Instituto de Parasitología y Biomedicina
"López - Neyra"
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Identificación y caracterización de secuencias reguladoras y funcionales contenidas en el elemento móvil L1Tc de Trypanosoma cruzi. Caracterización de proteínas recombinantes de Leishmania y Trypanosoma cruzi como marcadores celulares de la situación, progresión y/o control de leishmaniasis, en pacientes leishmaniosis/VIH+, y de la enfermedad de Chagas

Group Leader
    • María del Carmen Thomas Carazo     
        email: mcthomas (@ipb.csic.es)
        Tlf: 958181662

    Staff Research Posdoctoral
    • Francisco Macías Huete     

    Technical Assistants
    • Almudena López-Barajas de la Puerta     




    Identification and characterization of regulatory and functional sequences contained in the Trypanosoma Cruzi L1Tc mobile element.


    Long interspersed Elements-1 (LINE-1 or L1s) are abundant non-long terminal repeat (non-LTR) retrotransposons in mammalian genomes autonomously mobilized via a RNA intermediate through a mechanism that requires various enzymatic activities. The LINEs enzymatic machinery is, moreover, responsible for mobilization of SINEs although the enzymatic and functional characteristics of the enzymes encoded by LINEs are still unknown. Interestingly, the T. cruzi genome contains 30% of repeated sequences most of them SINEs and LINEs essential in the parasite?s biology.


    Regarding to DNA mobile elements, our research is focused on the L1Tc non-LTR retrotransposons from Trypanosoma cruzi.


    Transcription is the first step in mobilization of LINEs and consequently one of our objectives is to characterize and to analyze the functionality of the putative promoter sequence from the L1Tc LINE. In addition we are studying the enzymatic properties and functional requirements of the RT-RNaseH bifunctional protein encoded by the element as well as identifying and characterizing the sequence responsible for the nucleic acids chaperone activity and the nucleic acids binding capacity of C2-L1Tc protein.

    Characterization of Leishmania and trypanosoma cruzi recombinant proteins as cellular markers of the situation, progression and control of Leishmaniosis in Leishmaniosis/HIV+ patients, and chagas´Disease. Protozoan parasites from the genus Leishmania are etiological agents of a wide spectrum of human severe diseases known as leishmaniasis. In spite of there is an acquire immunity against Leishmania the infection rate is increasing especially in immunodepressed patients. Specific chemotherapy results inefficient and toxic and there is not an antileishmania vaccine. The illness control requires the induction of a multiple immune response against diverse and specific antigens of the parasite.

    Our Resereach in this area is focused on to identify proteins and antigenic proteins whose properties make them good candidates for developing efficient immunotherapies against leishmaniosis. In this context we are producing DNA chimerical molecules composed by sequences coding for several proteins of Leishmania infantum associated to the immunomodulator molecule T-HSP70. The ability of these molecules to produce an efficient immune response against infection is being determined in mice. Protection assays against the parasite are also being carried out on the murine experimental system analyzing as infection parameters, the histological pattern and parasitemia level in target tissues (spleen and liver). The antigenic capacity (humoral and cellular) of the said recombinant proteins is also being tested in natural infection on sera and peripheral blood cells from HIV+/leishmaniasis patients.

    The protozoan parasite Trypanosoma cruzi is the etiological agent causing Chagas? disease or American trypanosomiasis, now ranked as the most serious disease in Latin America. The host?s ability to generate a cellular response against the parasite is absolutely essential in the evolution and severity of Chagas? disease. The identification of T cells responding to specific antigens of the parasite proves useful when establishing markers of the status and evolution of the disease.

    Our research in this field is directed to identify cellular markers that allow links to be established between the specific responses found in different groups of Chagasic patients to the markers, severity of the disease and the post-treatment evolution of Chagas? disease. For this purpose, we have isolated and characterized several genes coding for specific T. cruzi antigens and over produced the correspondent recombinant proteins. Thus, we are interested in to establish a series of parameters, related to specific humoral and cellular responses, which could be indicative of the stage of the disease in Chagasic patients.




