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Morales-Velásquez M, Barón-Vera JP, Osorio-Pulgarín MI, Sánchez-Jiménez MM, Ospina-Villa JD. Biomarkers for the diagnosis, treatment follow-up, and prediction of cardiac complications in Chagas disease in chronic phase: Recent advances. Parasite Immunol 2023; 45:e13013. [PMID: 37795913 DOI: 10.1111/pim.13013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 08/10/2023] [Accepted: 09/19/2023] [Indexed: 10/06/2023]
Abstract
Chagas disease is caused by the Trypanosoma cruzi parasite and is transmitted by infected triatomine bugs. This infection affects approximately 8 million people in the Americas, and due to globalisation and displacement, it is becoming increasingly common to find infected patients worldwide. Diagnosis of the disease in its acute form is relatively simple, as the parasite can be detected in peripheral blood smears, and symptoms are visible. However, in its chronic condition, the parasite is almost undetectable, and indirect tests are necessary to determine the presence of antibodies in infected patients. It is important to note that a single test is not enough to confirm the disease in this phase, as a second serological test should confirm the diagnosis. If the results are contradictory, a third test should be performed to confirm or discard the disease. Unfortunately, laboratories may not have access to all necessary tests in many rural areas where the disease is more frequent. Rapid tests to diagnose this disease present problems, such as significant variations in sensitivity and specificity in different countries. Therefore, searching for new biomarkers that allow for optimal correlation is essential. In this work, we have searched scientific literature from the last 10 years for mentions of novel biomarkers for diagnosis, treatment follow-up, and prediction of cardiac complications in Chagas disease in its chronic phase.
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Affiliation(s)
| | - Juan Pablo Barón-Vera
- Instituto Colombiano de Medicina Tropical, Universidad CES, Sabaneta, Antioquia, Colombia
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Cutshaw MK, Sciaudone M, Bowman NM. Risk Factors for Progression to Chronic Chagas Cardiomyopathy: A Systematic Review and Meta-Analysis. Am J Trop Med Hyg 2023; 108:791-800. [PMID: 36848894 PMCID: PMC10076993 DOI: 10.4269/ajtmh.22-0630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 12/19/2022] [Indexed: 03/01/2023] Open
Abstract
Approximately one-third of people with chronic Trypanosoma cruzi infection develop Chagas cardiomyopathy, which carries a poor prognosis. Accurate prediction of which individuals will go on to develop Chagas cardiomyopathy remains elusive. We performed a systematic review of literature comparing characteristics of individuals with chronic Chagas disease with or without evidence of cardiomyopathy. Studies were not excluded on the basis of language or publication date. Our review yielded a total of 311 relevant publications. We further examined the subset of 170 studies with data regarding individual age, sex, or parasite load. A meta-analysis of 106 eligible studies indicated that male sex was associated with having Chagas cardiomyopathy (Hedge's g: 1.56, 95% CI: 1.07-2.04), and a meta-analysis of 91 eligible studies indicated that older age was associated with having Chagas cardiomyopathy (Hedge's g: 0.66, 95% CI: 0.41-0.91). A meta-analysis of four eligible studies did not find an association between parasite load and disease state. This study provides the first systematic review to assess whether age, sex, and parasite load are associated with Chagas cardiomyopathy. Our findings suggest that older and male patients with Chagas disease are more likely to have cardiomyopathy, although we are unable to identify causal relationships due to the high heterogeneity and predominantly retrospective study designs in the current literature. Prospective, multidecade studies are needed to better characterize the clinical course of Chagas disease and identify risk factors for progression to Chagas cardiomyopathy.
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Affiliation(s)
| | - Michael Sciaudone
- Section of Infectious Diseases, Tulane University School of Medicine, New Orleans, Louisiana
| | - Natalie M. Bowman
- Division of Infectious Diseases, Department of Medicine, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina
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3
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Madeira RP, Meneghetti P, Barros LAD, Buck PDC, Mady C, Ianni BM, Fernandez-Becerra C, Torrecilhas AC. Isolation and molecular characterization of circulating extracellular vesicles from blood of chronic Chagas disease patients. Cell Biol Int 2022; 46:883-894. [PMID: 35253308 DOI: 10.1002/cbin.11787] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 02/21/2022] [Accepted: 03/03/2022] [Indexed: 11/11/2022]
Abstract
