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Zhou F, Xu X, Cui X, Pan W. Development and Evaluation of a Fusion Polyprotein Based on HspX and Other Antigen Sequences for the Serodiagnosis of Tuberculosis. Front Immunol 2021; 12:726920. [PMID: 34671347 PMCID: PMC8521024 DOI: 10.3389/fimmu.2021.726920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 09/17/2021] [Indexed: 11/13/2022] Open
Abstract
Background The lack of suitable diagnostic tools contributes to the high prevalence of tuberculosis (TB) worldwide. Serological tests, based on multiple target antigens, represent an attractive option for diagnosis of this disease due to their rapidity, convenience, and low cost. Methods Measures to reduce non-specific reactions and thereby improve the specificity of serological tests were investigated, including blocking antibodies against common bacteria in serum samples and synthesizing polypeptides covering non-conserved dominant B-cell epitopes of antigens. In addition, a fusion polyprotein containing HspX and eight other antigen sequences was constructed and expressed to increase overall sensitivity of the tests. Results Inclusion of Escherichia coli lysate partially increased the specificity of the serological tests, while synthesis and inclusion of peptides containing non-conserved sequences of TB antigens as well as dominant B-cell epitopes reduced non-specific reactions without a decrease in sensitivity of the tests. A polyprotein fusing HspX and eight other antigen sequences was constructed and displayed 60.2% sensitivity, which was higher than that of HspX and the other individual antigen segments. Moreover, the specificity of the polyprotein was 93.8%, which was not significantly decreased when compared with HspX and the other individual antigen segments. Conclusions The roles of the fusion polyprotein in the humoral immune response against TB infection were demonstrated and provide a potential novel approach for the development of TB diagnostics.
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Affiliation(s)
- Fangbin Zhou
- Department of Tropical Diseases, Naval Medical University, Shanghai, China
- Clinical Medical Research Center, The Second Clinical Medical College, Shenzhen People’s Hospital, Jinan University, Shenzhen, China
- Institute for Infectious Diseases and Vaccine Development, Tongji University School of Medicine, Shanghai, China
| | - Xindong Xu
- Institute for Infectious Diseases and Vaccine Development, Tongji University School of Medicine, Shanghai, China
| | - Xiaobing Cui
- Institute for Infectious Diseases and Vaccine Development, Tongji University School of Medicine, Shanghai, China
| | - Weiqing Pan
- Department of Tropical Diseases, Naval Medical University, Shanghai, China
- Institute for Infectious Diseases and Vaccine Development, Tongji University School of Medicine, Shanghai, China
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Arif S, Akhter M, Khaliq A, Nisa ZU, Khan IH, Akhtar MW. Serodiagnostic evaluation of fusion proteins from multiple antigens of Mycobacterium tuberculosis for active TB. Tuberculosis (Edinb) 2021; 127:102053. [PMID: 33561630 DOI: 10.1016/j.tube.2021.102053] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 01/07/2021] [Accepted: 01/18/2021] [Indexed: 10/22/2022]
Abstract
Tuberculosis (TB) is a global health problem, being prevalent in the developing countries. A rapid, reliable and cost effective diagnostic method would help in controlling TB in the endemic populations. Development of suitable fusion molecules detecting multiple antibodies produced against Mycobacterium tuberculosis antigens would enhance sensitivity of serodiagnostic assays. In this study, EspC, CFP7 and PPE57 antigens of M. tuberculosis were selected for constructing fusion molecules after prediction of B-cell epitopes using in silico tools. Fusion proteins EspC-CFP7, HspX-EspC-CFP7 and HspX-EspC-CFP7-PPE57 were expressed in E.coli (BL21). The serodiagnostic potential of the individual antigens and their fusions was analyzed by screening 230 plasma samples of pulmonary TB patients. The single antigens HspX, EspC, CFP7, PPE57 showed sensitivities of 30%, 31%, 22% and 35%, respectively. The fusion protein EspC-CFP7 showed sensitivity of 43%. Linking of HspX antigen to the N-terminus of EspC-CFP7 fusion molecule increased sensitivity to 58%, while joining PPE57 antigen to the C-terminus of HspX-EspC-CFP7 increased sensitivity to 69%. The fusion protein HspX-EspC-CFP7-PPE57 seems to be a promising molecule for use in the development of fusions with higher sensitivity.
