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Gong W, Pan C, Cheng P, Wang J, Zhao G, Wu X. Peptide-Based Vaccines for Tuberculosis. Front Immunol 2022; 13:830497. [PMID: 35173740 PMCID: PMC8841753 DOI: 10.3389/fimmu.2022.830497] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 01/10/2022] [Indexed: 12/12/2022] Open
Abstract
Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis. As a result of the coronavirus disease 2019 (COVID-19) pandemic, the global TB mortality rate in 2020 is rising, making TB prevention and control more challenging. Vaccination has been considered the best approach to reduce the TB burden. Unfortunately, BCG, the only TB vaccine currently approved for use, offers some protection against childhood TB but is less effective in adults. Therefore, it is urgent to develop new TB vaccines that are more effective than BCG. Accumulating data indicated that peptides or epitopes play essential roles in bridging innate and adaptive immunity and triggering adaptive immunity. Furthermore, innovations in bioinformatics, immunoinformatics, synthetic technologies, new materials, and transgenic animal models have put wings on the research of peptide-based vaccines for TB. Hence, this review seeks to give an overview of current tools that can be used to design a peptide-based vaccine, the research status of peptide-based vaccines for TB, protein-based bacterial vaccine delivery systems, and animal models for the peptide-based vaccines. These explorations will provide approaches and strategies for developing safer and more effective peptide-based vaccines and contribute to achieving the WHO's End TB Strategy.
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Affiliation(s)
- Wenping Gong
- Tuberculosis Prevention and Control Key Laboratory/Beijing Key Laboratory of New Techniques of Tuberculosis Diagnosis and Treatment, Senior Department of Tuberculosis, The 8th Medical Center of PLA General Hospital, Beijing, China
| | - Chao Pan
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing, China
| | - Peng Cheng
- Tuberculosis Prevention and Control Key Laboratory/Beijing Key Laboratory of New Techniques of Tuberculosis Diagnosis and Treatment, Senior Department of Tuberculosis, The 8th Medical Center of PLA General Hospital, Beijing, China
- Hebei North University, Zhangjiakou City, China
| | - Jie Wang
- Tuberculosis Prevention and Control Key Laboratory/Beijing Key Laboratory of New Techniques of Tuberculosis Diagnosis and Treatment, Senior Department of Tuberculosis, The 8th Medical Center of PLA General Hospital, Beijing, China
| | - Guangyu Zhao
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Xueqiong Wu
- Tuberculosis Prevention and Control Key Laboratory/Beijing Key Laboratory of New Techniques of Tuberculosis Diagnosis and Treatment, Senior Department of Tuberculosis, The 8th Medical Center of PLA General Hospital, Beijing, China
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Abhishek S, Saikia UN, Gupta A, Bansal R, Gupta V, Singh N, Laal S, Verma I. Transcriptional Profile of Mycobacterium tuberculosis in an in vitro Model of Intraocular Tuberculosis. Front Cell Infect Microbiol 2018; 8:330. [PMID: 30333960 PMCID: PMC6175983 DOI: 10.3389/fcimb.2018.00330] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 08/28/2018] [Indexed: 12/18/2022] Open
Abstract
Background: Intraocular tuberculosis (IOTB), an extrapulmonary manifestation of tuberculosis of the eye, has unique and varied clinical presentations with poorly understood pathogenesis. As it is a significant cause of inflammation and visual morbidity, particularly in TB endemic countries, it is essential to study the pathogenesis of IOTB. Clinical and histopathologic studies suggest the presence of Mycobacterium tuberculosis in retinal pigment epithelium (RPE) cells. Methods: A human retinal pigment epithelium (ARPE-19) cell line was infected with a virulent strain of M. tuberculosis (H37Rv). Electron microscopy and colony forming units (CFU) assay were performed to monitor the M. tuberculosis adherence, invasion, and intracellular replication, whereas confocal microscopy was done to study its intracellular fate in the RPE cells. To understand the pathogenesis, the transcriptional profile of M. tuberculosis in ARPE-19 cells was studied by whole genome microarray. Three upregulated M. tuberculosis transcripts were also examined in human IOTB vitreous samples. Results: Scanning electron micrographs of the infected ARPE-19 cells indicated adherence of bacilli, which were further observed to be internalized as monitored by transmission electron microscopy. The CFU assay showed that 22.7 and 8.4% of the initial inoculum of bacilli adhered and invaded the ARPE-19 cells, respectively, with an increase in fold CFU from 1 dpi (0.84) to 5dpi (6.58). The intracellular bacilli were co-localized with lysosomal-associated membrane protein-1 (LAMP-1) and LAMP-2 in ARPE-19 cells. The transcriptome study of intracellular bacilli showed that most of the upregulated transcripts correspond to the genes encoding the proteins involved in the processes such as adherence (e.g., Rv1759c and Rv1026), invasion (e.g., Rv1971 and Rv0169), virulence (e.g., Rv2844 and Rv0775), and intracellular survival (e.g., Rv1884c and Rv2450c) as well as regulators of various metabolic pathways. Two of the upregulated transcripts (Rv1971, Rv1230c) were also present in the vitreous samples of the IOTB patients. Conclusions:M. tuberculosis is phagocytosed by RPE cells and utilizes these cells for intracellular multiplication with the involvement of late endosomal/lysosomal compartments and alters its transcriptional profile plausibly for its intracellular adaptation and survival. The findings of the present study could be important to understanding the molecular pathogenesis of IOTB with a potential role in the development of diagnostics and therapeutics for IOTB.