Extracellular vesicles (EVs) are lipid bilayer envelopes that encase several types of molecules. Their contents mostly reflect their cell origin and possible targets at other locations in the organism and can be modified in pathological conditions to interfere with intercellular communication, thus promoting disease establishment and development. These characteristics, in addition to their presence in virtually all body fluids, make such vesicles ideal for biomarker discovery in human diseases. Here we describe the effect of different anticoagulants and the combination of two purification methods for isolation and characterization of circulating extracellular vesicles from blood of chronic Chagas disease (CCD) patients. We illustrated this procedure by studying a population of patients with Chagas disease at the indeterminate chronic stage, in which the Trypanosoma cruzi is very scarce in circulation. EVs were harvested from blood collected without or with different anticoagulants. Protein and nanoparticle tracking analysis was used to measure EVs size and concentration. The EVs were purified by ultracentrifugation, followed by size exclusion chromatography and characterized by chemiluminescent ELISA and Dot Blot using antibodies that recognized parasite-derived EVs, such as hyperimmune sera, polyclonal and monoclonal antibodies against trans-sialidase and mucins. In parallel, antibodies against classical human EV markers CD9, CD63, CD81 and CD82, were also analyzed. The results showed that anticoagulants did not interfere with the analyzed parameters and circulating EVs from CCD patients contain T. cruzi antigens and classical human exosomal markers. Overall, our protocol is adequate for the isolation of the total circulating extracellular vesicles and can serve as an important basis for further studies on biomarker discovery in Chagas' disease. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Rafael Pedro Madeira
- Disciplina de Infectologia, Departamento de Medicina, Universidade Federal de São Paulo (UNIFESP), São Paulo, Brasil.,Laboratório de Imunologia Celular e Bioquímica de Fungos e Protozoários, Departamento de Ciências Farmacêuticas, Universidade Federal de São Paulo (UNIFESP), Diadema, Brasil
| | - Paula Meneghetti
- Laboratório de Imunologia Celular e Bioquímica de Fungos e Protozoários, Departamento de Ciências Farmacêuticas, Universidade Federal de São Paulo (UNIFESP), Diadema, Brasil
| | - Lucas Alexandre de Barros
- Laboratório de Imunologia Celular e Bioquímica de Fungos e Protozoários, Departamento de Ciências Farmacêuticas, Universidade Federal de São Paulo (UNIFESP), Diadema, Brasil
| | - Paula de Cassia Buck
- Unidade Clínica de Miocardiopatias, Instituto do Coração, Universidade de São Paulo (USP), São Paulo, Brasil
| | - Charles Mady
- Unidade Clínica de Miocardiopatias, Instituto do Coração, Universidade de São Paulo (USP), São Paulo, Brasil
| | - Barbara Maria Ianni
- Unidade Clínica de Miocardiopatias, Instituto do Coração, Universidade de São Paulo (USP), São Paulo, Brasil
| | - Carmen Fernandez-Becerra
- ISGlobal, Hospital Cl ́ınic - Universitat de Barcelona, Barcelona, Spain.,Institut d'Investigacio ́ en Ciències de la Salut Germans Trias i Pujol, Badalona, Spain.,CIBER de Enfermedades Infecciosas (CIBERINFEC), Spain
| | - Ana Claudia Torrecilhas
- Laboratório de Imunologia Celular e Bioquímica de Fungos e Protozoários, Departamento de Ciências Farmacêuticas, Universidade Federal de São Paulo (UNIFESP), Diadema, Brasil
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4
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Alonso-Vega C, Urbina JA, Sanz S, Pinazo MJ, Pinto JJ, Gonzalez VR, Rojas G, Ortiz L, Garcia W, Lozano D, Soy D, Maldonado RA, Nagarkatti R, Debrabant A, Schijman A, Thomas MC, López MC, Michael K, Ribeiro I, Gascon J, Torrico F, Almeida IC. New chemotherapy regimens and biomarkers for Chagas disease: the rationale and design of the TESEO study, an open-label, randomised, prospective, phase-2 clinical trial in the Plurinational State of Bolivia. BMJ Open 2021; 11:e052897. [PMID: 34972765 PMCID: PMC8720984 DOI: 10.1136/bmjopen-2021-052897] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
INTRODUCTION Chagas disease (CD) affects ~7 million people worldwide. Benznidazole (BZN) and nifurtimox (NFX) are the only approved drugs for CD chemotherapy. Although both drugs are highly effective in acute and paediatric infections, their efficacy in adults with chronic CD (CCD) is lower and variable. Moreover, the high incidence of adverse events (AEs) with both drugs has hampered their widespread use. Trials in CCD adults showed that quantitative PCR (qPCR) assays remain negative for 12 months after standard-of-care (SoC) BZN treatment in ~80% patients. BZN pharmacokinetic data and the nonsynchronous nature of the proliferative mammal-dwelling parasite stage suggested that a lower BZN/NFX dosing frequency, combined with standard or extended treatment duration, might have the same or better efficacy than either drug SoC, with fewer AEs. METHODS AND ANALYSIS New ThErapies and Biomarkers for ChagaS infEctiOn (TESEO) is an open-label, randomised, prospective, phase-2 clinical trial, with six treatment arms (75 patients/arm, 450 patients). Primary objectives are to compare the safety and efficacy of two new proposed chemotherapy regimens of BZN and NFX in adults with CCD with the current SoC for BZN and NFX, evaluated by qPCR and biomarkers for 36 months posttreatment and correlated with CD conventional serology. Recruitment of patients was initiated on 18 December 2019 and on 20 May 2021, 450 patients (study goal) were randomised among the six treatment arms. The treatment phase was finalised on 18 August 2021. Secondary objectives include evaluation of population pharmacokinetics of both drugs in all treatment arms, the incidence of AEs, and parasite genotyping. ETHICS AND DISSEMINATION The TESEO study was approved by the National Institutes of Health (NIH), U.S. Food and Drug Administration (FDA), federal regulatory agency of the Plurinational State of Bolivia and the Ethics Committees of the participating institutions. The results will be disseminated via publications in peer-reviewed journals, conferences and reports to the NIH, FDA and participating institutions. TRIAL REGISTRATION NUMBER NCT03981523.
