to a single infectious agent. The cell envelope of Mycobacterium tuberculosis (Mtb), the causative agent of the disease in humans, is a source of unique glycoconjugates and the most distinctive feature of the biology of this organism. It is the basis of much of Mtb pathogenesis and one of the major causes of its intrinsic resistance to chemotherapeutic agents. At the same time, the unique structures of Mtb cell envelope glycoconjugates, their antigenicity and essentiality for mycobacterial growth provide opportunities for drug, vaccine, diagnostic and biomarker development, as clearly illustrated by recent advances in all of these translational aspects. This review focuses on our current understanding of the structure and biogenesis of Mtb glycoconjugates with particular emphasis on one of the most intriguing and least understood aspect of the physiology of mycobacteria: the translocation of these complex macromolecules across the different layers of the cell envelope. It further reviews the rather impressive progress made in the last 10 years in the discovery and development of novel inhibitors targeting their biogenesis.
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Affiliation(s)
- Shiva Kumar Angala
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University , Fort Collins, CO , USA
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57
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Comparison of ambient air survival of Mycobacterium tuberculosis clinical strains associated with different epidemiological phenotypes. Int J Mycobacteriol 2014; 3:211-3. [DOI: 10.1016/j.ijmyco.2014.04.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2014] [Accepted: 04/13/2014] [Indexed: 11/20/2022] Open
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58
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Prozorov AA, Fedorova IA, Bekker OB, Danilenko VN. The virulence factors of Mycobacterium tuberculosis: Genetic control, new conceptions. RUSS J GENET+ 2014. [DOI: 10.1134/s1022795414080055] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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59
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Fuchs M, Kämpfer S, Helmsing S, Spallek R, Oehlmann W, Prilop W, Frank R, Dübel S, Singh M, Hust M. Novel human recombinant antibodies against Mycobacterium tuberculosis antigen 85B. BMC Biotechnol 2014; 14:68. [PMID: 25033887 PMCID: PMC4119940 DOI: 10.1186/1472-6750-14-68] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Accepted: 07/01/2014] [Indexed: 11/10/2022] Open
Abstract
Background Tuberculosis is the leading cause of death due to bacterial infections worldwide, mainly caused by Mycobacterium tuberculosis. The antigen 85 complex comprises a set of major secreted proteins of M. tuberculosis, which are potential biomarkers for diagnostic. Results In this work, the first human single chain fragment variable (scFv) antibodies specific for the tuberculosis biomarker 85 B were selected by phage display from naïve antibody gene libraries (HAL7/8). Produced as scFv-Fc in mammalian cells, these antibodies were further characterized and analysed for specificity and applicability in different tuberculosis antigen detection assays. Sandwich detection of recombinant 85 B was successful in enzyme linked immunosorbent assay (ELISA), lateral flow immunoassay and immunoblot. Whereas detection of M. tuberculosis cell extracts and culture filtrates was only possible in direct ELISA and immunoblot assays. It was found that the conformation of 85 B, depending on sample treatment, influenced antigen detection. Conclusions Recombinant antibodies, selected by phage display, may be applicable for 85 B detection in various assays. These antibodies are candidates for the development of future point of care tuberculosis diagnostic kits. Using 85 B as a biomarker, the antigen conformation influenced by sample treatment is important.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Michael Hust
- Technische Universität Braunschweig, Institut für Biochemie und Biotechnologie, Spielmannstr,7, 38106 Braunschweig, Germany.
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60
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Favrot L, Lajiness DH, Ronning DR. Inactivation of the Mycobacterium tuberculosis antigen 85 complex by covalent, allosteric inhibitors. J Biol Chem 2014; 289:25031-40. [PMID: 25028518 DOI: 10.1074/jbc.m114.582445] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The rise of multidrug-resistant and totally drug-resistant tuberculosis and the association with an increasing number of HIV-positive patients developing tuberculosis emphasize the necessity to find new antitubercular targets and drugs. The antigen 85 (Ag85) complex from Mycobacterium tuberculosis plays important roles in the biosynthesis of major components of the mycobacterial cell envelope. For this reason, Ag85 has emerged as an attractive drug target. Recently, ebselen was identified as an effective inhibitor of the Ag85 complex through covalent modification of a cysteine residue proximal to the Ag85 active site and is therefore a covalent, allosteric inhibitor. To expand the understanding of this process, we have solved the x-ray crystal structures of Ag85C covalently modified with ebselen and other thiol-reactive compounds, p-chloromercuribenzoic acid and iodoacetamide, as well as the structure of a cysteine to glycine mutant. All four structures confirm that chemical modification or mutation at this particular cysteine residue leads to the disruption of the active site hydrogen-bonded network essential for Ag85 catalysis. We also describe x-ray crystal structures of Ag85C single mutants within the catalytic triad and show that a mutation of any one of these three residues promotes the same conformational change observed in the cysteine-modified forms. These results provide evidence for active site dynamics that may afford new strategies for the development of selective and potent Ag85 inhibitors.
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Affiliation(s)
- Lorenza Favrot
- From the Department of Chemistry and Biochemistry, University of Toledo, Toledo, Ohio 43606-3390
| | - Daniel H Lajiness
- From the Department of Chemistry and Biochemistry, University of Toledo, Toledo, Ohio 43606-3390
| | - Donald R Ronning
- From the Department of Chemistry and Biochemistry, University of Toledo, Toledo, Ohio 43606-3390
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61
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Backus KM, Dolan MA, Barry CS, Joe M, McPhie P, Boshoff HIM, Lowary TL, Davis BG, Barry CE. The three Mycobacterium tuberculosis antigen 85 isoforms have unique substrates and activities determined by non-active site regions. J Biol Chem 2014; 289:25041-53. [PMID: 25028517 DOI: 10.1074/jbc.m114.581579] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The three isoforms of antigen 85 (A, B, and C) are the most abundant secreted mycobacterial proteins and catalyze transesterification reactions that synthesize mycolated arabinogalactan, trehalose monomycolate (TMM), and trehalose dimycolate (TDM), important constituents of the outermost layer of the cellular envelope of Mycobacterium tuberculosis. These three enzymes are nearly identical at the active site and have therefore been postulated to exist to evade host immunity. Distal to the active site is a second putative carbohydrate-binding site of lower homology. Mutagenesis of the three isoforms at this second site affected both substrate selectivity and overall catalytic activity in vitro. Using synthetic and natural substrates, we show that these three enzymes exhibit unique selectivity; antigen 85A more efficiently mycolates TMM to form TDM, whereas C (and to a lesser extent B) has a higher rate of activity using free trehalose to form TMM. This difference in substrate selectivity extends to the hexasaccharide fragment of cell wall arabinan. Mutation of secondary site residues from the most active isoform (C) into those present in A or B partially interconverts this substrate selectivity. These experiments in combination with molecular dynamics simulations reveal that differences in the N-terminal helix α9, the adjacent Pro(216)-Phe(228) loop, and helix α5 are the likely cause of changes in activity and substrate selectivity. These differences explain the existence of three isoforms and will allow for future work in developing inhibitors.
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Affiliation(s)
- Keriann M Backus
- From the Tuberculosis Research Section, Laboratory of Clinical Infectious Diseases, and the Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford OX1 3TA, United Kingdom
| | - Michael A Dolan
- the Bioinformatics and Computational Biosciences Branch, NIAID, National Institutes of Health, Bethesda, Maryland 20892
| | - Conor S Barry
- the Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford OX1 3TA, United Kingdom
| | - Maju Joe
- the Alberta Glycomics Centre and Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada, and
| | - Peter McPhie
- the Laboratory of Biochemistry and Genetics, NIDDK, National Institutes of Health, Bethesda, Maryland 20892
| | - Helena I M Boshoff
- From the Tuberculosis Research Section, Laboratory of Clinical Infectious Diseases, and
| | - Todd L Lowary
- the Alberta Glycomics Centre and Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada, and
| | - Benjamin G Davis
- the Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford OX1 3TA, United Kingdom,
| | - Clifton E Barry
- From the Tuberculosis Research Section, Laboratory of Clinical Infectious Diseases, and
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Nobre A, Alarico S, Maranha A, Mendes V, Empadinhas N. The molecular biology of mycobacterial trehalose in the quest for advanced tuberculosis therapies. MICROBIOLOGY-SGM 2014; 160:1547-1570. [PMID: 24858083 DOI: 10.1099/mic.0.075895-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Trehalose is a natural glucose disaccharide identified in the 19th century in fungi and insect cocoons, and later across the three domains of life. In members of the genus Mycobacterium, which includes the tuberculosis (TB) pathogen and over 160 species of nontuberculous mycobacteria (NTM), many of which are opportunistic pathogens, trehalose has been an important focus of research over the last 60 years. It is a crucial player in the assembly and architecture of the remarkable mycobacterial cell envelope as an element of unique highly antigenic glycolipids, namely trehalose dimycolate ('cord factor'). Free trehalose has been detected in the mycobacterial cytoplasm and occasionally in oligosaccharides with unknown function. TB and NTM infection statistics and death toll, the decline in immune responses in the aging population, human immunodeficiency virus/AIDS or other debilitating conditions, and the proliferation of strains with different levels of resistance to the dated drugs in use, all merge into a serious public-health threat urging more effective vaccines, efficient diagnostic tools and new drugs. This review deals with the latest findings on mycobacterial trehalose biosynthesis, catabolism, processing and recycling, as well with the ongoing quest for novel trehalose-related mechanisms to be targeted by novel TB therapeutics. In this context, the drug-discovery pipeline has recently included new lead compounds directed toward trehalose-related targets highlighting the potential of these pathways to stem the tide of rising drug resistance.