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Affiliation(s)
- Sudhanshu Abhishek
- Department of Biochemistry, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Uma Nahar Saikia
- Department of Histopathology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Amod Gupta
- Department of Ophthalmology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Reema Bansal
- Department of Ophthalmology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Vishali Gupta
- Department of Ophthalmology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Nirbhai Singh
- Department of Ophthalmology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Suman Laal
- Department of Pathology, New York University Langone Medical Center, New York, NY, United States
- Veterans Affairs New York Harbor Healthcare System, New York, NY, United States
| | - Indu Verma
- Department of Biochemistry, Postgraduate Institute of Medical Education and Research, Chandigarh, India
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Takenami I, de Oliveira CC, Lima FR, Soares J, Machado A, Riley LW, Arruda S. Immunoglobulin G response to mammalian cell entry 1A (Mce1A) protein as biomarker of active tuberculosis. Tuberculosis (Edinb) 2016; 100:82-88. [PMID: 27553414 DOI: 10.1016/j.tube.2016.07.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 07/19/2016] [Indexed: 11/28/2022]
Abstract
Cell wall components are major determinants of virulence of Mycobacterium tuberculosis and they contribute to the induction of both humoral and cell-mediated immune response. The mammalian cell entry protein 1A (Mce1A), in the cell wall of M. tuberculosis, mediates entry of the pathogen into mammalian cells. Here, we examined serum immunoglobulin levels (IgA, IgM and total IgG) against Mce1A as a potential biomarker for diagnosis and monitoring tuberculosis (TB) treatment response. Serum samples of 39 pulmonary TB patients and 65 controls (15 healthy household contacts, 19 latently infected household contacts, 13 non-TB and 18 leprosy patients) were screened by ELISA. The median levels of all immunoglobulin classes were significantly higher in TB patients when compared with control groups. The positive test results for IgA, IgM and total IgG were 62, 54 and 82%, respectively. For comparison, routine sputum smear examination diagnosed only 26 (67%) of 39 TB cases. Sensitivities of IgA, IgM and IgG test were 59, 51.3 and 79.5%, respectively, while the specificities observed were 77.3, 83.3 and 84.4%, respectively. A significant decrease compared with baseline was also shown after TB treatment. These results suggest that circulating total IgG antibody to Mce1A could be a complementary tool to diagnosis pulmonary TB.
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Affiliation(s)
- Iukary Takenami
- Laboratório Avançado de Saúde Pública, Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, P.O. Box 121, Salvador, BA 40296 710, Brazil.
| | - Carolina C de Oliveira
- Laboratório Avançado de Saúde Pública, Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, P.O. Box 121, Salvador, BA 40296 710, Brazil.
| | - Filipe R Lima
- Laboratório Avançado de Saúde Pública, Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, P.O. Box 121, Salvador, BA 40296 710, Brazil; Escola Bahiana de Medicina e Saúde Pública, P.O. Box 3386, Salvador, BA 41150 100, Brazil.
| | - Jéssica Soares
- Laboratório Avançado de Saúde Pública, Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, P.O. Box 121, Salvador, BA 40296 710, Brazil; Escola Bahiana de Medicina e Saúde Pública, P.O. Box 3386, Salvador, BA 41150 100, Brazil.
| | - Almério Machado
- Escola Bahiana de Medicina e Saúde Pública, P.O. Box 3386, Salvador, BA 41150 100, Brazil; Hospital Especializado Octávio Mangabeira, Secretaria da Saúde do Estado da Bahia, Salvador, BA 40320-350, Brazil.
| | - Lee W Riley
- Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, 530E Li Ka Shing Bldg, Berkeley, CA 94720, USA.
| | - Sérgio Arruda
- Laboratório Avançado de Saúde Pública, Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, P.O. Box 121, Salvador, BA 40296 710, Brazil; Escola Bahiana de Medicina e Saúde Pública, P.O. Box 3386, Salvador, BA 41150 100, Brazil.