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Affiliation(s)
| | - Julio A Urbina
- Center for Biochemistry and Biophysics, Venezuelan Institute for Scientific Research (IVIC), Caracas, Distrito Capital, Venezuela, Bolivarian Republic of
| | - Sergi Sanz
- Biostatistics and Data Management Unit, Barcelona Institute for Global Health, Barcelona, Spain
- Consorcio de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
- Department of Basic Clinical Practice, Universitat de Barcelona, Barcelona, Spain
| | - María-Jesús Pinazo
- Barcelona Institute for Global Health (ISGLOBAL), Barcelona, Spain
- CIBER de Enfermedades Infecciosas (CIBERINFEC), Madrid, Spain
| | - Jimy José Pinto
- Fundación Ciencia y Estudios Aplicados para el Desarrollo en Salud y Medio Ambiente (CEADES), Cochabamba, Bolivia, Plurinational State of
| | - Virginia R Gonzalez
- Department of Biological Sciences, The University of Texas at El Paso, El Paso, Texas, USA
| | - Gimena Rojas
- Fundación Ciencia y Estudios Aplicados para el Desarrollo en Salud y Medio Ambiente (CEADES), Cochabamba, Bolivia, Plurinational State of
| | - Lourdes Ortiz
- Fundación Ciencia y Estudios Aplicados para el Desarrollo en Salud y Medio Ambiente (CEADES), Tarija, Bolivia, Plurinational State of
- Universidad Autónoma Juan Misael Saracho, Tarija, Bolivia, Plurinational State of
| | - Wilson Garcia
- Centro Plataforma Chagas Sucre, Fundación Ciencia y Estudios Aplicados para el Desarrollo en Salud y Medio Ambiente (CEADES), Sucre, Bolivia, Plurinational State of
- Programa Departamental de Chagas Chuquisaca, Servicio Departamental de Salud de Chuquisaca, Chuquisaca, Bolivia, Plurinational State of
| | - Daniel Lozano
- Fundación Ciencia y Estudios Aplicados para el Desarrollo en Salud y Medio Ambiente (CEADES), Cochabamba, Bolivia, Plurinational State of
| | - Dolors Soy
- Pharmacy Service, Division of Medicines, Hospital Clinic de Barcelona, Barcelona, Spain
- Institut de Investigació Biomèdica Agustí Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Barcelona, Spain
| | - Rosa A Maldonado
- Department of Biological Sciences, The University of Texas at El Paso, El Paso, Texas, USA
| | - Rana Nagarkatti
- Division of Emerging and Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration (FDA), Silver Spring, Maryland, USA
| | - Alain Debrabant
- Division of Emerging and Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration (FDA), Silver Spring, Maryland, USA
| | - Alejandro Schijman
- Laboratorio de Biología Molecular de la Enfermedad de Chagas, Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Buenos Aires, Argentina
- National Scientific and Technical Research Council (CONICET), Buenos Aires, Argentina
| | - M Carmen Thomas
- Consejo Superior de Investigaciones Científicas, Instituto de Parasitología y Biomedicina López-Neyra, Granada, Spain
| | - Manuel Carlos López
- Consejo Superior de Investigaciones Científicas, Instituto de Parasitología y Biomedicina López-Neyra, Granada, Spain
| | - Katja Michael
- Department of Chemistry and Biochemistry, The University of Texas at El Paso, El Paso, Texas, USA
| | - Isabela Ribeiro
- Dynamic Portfolio Unit, Drugs for Neglected Diseases initiative, Geneva, Switzerland
| | - Joaquim Gascon
- Barcelona Institute for Global Health (ISGLOBAL), Barcelona, Spain
- CIBER de Enfermedades Infecciosas (CIBERINFEC), Madrid, Spain
| | - Faustino Torrico
- Fundación Ciencia y Estudios Aplicados para el Desarrollo en Salud y Medio Ambiente (CEADES), Cochabamba, Bolivia, Plurinational State of
| | - Igor C Almeida
- Department of Biological Sciences, The University of Texas at El Paso, El Paso, Texas, USA
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Alonso-Padilla J, López MC, Esteva M, Zrein M, Casellas A, Gómez I, Granjon E, Méndez S, Benítez C, Ruiz AM, Sanz S, Gascón J, Thomas MC, Pinazo MJ, Abril M, de Noya BA, Jorge TA, Chatelain E, Grijalva MJ, Guhl F, Hasslocher-Moreno AM, Luquetti AO, Noya O, Ramsey JM, Ribeiro I, Longhi SA, Schijman AG, Sosa-Estani S, Torrico F, Viotti R. Serological reactivity against T. cruzi-derived antigens: Evaluation of their suitability for the assessment of response to treatment in chronic Chagas disease. Acta Trop 2021; 221:105990. [PMID: 34090864 DOI: 10.1016/j.actatropica.2021.105990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 05/20/2021] [Accepted: 05/26/2021] [Indexed: 10/21/2022]
Abstract
Chagas disease, caused by the protozoan Trypanosoma cruzi, affects more than 6 million people worldwide. Following a mostly asymptomatic acute phase, the disease progresses to a long-lasting chronic phase throughout which life-threatening disorders to the heart and/or gastrointestinal tract will manifest in about 30% of those chronically infected. During the chronic phase, the parasitemia is low and intermittent, while a high level of anti-T. cruzi antibodies persist for years. These two features hamper post-chemotherapeutic follow-up of patients with the tools available. The lack of biomarkers for timely assessment of therapeutic response discourages a greater use of the two available anti-parasitic drugs, and complicates the evaluation of new drugs in clinical trials. Herein, we investigated in a blinded case-control study the serological reactivity over time of a group of parasite-derived antigens to potentially address follow up of T. cruzi chronically infected subjects after treatment. We tested PFR2, KMP11, HSP70, 3973, F29 and the InfYnity multiplexed antigenic array, by means of serological assays on a multi-national retrospective collection of samples. Some of the antigens exhibited promising results, underscoring the need for further studies to determine their potential role as treatment response biomarkers.
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Ruiz-Márvez E, Ramírez CA, Rodríguez ER, Flórez MM, Delgado G, Guzmán F, Gómez-Puertas P, Requena JM, Puerta CJ. Molecular Characterization of Tc964, A Novel Antigenic Protein from Trypanosoma cruzi. Int J Mol Sci 2020; 21:E2432. [PMID: 32244527 PMCID: PMC7177413 DOI: 10.3390/ijms21072432] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 03/15/2020] [Accepted: 03/17/2020] [Indexed: 11/16/2022] Open
Abstract
The Tc964 protein was initially identified by its presence in the interactome associated with the LYT1 mRNAs, which code for a virulence factor of Trypanosoma cruzi. Tc964 is annotated in the T. cruzi genome as a hypothetical protein. According to phylogenetic analysis, the protein is conserved in the different genera of the Trypanosomatidae family; however, recognizable orthologues were not identified in other groups of organisms. Therefore, as a first step, an in-depth molecular characterization of the Tc946 protein was carried out. Based on structural predictions and molecular dynamics studies, the Tc964 protein would belong to a particular class of GTPases. Subcellular fractionation analysis indicated that Tc964 is a nucleocytoplasmic protein. Additionally, the protein was expressed as a recombinant protein in order to analyze its antigenicity with sera from Chagas disease (CD) patients. Tc964 was found to be antigenic, and B-cell epitopes were mapped by the use of synthetic peptides. In parallel, the Leishmania major homologue (Lm964) was also expressed as recombinant protein and used for a preliminary evaluation of antigen cross-reactivity in CD patients. Interestingly, Tc964 was recognized by sera from Chronic CD (CCD) patients at different stages of disease severity, but no reactivity against this protein was observed when sera from Colombian patients with cutaneous leishmaniasis were analyzed. Therefore, Tc964 would be adequate for CD diagnosis in areas where both infections (CD and leishmaniasis) coexist, even though additional assays using larger collections of sera are needed in order to confirm its usefulness for differential serodiagnosis.
