A Drug Repurposing Approach Reveals Targetable Epigenetic Pathways in Plasmodium vivax Hypnozoites.

Radical cure of Plasmodium vivax malaria must include elimination of quiescent "hypnozoite" forms in the liver; however, the only FDA-approved treatments are contraindicated in many vulnerable populations. To identify new drugs and drug targets, we screened the Repurposing, Focused Rescue, and Accelerated Medchem library against P. vivax liver stages and identified the DNA methyltransferase inhibitors hydralazine and cadralazine as active against hypnozoites. We then used bisulfite sequencing and immunostaining to identify cytosine modifications in the infectious stage (sporozoites) and liver stages, respectively. A subsequent screen of epigenetic inhibitors revealed hypnozoites are broadly sensitive to histone acetyltransferase and methyltransferase inhibitors, indicating that several epigenetic mechanisms are likely modulating hypnozoite persistence. Our data present an avenue for the discovery and development of improved radical cure antimalarials

Analytical Validation of Quantitative Real-Time PCR Methods for Quantification of Trypanosoma cruzi DNA in Blood Samples from Chagas Disease Patients

Submitted by sandra infurna ([email protected]) on 2016-03-01T11:27:17Z No. of bitstreams: 1 constança_brito_etal_IOC_2015.pdf: 498816 bytes, checksum: a4657816d73aedff572e1e40cccfba4a (MD5)Approved for entry into archive by sandra infurna ([email protected]) on 2016-03-01T14:37:34Z (GMT) No. of bitstreams: 1 constança_brito_etal_IOC_2015.pdf: 498816 bytes, checksum: a4657816d73aedff572e1e40cccfba4a (MD5)Made available in DSpace on 2016-03-01T14:37:34Z (GMT). No. of bitstreams: 1 constança_brito_etal_IOC_2015.pdf: 498816 bytes, checksum: a4657816d73aedff572e1e40cccfba4a (MD5) Previous issue date: 2015Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI-CONICET). Laboratory of Molecular Biology of Chagas Disease (LaBMECh). Buenos Aires, Argentina.Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI-CONICET). Laboratory of Molecular Biology of Chagas Disease (LaBMECh). Buenos Aires, Argentina.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular e Doenças Endêmicas. Rio de Janeiro, RJ, Brasil.Universidade Federal do Triângulo Mineiro. Laboratório da Disciplina de Patologia. Uberaba, MG, Brasil.Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI-CONICET). Laboratory of Molecular Biology of Chagas Disease (LaBMECh). Buenos Aires, Argentina.National Institute of Parasitology “Dr. Mario Fatala Chabén”. Buenos Aires, Argentina.Universidad de Los Andes. Center for Research in Tropical Microbiology and Parasitology. Bogotá, Colombia.CONICET-Universidad Nacional de Salta. The Institute of Experimental Pathology. Salta, Argentina.Pontificia Universidad Javeriana. Laboratory of Molecular Parasitology. Bogota, Colombia.Instituto de Salud Carlos III. National Center for Microbiology. Madrid, Spain.Universidad Central de Venezuela. Institute of Tropical Medicine. Caracas, Venezuela.Universidad Nacional Autónoma de México. Biomedical Research Institute. Mexico, DF, Mexico.Instituto Nacional de Laboratorios en Salud. Laboratory of Parasitology and Molecular Biology. La Paz, Bolivia.Universidade Federal do Rio Grande do Norte. Departamento de Microbiologia e Parasitologia. Natal, RN, Brasil.Hospital and University LaboratoryCH Andrée Rosemon. Cayenne, French Guiana.Centers for Disease Control and Prevention. Division of Parasitic Diseases and Malaria. Atlanta, Georgia, USA.Instituto Nacional de Salud. National Center for Public Health. Lima, Peru.Instituto Nacional de Cardiología “Ignacio Chávez”. Laboratory of Genomics. Mexico, DF, Mexico.Universidad Peruana Cayetano Heredia. Laboratory for Research in Infectious Diseases. Lima, Peru.Universidad de los Andes. Department of Biology. Merida, Venezuela.Instituto Pasteur