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Affiliation(s)
- Ana Nobre
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Susana Alarico
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Ana Maranha
- Biosciences PhD Program, Department of Life Sciences, University of Coimbra, Coimbra, Portugal.,CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Vitor Mendes
- Department of Biochemistry, University of Cambridge, Cambridge, UK.,CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Nuno Empadinhas
- III/UC-Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal.,CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
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63
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Differential macrophage response to slow- and fast-growing pathogenic mycobacteria. BIOMED RESEARCH INTERNATIONAL 2014; 2014:916521. [PMID: 24949482 PMCID: PMC4052160 DOI: 10.1155/2014/916521] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 04/10/2014] [Accepted: 04/30/2014] [Indexed: 02/05/2023]
Abstract
Nontuberculous mycobacteria (NTM) have recently been recognized as important species that cause disease even in immunocompetent individuals. The mechanisms that these species use to infect and persist inside macrophages are not well characterised. To gain insight concerning this process we used THP-1 macrophages infected with M. abscessus, M. fortuitum, M. celatum, and M. tuberculosis. Our results showed that slow-growing mycobacteria gained entrance into these cells with more efficiency than fast-growing mycobacteria. We have also demonstrated that viable slow-growing M. celatum persisted inside macrophages without causing cell damage and without inducing reactive oxygen species (ROS), as M. tuberculosis caused. In contrast, fast-growing mycobacteria destroyed the cells and induced high levels of ROS. Additionally, the macrophage cytokine pattern induced by M. celatum was different from the one induced by either M. tuberculosis or fast-growing mycobacteria. Our results also suggest that, in some cases, the intracellular survival of mycobacteria and the immune response that they induce in macrophages could be related to their growth rate. In addition, the modulation of macrophage cytokine production, caused by M. celatum, might be a novel immune-evasion strategy used to survive inside macrophages that is different from the one reported for M. tuberculosis.
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Ackart DF, Hascall-Dove L, Caceres SM, Kirk NM, Podell BK, Melander C, Orme IM, Leid JG, Nick JA, Basaraba RJ. Expression of antimicrobial drug tolerance by attached communities of Mycobacterium tuberculosis. Pathog Dis 2014; 70:359-69. [PMID: 24478060 PMCID: PMC4361083 DOI: 10.1111/2049-632x.12144] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 01/15/2014] [Accepted: 01/16/2014] [Indexed: 11/28/2022] Open
Abstract
There is an urgent need to improve methods used to screen antituberculosis drugs. An in vitro assay was developed to test drug treatment strategies that specifically target drug-tolerant Mycobacterium tuberculosis. The H37Rv strain of M. tuberculosis survived antimicrobial treatment as attached microbial communities when maintained in tissue culture media (RPMI-1640) with or without lysed human peripheral blood leukocytes. When cultured planktonically in the presence of Tween-80, bacilli failed to form microbial communities or reach logarithmic phase growth yet remained highly susceptible to antimicrobial drugs. In the absence of Tween, bacilli tolerated drug therapy by forming complex microbial communities attached to untreated well surfaces or to the extracellular matrix derived from lysed human leukocytes. Treatment of microbial communities with DNase I or Tween effectively dispersed bacilli and restored drug susceptibility. These data demonstrate that in vitro expression of drug tolerance by M. tuberculosis is linked to the establishment of attached microbial communities and that dispersion of bacilli targeting the extracellular matrix including DNA restores drug susceptibility. Modifications of this in vitro assay may prove beneficial in a high-throughput platform to screen new antituberculosis drugs especially those that target drug-tolerant bacilli.
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Affiliation(s)
- David F. Ackart
- Department of Microbiology, Immunology and Pathology, Mycobacterial Research Laboratories, Colorado State University, Fort Collins, CO, United States of America
| | - Laurel Hascall-Dove
- Department of Microbiology, Immunology and Pathology, Mycobacterial Research Laboratories, Colorado State University, Fort Collins, CO, United States of America
| | - Silvia M. Caceres
- Department of Medicine, National Jewish Health, Denver, CO, United States of America
| | - Natalie M. Kirk
- Department of Microbiology, Immunology and Pathology, Mycobacterial Research Laboratories, Colorado State University, Fort Collins, CO, United States of America
| | - Brendan K. Podell
- Department of Microbiology, Immunology and Pathology, Mycobacterial Research Laboratories, Colorado State University, Fort Collins, CO, United States of America
| | - Christian Melander
- Department of Chemistry, North Carolina State University, Raleigh, NC, United States of America
| | - Ian M. Orme
- Department of Microbiology, Immunology and Pathology, Mycobacterial Research Laboratories, Colorado State University, Fort Collins, CO, United States of America
| | - Jeff G. Leid
- Medical Products Division, W.L. Gore and Associates, Flagstaff, AZ, United States of America
| | - Jerry A. Nick
- Department of Medicine, National Jewish Health, Denver, CO, United States of America
| | - Randall J. Basaraba
- Department of Microbiology, Immunology and Pathology, Mycobacterial Research Laboratories, Colorado State University, Fort Collins, CO, United States of America
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Burroughs AM, Aravind L. A highly conserved family of domains related to the DNA-glycosylase fold helps predict multiple novel pathways for RNA modifications. RNA Biol 2014; 11:360-72. [PMID: 24646681 PMCID: PMC4075521 DOI: 10.4161/rna.28302] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
A protein family including mammalian NEMF, Drosophila caliban, yeast Tae2, and bacterial FpbA-like proteins was first defined over a decade ago and found to be universally distributed across the three domains/superkingdoms of life. Since its initial characterization, this family of proteins has been tantalizingly linked to a wide range of biochemical functions. Tapping the enormous wealth of genome information that has accumulated since the initial characterization of these proteins, we perform a detailed computational analysis of the family, identifying multiple conserved domains. Domains identified include an enzymatic domain related to the formamidopyrimidine (Fpg), MutM, and Nei/EndoVIII family of DNA glycosylases, a novel, predicted RNA-binding domain, and a domain potentially mediating protein–protein interactions. Through this characterization, we predict that the DNA glycosylase-like domain catalytically operates on double-stranded RNA, as part of a hitherto unknown base modification mechanism that probably targets rRNAs. At least in archaea, and possibly eukaryotes, this pathway might additionally include the AMMECR1 family of proteins. The predicted RNA-binding domain associated with this family is also observed in distinct architectural contexts in other proteins across phylogenetically diverse prokaryotes. Here it is predicted to play a key role in a new pathway for tRNA 4-thiouridylation along with TusA-like sulfur transfer proteins.
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Affiliation(s)
- A Maxwell Burroughs
- 1National Center for Biotechnology Information; National Library of Medicine; National Institutes of Health; Bethesda, MD USA
| | - L Aravind
- 1National Center for Biotechnology Information; National Library of Medicine; National Institutes of Health; Bethesda, MD USA
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Chaudhuri R, Kulshreshtha D, Raghunandanan MV, Ramachandran S. Integrative immunoinformatics for Mycobacterial diseases in R platform. SYSTEMS AND SYNTHETIC BIOLOGY 2014; 8:27-39. [PMID: 24592289 DOI: 10.1007/s11693-014-9135-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Revised: 02/04/2014] [Accepted: 02/05/2014] [Indexed: 11/25/2022]
Abstract
The sequencing of genomes of the pathogenic Mycobacterial species causing pulmonary and extrapulmonary tuberculosis, leprosy and other atypical mycobacterial infections, offer immense opportunities for discovering new therapeutics and identifying new vaccine candidates. Enhanced RV, which uses additional algorithms to Reverse Vaccinology (RV), has increased potential to reduce likelihood of undesirable features including allergenicity and immune cross reactivity to host. The starting point for MycobacRV database construction includes collection of known vaccine candidates and a set of predicted vaccine candidates identified from the whole genome sequences of 22 mycobacterium species and strains pathogenic to human and one non-pathogenic Mycobacterium tuberculosis H37Ra strain. These predicted vaccine candidates are the adhesins and adhesin-like proteins obtained using SPAAN at Pad > 0.6 and screening for putative extracellular or surface localization characteristics using PSORTb v.3.0 at very stringent cutoff. Subsequently, these protein sequences were analyzed through 21 publicly available algorithms to obtain Orthologs, Paralogs, BetaWrap Motifs, Transmembrane Domains, Signal Peptides, Conserved Domains, and similarity to human proteins, T cell epitopes, B cell epitopes, Discotopes and potential Allergens predictions. The Enhanced RV information was analysed in R platform through scripts following well structured decision trees to derive a set of nonredundant 233 most probable vaccine candidates. Additionally, the degree of conservation of potential epitopes across all orthologs has been obtained with reference to the M. tuberculosis H37Rv strain, the most commonly used strain in M. tuberculosis studies. Utilities for the vaccine candidate search and analysis of epitope conservation across the orthologs with reference to M. tuberculosis H37Rv strain are available in the mycobacrvR package in R platform accessible from the "Download" tab of MycobacRV webserver. MycobacRV an immunoinformatics database of known and predicted mycobacterial vaccine candidates has been developed and is freely available at http://mycobacteriarv.igib.res.in.
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Affiliation(s)
- Rupanjali Chaudhuri
- CSIR-Institute of Genomics and Integrative Biology, Near Jubilee Hall, Mall Road, Delhi, 110 007 India
| | - Deepika Kulshreshtha
- CSIR-Institute of Genomics and Integrative Biology, Near Jubilee Hall, Mall Road, Delhi, 110 007 India
| | | | - Srinivasan Ramachandran
- CSIR-Institute of Genomics and Integrative Biology, Near Jubilee Hall, Mall Road, Delhi, 110 007 India
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Deng YH, He HY, Zhang FJ. Immunogenicity and protective efficacy conferred by a novel recombinant Mycobacterium bovis bacillus Calmette-Guérin strain expressing interleukin-12p70 of human cytokine and Ag85A of Mycobacterium tuberculosis fusion protein. Scand J Immunol 2013; 78:497-506. [PMID: 24283772 DOI: 10.1111/sji.12116] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Accepted: 09/13/2013] [Indexed: 11/27/2022]
Abstract
Mycobacterium bovis bacillus Calmette-Guérin (BCG) immunization provides protection against tuberculosis (TB) in infants, but the antituberculosis protective immunity wanes gradually after initial immunization and lasts less than 15 years. Therefore, more efficacious vaccines are urgently needed. In this study, we constructed a new tuberculosis vaccine of recombinant BCG strain (rBCG-IA), which could express IL-12p70 of human cytokine and Ag85A of M. tuberculosis fusion protein, and investigated its immunogenicity in BALB/c mice by measuring antibody titres, proliferation rate of splenocytes, ratios of CD4(+) T and CD8(+) T cells stimulated by specific antigens and levels of IFN-γ production in antigen-stimulated splenocyte cultures. Meanwhile, we evaluated its protective efficacy against M. tuberculosis H37Rv infection through detecting lung histopathology, organ bacterial loads and lung acid-fast stain. Immunogenicity experiments illustrated that from 2nd to 8th week after immunization, the rBCG-IA vaccine was able to induce the highest level of antibody titres, proliferation rate of splenocytes and IFN-γ production among groups and gained improved ratio of CD4(+) T and CD8(+) T cells from 6th to 8th week after vaccination. And from 2nd to 8th week after M. tuberculosis H37Rv infection, the score of pathology and bacterial loads in the rBCG-IA group were obviously lower than that in rBCG-I group, rBCG-A group or control group (PBST group), but similar to that in BCG group. This study suggested that rBCG-IA was able to elicit stronger humoral and cellular immune responses, but could only confer similar protective efficacy compared with its parental BCG vaccine.