    - U01: new chemotherapy regimens and biomarkers for chagas disease. PROYECTO, NIH NIAID Clinical Trial Implementation Cooperative, Ref: INT-USA/0831, (2018 - 2023).





    -Garcia-Castro A; Egui Machado A; Thomas Carazo MC; Lopez Lopez Manuel Carlos, Humoral and Cellular Immune Response in Asymptomatic Dogs with Visceral Leishmaniasis: A Review., Vaccines, 2022, Vol. 10: 947, ARTÍCULO DE REVISIÓN, Id:894194

    -Alonso-Vega, C.; Urbina, J.A.; Sanz, S.; Pinazo, M.J.; Pinto, J.J.; Gonzalez, V.R.; Rojas, G.; Ortiz, L.; Garcia, W.; Lozano, D.; Soy, D.; Maldonado, R.A.; Nagarkatti, R.; Debrabant, A.; Schijman, A.; Thomas, M.C.; López, M.C.; Michael, K.; Ribeiro, I.; Gascon, J.; Torrico, F.; Almeida, I.C., 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, Vol. 11: 12-e052897, ARTÍCULO, Id:868154

    -Mateus J; Nocua P; Lasso P; López MC; Thomas MC; Egui A; Cuervo C; González JM; Puerta CJ; Cuellar A., CD8+ T cell response quality is related to parasite control in an animal model of single and mixed chronic Trypanosoma cruzi infections, Frontiers in cellular and infection microbiology, 2021, Vol. 11: 723121, ARTÍCULO, Id:865569

    -Gómez, I.; Thomas, M.C.; Palacios, G.; Egui, A.; Carrilero, B.; Simón, M.; Valladares, B.; Segovia, M.; Carmelo, E.; López, M.C., Differential Expression of Immune Response Genes in Asymptomatic Chronic Chagas Disease Patients Versus Healthy Subjects, Frontiers in cellular and infection microbiology, 2021, Vol. 11: 722984, ARTÍCULO, Id:854449

    -Gómez, I.; López, M.C.; Rastrojo, A.; Lorenzo-Díaz, F.; Requena, J.M.; Aguado, B.; Valladares, B.; Thomas, M.C., Variability of the Pr77 sequence of L1Tc retrotransposon among six T. cruzi strains belonging to different discrete typing units (DTUs), Acta Tropica, 2021, Vol. 222: 106053, ARTÍCULO, Id:852664

    -Alonso-Padilla, J.; López, M.C.; Esteva, M.; Zrein, M.; Casellas, A.; Gómez, I.; Granjon, E.; Méndez, S.; Benítez, C.; Ruiz, A.M.; Sanz, S.; Gascón, J.; Thomas, M.C.; Pinazo, M.J.; Abril, M.; de Noya, B.A.; Jorge, T.A.; Chatelain, E.; Grijalva, M.J.; Guhl, F.; Hasslocher-Moreno, A.M.; Luquetti, A.O.; Noya, O.; Ramsey, J.M.; Ribeiro, I.; Longhi, S.A.; Schijman, A.G.; 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 Tropica, 2021, Vol. 221: 105990, ARTÍCULO, Id:851634

    -Macías, F.; Afonso-Lehmann, R.; Carreira, P.E.; Thomas, M.C., TBP and SNAP50 transcription factors bind specifically to the Pr77 promoter sequence from trypanosomatid non-LTR retrotransposons, Parasites and Vectors, 2021, Vol. 14: 1-313, ARTÍCULO, Id:846906

    -Pérez-Antón E; Egui A; Thomas MC; Carrilero B; Simón M; López-Ruz MÁ; Segovia M; López MC., A proportion of CD4+ T cells from patients with chronic Chagas disease undergo a dysfunctional process, which is partially reversed by benznidazole treatment., PLoS Neglected Tropical Diseases, 2021, Vol. 15: e00090592-e0009059, ARTÍCULO, Id:841082