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Polyclonal antibody against conserved sequences of mce1A protein blocks MTB infection in macrophages. Appl Microbiol Biotechnol 2011; 93:2463-73. [PMID: 22159737 DOI: 10.1007/s00253-011-3754-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Revised: 11/03/2011] [Accepted: 11/21/2011] [Indexed: 10/14/2022]
Abstract
The pathogenesis of Mycobacterium tuberculosis is largely due to its ability to enter and survive within human macrophages. It is suggested that a specific protein namely mammalian cell entry protein is involved in the pathogenesis and the specific gene for this protein mce1A has been identified in several pathogenic organisms such as Rickettsia, Shigella, Escherichia coli, Helicobacter, Streptomyces, Klebsiella, Vibrio, Neisseria, Rhodococcus, Nocardioides, Saccharopolyspora erthyrae, and Pseudomonas. Analysis of mce1 operons in the above mentioned organisms through bioinformatics tools has revealed the presence of unique sequences (conserved regions) suggesting that these sequences may be involved in the process of infection. Presently, the mce1A full-length (1,365 bp) region from Mycobacterium bovis and its conserved regions (303 bp) were cloned in to an expression vector and the purified expressed proteins of molecular weight ~47 and ~11 kDa, respectively, were injected to rabbits to raise the polyclonal antibodies. The purified polyclonal antibodies were checked for their ability to inhibit the Mycobacterium infection in cultured human macrophages. In macrophage invasion assay, when antibody added at high concentration, decrease in viable counts was observed in all cell cultures within the first 5 days after infection, where the intracellular bacterial CFU obtained from the infected MTB increased by the 3rd day at low concentration of antibody. The macrophage invasion assay has indicated that the purified antibodies of mce1A conserved region can inhibit the infection of Mycobacterium.
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de Souza GA, Leversen NA, Målen H, Wiker HG. Bacterial proteins with cleaved or uncleaved signal peptides of the general secretory pathway. J Proteomics 2011; 75:502-10. [PMID: 21920479 DOI: 10.1016/j.jprot.2011.08.016] [Citation(s) in RCA: 148] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Revised: 08/16/2011] [Accepted: 08/18/2011] [Indexed: 11/29/2022]
Abstract
Correct protein compartmentalization is a key step for molecular function and cell viability, and this is especially true for membrane and externalized proteins of bacteria. Recent proteomic reports of Bacillus subtilis have shown that many proteins with Sec-like signal peptides and absence of a transmembrane helix domain are still observed in membrane-enriched fractions, but further evidence about signal peptide cleavage or soluble protein contamination is still needed. Here we report a proteomic screening of identified peptides in culture filtrate, membrane fraction and whole cell lysate of Mycobacterium tuberculosis. We were able to detect peptide sequencing evidence that shows that the predicted signal peptide was kept uncleaved for several types of proteins such as mammalian cell entry (Mce) proteins and PE or PE-PGRS proteins. Label-free quantitation of all proteins identified in each fraction showed that the majority of these proteins with uncleaved signal peptides are, indeed, enriched in the Triton X-114 lipid phase. Some of these proteins are likely to be located in the inner membrane while others may be outer membrane proteins.
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Affiliation(s)
- Gustavo A de Souza
- Section for Microbiology and Immunology, the Gade Institute, University of Bergen, N-5021 Bergen, Norway
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Pasricha R, Chandolia A, Ponnan P, Saini NK, Sharma S, Chopra M, Basil MV, Brahmachari V, Bose M. Single nucleotide polymorphism in the genes of mce1 and mce4 operons of Mycobacterium tuberculosis: analysis of clinical isolates and standard reference strains. BMC Microbiol 2011; 11:41. [PMID: 21345183 PMCID: PMC3050694 DOI: 10.1186/1471-2180-11-41] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2010] [Accepted: 02/23/2011] [Indexed: 12/02/2022] Open
Abstract
Background The presence of four mammalian cell entry (mce) operons in Mycobacterium tuberculosis suggests the essentiality of the functions of the genes in these operons. The differential expression of the four mce operons in different phases of in vitro growth and in infected animals reported earlier from our laboratory further justifies the apparent redundancy for these genes in the genome. Here we investigate the extent of polymorphism in eight genes in the mce1 and mce4 operons of M. tuberculosis from four standard reference strains (H37Rv, H37Ra, LVS (Low Virulent Strain) and BCG) and 112 clinical isolates varying in their drug susceptibility profile, analysed by direct sequencing and Sequenom MassARRAY platform. Results We discovered 20 single nucleotide polymorphisms (SNPs) in the two operons. The comparative analysis of the genes of mce1 and mce4 operons revealed that yrbE1A [Rv0167] was most polymorphic in mce1 operon while yrbE4A [Rv3501c] and lprN [Rv3495c] had the highest number of SNPs in the mce4 operon. Of 20 SNPs, 12 were found to be nonsynonymous and were further analysed for their pathological relevance to M. tuberculosis using web servers PolyPhen and PMut, which predicted five deleterious nonsynonymous SNPs. A mutation from proline to serine at position 359 of the native Mce1A protein was most deleterious as predicted by both PolyPhen and PMut servers. Energy minimization of the structure of native Mce1A protein and mutated protein was performed using InsightII. The mutated Mce1A protein showed structural changes that could account for the effects of this mutation. Conclusions Our results show that SNPs in the coding sequences of mce1 and mce4 operons in clinical isolates can be significantly high. Moreover, mce4 operon is significantly more polymorphic than mce1 operon (p < 0.001). However, the frequency of nonsynonymous substitutions is higher in mce1 operon and synonymous substitutions are more in mce4 operon. In silico modeling predict that nonsynonymous SNP at mce1A [Rv0169], a virulence gene could play a pivotal role in causing functional changes in M. tuberculosis that may reflect upon the biology of the bacteria.