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Affiliation(s)
- Y H Deng
- Department of Human Anatomy, Medical College, Kunming University of Science and Technology, Kunming, China
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Tuberculosis diagnosis using immunodominant, secreted antigens of Mycobacterium tuberculosis. Tuberculosis (Edinb) 2013; 93:381-8. [PMID: 23602700 DOI: 10.1016/j.tube.2013.03.003] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 03/11/2013] [Accepted: 03/23/2013] [Indexed: 12/19/2022]
Abstract
Tuberculosis (TB) remains a major public health concern in most low-income countries. Hence, rapid and sensitive TB diagnostics play an important role in detecting and preventing the disease. In addition to established diagnostic methods, several new approaches have been reported. Some techniques are simple but time-consuming, while others require complex instrumentation. One prominent and readily available approach is to detect proteins that Mycobacterium tuberculosis secretes, such as Mpt64, the 6-kDa early secreted antigenic target (Esat6), the 10-kDa culture filtrate protein (Cfp10), and the antigen 85 (Ag85) complex. Although their functions are not fully understood, a growing body of molecular evidence implicates them in M. tuberculosis virulence. Currently these biomarkers are either being used or investigated for use in skin patch tests, biosensor analyses, and immunochromatographic, immunohistochemical, polymerase chain reaction-based, and enzyme-linked immunosorbent assays. This review provides a comprehensive discussion of the roles these immunodominant antigens play in M. tuberculosis pathogenesis and compares diagnostic methods based on the detection of these proteins with more established tests for TB.
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Alvarez-Corrales N, Ahmed RK, Rodriguez CA, Balaji KN, Rivera R, Sompallae R, Vudattu NK, Hoffner SE, Zumla A, Pineda-Garcia L, Maeurer M. Differential cellular recognition pattern to M. tuberculosis targets defined by IFN-γ and IL-17 production in blood from TB + patients from Honduras as compared to health care workers: TB and immune responses in patients from Honduras. BMC Infect Dis 2013; 13:125. [PMID: 23497342 PMCID: PMC3599548 DOI: 10.1186/1471-2334-13-125] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Accepted: 02/25/2013] [Indexed: 01/02/2023] Open
Abstract
Background A better understanding of the quality of cellular immune responses directed against molecularly defined targets will guide the development of TB diagnostics and identification of molecularly defined, clinically relevant M.tb vaccine candidates. Methods Recombinant proteins (n = 8) and peptide pools (n = 14) from M. tuberculosis (M.tb) targets were used to compare cellular immune responses defined by IFN-γ and IL-17 production using a Whole Blood Assay (WBA) in a cohort of 148 individuals, i.e. patients with TB + (n = 38), TB- individuals with other pulmonary diseases (n = 81) and individuals exposed to TB without evidence of clinical TB (health care workers, n = 29). Results M.tb antigens Rv2958c (glycosyltransferase), Rv2962c (mycolyltransferase), Rv1886c (Ag85B), Rv3804c (Ag85A), and the PPE family member Rv3347c were frequently recognized, defined by IFN-γ production, in blood from healthy individuals exposed to M.tb (health care workers). A different recognition pattern was found for IL-17 production in blood from M.tb exposed individuals responding to TB10.4 (Rv0288), Ag85B (Rv1886c) and the PPE family members Rv0978c and Rv1917c. Conclusions The pattern of immune target recognition is different in regard to IFN-γ and IL-17 production to defined molecular M.tb targets in PBMCs from individuals frequently exposed to M.tb. The data represent the first mapping of cellular immune responses against M.tb targets in TB patients from Honduras.
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Affiliation(s)
- Nancy Alvarez-Corrales
- Escuela de Microbiología, Universidad Nacional Autónoma de Honduras (UNAH), Tegucigalpa, Honduras
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Deng YH, He HY, Zhang BS. Evaluation of protective efficacy conferred by a recombinant Mycobacterium bovis BCG expressing a fusion protein of Ag85A-ESAT-6. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2013; 47:48-56. [PMID: 23357605 DOI: 10.1016/j.jmii.2012.11.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Revised: 11/01/2012] [Accepted: 11/27/2012] [Indexed: 11/26/2022]
Abstract
BACKGROUND We previously constructed a recombinant bacille Calmette-Guérin (rBCG-AE) strain that could express a fused Ag85A-ESAT-6 protein. That study suggested that the rBCG-AE strain was able to induce a higher titer of antibody and elicit a more long-lived and stronger Th1-type cellular immune responses than the parental BCG strain, the rBCG-A strain (i.e., expressing Ag85A), or the rBCG-E strain (i.e., expressing ESAT-6). METHODS In the current study, we further investigated the strain's protective efficacy against Mycobacterium tuberculosis H37Rv infection in BALB/c mice through evaluating organ bacterial loads, lung histopathology, lung immunohistochemistry, and net weight gain or loss by using conventional BCG, rBCG-A, and rBCG-E as the controls. RESULTS From the 3rd to 9th weeks after the challenge infection, the bacterial counts were significantly lower in tissues (e.g., spleen and lung tissues) in the mice immunized with rBCG-AE than in the control group, but were higher than the counts in the BCG group. The pathological damage in the lung tissues of the rBCG-AE group gradually improved from the 6th to 9th weeks after being infected with M. tuberculosis H37Rv, but the score of pathological changes in the rBCG-AE group was obviously higher than the score in the BCG group. There was no difference in the percentage of IFN-γ and iNOS positive cells in the lung tissues of the rBCG-AE and BCG groups. CONCLUSION The results suggest that rBCG-AE can not promote protective efficacy against M. tuberculosis H37Rv infection, compared to the BCG vaccine.
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Affiliation(s)
- Yi-Hao Deng
- Department of Human Anatomy, College of Preclinical Medicine, Dali University, Dali 671000, China.
| | - Hong-Yun He
- Department of Human Anatomy, College of Preclinical Medicine, Dali University, Dali 671000, China
| | - Ben-Si Zhang
- Department of Human Anatomy, College of Preclinical Medicine, Dali University, Dali 671000, China
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Favrot L, Grzegorzewicz AE, Lajiness DH, Marvin RK, Boucau J, Isailovic D, Jackson M, Ronning DR. Mechanism of inhibition of Mycobacterium tuberculosis antigen 85 by ebselen. Nat Commun 2013; 4:2748. [PMID: 24193546 PMCID: PMC4049535 DOI: 10.1038/ncomms3748] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 10/10/2013] [Indexed: 11/09/2022] Open
Abstract
The increasing prevalence of drug-resistant tuberculosis highlights the need for identifying new antitubercular drugs that can treat these infections. The antigen 85 (Ag85) complex has emerged as an intriguing mycobacterial drug target due to its central role in synthesizing major components of the inner and outer leaflets of the mycobacterial outer membrane. Here we identify ebselen (EBS) as a potent inhibitor of the Mycobacterium tuberculosis Ag85 complex. Mass spectrometry data show that EBS binds covalently to a cysteine residue (C209) located near the Ag85C active site. The crystal structure of Ag85C in the presence of EBS shows that C209 modification restructures the active site, thereby disrupting the hydrogen-bonded network within the active site that is essential for enzymatic activity. C209 mutations display marked decreases in enzymatic activity. These data suggest that compounds using this mechanism of action will strongly inhibit the Ag85 complex and minimize the selection of drug resistance.
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Affiliation(s)
- Lorenza Favrot
- Department of Chemistry, University of Toledo, Toledo, Ohio 43606-3390
| | - Anna E. Grzegorzewicz
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado 80523-1682
| | | | - Rachel K. Marvin
- Department of Chemistry, University of Toledo, Toledo, Ohio 43606-3390
| | - Julie Boucau
- Department of Chemistry, University of Toledo, Toledo, Ohio 43606-3390
| | - Dragan Isailovic
- Department of Chemistry, University of Toledo, Toledo, Ohio 43606-3390
| | - Mary Jackson
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado 80523-1682
| | - Donald R. Ronning
- Department of Chemistry, University of Toledo, Toledo, Ohio 43606-3390
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Kuo CJ, Ptak CP, Hsieh CL, Akey BL, Chang YF. Elastin, a novel extracellular matrix protein adhering to mycobacterial antigen 85 complex. J Biol Chem 2012; 288:3886-96. [PMID: 23250738 DOI: 10.1074/jbc.m112.415679] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The antigen 85 complex (Ag85) consists of three predominantly secreted proteins (Ag85A, Ag85B, and Ag85C), which play a key role in the mycobacterial pathogenesis and also possess enzymatic mycolyltransferase activity involved in cell wall synthesis. Ag85 is not only considered to be a virulence factor because its expression is essential for intracellular survival within macrophages, but also because it contributes to adherence, invasion, and dissemination of mycobacteria in host cells. In this study, we report that the extracellular matrix components, elastin and its precursor (tropoelastin) derived from human aorta, lung, and skin, serve as binding partners of Ag85 from Mycobacterium tuberculosis. The binding affinity of M. tuberculosis Ag85 to human tropoelastin was characterized (K(D) = 0.13 ± 0.006 μm), and a novel Ag85-binding motif, AAAKAA(K/Q)(Y/F), on multiple tropoelastin modules was identified. In addition, the negatively charged Glu-258 of Ag85 was demonstrated to participate in an electrostatic interaction with human tropoelastin. Moreover, binding of Ag85 on elastin siRNA-transfected Caco-2 cells was significantly reduced (34.3%), implying that elastin acts as an important ligand contributing to mycobacterial invasion.
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Affiliation(s)
- Chih-Jung Kuo
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA
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Rizzi C, Bianco MV, Blanco FC, Soria M, Gravisaco MJ, Montenegro V, Vagnoni L, Buddle B, Garbaccio S, Delgado F, Leal KS, Cataldi AA, Dellagostin OA, Bigi F. Vaccination with a BCG strain overexpressing Ag85B protects cattle against Mycobacterium bovis challenge. PLoS One 2012; 7:e51396. [PMID: 23251517 PMCID: PMC3519572 DOI: 10.1371/journal.pone.0051396] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Accepted: 10/31/2012] [Indexed: 12/29/2022] Open
Abstract
Mycobacterium bovis is the causative agent of tuberculosis in cattle but also infects other animals, including humans. Previous studies in cattle have demonstrated that the protection induced by BCG is not complete. In order to improve the protection efficacy of BCG, in this study we overexpressed Ag85B in a BCG Pasteur strain, by using an expression system based on the use of an auxotrophic strain for the leucine amino acid, and complementation with leuD. We found that vaccination of cattle with BCG overexpressing Ag85B induced higher production of IL-17 and IL-4 mRNA upon purified protein derivative (PPDB) stimulation of peripheral blood mononuclear cells (PBMCs) than vaccination with BCG. Moreover, the IL-17 mRNA expression after vaccination negatively correlated with disease severity resulting from a subsequent challenge with M. bovis, suggesting that this cytokine is a potential biomarker of cattle protection against bovine tuberculosis. Importantly, vaccination with the recombinant BCG vaccine protected cattle better than the wild-type BCG Pasteur.
