RAMENDRA PATI PANDEY
Projetos de Pesquisa
Unidades Organizacionais
LIM/19 - Laboratório de Histocompatibilidade e Imunidade Celular, Hospital das Clínicas, Faculdade de Medicina
6 resultados
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- Disease Tolerance and Pathogen Resistance Genes May Underlie Trypanosoma cruzi Persistence and Differential Progression to Chagas Disease Cardiomyopathy(2018) CHEVILLARD, Christophe; NUNES, Joao Paulo Silva; FRADE, Amanda Farage; ALMEIDA, Rafael Ribeiro; PANDEY, Ramendra Pati; NASCIMENTO, Marilda Savoia; KALIL, Jorge; CUNHA-NETO, EdecioChagas disease is caused by infection with the protozoan Trypanosoma cruzi and affects over 8 million people worldwide. In spite of a powerful innate and adaptive immune response in acute infection, the parasite evades eradication, leading to a chronic persistent infection with low parasitism. Chronically infected subjects display differential patterns of disease progression. While 30% develop chronic Chagas disease cardiomyopathy (CCC)-a severe inflammatory dilated cardiomyopathy-decades after infection, 60% of the patients remain disease-free, in the asymptomatic/indeterminate (ASY) form, and 10% develop gastrointestinal disease. Infection of genetically deficient mice provided a map of genes relevant for resistance to T. cruzi infection, leading to the identification of multiple genes linked to survival to infection. These include pathogen resistance genes (PRG) needed for intracellular parasite destruction, and genes involved in disease tolerance (protection against tissue damage and acute phase death-DTG). All identified DTGs were found to directly or indirectly inhibit IFN-gamma production or Th1 differentiation. We hypothesize that the absolute need for DTG to control potentially lethal IFN-gamma PRG activity leads to T. cruzi persistence and establishment of chronic infection. IFN-gamma production is higher in CCC than ASY patients, and is the most highly expressed cytokine in CCC hearts. Key DTGs that downmodulate IFN-gamma, like IL-10, and Ebi3/IL27p28, are higher in ASY patients. Polymorphisms in PRG and DTG are associated with differential disease progression. We thus hypothesize that ASY patients are disease tolerant, while an imbalance of DTG and IFN-gamma PRG activity leads to the inflammatory heart damage of CCC.
conferenceObject Repurposed drugs acting on host mechanisms of T. cruzi invasion synergize with Benznidazole: New therapies for Chagas disease(2019) PANDEY, R. P.; NASCIMENTO, M. Savoia; BARRIOS, L.; GIBALDI, D.; LANNES-VIEIRA, J.; KALIL, J.; CUNHA-NETO, E.conferenceObject POTENTIATION OF BENZNIDAZOLE EFFECT BY COADMINISTRATION OF REPURPOSED DRUGS ACTING IN THE INVASION OF HOST CELLS BY TRYPANOSOMA CRUZI(2017) PANDEY, Ramendra P.; SAVOIA, Marilda; SABINO, Ester; KALIL, Jorge; CUNHA-NETO, Edecio- Vimentin and Anti Vimentin Antibodies in Chagas' Disease(2018) NASCIMENTO, Marilda Savoia; STOLF, Anna Maria Simonsen; ANDRADE JUNIOR, Heitor Franco de; PANDEY, Ramendra Pati; UMEZAWA, Eufrosina SetsuBackground: Vimentin is a main structural protein of the cell, a component of intermediate cell filaments and immersed in cytoplasm. Vimentin is mimicked by some bacterial proteins and anti-vimentin antibodies occur in autoimmune cardiac disease, as rheumatic fever. In this work we studied vimentin distribution on LLC-MK2 cells infected with T. cruzi and anti-vimentin antibodies in sera from several clinical pictures of Chagas' disease or American Trypanosomiasis, in order to elucidate any vimentin involvement in the humoral response of this pathology. Objective: We standardized an indirect immunofluorescence assay (IFI) to determine sub cellular expression in either parasites and host cells, and ELISA to evaluate anti-vimentin antibodies in sera fron chagasic patients. Methods: We analyzed the distribution of vimentin in culture cells using indirect fluorescent assays, using as external controls anti-T. cruzi sera, derived from chronic infected patients for identification of the parasites in the same model. After infection and growth of T.cruzi amastigotes, those cells express larger amounts of vimentin, with heavy staining of cytoplasm outside the parasitophorous vacuole and some particle shadowing patterns, suggesting that vimentin are associated with cell cytoplasm. Anti-vimentin antibodies were present in most American trypanosomiasis samples, but notably, they are much more present in acute (76, 9%) or clinical defined syndromes, especially cardiac disease (87, 9%). Paradoxically, they were relatively infrequent in asymptomatic (25%) infected patients, which had a clearly positive serological reaction to parasite antigens, but had low frequency of anti-vimentin antibodies, similar to controls (2,5%). Conclusion: Our current data revealed that anti-vimentin antibodies induced during T. cruzi infection could be a marker of active disease in the host and its levels could also justify drug therapy in American Trypanosomiasis chronic infection, as a large group of asymptomatic patients would be submitted to treatment with frequent adverse reactions of the available drugs. Anti-vimentin antibodies could be a marker of cardiac muscle cell damage, appearing in American Trypanosomiasis patients during active muscle cell damage.
conferenceObject Therapeutic evaluation of drug combination against Trypanosoma cruzi(2016) PANDEY, R. P.; KURAMOTO, A.; KALIL, J.; CUNHA-NETO, E.- Integration of miRNA and gene expression profiles suggest a role for miRNAs in the pathobiological processes of acute Trypanosoma cruzi infection(2017) FERREIRA, Ludmila Rodrigues Pinto; FERREIRA, Frederico Moraes; LAUGIER, Laurie; CABANTOUS, Sandrine; NAVARRO, Isabela Cunha; CANDIDO, Darlan da Silva; RIGAUD, Vagner Carvalho; REAL, Juliana Monte; PEREIRA, Glaucia Vilar; PEREIRA, Isabela Resende; RUIVO, Leonardo; PANDEY, Ramendra Pati; SAVOIA, Marilda; KALIL, Jorge; LANNES-VIEIRA, Joseli; NAKAYA, Helder; CHEVILLARD, Christophe; CUNHA-NETO, EdecioChagas disease, caused by the parasite Trypanosoma cruzi, is endemic in Latin America. Its acute phase is associated with high parasitism, myocarditis and profound myocardial gene expression changes. A chronic phase ensues where 30% develop severe heart lesions. Mouse models of T. cruzi infection have been used to study heart damage in Chagas disease. The aim of this study was to provide an interactome between miRNAs and their targetome in Chagas heart disease by integrating gene and microRNA expression profiling data from hearts of T. cruzi infected mice. Gene expression profiling revealed enrichment in biological processes and pathways associated with immune response and metabolism. Pathways, functional and upstream regulator analysis of the intersections between predicted targets of differentially expressed microRNAs and differentially expressed mRNAs revealed enrichment in biological processes and pathways such as IFN gamma, TNF alpha, NF-kappa B signaling signatures, CTL-mediated apoptosis, mitochondrial dysfunction, and Nrf2-modulated antioxidative responses. We also observed enrichment in other key heart disease-related processes like myocarditis, fibrosis, hypertrophy and arrhythmia. Our correlation study suggests that miRNAs may be implicated in the pathophysiological processes taking place the hearts of acutely T. cruzi-infected mice.