de Montevideo. Molecular Biology Unit. Montevideo, Uruguay.Universidad de Chile. Basic Clinical Parasitology Laboratory. Santiago, Chile.Pontificia Universidad Católica de Ecuador. Research Center for Infectious Diseases. Quito, Ecuador.Hospital Clinic and Barcelona Centre for International Health Research (CRESIB). Microbiology Department. Barcelona, Spain.State Laboratory of Public Health. Acapulco, Mexico.Instituto de Salud Pública. Biomedical Department. Santiago, Chile.Universidad Mayor de San Simón. Laboratory of Molecular Biology. Cochabamba, Bolivia.Universidad Nacional de Asunción. Research Institute for Health Sciences. Asuncion, Paraguay.Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI-CONICET). Laboratory of Molecular Biology of Chagas Disease (LaBMECh). Buenos Aires, Argentina.Universidad Mayor de San Simón. Laboratory of Molecular Biology. Cochabamba, Bolivia.Universidade Federal do Rio Grande do Norte. Departamento de Microbiologia e Parasitologia. Natal, RN, Brasil.Universidade Federal do Rio Grande do Norte. Departamento de Microbiologia e Parasitologia. Natal, RN, Brasil.Universidad Nacional Autónoma de México. Biomedical Research Institute. Mexico, DF, Mexico.Universidad Central de Venezuela. Institute of Tropical Medicine. Caracas, Venezuela.Pontificia Universidad Javeriana. Laboratory of Molecular Parasitology. Bogota, Colombia.National Institute of Parasitology “Dr. Mario Fatala Chabén”. Buenos Aires, Argentina.CONICET-Universidad Nacional de Salta. The Institute of Experimental Pathology. Salta, Argentina.National Institute of Parasitology “Dr. Mario Fatala Chabén”. Buenos Aires, Argentina.Universidad de Los Andes. Center for Research in Tropical Microbiology and Parasitology. Bogotá, Colombia.Drugs for Neglected Diseases Initiative (DNDi). Geneva, SwitzerlandHospital and University LaboratoryCH Andrée Rosemon. Cayenne, French Guiana.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular e Doenças Endêmicas. Rio de Janeiro, RJ, Brasil.Pan American Health Organization/World Health Organization (PAHO). Communicable Diseases and Health Analysis Department/WHO). Rio de Janeiro, RJ, Brasil.Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI-CONICET). Laboratory of Molecular Biology of Chagas Disease (LaBMECh). Buenos Aires, Argentina.An international study was performed by 26 experienced PCR laboratories from 14 countries to assess the performance of duplex quantitative real-time PCR (qPCR) strategies on the basis of TaqMan probes for detection and quantification of parasitic loads in peripheral blood samples from Chagas disease patients. Two methods were studied: Satellite DNA (SatDNA) qPCR and kinetoplastid DNA (kDNA) qPCR. Both methods included an internal amplification control. Reportable range, analytical sensitivity, limits of detection and quantification, and precision were estimated according to international guidelines. In addition, inclusivity and exclusivity were estimated with DNA from stocks representing the different Trypanosoma cruzi discrete typing units and Trypanosoma rangeli and Leishmania spp. Both methods were challenged against 156 blood samples provided by the participant laboratories, including samples from acute and chronic patients with varied clinical findings, infected by oral route or vectorial transmission. kDNA qPCR showed better analytical sensitivity than SatDNA qPCR with limits of detection of 0.23 and 0.70 parasite equivalents/mL, respectively. Analyses of clinical samples revealed a high concordance in terms of sensitivity and parasitic loads determined by both SatDNA and kDNA qPCRs. This effort is a major step toward international validation of qPCR methods for the quantification of T. cruzi DNA in human blood samples, aiming to provide an accurate surrogate biomarker for diagnosis and treatment monitoring for patients with Chagas disease