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Affiliation(s)
- Caroline Rizzi
- Núcleo de Biotecnologia, CDTec, Universidade Federal de Pelotas, Pelotas, Brazil
| | - María Verónica Bianco
- Instituto de Biotecnología, CICVyA-INTA, N. Repetto y De los Reseros, Buenos Aires, Argentina
| | - Federico Carlos Blanco
- Instituto de Biotecnología, CICVyA-INTA, N. Repetto y De los Reseros, Buenos Aires, Argentina
| | - Marcelo Soria
- Microbiología Agrícola, Facultad de Agronomía, Universidad de Buenos Aires, INBA-CONICET, Ciudad de Buenos Aires, Argentina
| | - María José Gravisaco
- Instituto de Biotecnología, CICVyA-INTA, N. Repetto y De los Reseros, Buenos Aires, Argentina
| | - Valeria Montenegro
- Instituto de Biotecnología, CICVyA-INTA, N. Repetto y De los Reseros, Buenos Aires, Argentina
| | - Lucas Vagnoni
- Instituto de Patobiología, CICVyA- INTA, N. Repetto y De los Reseros, Buenos Aires, Argentina
| | - Bryce Buddle
- AgResearch, Hopkirk Research Institute, Palmerston North, New Zealand
| | - Sergio Garbaccio
- Instituto de Patobiología, CICVyA- INTA, N. Repetto y De los Reseros, Buenos Aires, Argentina
| | - Fernando Delgado
- Instituto de Patobiología, CICVyA- INTA, N. Repetto y De los Reseros, Buenos Aires, Argentina
| | - Karen Silva Leal
- Núcleo de Biotecnologia, CDTec, Universidade Federal de Pelotas, Pelotas, Brazil
| | - Angel Adrián Cataldi
- Instituto de Biotecnología, CICVyA-INTA, N. Repetto y De los Reseros, Buenos Aires, Argentina
| | | | - Fabiana Bigi
- Instituto de Biotecnología, CICVyA-INTA, N. Repetto y De los Reseros, Buenos Aires, Argentina
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Cervantes-Villagrana AR, Hernández-Pando R, Biragyn A, Castañeda-Delgado J, Bodogai M, Martínez-Fierro M, Sada E, Trujillo V, Enciso-Moreno A, Rivas-Santiago B. Prime-boost BCG vaccination with DNA vaccines based in β-defensin-2 and mycobacterial antigens ESAT6 or Ag85B improve protection in a tuberculosis experimental model. Vaccine 2012. [PMID: 23196205 DOI: 10.1016/j.vaccine.2012.11.042] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The World Health Organization (WHO) has estimated that there are about 8 million new cases annually of active Tuberculosis (TB). Despite its irregular effectiveness (0-89%), the Bacillus Calmette-Guérin) BCG is the only vaccine available worldwide for prevention of TB; thus, the design is important of novel and more efficient vaccination strategies. Considering that β-defensin-2 is an antimicrobial peptide that induces dendritic cell maturation through the TLR-4 receptor and that both ESAT-6 and Ag85B are immunodominant mycobacterial antigens and efficient activators of the protective immune response, we constructed two DNA vaccines by the fusion of the gene encoding β-defensin-2 and antigens ESAT6 (pDE) and 85B (pDA). After confirming efficient local antigen expression that induced high and stable Interferon gamma (IFN-γ) production in intramuscular (i.m.) vaccinated Balb/c mice, groups of mice were vaccinated with DNA vaccines in a prime-boost regimen with BCG and with BCG alone, and 2 months later were challenged with the mild virulence reference strain H37Rv and the highly virulent clinical isolate LAM 5186. The level of protection was evaluated by survival, lung bacilli burdens, and extension of tissue damage (pneumonia). Vaccination with both DNA vaccines showed similar protection to that of BCG. After the challenge with the highly virulent Mycobacterium tuberculosis strain, animals that were prime-boosted with BCG and then boosted with both DNA vaccines showed significant higher survival and less tissue damage than mice vaccinated only with BCG. These results suggest that improvement of BCG vaccination, such as the prime-boost DNA vaccine, represents a more efficient vaccination scheme against TB.
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de Sousa EM, da Costa AC, Trentini MM, de Araújo Filho JA, Kipnis A, Junqueira-Kipnis AP. Immunogenicity of a fusion protein containing immunodominant epitopes of Ag85C, MPT51, and HspX from Mycobacterium tuberculosis in mice and active TB infection. PLoS One 2012; 7:e47781. [PMID: 23133523 PMCID: PMC3485045 DOI: 10.1371/journal.pone.0047781] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Accepted: 09/17/2012] [Indexed: 12/29/2022] Open
Abstract
Tuberculosis (TB) remains a major global health problem. The only vaccine against tuberculosis, attenuated Mycobacterium bovis Bacillus Calmette-Guerin (BCG), has demonstrated relatively low efficacy and does not provide satisfactory protection against the disease in adults. More effective vaccines and better therapies are urgently needed to reduce the global spread of TB. This study evaluated the immunogenicity of a recombinant M. tuberculosis Ag85C-MPT51-HspX fusion protein (CMX) in mice and individuals with active tuberculosis. BALB/c mice were immunized with the CMX protein liposome-encapsulated with CpG DNA or with CpGDNA liposome-encapsulated, liposome or saline as negative controls. The immunization produced high levels of anti-CMX -specific IgG1 and IgG2a antibodies and induced an increase in the relative and absolute numbers of specific TCD4 IFN-γ+ and TNF-α+ cells in the spleen. Sera from a cohort of individuals with active tuberculosis contained higher levels of IgG and IgM that recognized CMX when compared to healthy individuals. In conclusion, this protein was shown to be immunogenic both in mice and humans.
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Affiliation(s)
- Eduardo Martins de Sousa
- Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, Goiás, Brazil
| | - Adeliane Castro da Costa
- Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, Goiás, Brazil
| | - Monalisa Martins Trentini
- Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, Goiás, Brazil
| | | | - André Kipnis
- Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, Goiás, Brazil
| | - Ana Paula Junqueira-Kipnis
- Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, Goiás, Brazil
- * E-mail:
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Forrellad MA, Klepp LI, Gioffré A, Sabio y García J, Morbidoni HR, de la Paz Santangelo M, Cataldi AA, Bigi F. Virulence factors of the Mycobacterium tuberculosis complex. Virulence 2012; 4:3-66. [PMID: 23076359 PMCID: PMC3544749 DOI: 10.4161/viru.22329] [Citation(s) in RCA: 379] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The Mycobacterium tuberculosis complex (MTBC) consists of closely related species that cause tuberculosis in both humans and animals. This illness, still today, remains to be one of the leading causes of morbidity and mortality throughout the world. The mycobacteria enter the host by air, and, once in the lungs, are phagocytated by macrophages. This may lead to the rapid elimination of the bacillus or to the triggering of an active tuberculosis infection. A large number of different virulence factors have evolved in MTBC members as a response to the host immune reaction. The aim of this review is to describe the bacterial genes/proteins that are essential for the virulence of MTBC species, and that have been demonstrated in an in vivo model of infection. Knowledge of MTBC virulence factors is essential for the development of new vaccines and drugs to help manage the disease toward an increasingly more tuberculosis-free world.
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Khattak FA, Kumar A, Kamal E, Kunisch R, Lewin A. Illegitimate recombination: an efficient method for random mutagenesis in Mycobacterium avium subsp. hominissuis. BMC Microbiol 2012; 12:204. [PMID: 22966811 PMCID: PMC3511198 DOI: 10.1186/1471-2180-12-204] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Accepted: 09/07/2012] [Indexed: 01/04/2023] Open
Abstract
Background The genus Mycobacterium (M.) comprises highly pathogenic bacteria such as M. tuberculosis as well as environmental opportunistic bacteria called non-tuberculous mycobacteria (NTM). While the incidence of tuberculosis is declining in the developed world, infection rates by NTM are increasing. NTM are ubiquitous and have been isolated from soil, natural water sources, tap water, biofilms, aerosols, dust and sawdust. Lung infections as well as lymphadenitis are most often caused by M. avium subsp. hominissuis (MAH), which is considered to be among the clinically most important NTM. Only few virulence genes from M. avium have been defined among other things due to difficulties in generating M. avium mutants. More efforts in developing new methods for mutagenesis of M. avium and identification of virulence-associated genes are therefore needed. Results We developed a random mutagenesis method based on illegitimate recombination and integration of a Hygromycin-resistance marker. Screening for mutations possibly affecting virulence was performed by monitoring of pH resistance, colony morphology, cytokine induction in infected macrophages and intracellular persistence. Out of 50 randomly chosen Hygromycin-resistant colonies, four revealed to be affected in virulence-related traits. The mutated genes were MAV_4334 (nitroreductase family protein), MAV_5106 (phosphoenolpyruvate carboxykinase), MAV_1778 (GTP-binding protein LepA) and MAV_3128 (lysyl-tRNA synthetase LysS). Conclusions We established a random mutagenesis method for MAH that can be easily carried out and combined it with a set of phenotypic screening methods for the identification of virulence-associated mutants. By this method, four new MAH genes were identified that may be involved in virulence.
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Affiliation(s)
- Faisal Asghar Khattak
- Robert Koch-Institute, Division 16 Mycology/Parasitology/Intracellular Pathogens, Nordufer 20, Berlin 13353, Germany
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78
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Favrot L, Ronning DR. Targeting the mycobacterial envelope for tuberculosis drug development. Expert Rev Anti Infect Ther 2012; 10:1023-36. [PMID: 23106277 PMCID: PMC3571691 DOI: 10.1586/eri.12.91] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The bacterium that causes tuberculosis, Mycobacterium tuberculosis, possesses a rather unique outer membrane composed largely of lipids that possess long-chain and branched fatty acids, called mycolic acids. These lipids form a permeability barrier that prevents entry of many environmental solutes, thereby making these bacteria acid-fast and able to survive extremely hostile surroundings. Antitubercular drugs must penetrate this layer to reach their target. This review highlights drug development efforts that have added to the slowly growing tuberculosis drug pipeline, identified new enzyme activities to target with drugs and increased the understanding of important biosynthetic pathways for mycobacterial outer membrane and cell wall core assembly. In addition, a portion of this review looks at discovery efforts aimed at weakening this barrier to decrease mycobacterial virulence, decrease fitness in the host or enhance the efficacy of the current drug repertoire by disrupting the permeability barrier.