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Affiliation(s)
- Elizabeth Ruiz-Márvez
- Grupo de Investigación en Enfermedades Infecciosas, Departamento de Microbiología, Facultad de Ciencias, Pontificia Universidad Javeriana, Carrera 7 # 40- 62, Bogotá, Colombia; (E.R.-M.); (C.A.R.); (E.R.R.)
| | - César Augusto Ramírez
- Grupo de Investigación en Enfermedades Infecciosas, Departamento de Microbiología, Facultad de Ciencias, Pontificia Universidad Javeriana, Carrera 7 # 40- 62, Bogotá, Colombia; (E.R.-M.); (C.A.R.); (E.R.R.)
| | - Eliana Rocío Rodríguez
- Grupo de Investigación en Enfermedades Infecciosas, Departamento de Microbiología, Facultad de Ciencias, Pontificia Universidad Javeriana, Carrera 7 # 40- 62, Bogotá, Colombia; (E.R.-M.); (C.A.R.); (E.R.R.)
| | - Magda Mellisa Flórez
- Grupo de Investigación en Inmunotoxicología, Departamento de Farmacia, Facultad de Ciencias, Universidad Nacional de Colombia, Carrera 30 # 45-01, Bogota; Colombia; (M.M.F.); (G.D.)
| | - Gabriela Delgado
- Grupo de Investigación en Inmunotoxicología, Departamento de Farmacia, Facultad de Ciencias, Universidad Nacional de Colombia, Carrera 30 # 45-01, Bogota; Colombia; (M.M.F.); (G.D.)
| | - Fanny Guzmán
- Núcleo de Biotecnología Curauma (NBC), Pontificia Universidad Católica de Valparaiso, Avenida Universidad 2373223, Curauma, Valparaiso-Chile;
| | - Paulino Gómez-Puertas
- Grupo de Modelado Molecular del Centro de Biología Molecular Severo Ochoa, Microbes in Health and Welfare Department, Universidad Autónoma de Madrid (CBMSO, CSIC-UAM), 28049 Madrid, Spain;
| | - José María Requena
- Grupo Regulación de la Expresión Génica en Leishmania del Centro de Biología Molecular Severo Ochoa, Molecular Biology Department, Universidad Autónoma de Madrid (CBMSO, CSIC-UAM), 28049 Madrid, Spain;
| | - Concepción J. Puerta
- Grupo de Investigación en Enfermedades Infecciosas, Departamento de Microbiología, Facultad de Ciencias, Pontificia Universidad Javeriana, Carrera 7 # 40- 62, Bogotá, Colombia; (E.R.-M.); (C.A.R.); (E.R.R.)
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Differential phenotypic and functional profile of epitope-specific cytotoxic CD8 + T cells in benznidazole-treated chronic asymptomatic Chagas disease patients. Biochim Biophys Acta Mol Basis Dis 2019; 1866:165629. [PMID: 31816438 DOI: 10.1016/j.bbadis.2019.165629] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 10/18/2019] [Accepted: 10/28/2019] [Indexed: 12/11/2022]
Abstract
One of the greatest challenges in Chagas disease research is the search for tools that will enable the assessment of pharmacological treatment efficacy. A recently described set of serological biomarkers composed of four parasite antigens and established criteria of treatment efficacy allowed the evaluation of the impact of benznidazole treatment a short/medium time after the treatment. In addition, cellular immunological parameters have also been described as potential indicators of the treatment response. The cytotoxic CD8+ T cells specific to five epitopes in the PFR2, PFR3, TcCA-2 and KMP11 antigens have been analysed, and these epitopes have been shown to be recognized, processed and presented in the context of a natural T. cruzi infection. In the present manuscript, we characterized these antigen-specific CD8+ T cells in indeterminate chronic Chagas disease patients both before and after (from 11 to 28 months) benznidazole treatment. The results indicate that there is a differential memory CD8+ T cell profile depending on the antigenic epitope and that the benznidazole treatment modulates the memory, differentiation and senescence phenotypes of the epitope-specific CD8+ T cells. Moreover, in these patients, the reactivity of sera against the referred set of biomarkers was evaluated. The data obtained show that the patients who met the established therapeutic efficacy criteria presented a differential phenotypic profile of the antigen-specific CD8+ T cells even prior to treatment compared to the patients who did not meet the therapeutic efficacy criteria, and this behaviour is associated with a better functionality of these CD8+ T cells.
