EDUARDO MILTON RAMOS SANCHEZ
Projetos de Pesquisa
Unidades Organizacionais
LIM/38 - Laboratório de Epidemiologia e Imunobiologia, Hospital das Clínicas, Faculdade de Medicina
3 resultados
Resultados de Busca
Agora exibindo 1 - 3 de 3
- Dual Host-Intracellular Parasite Transcriptome of Enucleated Cells Hosting Leishmania amazonensis: Control of Half-Life o Host Cell Transcripts by the Parasite(2020) ORIKAZA, Cristina M.; PESSOA, Carina C.; V, Fernanda Paladino; V, Pilar T. Florentino; BARBIERI, Clara L.; GOTO, Hiro; RAMOS-SANCHEZ, Eduardo Milton; SILVEIRA, Jose Franco; RABINOVITCH, Michel; MORTARA, Renato A.; REAL, FernandoEnucleated cells or cytoplasts (cells whose nucleus is removed in vitro) represent an unexplored biological model for intracellular infection studies due to the abrupt interruption of nuclear processing and new RNA synthesis by the host cell in response to pathogen entry. Using enucleated fibroblasts hosting the protozoan parasite Leishmania amazonensis, we demonstrate that parasite multiplication and biogenesis of large parasitophorous vacuoles in which parasites multiply are independent of the host cell nucleus. Dual RNA sequencing of both host cytoplast and intracellular parasite transcripts identified host transcripts that are more preserved or degraded upon interaction with parasites and also parasite genes that are differentially expressed when hosted by nucleated or enucleated cells. Cytoplasts are suitable host cells, which persist in culture for more than 72 h and display functional enrichment of transcripts related to mitochondrial functions and mRNA translation. Crosstalk between nucleated host de novo gene expression in response to intracellular parasitism and the parasite gene expression to counteract or benefit from these host responses induces a parasite transcriptional profile favoring parasite multiplication and aerobic respiration, and a host-parasite transcriptional landscape enriched in host cell metabolic functions related to NAD, fatty acid, and glycolytic metabolism. Conversely, interruption of host nucleus-parasite cross talk by infection of enucleated cells generates a host-parasite transcriptional landscape in which cytoplast transcripts are enriched in phagolysosome-related pathway, prosurvival, and SerpinB-mediated immunomodulation. In addition, predictive in since analyses indicated that parasite transcript products secreted within cytoplasts interact with host transcript products conserving the host V-ATPase proton translocation function and glutamine/proline metabolism. The collective evidence indicates parasite-mediated control of host cell transcripts half-life that is beneficial to parasite intracellular multiplication and escape from host immune responses. These findings will contribute to improved drug targeting and serve as database for L. arnazonensis-host cell interactions.
- 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.
- Memory CD4+ and CD8+ T lymphocyte proliferation in vaccinated dairy cows with different histories of Staphylococcus aureus mastitis(2022) SOARES, Thais C. S.; SANTOS, Kamila R.; LIMA, Daniel M.; MAIA, Raysa Brenda M.; RAMOS-SANCHEZ, Eduardo M.; REIS, Luiza C.; GIDLUND, Magnus; CUNHA, Adriano F. da; ORDINOLA-RAMIREZ, Carla M.; CERQUEIRA, Monica M. O. P.; HEINEMANN, Marcos B.; LIBERA, Alice M. M. P. Della; GOTO, Hiro; SOUZA, Fernando N.Staphylococcus aureus mastitis constitutes a serious threat to dairy cows. The reasons why available vaccines are not fully effective remain poorly understood; thus, in the present study, we investigated CD4(+) and CD8(+) T lymphocyte proliferation in dairy cows vaccinated with a polyvalent mastitis vaccine that had distinct precedent Staphylococcus aureus mastitis. We studied 17 S. aureus-infected dairy cows (11 vaccinated and six unvaccinated) and eight vaccinated healthy dairy cows with no previous S. aureus mastitis infections. Flow cytometry was used to assess lymphocyte proliferation using an anti-Ki67 antibody, and monoclonal antibodies were used to identify T cell subsets. S. aureus-infected cows exhibited reduced overall lymphocyte proliferation, including CD4(+) T lymphocyte proliferation, and memory lymphocyte proliferation in response to S. aureus isolate stimulus. Immunization did not influence the expansion of blood lymphocyte populations. Furthermore, CD8(+) T cells, memory CD8(+) T lymphocytes, and effector memory CD8(+) T lymphocytes displayed reduced proliferation 21 days after the third vaccine dose compared with before vaccination at time zero. The present data demonstrates an overall negative regulation of the T-cell response suggesting its detrimental impact leading to the persistence of S. aureus intramammary infections. Furthermore, the lack of vaccination effect on T-cell mediated immunity (e.g., proliferation) may be related to poor vaccine efficacy.