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Affiliation(s)
- Lorenza Favrot
- Department of Chemistry, University of Toledo, Toledo, OH 43606, USA
| | - Donald R Ronning
- Department of Chemistry, University of Toledo, Toledo, OH 43606, USA
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79
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Giovannini D, Cappelli G, Jiang L, Castilletti C, Colone A, Serafino A, Wannenes F, Giacò L, Quintiliani G, Fraziano M, Nepravishta R, Colizzi V, Mariani F. A new Mycobacterium tuberculosis smooth colony reduces growth inside human macrophages and represses PDIM Operon gene expression. Does an heterogeneous population exist in intracellular mycobacteria? Microb Pathog 2012; 53:135-46. [DOI: 10.1016/j.micpath.2012.06.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Revised: 06/18/2012] [Accepted: 06/26/2012] [Indexed: 11/30/2022]
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80
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Lamrabet O, Drancourt M. Genetic engineering of Mycobacterium tuberculosis: a review. Tuberculosis (Edinb) 2012; 92:365-76. [PMID: 22789498 DOI: 10.1016/j.tube.2012.06.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Accepted: 06/06/2012] [Indexed: 01/01/2023]
Abstract
Genetic engineering has been used for decades to mutate and delete genes in the Mycobacterium tuberculosis genome with the translational goal of producing attenuated mutants with conserved susceptibility to antituberculous antibiotics. The development of plasmids and mycobacteriophages that can transfer DNA into the M. tuberculosis chromosome has effectively overcome M. tuberculosis slow growth rate and the capsule and mycolic acid wall, which limit DNA uptake. The use of genetic engineering techniques has shed light on many aspects of pathogenesis mechanisms, including cellular growth, mycolic acid biosynthesis, metabolism, drug resistance and virulence. Moreover, such research gave clues to the development of new vaccines or new drugs for routine clinical practice. The use of genetic engineering tools is mainly based on the underlying concept that altering or reducing the M. tuberculosis genome could decrease its virulence. A contrario, recent post-genomic analyses indicated that reduced bacterial genomes are often associated with increased bacterial virulence and that M. tuberculosis acquired genes by lateral genetic exchange during its evolution. Therefore, ancestors utilizing genetic engineering to add genes to the M. tuberculosis genome may lead to new vaccines and the availability of M. tuberculosis isolates with increased susceptibility to antituberculous antibiotics.
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Affiliation(s)
- Otmane Lamrabet
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, UMR CNRS 6236 IRD 3R198, Méditerranée Infection, FRIDMM, Aix-Marseille Université, Marseille, France.
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81
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Saikolappan S, Estrella J, Sasindran SJ, Khan A, Armitige LY, Jagannath C, Dhandayuthapani S. The fbpA/sapM double knock out strain of Mycobacterium tuberculosis is highly attenuated and immunogenic in macrophages. PLoS One 2012; 7:e36198. [PMID: 22574140 PMCID: PMC3344844 DOI: 10.1371/journal.pone.0036198] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Accepted: 03/31/2012] [Indexed: 12/30/2022] Open
Abstract
Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), is the leading cause of death due to bacterial infections in mankind, and BCG, an attenuated strain of Mycobacterium bovis, is an approved vaccine. BCG sequesters in immature phagosomes of antigen presenting cells (APCs), which do not fuse with lysosomes, leading to decreased antigen processing and reduced Th1 responses. However, an Mtb derived ΔfbpA attenuated mutant underwent limited phagosome maturation, enhanced immunogenicity and was as effective as BCG in protecting mice against TB. To facilitate phagosome maturation of ΔfbpA, we disrupted an additional gene sapM, which encodes for an acid phosphatase. Compared to the wild type Mtb, the ΔfbpAΔsapM (double knock out; DKO) strain was attenuated for growth in mouse macrophages and PMA activated human THP1 macrophages. Attenuation correlated with increased oxidants in macrophages in response to DKO infection and enhanced labeling of lysosomal markers (CD63 and rab7) on DKO phagosomes. An in vitro Antigen 85B peptide presentation assay was used to determine antigen presentation to T cells by APCs infected with DKO or other mycobacterial strains. This revealed that DKO infected APCs showed the strongest ability to present Ag85B to T cells (>2500 pgs/mL in 4 hrs) as compared to APCs infected with wild type Mtb or ΔfbpA or ΔsapM strain (<1000 pgs/mL in 4 hrs), indicating that DKO strain has enhanced immunogenicity than other strains. The ability of DKO to undergo lysosomal fusion and vacuolar acidification correlated with antigen presentation since bafilomycin, that inhibits acidification in APCs, reduced antigen presentation. Finally, the DKO vaccine elicited a better Th1 response in mice after subcutaneous vaccination than either ΔfbpA or ΔsapM. Since ΔfbpA has been used in mice as a candidate vaccine and the DKO (ΔfbpAΔsapM) mutant is more immunogenic than ΔfbpA, we propose the DKO is a potential anti-tuberculosis vaccine.
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Affiliation(s)
- Sankaralingam Saikolappan
- Regional Academic Health Center and Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, Edinburg, Texas, United States of America
| | - Jaymie Estrella
- Department of Pathology and Laboratory Medicine, University of Texas Health Science Center at Houston, Houston, Texas, United States of America
| | - Smitha J. Sasindran
- Regional Academic Health Center and Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, Edinburg, Texas, United States of America
| | - Arshad Khan
- Department of Pathology and Laboratory Medicine, University of Texas Health Science Center at Houston, Houston, Texas, United States of America
| | - Lisa Y. Armitige
- Department of Pathology and Laboratory Medicine, University of Texas Health Science Center at Houston, Houston, Texas, United States of America
| | - Chinnaswamy Jagannath
- Department of Pathology and Laboratory Medicine, University of Texas Health Science Center at Houston, Houston, Texas, United States of America
| | - Subramanian Dhandayuthapani
- Regional Academic Health Center and Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, Edinburg, Texas, United States of America
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82
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Lee WB, Kang JS, Yan JJ, Lee MS, Jeon BY, Cho SN, Kim YJ. Neutrophils Promote Mycobacterial Trehalose Dimycolate-Induced Lung Inflammation via the Mincle Pathway. PLoS Pathog 2012; 8:e1002614. [PMID: 22496642 PMCID: PMC3320589 DOI: 10.1371/journal.ppat.1002614] [Citation(s) in RCA: 114] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Accepted: 02/15/2012] [Indexed: 11/18/2022] Open
Abstract
Trehalose 6,6'-dimycolate (TDM), a cord factor of Mycobacterium tuberculosis (Mtb), is an important regulator of immune responses during Mtb infections. Macrophages recognize TDM through the Mincle receptor and initiate TDM-induced inflammatory responses, leading to lung granuloma formation. Although various immune cells are recruited to lung granulomas, the roles of other immune cells, especially during the initial process of TDM-induced inflammation, are not clear. In this study, Mincle signaling on neutrophils played an important role in TDM-induced lung inflammation by promoting adhesion and innate immune responses. Neutrophils were recruited during the early stage of lung inflammation following TDM-induced granuloma formation. Mincle expression on neutrophils was required for infiltration of TDM-challenged sites in a granuloma model induced by TDM-coated-beads. TDM-induced Mincle signaling on neutrophils increased cell adherence by enhancing F-actin polymerization and CD11b/CD18 surface expression. The TDM-induced effects were dependent on Src, Syk, and MAPK/ERK kinases (MEK). Moreover, coactivation of the Mincle and TLR2 pathways by TDM and Pam3CSK4 treatment synergistically induced CD11b/CD18 surface expression, reactive oxygen species, and TNFα production by neutrophils. These synergistically-enhanced immune responses correlated with the degree of Mincle expression on neutrophil surfaces. The physiological relevance of the Mincle-mediated anti-TDM immune response was confirmed by defective immune responses in Mincle⁻/⁻ mice upon aerosol infections with Mtb. Mincle-mutant mice had higher inflammation levels and mycobacterial loads than WT mice. Neutrophil depletion with anti-Ly6G antibody caused a reduction in IL-6 and monocyte chemotactic protein-1 expression upon TDM treatment, and reduced levels of immune cell recruitment during the initial stage of infection. These findings suggest a new role of Mincle signaling on neutrophils during anti-mycobacterial responses.