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A Parasite Biomarker Set for Evaluating Benznidazole Treatment Efficacy in Patients with Chronic Asymptomatic Trypanosoma cruzi Infection. Antimicrob Agents Chemother 2019; 63:AAC.02436-18. [PMID: 31358581 DOI: 10.1128/aac.02436-18] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 07/18/2019] [Indexed: 12/20/2022] Open
Abstract
One of the current greatest challenges of Chagas disease is the establishment of biomarkers to assess the efficacy of drugs in a short period of time. In this context, the reactivity of sera from 66 adults with chronic indeterminate Chagas disease (IND) for a set of four Trypanosoma cruzi antigens (KMP11, PFR2, HSP70, and 3973d) was analyzed before and after benznidazole treatment. The results showed that the reactivity against these antigens decreased at 9, 24, and 48 months after treatment. Moreover, the 42.4% and 68.75% of IND patients met the established standard criteria of therapeutic efficacy (STEC) at 24 and 48 months posttreatment, respectively. Meeting the STEC implied that there was a continuous decrease in the reactivity of the patient sera against the four antigens after treatment and that there was a substantial decrease in the reactivity for at least two of the antigens. This important decrease in reactivity may be associated with a drastic reduction in the parasite load, but it is not necessarily associated with a parasitological cure. After treatment, a positive PCR result was only obtained in patients who did not meet the STEC. The percentage of granzyme B+/perforin+ CD8+ T cells was significantly higher in patients who met the STEC than in those who did not meet the STEC (35.2% versus 2.2%; P < 0.05). Furthermore, the patients who met the STEC exhibited an increased quality of the multifunctional response of the antigen-specific CD8+ T cells compared with that in the patients who did not meet the STEC.
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Ferrer MJ, Wehrendt DP, Bonilla M, Comini MA, Tellez-Iñón MT, Potenza M. Production of Recombinant Trypanosoma cruzi Antigens in Leishmania tarentolae. Methods Mol Biol 2019; 1955:105-118. [PMID: 30868522 DOI: 10.1007/978-1-4939-9148-8_8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Trypanosomatids are unicellular organisms that colonize a wide diversity of environments and hosts. For instance, Trypanosoma cruzi is a human pathogen responsible for Chagas diseases, while Leishmania tarentolae infects amphibians and became a biotechnological tool suitable for recombinant protein expression. T. cruzi antigens are needed for the development of improved epitope-based methods for diagnosis and treatment of Chagas disease. Molecular cloning for the production of recombinant proteins offers the possibility to obtain T. cruzi antigens at high yield and purity. L. tarentolae appears as the ideal expression host to obtain recombinant T. cruzi antigens with a structure and posttranslational modifications typical of trypanosomatids. In this chapter, we present a protocol for the analytical to mid-scale production of recombinant T. cruzi antigens, using L. tarentolae as expression host (LEXSY® inducible system).
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Affiliation(s)
- María José Ferrer
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, "Dr. Héctor Torres" (INGEBI-CONICET), Buenos Aires, Argentina
| | - Diana Patricia Wehrendt
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, "Dr. Héctor Torres" (INGEBI-CONICET), Buenos Aires, Argentina
| | - Mariana Bonilla
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Marcelo Alberto Comini
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - María Teresa Tellez-Iñón
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, "Dr. Héctor Torres" (INGEBI-CONICET), Buenos Aires, Argentina
| | - Mariana Potenza
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, "Dr. Héctor Torres" (INGEBI-CONICET), Buenos Aires, Argentina.
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Egui A, Lasso P, Pérez-Antón E, Thomas MC, López MC. Dynamics of T Cells Repertoire During Trypanosoma cruzi Infection and its Post-Treatment Modulation. Curr Med Chem 2018; 26:6519-6543. [PMID: 30381063 DOI: 10.2174/0929867325666181101111819] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 09/11/2018] [Accepted: 09/25/2018] [Indexed: 01/16/2023]
Abstract
Chagas disease courses with different clinical phases and has a variable clinical presentation and progression. The acute infection phase mostly exhibits a non-specific symptomatology. In the absence of treatment, the acute phase is followed by a chronic phase, which is initially asymptomatic. This chronic asymptomatic phase of the disease is characterized by a fragile balance between the host's immune response and the parasite replication. The loss of this balance is crucial for the progression of the sickness. The virulence and tropism of the T. cruzi infecting strain together to the inflammation processes in the cardiac tissue are the main factors for the establishment and severity of the cardiomyopathy. The efficacy of treatment in chronic Chagas disease patients is controversial. However, several studies carried out in chronic patients demonstrated that antiparasitic treatment reduces parasite load in the bloodstream and leads to an improvement in the immune response against the Trypanosoma cruzi parasite. The present review is mainly focused on the cellular patterns associated to the clinical status and the evolution of the disease in chronic patients, as well as the effectiveness of the treatment related to T. cruzi infection control. Therefore, an emphasis is placed on the dynamics of specific-antigens T cell subpopulations, their memory and activation phenotypes, their functionality and their contribution to pathogenesis or disease control, as well as their association with risk of congenital transmission of the parasite.