    -Cantos-Barreda, A.; Escribano, D.; Siriyasatien, P.; Cerón, J.J.; Thomas, M.C.; Afonso-Lehmann, R.N.; López, M.C.; Bernal, L.J.; Phumee, A.; Lubas, G.; Martínez-Subiela, S., Detection of Leishmania infantum DNA by real-time PCR in saliva of dogs, Comparative Immunology, Microbiology and Infectious Diseases, 2020, Vol. 73: 101542, ARTÍCULO, Id:815998

    -Gómez, I.; Rastrojo, A.; Lorenzo-Diáz, F.; Sánchez-Luque, F.J.; MacIás, F.; Aguado, B.; Valladares, B.; Requena, J.M.; López, M.C.; Thomas, M.C., Trypanosoma cruzi Ikiakarora (TcIII) Draft Genome Sequence, Microbiology Resource Announcements, 2020, Vol. 9: 27-e00453-20, ARTÍCULO, Id:815969

    -Gómez, I.; Rastrojo, A.; Sanchez-Luque, F.J.; Lorenzo-Díaz, F.; Macías, F.; Valladares, B.; Aguado, B.; Requena, J.M.; López, M.C.; Carmen Thomas, M., Draft Genome sequence of the trypanosoma cruzi B. M. López strain (TCIA), isolated from a Colombian patient, Microbiology Resource Announcements, 2020, Vol. 9: 18-e00031-20, ARTÍCULO, Id:809266

    -Alonso-Padillaid, J.; Abril, M.; de Noya, B.A.; Almeida, I.C.; Angheben, A.; Jorge, T.A.; Chatelain, E.; Esteva, M.; Gascón, J.; Grijalva, M.J.; Guhl, F.; Hasslochermoreno, A.M.; López, M.C.; Luquetti, A.; Noya, O.; Pinazo, M.J.; Ramsey, J.M.; Ribeiro, I.; Ruiz, A.M.; Schijman, A.G.; Sosa-Estani, S.; Carmen Thomas, M.; Torrico, F.; Zreinid, M.; Picado, A., Target product profile for a test for the early assessment of treatment efficacy in chagas disease patients: An expert consensus, PLoS Neglected Tropical Diseases, 2020, Vol. 14: 1-10, ARTÍCULO, Id:808851

    -Pérez-Antón, E.; Egui, A.; Thomas, M.C.; Simón, M.; Segovia, M.; López, M.C., Immunological exhaustion and functional profile of CD8+ T lymphocytes as cellular biomarkers of therapeutic efficacy in chronic Chagas disease patients, Acta Tropica, 2020, Vol. 202: 105242, ARTÍCULO, Id:804208

    -Egui, A.; López, M.C.; Gómez, I.; Simón, M.; Segovia, M.; Thomas, M.C., Differential phenotypic and functional profile of epitope-specific cytotoxic CD8+ T cells in benznidazole-treated chronic asymptomatic Chagas disease patients, Biochimica et Biophysica Acta - Molecular Basis of Disease, 2020, Vol. 1866: 3-165629, ARTÍCULO, Id:790664

    -Franco-Martínez, L.; Villar, M.; Tvarijonaviciute, A.; Escribano, D.; Bernal, L.J.; Cerón, J.J.; Thomas, M.d.C.; Mateos-Hernández, L.; Tecles, F.; de la Fuente, J.; López, M.C.; Martínez-Subiela, S., Serum proteome of dogs at subclinical and clinical onset of canine leishmaniosis, Transboundary and Emerging Diseases, 2020, Vol. 97: 318-327, ARTÍCULO, Id:774803

    -Cantos-Barreda, A.; Escribano, D.; Egui, A.; Thomas, M.C.; López, M.C.; Tecles, F.; Bernal, L.J.; Cerón, J.J.; Martínez-Subiela, S., One-year follow-up of anti-Leishmania antibody concentrations in serum and saliva from experimentally infected dogs, International Journal for Parasitology, 2019, Vol. 49: 893-900, ARTÍCULO, Id:771543