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Affiliation(s)
- Rashmi Pasricha
- Department of Microbiology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi-110007, India
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Saini NK, Sharma M, Chandolia A, Pasricha R, Brahmachari V, Bose M. Characterization of Mce4A protein of Mycobacterium tuberculosis: role in invasion and survival. BMC Microbiol 2008; 8:200. [PMID: 19019220 PMCID: PMC2596156 DOI: 10.1186/1471-2180-8-200] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2008] [Accepted: 11/19/2008] [Indexed: 01/21/2023] Open
Abstract
Background The mce4 operon is one of the four homologues of mammalian cell entry (mce) operons of Mycobacterium tuberculosis. The mce4A (Rv3499c) gene within this operon is homologous to mce1A (Rv0169), that has a role in host cell invasion by M. tuberculosis. Our earlier reports show that mce4 operon is expressed during the stationary phase of growth of the bacillus in culture and during the course of infection in mammalian hosts. M. tuberculosis carrying mutation in mce4 operon shows growth defect and reduced survival in infected mice. However, the intracellular localization of Mce4A protein and its direct role in cell entry or survival of the bacillus has not been demonstrated so far. Results By transmission electron microscopy we have demonstrated that recombinant Mce4A protein facilitates the invasion of non-pathogenic strain of E. coli into non-phagocytic HeLa cells. We observe that mce4A gene has a role comparable to mce1A in the survival of recombinant E. coli in human macrophages. Using antibodies raised against Mce4A protein, we show that the protein is localized in the cell wall fraction of M. tuberculosis H37Rv stationary phase culture only. Conclusion Mce4A protein is expressed during the stationary phase of broth culture and localizes in the cell wall fraction of M. tuberculosis. Mce4A protein expressed in non-pathogenic E. coli enables it to enter and survive within HeLa cells and the macrophages. As Mce4A protein is expressed during later phase of mycobacterial growth, our results raise the possibility of it playing a role in maintenance of persistent tubercular infection.
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Affiliation(s)
- Neeraj Kumar Saini
- Department of Microbiology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India.
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El-Shazly S, Ahmad S, Mustafa AS, Al-Attiyah R, Krajci D. Internalization by HeLa cells of latex beads coated with mammalian cell entry (Mce) proteins encoded by the mce3 operon of Mycobacterium tuberculosis. J Med Microbiol 2007; 56:1145-1151. [PMID: 17761475 DOI: 10.1099/jmm.0.47095-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The mammalian cell entry (Mce) operon 3 (mce3) is one of four homologous mce operons of Mycobacterium tuberculosis, encoding six (Mce3A-F) invasin-like membrane-associated proteins. Previous studies have shown that recombinant expression of Mce1A encoded by the mce1 operon in Escherichia coli allows this non-pathogenic bacterium to invade and survive inside macrophages, and latex beads coated with Mce1A are internalized by non-phagocytic HeLa cells. However, the role of other mce1 operon proteins (Mce1B-F) and proteins encoded by the operons mce2-4 in facilitating the internalization of M. tuberculosis in mammalian cells has not been studied. This study was carried out to determine whether Mce proteins encoded by the mce3 operon also facilitated the internalization of latex beads by HeLa cells. Recombinant pure Mce3A and lipoprotein LprM (Mce3E) were expressed and purified from E. coli cells. Mce1A expressed as a fusion protein with glutathione S-transferase (GST-Mce1A) and GST alone, purified similarly from E. coli cells, were used as control proteins. Fluorescent latex beads coated with purified proteins were used to study their uptake by HeLa cells using fluorescence microscopy, flow cytometry and electron microscopy. Fluorescence microscopy and flow cytometry showed an association of HeLa cells with beads coated with both Mce3A and LprM, whilst GST-Mce1A and GST yielded the expected results. Transmission electron microscopy confirmed the uptake of beads coated with Mce3A or LprM by HeLa cells. The data showed that Mce3A encoded by the mce3 operon facilitated the uptake and internalization of latex beads by HeLa cells. The data also showed, for the first time, the role of another Mce protein (LprM/Mce3E) in facilitating the interaction and internalization of M. tuberculosis by mammalian cells.