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Affiliation(s)
- Adriana Egui
- Instituto de Parasitologia y Biomedicina Lopez-Neyra, Consejo Superior de Investigaciones Científicas; Granada, Spain
| | - Paola Lasso
- Grupo de Inmunobiologia y Biologia Celular, Pontificia Universidad Javeriana; Bogota, Colombia
| | - Elena Pérez-Antón
- Instituto de Parasitologia y Biomedicina Lopez-Neyra, Consejo Superior de Investigaciones Científicas; Granada, Spain
| | - M Carmen Thomas
- Instituto de Parasitologia y Biomedicina Lopez-Neyra, Consejo Superior de Investigaciones Científicas; Granada, Spain
| | - Manuel Carlos López
- Instituto de Parasitologia y Biomedicina Lopez-Neyra, Consejo Superior de Investigaciones Científicas; Granada, Spain
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Performance of Leishmania PFR1 recombinant antigen in serological diagnosis of asymptomatic canine leishmaniosis by ELISA. BMC Vet Res 2017; 13:304. [PMID: 29061137 PMCID: PMC5654103 DOI: 10.1186/s12917-017-1224-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 10/16/2017] [Indexed: 11/18/2022] Open
Abstract
Background Leishmania infantum is a protozoan parasite transmitted by phlebotomine sand flies that causes life-threatening disease in humans and dogs. The dog is the primary reservoir of the parasite and early diagnosis of canine leishmaniosis is crucial at the clinical and epidemiological level. The currently available serological tests for CanL diagnostic show limitations therefore the aim of the present study was to investigate the diagnostic performance of an indirect antibody ELISA based on the Leishmania infantum recombinant antigen PFR1 in asymptomatically infected dogs. One hundred fifty-six dogs including Leishmania-free experimental Beagles and pet dogs from England, Scotland and Leishmania-endemic Murcia in Spain, were tested with the assay. The later were also tested with two commercial L. infantum crude antigen ELISAs (INgezim and Civtest, respectively) and a real-time kinetoplast PCR test. Results Anti-PFR1 antibodies were detected in the four groups of dogs, and the mean log-transformed optical density (OD) values were lowest in Beagles and in dogs from England and highest among dogs from Murcia (p < 0.05). Using the highest OD in beagles as the PFR1 ELISA cut-off point, the estimated seroprevalence was 27% (14-40%) in dogs from Murcia, 4% (0-9%) in dogs from Scotland and 3% (0-8%) in dogs from England (p < 0.05). Seroprevalence in dogs from Murcia according to the INgezim and Civtest ELISAs were 24% (12-37%) and 31% (18-45%), respectively, whilst the prevalence of infection based on PCR in these dogs was 73% (60-86). The percentages of PFR1-positive dogs that tested negative on the INgezim and Civtest ELISAs were 30% and 35%, respectively, and all of them tested positive on the PCR test. Relative to the PCR, the specificity, sensitivity and area under the ROC curve of the PFR1 ELISA were 100%, 36% and 0.74 (0.63-0.86), respectively. Conclusions The ability shown by the PFR1 ELISA to detect infected dogs that go undetected by the crude antigen ELISAs is clinically and epidemiologically useful and PFR1 could be considered a candidate for a multi-antigen-based immunoassay for early detection of L. infantum infected dogs. Electronic supplementary material The online version of this article (10.1186/s12917-017-1224-z) contains supplementary material, which is available to authorized users.
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Balouz V, Agüero F, Buscaglia CA. Chagas Disease Diagnostic Applications: Present Knowledge and Future Steps. ADVANCES IN PARASITOLOGY 2016; 97:1-45. [PMID: 28325368 PMCID: PMC5363286 DOI: 10.1016/bs.apar.2016.10.001] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Chagas disease, caused by the protozoan Trypanosoma cruzi, is a lifelong and debilitating illness of major significance throughout Latin America and an emergent threat to global public health. Being a neglected disease, the vast majority of Chagasic patients have limited access to proper diagnosis and treatment, and there is only a marginal investment into R&D for drug and vaccine development. In this context, identification of novel biomarkers able to transcend the current limits of diagnostic methods surfaces as a main priority in Chagas disease applied research. The expectation is that these novel biomarkers will provide reliable, reproducible and accurate results irrespective of the genetic background, infecting parasite strain, stage of disease, and clinical-associated features of Chagasic populations. In addition, they should be able to address other still unmet diagnostic needs, including early detection of congenital T. cruzi transmission, rapid assessment of treatment efficiency or failure, indication/prediction of disease progression and direct parasite typification in clinical samples. The lack of access of poor and neglected populations to essential diagnostics also stresses the necessity of developing new methods operational in point-of-care settings. In summary, emergent diagnostic tests integrating these novel and tailored tools should provide a significant impact on the effectiveness of current intervention schemes and on the clinical management of Chagasic patients. In this chapter, we discuss the present knowledge and possible future steps in Chagas disease diagnostic applications, as well as the opportunity provided by recent advances in high-throughput methods for biomarker discovery.
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Affiliation(s)
- Virginia Balouz
- Instituto de Investigaciones Biotecnológicas - Instituto Tecnológico de Chascomús (IIB-INTECH), Universidad Nacional de San Martín (UNSAM) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), San Martín, B 1650 HMP, Buenos Aires, Argentina
| | - Fernán Agüero
- Instituto de Investigaciones Biotecnológicas - Instituto Tecnológico de Chascomús (IIB-INTECH), Universidad Nacional de San Martín (UNSAM) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), San Martín, B 1650 HMP, Buenos Aires, Argentina
| | - Carlos A. Buscaglia
- Instituto de Investigaciones Biotecnológicas - Instituto Tecnológico de Chascomús (IIB-INTECH), Universidad Nacional de San Martín (UNSAM) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), San Martín, B 1650 HMP, Buenos Aires, Argentina
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Santos FLN, Celedon PAF, Zanchin NIT, Brasil TDAC, Foti L, de Souza WV, Silva ED, Gomes YDM, Krieger MA. Performance Assessment of Four Chimeric Trypanosoma cruzi Antigens Based on Antigen-Antibody Detection for Diagnosis of Chronic Chagas Disease. PLoS One 2016; 11:e0161100. [PMID: 27517281 PMCID: PMC4982698 DOI: 10.1371/journal.pone.0161100] [Citation(s) in RCA: 25] [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: 06/15/2016] [Accepted: 07/31/2016] [Indexed: 11/18/2022] Open
Abstract
The performance of serologic tests in chronic Chagas disease diagnosis largely depends on the type and quality of the antigen preparations that are used for detection of anti-Trypanosoma cruzi antibodies. Whole-cell T. cruzi extracts or recombinant proteins have shown variation in the performance and cross-reactivity. Synthetic chimeric proteins comprising fragments of repetitive amino acids of several different proteins have been shown to improve assay performances to detect Chagasic infections. Here, we describe the production of four chimeric T. cruzi proteins and the assessment of their performance for diagnostic purposes. Circular Dichroism spectra indicated the absence of well-defined secondary structures, while polydispersity evaluated by Dynamic Light Scattering revealed only minor aggregates in 50 mM carbonate-bicarbonate (pH 9.6), demonstrating that it is an appropriate buffering system for sensitizing microplates. Serum samples from T. cruzi-infected and non-infected individuals were used to assess the performance of these antigens for detecting antibodies against T. cruzi, using both enzyme-linked immunosorbent assay and a liquid bead array platform. Performance parameters (AUC, sensitivity, specificity, accuracy and J index) showed high diagnostic accuracy for all chimeric proteins for detection of specific anti-T. cruzi antibodies and differentiated seropositive individuals from those who were seronegative. Our data suggest that these four chimeric proteins are eligible for phase II studies.
