EDUARDO MILTON RAMOS SANCHEZ
Projetos de Pesquisa
Unidades Organizacionais
LIM/38 - Laboratório de Epidemiologia e Imunobiologia, Hospital das Clínicas, Faculdade de Medicina
4 resultados
Resultados de Busca
Agora exibindo 1 - 4 de 4
- ATP6V(0)d2 controls Leishmania parasitophorous vacuole biogenesis via cholesterol homeostasis(2019) PESSOA, Carina Carraro; REIS, Luiza Campos; RAMOS-SANCHEZ, Eduardo Milton; ORIKAZA, Cristina Mary; CORTEZ, Cristian; LEVATTI, Erica Valadares de Castro; BADARO, Ana Carolina Benites; YAMAMOTO, Joyce Umbelino da Silva; D'ALMEIDA, Vania; GOTO, Hiro; MORTARA, Renato Arruda; REAL, FernandoV-ATPases are part of the membrane components of pathogen-containing vacuoles, although their function in intracellular infection remains elusive. In addition to organelle acidification, V-ATPases are alternatively implicated in membrane fusion and anti-inflammatory functions controlled by ATP6V(0)d2, the d subunit variant of the V-ATPase complex. Therefore, we evaluated the role of ATP6V(0)d2 in the biogenesis of pathogen-containing vacuoles using ATP6V(0)d2 knock-down macrophages infected with the protozoan parasite Leishmania amazonensis. These parasites survive within IFN gamma/LPS-activated inflammatory macrophages, multiplying in large/fusogenic parasitophorous vacuoles (PVs) and inducing ATP6V(0)d2 upregulation. ATP6V(0)d2 knock-down decreased macrophage cholesterol levels and inhibited PV enlargement without interfering with parasite multiplication. However, parasites required ATP6V(0)d2 to resist the influx of oxidized low-density lipoprotein (ox-LDL)-derived cholesterol, which restored PV enlargement in ATP6V(0)d2 knock-down macrophages by replenishing macrophage cholesterol pools. Thus, we reveal parasite-mediated subversion of host V-ATPase function toward cholesterol retention, which is required for establishing an inflammation-resistant intracellular parasite niche. Author summary V-ATPases control acidification and other processes at intracellular vesicles that bacteria and parasites exploit as compartments for replication and immune evasion. We report that the protozoan intracellular parasite Leishmania amazonensis resists inflammatory macrophage immune responses and upregulates an alternative isoform of subunit d of V-ATPase (ATP6V(0)d2). Leishmania are still sequestered within acidified parasitophorous vacuoles (PVs) in cells lacking ATP6V(0)d2, but these PVs do not enlarge in volume, a distinguishing feature of intracellular infection by these parasites. Cholesterol levels in ATP6V(0)d2-deficient cells are reduced and exogenous cholesterol repletion can restore vacuole size, leading to enhanced parasite killing. This study demonstrates the ATP6V(0)d2-mediated interplay of macrophage cholesterol retention and control of the biogenesis of large pathogen-containing vacuoles. The study provides grounds for the development of new therapeutic strategies for diseases caused by intracellular pathogens sheltered in host cell compartments.
conferenceObject Altered expression of microRNAs in infections with cutaneous and visceral strains of Leishmania(2019) GOTO, H.; SOUZA, M. A.; RAMOS-SANCHEZ, E. M.; MUXEL, S. M.; BRITO, M. E. F.; PEREIRA, V. R. A.; FLOETER-WINTER, L. M.- Letters to the editor: A comment on ""Control of bovine mastitis in the 21st century: Immunize or tolerate?""(2019) SOUZA, Fernando N.; SANCHEZ, Eduardo M. R.; LIBERA, Alice M. M. P. Della; HEINEMANN, Marcos B.
- Molecular, serological, and parasitological detection of Babesia vogeli in dogs in the state of Piaui, Brazil(2019) BRAGA, Juliana Fortes Vilarinho; SOUZA, Francisco de Assis Leite; SILVA, Lucilene dos Santos; FONSECA, Luciano Santos da; PINHO, Flaviane Alves de; FOTORAN, Wesley Luzetti; RAMOS-SANCHEZ, Eduardo Milton; COSTA-JUNIOR, Livio Martins; RIBEIRO, Mucio Flavio Barbosa; SILVA, Silvana Maria Medeiros de SousaStudies on canine babesiosis in northeastern Brazil are scarce, although the weather conditions in this region are favorable for the development of the tick vector. This study determined the prevalence of Babesia vogeli in dogs sampled in Teresina, state of Piaui, northeast Brazil, using direct and indirect diagnostic methods and performed a phylogenetic analysis of 18S rRNA sequences. A total of 315 dogs were screened during routine care regardless of clinical suspicion. Blood was collected by jugular venipuncture to perform indirect immunofluorescence assay (IFA) and polymerase chain reaction (PCR) and for parasite screening in peripheral blood smears. Positivity was 2.2% (7/315) by microscopy, 4.8% (15/315) by PCR, and 48.6% (153/315) by IFA. PCR amplified a 602-bp fragment of the piroplasmid 18S rRNA gene, and sequence alignment and analysis revealed 99% homology with B. vogeli isolates from other regions of Brazil and other countries. In addition, there was high variability among sequences from other northeast states of Brazil. This study is the first to perform the molecular analysis of B. vogeli in Piaui. The results demonstrate that canine babesiosis is endemic in dogs sampled in Teresina and that PCR may be the method of choice to perform parasite screening in this region.