    -Egui, A.; Carmen Thomas, M.; Fernández-Villegas, A.; Pérez-Antón, E.; Gómez, I.; Carrilero, B.; del Pozo, Á.; Ceballos, M.; Andrés-León, E.; López-Ruz, M.Á.; Gainza, E.; Oquiñena, E.; Segovia, M.; López, M.C., A Parasite Biomarker Set for Evaluating Benznidazole Treatment Efficacy in Patients with Chronic Asymptomatic Trypanosoma cruzi Infection, Antimicrobial Agents and Chemotherapy, 2019, Vol. 63: 10-e02436-18, ARTÍCULO, Id:771537

    -Simón, M.; Gil-Gallardo, L.J.; Asunción Iborra, M.; Carrilero, B.; López, M.C.; Romay-Barja, M.; Murcia, L.; Carmen Thomas, M.; Benito, A.; Segovia, M., An observational longitudinal study to evaluate tools and strategies available for the diagnosis of Congenital Chagas Disease in a non-endemic country, Acta Tropica, 2019, Vol. 199: 105127, ARTÍCULO, Id:770497

    -Franco-Martínez, L.; Tvarijonaviciute, A.; Horvati¿, A.; Guillemin, N.; Bernal, L.J.; Bari¿ Rafaj, R.; Cerón, J.J.; Thomas, M.d.C.; López, M.C.; Tecles, F.; Martínez-Subiela, S.; Mrljak, V., Changes in saliva of dogs with canine leishmaniosis: A proteomic approach, Veterinary Parasitology, 2019, Vol. 272: 44-52, ARTÍCULO, Id:767572

    -Egui A; Lasso P; Perez-Anton E; Thomas MC; Lopez MC, Dynamics of T cells repertoire during Trypanosoma cruzi infection and its post-treatment modulation., Current Medicinal Chemistry, 2019, Vol. 26: 1-22, ARTÍCULO, Id:756060

    -Risueño, J.; Spitzová, T.; Bernal, L.J.; Muñoz, C.; López, M.C.; Thomas, M.C.; Infante, J.J.; Volf, P.; Berriatua, E., Longitudinal monitoring of anti-saliva antibodies as markers of repellent efficacy against Phlebotomus perniciosus and Phlebotomus papatasi in dogs, Medical and Veterinary Entomology, 2019, Vol. 33: 99-109, ARTÍCULO, Id:743780

    -Egui A; Ledesma D; Pérez-Antón E; Montoya A; Gómez I; Robledo SM; Infante JJ; Vélez ID; López MC; Thomas MC, Phenotypic and Functional Profiles of Antigen-Specific CD4+ and CD8+ T Cells Associated With Infection Control in Patients With Cutaneous Leishmaniasis., Frontiers in cellular and infection microbiology, 2018, Vol. 8: 393-393, ARTÍCULO, Id:756009

    -Pérez-Antón, E.; Egui, A.; Thomas, M.C.; Puerta, C.J.; González, J.M.; Cuéllar, A.; Segovia, M.; López, M.C., Impact of benznidazole treatment on the functional response of Trypanosoma cruzi antigen-specific CD4+CD8+T cells in chronic Chagas disease patients, PLoS Neglected Tropical Diseases, 2018, Vol. 12: 5-e0006480, ARTÍCULO, Id:723199

    -Macías, F.; Afonso-Lehmann, R.; López, M.C.; Gómez, I.; Carmen Thomas, M., Biology of trypanosoma cruzi retrotransposons: From an enzymatic to a structural point of view, Current Genomics, 2018, Vol. 19: 110-118, ARTÍCULO DE REVISIÓN, Id:715936






    Inmaculada María Gómez García

    "Identificación de macromoléculas como potenciales biomarcadores útiles para el control de la enfermedad de Chagas"

    Instituto de Parasitología y Biomedicina "López-Neyra" CSIC





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