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Affiliation(s)
- Sherief El-Shazly
- Department of Microbiology, Faculty of Medicine, Kuwait University, Kuwait
| | - Suhail Ahmad
- Department of Microbiology, Faculty of Medicine, Kuwait University, Kuwait
| | - Abu S Mustafa
- Department of Microbiology, Faculty of Medicine, Kuwait University, Kuwait
| | - Raja Al-Attiyah
- Department of Microbiology, Faculty of Medicine, Kuwait University, Kuwait
| | - Dimitrolos Krajci
- Department of Anatomy, Faculty of Medicine, Kuwait University, Kuwait
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Xue LJ, Cao MM, Luan J, Ren H, Pan X, Cao J, Qi ZT. Mammalian cell entry protein of Mycobacterium tuberculosis induces the proinflammatory response in RAW 264.7 murine macrophage-like cells. Tuberculosis (Edinb) 2006; 87:185-92. [PMID: 17046327 DOI: 10.1016/j.tube.2006.07.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2006] [Revised: 06/14/2006] [Accepted: 07/20/2006] [Indexed: 11/29/2022]
Abstract
Mammalian cell entry (Mce1A) protein of Mycobacterium tuberculosis (Mtb) is involved in bacterial entry and survival in macrophages, which has been shown to induce production of tumor necrosis factor alpha (TNF-alpha). It remains unclear whether and how Mce1A functions upon the type I interleukin-1 receptor-associated protein kinase (IRAK-1) and TNF receptor-associated factor 6 (TRAF-6) of important proinflammatory cytokines. In this study, His-tagged Mce1A was expressed and purified. Also, two pieces of small interfering RNA (siRNA) were designed and synthesized by in vitro transcription, which exhibit specific and efficient silencing effect on mce1a expression. Furthermore, RAW 264.7 murine macrophage-like cells were exposed to His-tagged Mce1A or co-transfected with the Mce1A-expressing plasmid and efficient siRNA, and levels of IRAK-1 and TRAF-6 were then determined by Western blot. We show here that Mce1A induces up-regulations of IRAK-1 and TRAF-6 in macrophages in a dose-dependent manner. The level of Caspase-3 closely related with apoptosis was also determined, whereas no changes were observed. These results indicate that Mtb Mce1A protein induces a proinflammatory response in macrophages.
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Affiliation(s)
- Li-Jun Xue
- Department of Microbiology, State Key Laboratory of Medical Immunology, Second Military Medical University, Shanghai 200433, PR China
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Joshi SM, Pandey AK, Capite N, Fortune SM, Rubin EJ, Sassetti CM. Characterization of mycobacterial virulence genes through genetic interaction mapping. Proc Natl Acad Sci U S A 2006; 103:11760-5. [PMID: 16868085 PMCID: PMC1544243 DOI: 10.1073/pnas.0603179103] [Citation(s) in RCA: 134] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
We have previously shown that approximately 5% of the genes encoded by the genome of Mycobacterium tuberculosis are specifically required for the growth or survival of this bacterium during infection. This corresponds to hundreds of genes, most of which have no identifiable function. As a unique approach to characterize these genes, we developed a method to rapidly delineate functional pathways by identifying mutations that modify each other's phenotype, i.e., "genetic interactions". Using this method, we have defined a complex set of interactions between virulence genes in this pathogen, and find that the products of unlinked genes associate to form multisubunit transporters that are required for bacterial survival in the host. These findings implicate a previously undescribed family of transport systems in the pathogenesis of tuberculosis, and identify genes that are likely to function in the metabolism of their substrates. This method can be readily applied to other organisms at either the single pathway level, as described here, or at the system level to define quantitative genetic interaction networks.