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MESH Headings
- Adjuvants, Immunologic/adverse effects
- Adjuvants, Immunologic/chemistry
- Adjuvants, Immunologic/pharmacology
- Animals
- CD11b Antigen/genetics
- CD11b Antigen/immunology
- CD11b Antigen/metabolism
- CD18 Antigens/genetics
- CD18 Antigens/immunology
- CD18 Antigens/metabolism
- Cord Factors/adverse effects
- Cord Factors/chemistry
- Cord Factors/pharmacology
- Gene Expression Regulation/drug effects
- Gene Expression Regulation/genetics
- Gene Expression Regulation/immunology
- Granuloma, Respiratory Tract/chemically induced
- Granuloma, Respiratory Tract/genetics
- Granuloma, Respiratory Tract/immunology
- Granuloma, Respiratory Tract/metabolism
- Granuloma, Respiratory Tract/pathology
- Lectins, C-Type/genetics
- Lectins, C-Type/immunology
- Lectins, C-Type/metabolism
- Lung/immunology
- Lung/metabolism
- Lung/pathology
- Membrane Proteins/genetics
- Membrane Proteins/immunology
- Membrane Proteins/metabolism
- Mice
- Mice, Knockout
- Mycobacterium tuberculosis/chemistry
- Mycobacterium tuberculosis/metabolism
- Neutrophil Infiltration/drug effects
- Neutrophil Infiltration/genetics
- Neutrophil Infiltration/immunology
- Neutrophils/immunology
- Neutrophils/metabolism
- Neutrophils/pathology
- Pneumonia/chemically induced
- Pneumonia/genetics
- Pneumonia/immunology
- Pneumonia/metabolism
- Pneumonia/pathology
- Protein Kinases/genetics
- Protein Kinases/immunology
- Protein Kinases/metabolism
- Signal Transduction/drug effects
- Signal Transduction/genetics
- Signal Transduction/immunology
- Toll-Like Receptor 2/genetics
- Toll-Like Receptor 2/immunology
- Toll-Like Receptor 2/metabolism
- Tuberculosis, Pulmonary/genetics
- Tuberculosis, Pulmonary/immunology
- Tuberculosis, Pulmonary/metabolism
- Tuberculosis, Pulmonary/pathology
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Affiliation(s)
- Wook-Bin Lee
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, Republic of Korea
| | - Ji-Seon Kang
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, Republic of Korea
| | - Ji-Jing Yan
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, Republic of Korea
| | - Myeong Sup Lee
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, Republic of Korea
| | - Bo-Young Jeon
- Department of Microbiology and Institute of Immunology and Immunological Disease, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Sang-Nae Cho
- Department of Microbiology and Institute of Immunology and Immunological Disease, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Young-Joon Kim
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, Republic of Korea
- Department of Integrated Omics for Biomedical Science, WCU Program of Graduate School, Yonsei University, Seoul, Republic of Korea
- * E-mail:
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83
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Warrier T, Tropis M, Werngren J, Diehl A, Gengenbacher M, Schlegel B, Schade M, Oschkinat H, Daffe M, Hoffner S, Eddine AN, Kaufmann SHE. Antigen 85C inhibition restricts Mycobacterium tuberculosis growth through disruption of cord factor biosynthesis. Antimicrob Agents Chemother 2012; 56:1735-43. [PMID: 22290959 PMCID: PMC3318338 DOI: 10.1128/aac.05742-11] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Accepted: 01/04/2012] [Indexed: 11/20/2022] Open
Abstract
The antigen 85 (Ag85) protein family, consisting of Ag85A, -B, and -C, is vital for Mycobacterium tuberculosis due to its role in cell envelope biogenesis. The mycoloyl transferase activity of these proteins generates trehalose dimycolate (TDM), an envelope lipid essential for M. tuberculosis virulence, and cell wall arabinogalactan-linked mycolic acids. Inhibition of these enzymes through substrate analogs hinders growth of mycobacteria, but a link to mycolic acid synthesis has not been established. In this study, we characterized a novel inhibitor of Ag85C, 2-amino-6-propyl-4,5,6,7-tetrahydro-1-benzothiophene-3-carbonitrile (I3-AG85). I3-AG85 was isolated from a panel of four inhibitors that exhibited structure- and dose-dependent inhibition of M. tuberculosis division in broth culture. I3-AG85 also inhibited M. tuberculosis survival in infected primary macrophages. Importantly, it displayed an identical MIC against the drug-susceptible H37Rv reference strain and a panel of extensively drug-resistant/multidrug-resistant M. tuberculosis strains. Nuclear magnetic resonance analysis indicated binding of I3-AG85 to Ag85C, similar to its binding to the artificial substrate octylthioglucoside. Quantification of mycolic acid-linked lipids of the M. tuberculosis envelope showed a specific blockade of TDM synthesis. This was accompanied by accumulation of trehalose monomycolate, while the overall mycolic acid abundance remained unchanged. Inhibition of Ag85C activity also disrupted the integrity of the M. tuberculosis envelope. I3-AG85 inhibited the division of and reduced TDM synthesis in an M. tuberculosis strain deficient in Ag85C. Our results indicate that Ag85 proteins are promising targets for novel antimycobacterial drug design.
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Affiliation(s)
- Thulasi Warrier
- Department of Immunology, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Marielle Tropis
- Institute of Pharmacology and Structural Biology, CNRS, and University of Toulouse (Toulouse III), Toulouse, France
| | - Jim Werngren
- Swedish Institute for Communicable Disease Control, Solna, Sweden
| | - Anne Diehl
- NMR Group, Leibniz Institut für Molekulare Pharmakologie, Berlin, Germany
| | - Martin Gengenbacher
- Department of Immunology, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Brigitte Schlegel
- NMR Group, Leibniz Institut für Molekulare Pharmakologie, Berlin, Germany
| | - Markus Schade
- AstraZeneca Ltd., DECS Biophysics, Macclesfield, United Kingdom
| | - Hartmut Oschkinat
- NMR Group, Leibniz Institut für Molekulare Pharmakologie, Berlin, Germany
| | - Mamadou Daffe
- Institute of Pharmacology and Structural Biology, CNRS, and University of Toulouse (Toulouse III), Toulouse, France
| | - Sven Hoffner
- Swedish Institute for Communicable Disease Control, Solna, Sweden
| | - Ali Nasser Eddine
- Department of Immunology, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Stefan H. E. Kaufmann
- Department of Immunology, Max Planck Institute for Infection Biology, Berlin, Germany
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84
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Singhal N, Sharma P, Kumar M, Joshi B, Bisht D. Analysis of intracellular expressed proteins of Mycobacterium tuberculosis clinical isolates. Proteome Sci 2012; 10:14. [PMID: 22375954 PMCID: PMC3310783 DOI: 10.1186/1477-5956-10-14] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Accepted: 03/01/2012] [Indexed: 01/01/2023] Open
Abstract
Background Tuberculosis (TB) is the most threatening infectious disease globally. Although progress has been made to reduce global incidence of TB, emergence of multidrug resistant (MDR) TB threatens to undermine these advances. To combat the disease, novel intervention strategies effective against drug resistant and sensitive subpopulations of M. tuberculosis are urgently required as adducts in the present treatment regimen. Using THP-1 cells we have analyzed and compared the global protein expression profile of broth-cultured and intraphagosomally grown drug resistant and sensitive M.tuberculosis clinical isolates. Results On comparing the two dimensional (2-DE) gels, many proteins were found to be upregulated/expressed during intracellular state which were identified by matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS). Four proteins (adenosylhomocysteinase, aspartate carbomyltransferase, putatitive thiosulfate sulfurtransferase and universal stress protein) were present in both intracellular MDR and sensitive isolates and three of these belonged to intermediary metabolism and respiration category. Two proteins (alanine dehydrogenase and adenosine kinase) of intracellular MDR isolate and two (glucose-6-phosphate isomerase and ATP synthase epsilon chain) of intracellular sensitive isolate belonged to intermediary metabolism and respiration category. One protein (Peroxidase/Catalase) of intracellular MDR and three (HSPX, 14 kDa antigen and 10 kDa chaperonin) of sensitive isolate belonged to virulence, detoxification and adaptation category. ESAT-6 of intracellular MDR belonged to cell wall and cell processes category. Two proteins (Antigen 85-C and Antigen 85-A) of intracellular sensitive isolate were involved in lipid metabolism while probable peptidyl-prolyl cis-trans isomerase A was involved in information pathways. Four (Rv0635, Rv1827, Rv0036c and Rv2032) of intracellular MDR and two proteins (Rv2896c and Rv2558c) of sensitive isolate were hypothetical proteins which were functionally characterized using bioinformatic tools. Bioinformatic findings revealed that the proteins encoded by Rv0036, Rv2032c, Rv0635, Rv1827 and Rv2896c genes are involved in cellular metabolism and help in intracellular survival. Conclusions Mass spectrometry and bioinformatic analysis of both MDR and sensitive isolates of M. tuberculosis during intraphagosomal growth showed that majority of commonly upregulated/expressed proteins belonged to the cellular metabolism and respiration category. Inhibitors of the metabolic enzymes/intermediate can therefore serve as suitable drug targets against drug-resistant and sensitive subpopulations of M. tuberculosis.
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Affiliation(s)
- Neelja Singhal
- Department of Biochemistry, National JALMA Institute for Leprosy and other Mycobacterial Diseases, Tajganj, Agra 282001, India.
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85
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Ligon LS, Hayden JD, Braunstein M. The ins and outs of Mycobacterium tuberculosis protein export. Tuberculosis (Edinb) 2011; 92:121-32. [PMID: 22192870 DOI: 10.1016/j.tube.2011.11.005] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Revised: 11/10/2011] [Accepted: 11/11/2011] [Indexed: 11/25/2022]
Abstract
Mycobacterium tuberculosis is an important pathogen that infects approximately one-third of the world's population and kills almost two million people annually. An important aspect of M. tuberculosis physiology and pathogenesis is its ability to export proteins into and across the thick mycobacterial cell envelope, where they are ideally positioned to interact with the host. In addition to the specific proteins that are exported by M. tuberculosis, the systems through which these proteins are exported represent potential targets for future drug development. M. tuberculosis possesses two well-known and conserved export systems: the housekeeping Sec pathway and the Tat pathway. In addition, M. tuberculosis possesses specialized export systems including the accessory SecA2 pathway and five ESX pathways. Here we review the current understanding of each of these export systems, with a focus on M. tuberculosis, and discuss the contribution of each system to disease and physiology.
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Affiliation(s)
- Lauren S Ligon
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, CB #7290, Chapel Hill, NC 27599, USA
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86
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Kuo CJ, Bell H, Hsieh CL, Ptak CP, Chang YF. Novel mycobacteria antigen 85 complex binding motif on fibronectin. J Biol Chem 2011; 287:1892-902. [PMID: 22128161 DOI: 10.1074/jbc.m111.298687] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The members of the antigen 85 protein family (Ag85), consisting of members Ag85A, Ag85B, and Ag85C, are the predominantly secreted proteins of mycobacteria and possess the ability to specifically interact with fibronectin (Fn). Because Fn-binding proteins are likely to be important virulence factors of Mycobacterium spp., Ag85 may contribute to the adherence, invasion, and dissemination of organisms in host tissue. In this study, we reported the Fn binding affinity of Ag85A, Ag85B, and Ag85C from Mycobacterium avium subsp. paratuberculosis (MAP) (K(D) values were determined from 33.6 to 68.4 nm) and mapped the Ag85-binding motifs of Fn. Fn14, a type III module located on the heparin-binding domain II (Hep-2) of Fn, was discovered to interact with Ag85 from MAP. The peptide inhibition assay subsequently demonstrated that a peptide consisting of residues 17-26 from Fn14 ((17)SLLVSWQPPR(26), termed P17-26) could interfere with Ag85B binding to Fn (73.3% reduction). In addition, single alanine substitutions along the sequence of P17-26 revealed that the key residues involved in Ag85-Fn binding likely contribute through hydrophobic and charge interactions. Moreover, binding of Ag85 on Fn siRNA-transfected Caco2 cells was dramatically reduced (44.6%), implying the physiological significance of the Ag85-Fn interaction between mycobacteria and host cells during infection. Our results indicate that Ag85 binds to Fn at a novel motif and plays a critical role in mycobacteria adherence to host cells by initiating infection. Ag85 might serve as an important colonization factor potentially contributing to mycobacterial virulence.