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Affiliation(s)
| | | | - Nilson Ivo Tonin Zanchin
- Molecular Biology Institute of Paraná, Curitiba, PR, Brazil
- Carlos Chagas Institute, FIOCRUZ-PR, Curitiba, PR, Brazil
| | | | - Leonardo Foti
- Molecular Biology Institute of Paraná, Curitiba, PR, Brazil
- Carlos Chagas Institute, FIOCRUZ-PR, Curitiba, PR, Brazil
| | | | | | | | - Marco Aurélio Krieger
- Molecular Biology Institute of Paraná, Curitiba, PR, Brazil
- Carlos Chagas Institute, FIOCRUZ-PR, Curitiba, PR, Brazil
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Fernandez-Villegas A, Thomas MC, Carrilero B, Lasso P, Egui A, Murcia L, Segovia M, Alonso C, López MC. A 12-mer repetitive antigenic epitope fromTrypanosoma cruziis a potential marker of therapeutic efficacy in chronic Chagas' disease. J Antimicrob Chemother 2016; 71:2005-9. [DOI: 10.1093/jac/dkw090] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 02/29/2016] [Indexed: 11/14/2022] Open
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Cardoso MS, Reis-Cunha JL, Bartholomeu DC. Evasion of the Immune Response by Trypanosoma cruzi during Acute Infection. Front Immunol 2016; 6:659. [PMID: 26834737 PMCID: PMC4716143 DOI: 10.3389/fimmu.2015.00659] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 12/24/2015] [Indexed: 12/11/2022] Open
Abstract
Trypanosoma cruzi is the etiologic agent of Chagas disease, a neglected tropical disease that affects millions of people mainly in Latin America. To establish a life-long infection, T. cruzi must subvert the vertebrate host's immune system, using strategies that can be traced to the parasite's life cycle. Once inside the vertebrate host, metacyclic trypomastigotes rapidly invade a wide variety of nucleated host cells in a membrane-bound compartment known as the parasitophorous vacuole, which fuses to lysosomes, originating the phagolysosome. In this compartment, the parasite relies on a complex network of antioxidant enzymes to shield itself from lysosomal oxygen and nitrogen reactive species. Lysosomal acidification of the parasitophorous vacuole is an important factor that allows trypomastigote escape from the extremely oxidative environment of the phagolysosome to the cytoplasm, where it differentiates into amastigote forms. In the cytosol of infected macrophages, oxidative stress instead of being detrimental to the parasite, favors amastigote burden, which then differentiates into bloodstream trypomastigotes. Trypomastigotes released in the bloodstream upon the rupture of the host cell membrane express surface molecules, such as calreticulin and GP160 proteins, which disrupt initial and key components of the complement pathway, while others such as glycosylphosphatidylinositol-mucins stimulate immunoregulatory receptors, delaying the progression of a protective immune response. After an immunologically silent entry at the early phase of infection, T. cruzi elicits polyclonal B cell activation, hypergammaglobulinemia, and unspecific anti-T. cruzi antibodies, which are inefficient in controlling the infection. Additionally, the coexpression of several related, but not identical, epitopes derived from trypomastigote surface proteins delays the generation of T. cruzi-specific neutralizing antibodies. Later in the infection, the establishment of an anti-T. cruzi CD8(+) immune response focused on the parasite's immunodominant epitopes controls parasitemia and tissue infection, but fails to completely eliminate the parasite. This outcome is not detrimental to the parasite, as it reduces host mortality and maintains the parasite infectivity toward the insect vectors.
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Affiliation(s)
- Mariana S Cardoso
- Laboratório de Imunologia e Genômica de Parasitos, Departamento de Parasitologia, Universidade Federal de Minas Gerais , Belo Horizonte , Minas Gerais, Brazil
| | - João Luís Reis-Cunha
- Laboratório de Imunologia e Genômica de Parasitos, Departamento de Parasitologia, Universidade Federal de Minas Gerais , Belo Horizonte , Minas Gerais, Brazil
| | - Daniella C Bartholomeu
- Laboratório de Imunologia e Genômica de Parasitos, Departamento de Parasitologia, Universidade Federal de Minas Gerais , Belo Horizonte , Minas Gerais, Brazil
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Egui A, Thomas MC, Carrilero B, Segovia M, Alonso C, Marañón C, López MC. Differential phenotypic and functional profiles of TcCA-2 -specific cytotoxic CD8+ T cells in the asymptomatic versus cardiac phase in Chagasic patients. PLoS One 2015; 10:e0122115. [PMID: 25816096 PMCID: PMC4376724 DOI: 10.1371/journal.pone.0122115] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 02/22/2015] [Indexed: 11/18/2022] Open
Abstract
It has been reported that the immune response mediated by T CD8+ lymphocytes plays a critical role in the control of Trypanosoma cruzi infection and that the clinical symptoms of Chagas disease appear to be related to the competence of the CD8+ T immune response against the parasite. Herewith, in silico prediction and binding assays on TAP-deficient T2 cells were used to identify potential HLA-A*02:01 ligands in the T. cruzi TcCA-2 protein. The TcCA-2-specific CD8+ T cells were functionality evaluated by Granzyme B and cytokine production in peripheral blood mononuclear cells (PBMC) from Chagas disease patients stimulated with the identified HLA-A*02:01 peptides. The specific cells were phenotypically characterized by flow cytometry using several surface markers and HLA-A*02:01 APC-labeled dextramer loaded with the peptides. In the T. cruzi TcCA-2 protein four T CD8+ epitopes were identified which are processed and presented during Chagas disease. Interestingly, a differential cellular phenotypic profile could be correlated with the severity of the disease. The TcCA-2-specific T CD8+ cells from patients with cardiac symptoms are mainly effector memory cells (TEM and TEMRA) while, those present in the asymptomatic phase are predominantly naive cells (TNAIVE). Moreover, in patients with cardiac symptoms the percentage of cells with senescence features is significantly higher than in patients at the asymptomatic phase of the disease. We consider that the identification of these new class I-restricted epitopes are helpful for designing biomarkers of sickness pathology as well as the development of immunotherapies against T. cruzi infection.