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Affiliation(s)
- Swati M. Joshi
- *Department of Molecular Genetics and Microbiology, University of Massachusetts Medical School, Worcester, MA 01655; and
| | - Amit K. Pandey
- *Department of Molecular Genetics and Microbiology, University of Massachusetts Medical School, Worcester, MA 01655; and
| | - Nicole Capite
- *Department of Molecular Genetics and Microbiology, University of Massachusetts Medical School, Worcester, MA 01655; and
| | - Sarah M. Fortune
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, MA 02115
| | - Eric J. Rubin
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, MA 02115
| | - Christopher M. Sassetti
- *Department of Molecular Genetics and Microbiology, University of Massachusetts Medical School, Worcester, MA 01655; and
- To whom correspondence should be addressed. E-mail:
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Pajón R, Yero D, Lage A, Llanes A, Borroto CJ. Computational identification of beta-barrel outer-membrane proteins in Mycobacterium tuberculosis predicted proteomes as putative vaccine candidates. Tuberculosis (Edinb) 2006; 86:290-302. [PMID: 16542876 DOI: 10.1016/j.tube.2006.01.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2005] [Revised: 01/03/2006] [Accepted: 01/20/2006] [Indexed: 10/24/2022]
Abstract
Mycobacterial porins and other beta-barrel outer-membrane proteins are represented by the structure of Mycobacterium smegmatis porin MspA. On the basis of existing knowledge of beta-barrel outer-membrane proteins, several state of the art prediction methods, as well as a new in-house program (PROB) were employed for the systematic exploration of Mycobacterium tuberculosis predicted proteomes for potential beta-barrel structures. PROB allowed parameter optimization while functioning with an adaptive algorithm for the detection of outer-membrane beta-barrel proteins in highly divergent proteomes. As a result of the predictions, 114 proteins in total were predicted to be beta-barrel structures; of these, 40 were PE-PPE proteins, 8 Mce proteins, 24 hypothetical, 11 probable membrane proteins, 10 transporters, 4 lipoproteins, and 14 classified as other. The congruence among three of the predictors, PROB, TMB-Hunt, and BOMP, was low with only three proteins (MT0318, MT0356, and MT2423) predicted by the three. Overall, 79 new proteins for which no previous experimental work has been performed are reported. At least 10 of these have high potential of being not only surface-exposed but also served as putative vaccine candidates as determined by in silico predictions of CD4T cell MHC-II restricted epitopes.
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Affiliation(s)
- R Pajón
- Meningococcal Research Department, Vaccine Division, CIGB, Cubanacán, Playa. Havana City, Cuba.
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12
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Mitra D, Saha B, Das D, Wiker HG, Das AK. Correlating sequential homology of Mce1A, Mce2A, Mce3A and Mce4A with their possible functions in mammalian cell entry of Mycobacterium tuberculosis performing homology modeling. Tuberculosis (Edinb) 2005; 85:337-45. [PMID: 16256439 DOI: 10.1016/j.tube.2005.08.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
OBJECTIVE The striking homology of the Mycobacterium tuberculosis mammalian cell entry operons (mce1, mce2, mce3 and mce4) with other mycobacterial species and the proposed role of the mammalian cell entry protein 1A (Mce1A) of M. tuberculosis to facilitate invasion of host cells have led us to look into the finer details of these proteins in order to better understand their structure-function relationship. DESIGN We performed sequential alignments and secondary structure predictions of Mce1A, Mce2A, Mce3A and Mce4A, and compared these results with results from homology modeling by fold prediction and threading. RESULTS Sequential alignments showed that Mce1A and Mce2A are highly homologous, close to 70%, while the other combinations gave only about 30% similarities. The major parts of the proteins aligned without gaps and there were striking similarities by secondary structure predictions indicating that the proteins would have similar folds and to be alpha/beta proteins like the previously reported Mce1A model based on Colicin N. Fold prediction showed that the best templates for Mce2A were substrate-binding domain of DnaK and slow processing precursor penicillin acylase from Escherichia coli while the alpha-domains of Mce3A and Mce4A could both be modeled using the cytoplasmic domain of serine chemotaxis receptor as template. CONCLUSION Although different templates had to be used to model the MceA proteins, functional information may be derived that is relevant for their overall function in M. tuberculosis. The beta-domain is probably involved in binding with the receptors on target cells while the alpha-domain is more likely to be involved in pore formation. As predicted from the folds, Mce3A and Mce4A model structures indicate a lipid bound conformation and therefore may be required in signaling events of the mammalian cell entry process.