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Affiliation(s)
- Chih-Jung Kuo
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA
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87
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Roche CM, Smith A, Lindsey DR, Meher A, Schluns K, Arora A, Armitige LY, Jagannath C. The ΔfbpA attenuated candidate vaccine from Mycobacterium tuberculosis, H37Rv primes for a stronger T-bet dependent Th1 immunity in mice. Tuberculosis (Edinb) 2011; 91 Suppl 1:S96-104. [PMID: 22082615 DOI: 10.1016/j.tube.2011.10.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The ΔfbpA candidate vaccine derived from Mycobacterium tuberculosis (H37Rv) (Mtb) protects mice better than BCG against tuberculosis, and we investigated the hypothesis that ΔfbpA may induce a stronger Th1 immunity. Since T-bet transcription factor regulates Th1 immunity, mice infected with ΔfbpA, BCG vaccine and related mycobacteria were analyzed for T-bet positive T cells. Mouse dendritic cells (DCs) or macrophages were also pulsed with excretory-secreted antigens (ES; Antigen-85B, ESAT-6 and CFP10) and cocultured with T cells from immunized or naïve mice and tested for in vitro induction of T-bet and IFN-γ. In both models, ΔfbpA mutant induced a stronger response of T-bet(+)CD4 T cells, which correlated with an increased expansion of IFN-γ(+)CD4 T cells in vivo and in vitro. When DCs pulsed with ES antigens were allowed to stimulate T cells, ESAT-6 and CFP-10 failed to induce a recall expansion of T-bet(+)IFN-γ(+)CD4 T cells from BCG vaccinated mice. Thus, deletion of RD1 in BCG seems to reduce its ability to induce T-bet and induce stronger Th1 immunity. Finally, mice were vaccinated with ΔfbpA and BCG and challenged with virulent Mtb for evaluation of protection and T cell expansion. ΔfbpA vaccinated mice showed a rapid and stronger expansion of CD4(+)CXCR3(+) IFN-γ(+) T cells in the lungs of Mtb challenged mice, compared to those which had BCG vaccine. ΔfbpA immunized mice also showed a better decline of the Mtb bacterial counts of the lungs. Mtb derived ΔfbpA candidate vaccine therefore induces qualitatively better T-bet dependent Th1 immunity than BCG vaccine.
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Affiliation(s)
- Cherie M Roche
- Department of Pathology and Laboratory Medicine, University of Texas Health Sciences Center, 6431 Fannin, MSB 2.200, Houston, TX, USA
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88
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Orduña P, Cevallos MA, de León SP, Arvizu A, Hernández-González IL, Mendoza-Hernández G, López-Vidal Y. Genomic and proteomic analyses of Mycobacterium bovis BCG Mexico 1931 reveal a diverse immunogenic repertoire against tuberculosis infection. BMC Genomics 2011; 12:493. [PMID: 21981907 PMCID: PMC3199284 DOI: 10.1186/1471-2164-12-493] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Accepted: 10/08/2011] [Indexed: 12/03/2022] Open
Abstract
Background Studies of Mycobacterium bovis BCG strains used in different countries and vaccination programs show clear variations in the genomes and immune protective properties of BCG strains. The aim of this study was to characterise the genomic and immune proteomic profile of the BCG 1931 strain used in Mexico. Results BCG Mexico 1931 has a circular chromosome of 4,350,386 bp with a G+C content and numbers of genes and pseudogenes similar to those of BCG Tokyo and BCG Pasteur. BCG Mexico 1931 lacks Region of Difference 1 (RD1), RD2 and N-RD18 and one copy of IS6110, indicating that BCG Mexico 1931 belongs to DU2 group IV within the BCG vaccine genealogy. In addition, this strain contains three new RDs, which are 53 (RDMex01), 655 (RDMex02) and 2,847 bp (REDMex03) long, and 55 single-nucleotide polymorphisms representing non-synonymous mutations compared to BCG Pasteur and BCG Tokyo. In a comparative proteomic analysis, the BCG Mexico 1931, Danish, Phipps and Tokyo strains showed 812, 794, 791 and 701 protein spots, respectively. The same analysis showed that BCG Mexico 1931 shares 62% of its protein spots with the BCG Danish strain, 61% with the BCG Phipps strain and only 48% with the BCG Tokyo strain. Thirty-nine reactive spots were detected in BCG Mexico 1931 using sera from subjects with active tuberculosis infections and positive tuberculin skin tests. Conclusions BCG Mexico 1931 has a smaller genome than the BCG Pasteur and BCG Tokyo strains. Two specific deletions in BCG Mexico 1931 are described (RDMex02 and RDMex03). The loss of RDMex02 (fadD23) is associated with enhanced macrophage binding and RDMex03 contains genes that may be involved in regulatory pathways. We also describe new antigenic proteins for the first time.
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Affiliation(s)
- Patricia Orduña
- Programa de Inmunología Molecular Microbiana, Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, DF, México
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89
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Elamin AA, Stehr M, Spallek R, Rohde M, Singh M. The Mycobacterium tuberculosis Ag85A is a novel diacylglycerol acyltransferase involved in lipid body formation. Mol Microbiol 2011; 81:1577-92. [PMID: 21819455 DOI: 10.1111/j.1365-2958.2011.07792.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Mycobacterium tuberculosis accumulates large amounts of triacylglycerol (TAG) which acts as storage compounds for energy and carbon. The mycobacterial triacylglycerols stored in the form of intracellular lipid droplets are essential for long-term survival of M. tuberculosis during a dormant state. We report here that when the M. tuberculosis mycolytransferase Ag85A is overexpressed in Mycobacterium smegmatis mc(2)155, cell morphology was changed and the cells became grossly enlarged. A massive formation of lipid bodies and a change in lipid pattern was observed simultaneously. We suspected a possible role of Ag85A in the acyl lipid metabolism and discovered that the enzyme possesses acyl-CoA:diacylglycerol acyltransferase (DGAT) activity in addition to its well-known function as mycolyltransferase. Ag85A mediates the transesterification of diacylglycerol using long-chain acyl-CoA as acyl donors. The K(m) and K(cat) values for palmitoleoyl-coenzyme A were 390 µM and 55.54 min(-1) respectively. A docking model suggests that palmitoleoyl-coenzyme A and 1,2-dipalmitin occupy the same active site as trehalose 6,6'-dimycolate and trehalose 6'-monomycolate. The site-directed Ser126Ala mutation of the active site proved that this residue is involved in the catalytic activity of this enzyme. Although not proven conclusively for dormant stage of M. tuberculosis, our novel finding about the synthesis of TAGs by Ag85A strongly suggests that Ag85A may play a significant role in the formation of lipid storage bodies and thus also in the establishment and maintenance of a persistent tuberculosis infection.
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Affiliation(s)
- Ayssar A Elamin
- Department of Gene Regulation and Differentiation, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
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90
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Chang JR, Lin CH, Tsai SF, Su IJ, Tseng FC, Chen YT, Chiueh TS, Sun JR, Huang TS, Chen YS, Dou HY. Genotypic analysis of genes associated with transmission and drug resistance in the Beijing lineage of Mycobacterium tuberculosis. Clin Microbiol Infect 2010; 17:1391-6. [PMID: 21091972 DOI: 10.1111/j.1469-0691.2010.03436.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The Beijing genotype of Mycobacterium tuberculosis is an endemic lineage in East Asia that has disseminated worldwide. It is a major health concern, as it is geographically widespread and is considered to be hypervirulent. To elucidate its genetic diversity in Taiwan, phylogenetic reconstruction was performed using 338 M. tuberculosis Beijing family clinical isolates. Region-of-difference analysis revealed the strains from Taiwan to be distributed among six subgroups of a phylogenetic tree. Synonymous single nucleotide polymorphisms at 10 chromosomal positions were also analysed. Among the 338 isolates analysed for single-nucleotide polymorphisms by using mass spectrometry, the most frequent strain found was ST10 (53.3%), followed by ST19 (14.8%) and ST22 (14.5%). Tests of drug resistance showed that the sublineages ST10, ST19 and ST26 were over-represented in the multidrug-resistant population. The presence of mutations in putative genes coding for DNA repair enzymes, which could confer a mutator phenotype to facilitate spreading of the pathogen, did not demonstrate an association with multidrug resistance. Therefore, the DNA repair genes may be involved in transmission but not in drug resistance.
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Affiliation(s)
- J-R Chang
- Division of Infectious Diseases, National Health Research Institutes, Zhunan, Miaoli, Taiwan
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91
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Deng YH, Sun Z, Yang XL, Bao L. Improved immunogenicity of recombinant Mycobacterium bovis bacillus Calmette-Guérin strains expressing fusion protein Ag85A-ESAT-6 of Mycobacterium tuberculosis. Scand J Immunol 2010; 72:332-8. [PMID: 20883318 DOI: 10.1111/j.1365-3083.2010.02444.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Early secretory antigen target 6 (ESAT-6) is a dominant target for cell-mediated immunity in the early phase of tuberculosis (TB) in patients with TB, causing T-cell proliferation and gamma interferon (IFN-γ) production, which has been considered to be a protective antigen that can be used for future vaccine development. Ag85A is the most essential component for bacterial survival within macrophages and has been used in numerous vaccine preparations, which can induce strong cellular immune responses. In this study, we constructed a new recombinant bacilli Calmette-Guérin (BCG) strain (rBCG-AE) that could express fusion protein Ag85A-ESAT-6 of Mycobacterium tuberculosis and evaluated its immunogenicity in BALB/c mice. There was no evidence for increased virulence of this rBCG. Our experiments illustrated that the rBCG-AE was able to induce higher titer of antibody and elicit more long-lasting and stronger Th1 type cellular immune responses than the parental BCG strain, or rBCG-A (expressing Ag85A) strain, or rBCG-E (expressing ESAT-6) strain, which are characterized by the strong antibody response, the proliferation rate of splenocytes, the ratio of CD4(+) T and CD8(+) T cells stimulated by tuberculin-purified protein derivative and elevated levels of IFN-γ in antigen-stimulated splenocyte cultures. The results show that rBCG-AE is an improved TB vaccine for further study.