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Affiliation(s)
- Adriana Egui
- Instituto de Parasitología y Biomedicina López Neyra, Consejo Superior de Investigaciones Científicas (IPBLN-CSIC), PTS Granada, Avda. del Conocimiento S/N, 18016, Granada, Spain
| | - M. Carmen Thomas
- Instituto de Parasitología y Biomedicina López Neyra, Consejo Superior de Investigaciones Científicas (IPBLN-CSIC), PTS Granada, Avda. del Conocimiento S/N, 18016, Granada, Spain
| | - Bartolomé Carrilero
- Unidad Regional de Medicina Tropical, Hospital Virgen de la Arrixaca, Carretera Madrid-Cartagena s/n, El Palmar, 30120, Murcia, Spain
| | - Manuel Segovia
- Unidad Regional de Medicina Tropical, Hospital Virgen de la Arrixaca, Carretera Madrid-Cartagena s/n, El Palmar, 30120, Murcia, Spain
| | - Carlos Alonso
- Centro de Biología Molecular Severo Ochoa, CSIC-Universidad Autónoma de Madrid, Cantoblanco, Madrid, Spain
| | - Concepción Marañón
- Genomic Medicine Department, Centre for Genomics and Oncological Research (GENYO): Pfizer / University of Granada / Andalusian Regional Government, PTS Granada, Spain
| | - Manuel Carlos López
- Instituto de Parasitología y Biomedicina López Neyra, Consejo Superior de Investigaciones Científicas (IPBLN-CSIC), PTS Granada, Avda. del Conocimiento S/N, 18016, Granada, Spain
- * E-mail:
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Falconar AKI. Epitope reactions can be gauged by relative antibody discriminating specificity (RADS) values supported by deletion, substitution and cysteine bridge formation analyses: potential uses in pathogenesis studies. BMC Res Notes 2012; 5:208. [PMID: 22546090 PMCID: PMC3392722 DOI: 10.1186/1756-0500-5-208] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Accepted: 04/30/2012] [Indexed: 01/05/2023] Open
Abstract
Background Epitope-mapping of infectious agents is essential for pathogenesis studies. Since polyclonal antibodies (PAbs) and monoclonal antibodies (MAbs) are always polyspecific and can react with multiple epitopes, it is important to distinguish between specific and non-specific reactions. Relative antibody discriminating specificity (RADS) values, obtained from their relative ELISA reactions with L-amino acid peptides prepared in the natural versus reverse orientations (x-fold absorbance natural/absorbance reverse = RADS value) may be valuable for this purpose. PAbs generated against the dengue type-2 virus (DENV-2) nonstructural-1 (NS1) glycoprotein candidate vaccine also reacted with both DENV envelope (E) glycoproteins and blood-clotting proteins. New xKGSx/xSGKx amino acid motifs were identified on DENV-2 glycoproteins, HIV-1 gp41 and factor IXa. Their potential roles in DENV and HIV-1 antibody-enhanced replication (AER) and auto-immunity were assessed. In this study, a) RADS values were determined for MAbs and PAbs, generated in congeneic (H2: class II) mice against DENV NS1 glycoprotein epitopes, to account for their cross-reaction patterns, and b) MAb 1G5.3 reactions with xKGSx/xSGKx motifs present in the DENV-4 NS1, E and HIV-1 glycoproteins and factor IXa were assessed after the introduction of amino acid substitutions, deletions, or intra-/inter-cysteine (C-C) bridges. Results MAbs 1H7.4, 5H4.3, 3D1.4 and 1G5.3 had high (4.23- to 16.83-fold) RADS values against single epitopes on the DENV-2 NS1 glycoprotein, and MAb 3D1.4 defined the DENV complex-conserved LX1 epitope. In contrast, MAbs 1G5.4-A1-C3 and 1C6.3 had low (0.47- to 1.67-fold) RADS values against multiple epitopes. PAb DENV complex-reactions occurred through moderately-high (2.77- and 3.11-fold) RADS values against the LX1 epitope. MAb 1G5.3 reacted with xSGKx motifs present in DENV-4 NS1 and E glycoproteins, HIV-1 gp41 and factor IXa, while natural C-C bridge formations or certain amino acid substitutions increased its binding activity. Conclusions These results: i) were readily obtained using a standard 96-well ELISA format, ii) showed the LX1 epitope to be the immuno-dominant DENV complex determinant in the NS1 glycoprotein, iii) supported an antigenic co-evolution of the DENV NS1 and E glycoproteins, and iv) identified methods that made it possible to determine the role of anti-DENV PAb reactions in viral pathogenesis.
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Affiliation(s)
- Andrew K I Falconar
- Laboratorio de Investigaciones en Enfermedades Tropicales, Departamento de Medicina, Universidad del Norte, Km5 Antigua via Puerto Colombia, Barranquilla, Colombia.
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Pérez-Arellano JL. [Chagas disease in Spain, 2012]. Rev Clin Esp 2012; 212:344-6. [PMID: 22664216 DOI: 10.1016/j.rce.2012.04.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2012] [Accepted: 04/10/2012] [Indexed: 11/28/2022]
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