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Affiliation(s)
- Shaista Arif
- School of Biological Sciences, University of the Punjab, Lahore, Pakistan
| | - Mohsina Akhter
- School of Biological Sciences, University of the Punjab, Lahore, Pakistan
| | - Aasia Khaliq
- Armed Forces Institute of Pathology, Rawalpindi, Pakistan
| | | | - Imran H Khan
- Department of Pathology and Laboratory Medicine, University of California, Davis, USA
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Akhter M, Arif S, Khaliq A, Nisa ZU, Khan IH, Akhtar MW. Designing fusion molecules from antigens of Mycobacterium tuberculosis for detection of multiple antibodies in plasma of TB patients. Tuberculosis (Edinb) 2020; 124:101981. [PMID: 32810724 DOI: 10.1016/j.tube.2020.101981] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 07/15/2020] [Accepted: 07/26/2020] [Indexed: 02/06/2023]
Abstract
Tuberculosis (TB) is amongst the deadliest diseases worldwide. For effective control of TB a rapid, reliable and sensitive method for its diagnosis is essential. Serodiagnosis detecting multiple antibodies against antigens of Mycobacterium tuberculosis (Mtb) in blood samples could prove beneficial. Based on the epitope position in the molecule, two truncated variants of Rv1984c, i.e., Tn1Rv1984c and Tn2Rv1984c were expressed in Escherichia coli. Screening of the Rv1984c, Tn1Rv1984c and Tn2Rv1984c against 231 sera samples from the culture positive TB patients showed sensitivities of 34.2%, 49.4% and 26.8%, respectively. Another antigen Rv1352 was analyzed for the location of epitopes, which had not been reported before. A fusion molecule consisting of Tn1Rv1984c and Rv1352, expressed in E. coli, showed enhanced sensitivity of 62.8%. Joining another antigen Rv2031c to the N-terminus of Tn1Rv1984c-Rv1352, improved sensitivity to 71.4%. The fusion construct Rv2031c-Tn1Rv1984c-Rv1352 showed comparatively higher sensitivity of 73.4% in the male group as compared to 67% in the female group. Data derived for the secondary structure analysis through Circular Dichroism (CD) spectroscopy and prediction on the basis of molecular modelling was also in agreement. This construct can be a potential base for producing constructs with greater sensitivity through fusion of epitopes from additional Mtb antigens.
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Affiliation(s)
- Mohsina Akhter
- School of Biological Sciences, University of the Punjab, Lahore, Pakistan
| | - Shaista Arif
- School of Biological Sciences, University of the Punjab, Lahore, Pakistan
| | - Aasia Khaliq
- Armed Forces Institute of Pathology, Rawalpindi, Pakistan
| | | | - Imran H Khan
- Department of Pathology and Laboratory Medicine, University of California, Davis, USA
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Pathakumari B, Prabhavathi M, Anbarasu D, Paramanandhan P, Raja A. Dynamic IgG antibody response to immunodominant antigens of M. tuberculosis for active TB diagnosis in high endemic settings. Clin Chim Acta 2016; 461:25-33. [PMID: 27370403 DOI: 10.1016/j.cca.2016.06.033] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Revised: 06/27/2016] [Accepted: 06/27/2016] [Indexed: 10/21/2022]
Abstract
BACKGROUND Even though various techniques have been developed for rapid diagnosis of tuberculosis (TB), still there is an immense need for a simple, cost effective, highly sensitive and specific test. Hence, one of the possibilities is identification of Mycobacterium tuberculosis specific antibodies in infected serum by using specific antigens. METHODS We tested 10 recombinant M. tuberculosis antigens to evaluate IgG levels among Healthy control subjects (HCS), Healthy household contacts (HHC) and pulmonary TB patients (PTB) by ELISA. RESULTS The median IgG levels specific to all the antigens are higher in PTB than HHC and HCS. Amongst single antigens, 38-kDa antigen has showed maximum sensitivity of 50% than any other antigens at 95.5% specificity. Among the two antigen combination, 38-kDa+Rv1860 has showed maximum sensitivity of 66.6% with specificity of 92.2%. The same antigen combination (38-kDa and Rv1860) predominantly identifies smear negative and culture positive TB patients with 68% sensitivity and 92.2% specificity. Most of the antigens have exhibited higher antibody titre in cavitary TB than non cavitary. With regard to latent TB infection (LTBI) identification, Rv1860 has exhibited maximum sensitivity of 53.3% with 95% specificity. CONCLUSIONS IgG response to combination of recombinant mycobacterial antigens (38-kDa, Rv1860, Rv2204c and Rv0753c) presents good specificity with acceptable level of sensitivity for TB diagnosis.
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Affiliation(s)
- Balaji Pathakumari
- Department of Immunology, National Institute for Research in Tuberculosis (ICMR), No. 1, Mayor Sathyamoorthy Road, Chetput, Chennai 600 031, India
| | - Maddineni Prabhavathi
- Department of Immunology, National Institute for Research in Tuberculosis (ICMR), No. 1, Mayor Sathyamoorthy Road, Chetput, Chennai 600 031, India
| | - Deenadayalan Anbarasu
- Department of Immunology, National Institute for Research in Tuberculosis (ICMR), No. 1, Mayor Sathyamoorthy Road, Chetput, Chennai 600 031, India
| | - Pukazhvanthen Paramanandhan
- Department of Immunology, National Institute for Research in Tuberculosis (ICMR), No. 1, Mayor Sathyamoorthy Road, Chetput, Chennai 600 031, India
| | - Alamelu Raja
- Department of Immunology, National Institute for Research in Tuberculosis (ICMR), No. 1, Mayor Sathyamoorthy Road, Chetput, Chennai 600 031, India.