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Affiliation(s)
- D Mitra
- Department of Biotechnology, Indian Institute of Technology, Kharagpur 721 302, West Bengal, India
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13
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Ahmad S, El-Shazly S, Mustafa AS, Al-Attiyah R. The six mammalian cell entry proteins (Mce3A-F) encoded by the mce3 operon are expressed during in vitro growth of Mycobacterium tuberculosis. Scand J Immunol 2005; 62:16-24. [PMID: 16091122 DOI: 10.1111/j.1365-3083.2005.01639.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The pathogenesis of Mycobacterium tuberculosis is largely due to its ability to enter and survive within human macrophages. The mammalian cell entry (mce)3 operon is one of four homologous mce operons that encodes six putative invasin-like exported proteins (Mce3A-F), possibly involved in entry and survival of M. tuberculosis inside macrophages. We have recently shown that Mce3A, Mce3D and Mce3E are expressed and elicit antibody responses in a majority of human subjects during natural infection with M. tuberculosis. In this study, we demonstrate the expression of Mce3A-F proteins and their mRNA during in vitro growth of M. tuberculosis. To demonstrate the expression of mce3A-F proteins, the antibodies were raised in rabbits against three pure proteins (Mce3A, Mce3D and Mce3E), and their specificity was checked by immunoblotting with recombinant Mce1A-F proteins encoded by mce1 operon. The antibodies were also generated against all the six Mce3 proteins, which were expressed and purified as fusion proteins with glutathione S-transferase (GST) as the fusion partner (GST-Mce3A-F). The antibodies reacted, in each case, with a protein of expected molecular mass (Mr) for the corresponding Mce3 protein in the cell wall fraction but not in the soluble fraction of in vitro-grown M. tuberculosis cells. The presence of mRNA for mce3A-F genes was also shown by using mce3A-F gene-specific primers, and total RNA isolated from in vitro-grown M. tuberculosis cells by reverse transcription-polymerase chain reaction (RT-PCR). Pretreatment of the RNA preparation with RNase A abolished amplification in RT-PCR confirming that mce3A-F mRNA rather than genomic DNA was being amplified. The data show that Mce3A-F encoded by the mce3 operon are expressed during in vitro growth of M. tuberculosis.
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Affiliation(s)
- S Ahmad
- Department of Microbiology, Faculty of Medicine, Kuwait University, Kuwait.
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14
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Mayer KM, Shanklin J. A Structural Model of the Plant Acyl-Acyl Carrier Protein Thioesterase FatB Comprises Two Helix/4-Stranded Sheet Domains, the N-terminal Domain Containing Residues That Affect Specificity and the C-terminal Domain Containing Catalytic Residues. J Biol Chem 2005; 280:3621-7. [PMID: 15531590 DOI: 10.1074/jbc.m411351200] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Plant acyl-acyl carrier protein thioesterases (TEs) terminate the acyl-acyl carrier protein track of fatty acid biosynthesis and play an essential role in determining the amount and composition of fatty acids entering the storage lipid pool. A combination of bioinformatics tools was used to predict a three-dimensional model for Arabidopsis FatB (AtFatB), which comprises a fold similar to that of Escherichia coli TEII, an enzyme that is functionally similar to plant TEs but lacks significant sequence similarity and displays different inhibitor sensitivity. The catalytic residues in AtFatB, Cys-264 and His-229, localize to the same region of the model as catalytic residues found in other enzymes with helix/multi-stranded sheet motifs (hot dog folds). Based on the model, we identified Asn-227 as a possible third member of the proposed papain-like catalytic triad. The conversion of Asn-227 to Ala resulted in a loss of detectable activity (>200-fold reduction), similar to the result seen for the equivalent mutation in papain. Mapping of plant TE specificity-affecting mutations onto the structural model showed that these mutations all cluster around the catalytic triad. Also, superposition of the crystallographically determined structures of the complexes of 4-hydroxybenzoyl-CoA TE with substrate and beta-hydroxydecanoyl thiol ester dehydrase with inhibitor onto the AtFatB model showed that the substrate and inhibitor localize to the same region as the AtFatB catalytic triad in their respective structures. Together these data corroborate the structural model and show that the hot dog fold is common to enzymes from both prokaryotes and eukaryotes and that this fold supports at least three different catalytic mechanisms.