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Affiliation(s)
- Y H Deng
- Laboratory of Infection and Immunity, West China Center of Medical sciences, Sichuan University, Chengdu, China
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92
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T cell reactivity against mycolyl transferase antigen 85 of M. tuberculosis in HIV-TB coinfected subjects and in AIDS patients suffering from tuberculosis and nontuberculous mycobacterial infections. Clin Dev Immunol 2010; 2011. [PMID: 20936150 PMCID: PMC2948887 DOI: 10.1155/2011/640309] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2010] [Accepted: 08/16/2010] [Indexed: 11/23/2022]
Abstract
The mycolyl transferase antigen 85 complex is a major secreted protein family from mycobacterial culture filtrate, demonstrating powerful T cell stimulatory properties in most HIV-negative, tuberculin-positive volunteers with latent M.tuberculosis infection and only weak responses in HIV-negative tuberculosis patients. Here, we have analyzed T cell reactivity against PPD and Ag85 in HIV-infected individuals, without or with clinical symptoms of tuberculosis, and in AIDS patients with disease caused by nontuberculous mycobacteria. Whereas responses to PPD were not significantly different in HIV-negative and HIV-positive tuberculin-positive volunteers, responses to Ag85 were significantly decreased in the HIV-positive (CDC-A and CDC-B) group. Tuberculosis patients demonstrated low T cell reactivity against Ag85, irrespective of HIV infection, and finally AIDS patients suffering from NTM infections were completely nonreactive to Ag85. A one-year follow-up of twelve HIV-positive tuberculin-positive individuals indicated a decreased reactivity against Ag85 in patients developing clinical tuberculosis, highlighting the protective potential of this antigen.
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93
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Ojha AK, Trivelli X, Guerardel Y, Kremer L, Hatfull GF. Enzymatic hydrolysis of trehalose dimycolate releases free mycolic acids during mycobacterial growth in biofilms. J Biol Chem 2010; 285:17380-9. [PMID: 20375425 PMCID: PMC2878501 DOI: 10.1074/jbc.m110.112813] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Revised: 04/02/2010] [Indexed: 02/02/2023] Open
Abstract
Mycobacterial species, like other microbes, spontaneously form multicellular drug-tolerant biofilms when grown in vitro in detergent-free liquid media. The structure of Mycobacterium tuberculosis biofilms is formed through genetically programmed pathways and is built upon a large abundance of novel extracellular free mycolic acids (FM), although the mechanism of FM synthesis remained unclear. Here we show that the FM in Mycobacterium smegmatis biofilms is produced through the enzymatic release from constitutively present mycolyl derivatives. One of the precursors for FM is newly synthesized trehalose dimycolate (TDM), which is cleaved by a novel TDM-specific serine esterase, Msmeg_1529. Disruption of Msmeg_1529 leads to undetectable hydrolytic activity, reduced levels of FM in the mutant, and retarded biofilm growth. Furthermore, enzymatic hydrolysis of TDM remains conserved in M. tuberculosis, suggesting the presence of a TDM-specific esterase in this pathogen. Overall, this study provides the first evidence for an enzymatic release of free mycolic acids from cell envelope mycolates during mycobacterial growth.
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Affiliation(s)
- Anil K Ojha
- Department of Infectious Diseases and Microbiology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA.
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94
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95
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Single nucleotide polymorphisms in cell wall biosynthesis-associated genes and phylogeny of Mycobacterium tuberculosis lineages. INFECTION GENETICS AND EVOLUTION 2010; 10:459-66. [DOI: 10.1016/j.meegid.2010.03.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2009] [Revised: 03/01/2010] [Accepted: 03/02/2010] [Indexed: 11/20/2022]
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96
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The Rhodococcal Cell Envelope: Composition, Organisation and Biosynthesis. BIOLOGY OF RHODOCOCCUS 2010. [DOI: 10.1007/978-3-642-12937-7_2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
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97
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Identification of promoter-binding proteins of the fbp A and C genes in Mycobacterium tuberculosis. Tuberculosis (Edinb) 2009; 90:25-30. [PMID: 19959397 DOI: 10.1016/j.tube.2009.10.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Revised: 08/27/2009] [Accepted: 10/05/2009] [Indexed: 10/24/2022]
Abstract
The antigen 85 (Ag85) complex of Mycobacterium tuberculosis represents a promising candidate as a novel drug target and pathogenesis factor. Ag85 comprises three proteins Ag85A, B and C, (encoded by the genes fbpA, B, and C), which participate in cell wall biosynthesis, and interact with the host macrophage as fibronectin-binding proteins (fbps). Ag85 is also involved in the response to isoniazid (INH) treatment. The objective of this study was to identify potential fbp gene activators involved in the over-expression of fbp genes in response to INH. The biotinylated upstream promoter regions of fbpA and fbpC were used together with streptavidin-coated magnetic beads in DNA-binding assays, to isolate proteins with high-binding affinities from cytosolic extracts of INH-treated M. tuberculosis. Resolution of the DNA-binding proteins by 1D SDS-PAGE revealed 6 proteins with high-affinity for the fbpA promoter, and 7 with specificity the fbpC promoter. Mass spectrometric analyses [LC-ES(MS/MS)] identified proteins associated with drug resistance and stress/treatment responses, intermediary metabolism and cellular division, hypothetical proteins including a member of the MarR family of bacterial transcriptional regulators. The DNA-binding MarR protein shows potential as an authentic activator of fbp genes and functional validation of this factor is warranted.
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98
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Hunter RL, Armitige L, Jagannath C, Actor JK. TB research at UT-Houston--a review of cord factor: new approaches to drugs, vaccines and the pathogenesis of tuberculosis. Tuberculosis (Edinb) 2009; 89 Suppl 1:S18-25. [PMID: 20006299 PMCID: PMC3682682 DOI: 10.1016/s1472-9792(09)70007-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Tuberculosis remains a major threat as drug resistance continues to increase. Pulmonary tuberculosis in adults is responsible for 80% of clinical cases and nearly 100% of transmission of infection. Unfortunately, since we have no animal models of adult type pulmonary tuberculosis, the most important type of disease remains largely out of reach of modern science and many fundamental questions remain unanswered. This paper reviews research dating back to the 1950's providing compelling evidence that cord factor (trehalose 6,6 dimycolate [TDM]) is essential for understanding tuberculosis. However, the original papers by Bloch and Noll were too far ahead of their time to have immediate impact. We can now recognize that the physical and biologic properties of cord factor are unprecedented in science, especially its ability to switch between two sets of biologic activities with changes in conformation. While TDM remains on organisms, it protects them from killing within macrophages, reduces antibiotic effectiveness and inhibits the stimulation of protective immune responses. If it comes off organisms and associates with lipid, TDM becomes a driver of tissue damage and necrosis. Studies emanating from cord factor research have produced (1) a rationale for improving vaccines, (2) an approach to new drugs that overcome natural resistance to antibiotics, (3) models of caseating granulomas that reproduce multiple manifestations of human tuberculosis. (4) evidence that TDM is a key T cell antigen in destructive lesions of tuberculosis, and (5) a new understanding of the pathology and pathogenesis of postprimary tuberculosis that can guide more informative studies of long standing mysteries of tuberculosis.
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Affiliation(s)
- Robert L Hunter
- University of Texas--Houston Medical School, Department of Pathology and Laboratory, Houston, TX 77030, USA
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99
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Elamin AA, Stehr M, Oehlmann W, Singh M. The mycolyltransferase 85A, a putative drug target of Mycobacterium tuberculosis: development of a novel assay and quantification of glycolipid-status of the mycobacterial cell wall. J Microbiol Methods 2009; 79:358-63. [PMID: 19857528 DOI: 10.1016/j.mimet.2009.10.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2009] [Revised: 10/15/2009] [Accepted: 10/16/2009] [Indexed: 11/25/2022]
Abstract
The enzymes of the antigen 85 complex (Ag85A, B, and C) possess mycolyltransferase activity and catalyze the synthesis of the most abundant glycolipid of the mycobacterial cell wall, the cord factor. The cord factor (trehalose 6,6'-dimycolate, TDM) is essential for the integrity of the mycobacterial cell wall and pathogenesis of the bacillus. Thus, TDM biosynthesis is regarded as a potential drug target for control of Mycobacterium tuberculosis infections. Trehalose 6,6'-dimycolate (TDM) is synthesized from two molecules of trehalose-6'-monomycolate (TMM) by antigen 85A. We report here a novel enzyme assay using the natural substrate TMM. The novel colorimetric assay is based on the quantification of glucose from the degradation of trehalose, which is the product from catalytic activity of antigen 85A. Using the new assay, K(m) and K(cat) were determined with values of 129.6+/-8.1 microM and 65.4+/-4.1 min(-1), respectively. This novel assay is also suitable for robust high-throughput screening (HTS) for compound library screening against mycolyltransferase (antigen 85A). The assay is significantly faster and more convenient to use than all assays currently in use. The assay has a very low coefficient of variance (0.04) in 96-well plates and shows a Z' factor of 0.67-0.73, indicating the robustness of the assay. In addition, this new assay is highly suitable for the quantification of total TMM of the mycobacterial cell envelope.
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Affiliation(s)
- Ayssar A Elamin
- Department of Genome Analysis, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
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100
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Autophagy enhances the efficacy of BCG vaccine by increasing peptide presentation in mouse dendritic cells. Nat Med 2009; 15:267-76. [PMID: 19252503 DOI: 10.1038/nm.1928] [Citation(s) in RCA: 359] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2008] [Accepted: 01/12/2009] [Indexed: 02/02/2023]
Abstract
The variable efficacy of Bacille Calmette Guerin (BCG) vaccination against tuberculosis has prompted efforts to improve the vaccine. In this study, we used autophagy to enhance vaccine efficacy against tuberculosis in a mouse model. We examined the effect of autophagy on the processing of the immunodominant mycobacterial antigen Ag85B by antigen presenting cells (APCs), macrophages and dendritic cells (DCs). We found that rapamycin-induced autophagy enhanced Ag85B presentation by APCs infected with wild-type Mycobacterium tuberculosis H37Rv, H37Rv-derived DeltafbpA attenuated candidate vaccine or BCG. Furthermore, rapamycin enhanced localization of mycobacteria with autophagosomes and lysosomes. Rapamycin-enhanced antigen presentation was attenuated when autophagy was suppressed by 3-methyladenine or by small interfering RNA against beclin-1. Notably, mice immunized with rapamycin-treated DCs infected with either DeltafbpA or BCG showed enhanced T helper type 1-mediated protection when challenged with virulent Mycobacterium tuberculosis. Finally, overexpression of Ag85B in BCG induced autophagy in APCs and enhanced immunogenicity in mice, suggesting that vaccine efficacy can be enhanced by augmenting autophagy-mediated antigen presentation.
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