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Single Nucleotide Polymorphisms in P2X7 Gene Are Associated with Serum Immunoglobulin G Responses to Mycobacterium tuberculosis in Tuberculosis Patients. DISEASE MARKERS 2015; 2015:671272. [PMID: 26798189 PMCID: PMC4698936 DOI: 10.1155/2015/671272] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 10/14/2015] [Accepted: 10/18/2015] [Indexed: 01/12/2023]
Abstract
Objective. Our study investigated the association between single nucleotide polymorphisms (SNPs) in P2X7 gene and serum immunoglobulin G (IgG) responses to mycobacterium tuberculosis (MTB) in TB patients. Methods. A total of 103 TB patients were enrolled as case group and 87 healthy individuals at same geographical region as control group. The SNP detection of 1513A>C and -762T>C was performed using PCR-RFLP, and the levels of serum IgG responses to MTB in all subjects were determined. Results. AC and CC of 1513A>C and TC and CC of -762T>C had higher frequencies in case group than in control group. TB patients carrying TC and CC of -762T>C had higher positive rate of IgG responses to MTB than those carrying TT. Additionally, patients carrying TC and CC of -762T>C had more MTB in sputum than those carrying TT. Conclusion. P2X7 SNPs, 1513A>C and -762T>C, may be associated with the susceptibility to tuberculosis, and -762T>C SNP may contribute to the development of MTB. The mutant genotype of -762T>C (TC and CC) may lower human capability of phagocytosis to MTB, leading to an increased morbidity of TB.
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Zhang C, Song X, Zhao Y, Zhang H, Zhao S, Mao F, Bai B, Wu S, Shi C. Mycobacterium tuberculosis Secreted Proteins As Potential Biomarkers for the Diagnosis of Active Tuberculosis and Latent Tuberculosis Infection. J Clin Lab Anal 2014; 29:375-82. [PMID: 25131423 PMCID: PMC6807157 DOI: 10.1002/jcla.21782] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 05/21/2014] [Indexed: 11/10/2022] Open
Abstract
Background The detection of Mycobacterium tuberculosis (Mtb) specific human antibodies has been an important diagnostic aid in the diagnosis of tuberculosis (TB) cases with smear‐negative sputum samples, especially for the screening of high‐risk population. This study focused on the analysis and comparison of the four potential Mtb‐secreted proteins (ESAT6, CFP10, Ag85B, Hsp16.3) and the fusion protein Ag85B‐Hsp16.3 as new markers in the serodiagnosis between active TB and latent TB infection (LTBI). Methods These five recombinant proteins were produced and used in optimized ELISA to detect IgG serum antibodies against the four secreted proteins. The capacity of identifying infection was evaluated either in active TB patients or LTBI individuals, which was compared with the control groups consisting of hospitalized non‐TB individuals. Results The results showed that Ag85B‐Hsp16.3/ESAT6 and Hsp16.3/ESAT6 were the best‐associated antigens for serology diagnosis of the active TB and LTBI individuals because of their specificity, sensitivity, YI values, and positive rates, respectively. ELISA test demonstrated that 41.67% (25/60) of blood donors respond to Ag85B‐Hsp16.3/ESAT6. The consistency of this positive respond with clinical diagnosis almost reached 84% (21/25). Conclusion Thus, a combined test of multiple Mtb‐secreted proteins Ag85B, Hsp16.3, and ESAT6 may be the ascendant preliminary screening antigens for active TB or LTBI patients.
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Affiliation(s)
- Caiqin Zhang
- Division of Infection and Immunology, Laboratory Animal Center, Fourth Military Medical University, Xi'an, P.R. China
| | - Xiaoqin Song
- Division of Infection and Immunology, Laboratory Animal Center, Fourth Military Medical University, Xi'an, P.R. China
| | - Yong Zhao
- Division of Infection and Immunology, Laboratory Animal Center, Fourth Military Medical University, Xi'an, P.R. China
| | - Hai Zhang
- Division of Infection and Immunology, Laboratory Animal Center, Fourth Military Medical University, Xi'an, P.R. China
| | - Shanmin Zhao
- Division of Infection and Immunology, Laboratory Animal Center, Fourth Military Medical University, Xi'an, P.R. China
| | - Fengfeng Mao
- Division of Infection and Immunology, Laboratory Animal Center, Fourth Military Medical University, Xi'an, P.R. China
| | - Bing Bai
- Division of Infection and Immunology, Laboratory Animal Center, Fourth Military Medical University, Xi'an, P.R. China
| | - Shaoping Wu
- Department of Radiology, First Affiliated Hospital, Chengdu Medical College, Chengdu, P.R. China
| | - Changhong Shi
- Division of Infection and Immunology, Laboratory Animal Center, Fourth Military Medical University, Xi'an, P.R. China
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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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