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Affiliation(s)
- Kimberly M Mayer
- Biology Department, Brookhaven National Laboratory, Upton, New York 11973, USA
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15
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Cui D, Jin G, Gao T, Sun T, Tian F, Estrada GG, Gao H, Sarai A. Characterization of BRCAA1 and Its Novel Antigen Epitope Identification. Cancer Epidemiol Biomarkers Prev 2004. [DOI: 10.1158/1055-9965.1136.13.7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Abstract
Looking for novel breast cancer antigen epitopes is helpful for its treatment, diagnosis, and prevention. brcaa1 gene is mapped at 1q42.1-q43, its whole genome is 93.857 kb, including 18 exons and 17 introns. BRCAA1 protein is composed of 1,214 amino acids with 10 glycosylate sites, and shares 37% amino acid identity and an identical antigen epitope with Rb binding protein 1. The novel antigen epitope, SSKKQKRSHK, was predicted to locate in the region 610 to 619 sites, was synthesized, and its antibody was fabricated. Competent inhibition analysis showed that SSKKQKRSHK is the shortest effective peptide. The antigen epitope was mapped in the cytoplasm of MCF-7 cells. Immunohistochemistry analysis showed that the antigen epitope exhibited positive expression in 65% (39 of 60) breast cancer specimens and negative expression in 60 non-cancerous tissues. Statistical analysis shows that its expression is closely associated with status of ER and PR, with sensitivity of 100% and specificity of 81%, and confidence interval of 85.9% to 96.9%. ELISA analysis showed that the mean absorbance of sera antibody titers from breast cancer patients and healthy donors were 0401 ± 0.163 SD and 0.137 ± 0.121 SD, respectively. Sixty-four percent breast cancer patient sera and 13% healthy donor sera had higher titer than mean titer of healthy donors, and there exists significant difference between breast cancer patients and healthy donors (P < 0.001). In this study, a novel breast cancer antigen epitope, SSKKQKRSHK, is identified. Its expression is associated with characteristics that are themselves associated with prognosis of breast cancer, and its sera antibody level may be helpful for breast cancer diagnosis.
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Affiliation(s)
- Daxiang Cui
- 1Bio-Nano-Engineering Center, Max Planck Institute for Metals Research, Stuttgart, Germany
- 4Institute of Genetics Diagnosis, Fourth Military Medical University, Xi'an, PR China; and
| | - Guiqiu Jin
- 3Department of Bioinformatics of Tangdu Hospital,
| | - Tianwen Gao
- 2Department of Dermatology of Xijing Hospital,
| | - Tianbai Sun
- 1Bio-Nano-Engineering Center, Max Planck Institute for Metals Research, Stuttgart, Germany
| | - Furong Tian
- 1Bio-Nano-Engineering Center, Max Planck Institute for Metals Research, Stuttgart, Germany
| | - Giovani Gomez Estrada
- 1Bio-Nano-Engineering Center, Max Planck Institute for Metals Research, Stuttgart, Germany
| | - Huajian Gao
- 1Bio-Nano-Engineering Center, Max Planck Institute for Metals Research, Stuttgart, Germany
| | - Akinori Sarai
- 5Department of Biochemical Engineering and Science, Kyushu Institute of Technology, Lizuka, Japan
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16
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Harboe M, Das AK, Mitra D, Ulvund G, Ahmad S, Harkness RE, Das D, Mustafa AS, Wiker HG. Immunodominant B-cell epitope in the Mce1A mammalian cell entry protein of Mycobacterium tuberculosis cross-reacting with glutathione S-transferase. Scand J Immunol 2004; 59:190-7. [PMID: 14871296 DOI: 10.1111/j.0300-9475.2004.01383.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The TB1-5 76C monoclonal antibody raised against a synthetic 60-mer peptide in the N-terminal part of the Mce1A mammalian cell entry protein of Mycobacterium tuberculosis has previously been shown to react with a linear epitope in the KRRITPKD region, residues 131-138 in Mce1A, and to cross-react with Mce1F. Six additional monoclonal antibodies raised against the same peptide were also shown to cross-react with Mce1F. Four of them reacted with a linear epitope in the same area, indicating that this area is immunodominant but showed distinct differrences in fine specificity. Two monoclonal antibodies did not react with synthetic peptides from this region on the solid phase in enzyme-linked immunosorbent assay, indicating greater influence of conformation on reactivity. None of the monoclonal antibodies reacted with 14-mer synthetic peptides from the corresponding area in Mce2A, Mce3A, Mce4A, M. avium, M. smegmatis or M. leprae. The reaction pattern of the monoclonal antibodies was analysed in relation to our model of the Mce1A molecule (AK Das et al. Biochem Biophys Res Commun 2003;302:442-7). The epitope is located on the surface of Mce1A, at the distal beta-strand-loop region in the beta-domain supporting its potential role in promoting uptake of M. tuberculosis in host cells. Monoclonal antibody TB1-5 19C cross-reacted with glutathione S-transferase of Schistosoma japonicum containing a PKE triplet. Monoclonal antibody TB1-5 76C gave a major band at about 44 kDa in Western blotting of M. tuberculosis sonicate, whereas polyclonal rabbit anti-Mce1A peptide antibodies reacting with the extended TTPKNPTKRRITPKDVI area of Mce1A showed a distinct band above the 160 kDa molecular mass standard.
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Affiliation(s)
- M Harboe
- Institute of Immunology, Rikshospitalet University Hospital, Oslo, Norway
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