HIRO GOTO
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Medicina Preventiva, Faculdade de Medicina - Docente
LIM/38 - Laboratório de Epidemiologia e Imunobiologia, Hospital das Clínicas, Faculdade de Medicina - Líder
LIM/38 - Laboratório de Epidemiologia e Imunobiologia, Hospital das Clínicas, Faculdade de Medicina - Líder
5 resultados
Resultados de Busca
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- CD4(+) T Cells Alter the Stromal Microenvironment and Repress Medullary Erythropoiesis in Murine Visceral Leishmaniasis(2018) PREHAM, Olivier; PINHO, Flaviane A.; PINTO, Ana Isabel; RANI, Gulab Fatima; BROWN, Najmeeyah; HITCHCOCK, Ian S.; GOTO, Hiro; KAYE, Paul M.Human visceral leishmaniasis, a parasitic disease of major public health importance in developing countries, is characterized by variable degrees of severity of anemia, but the mechanisms underlying this change in peripheral blood have not been thoroughly explored. Here, we used an experimental model of visceral leishmaniasis in C57BL/6 mice to explore the basis of anemia following infection with Leishmania donovani. 28 days post-infection, mice showed bone marrow dyserythropoiesis by myelogram, with a reduction of TER119(+) CD71(-/+) erythroblasts. Reduction of medullary erythropoiesis coincided with loss of CD169(high) bone marrow stromal macrophages and a reduction of CXCL12-expressing stromal cells. Although the spleen is a site of extramedullary erythropoiesis and erythrophagocytosis, splenectomy did not impact the extent of anemia or affect the repression of medullary hematopoiesis that was observed in infected mice. In contrast, these changes in bone marrow erythropoiesis were not evident in B6.Rag2(-/-) mice, but could be fully reconstituted by adoptive transfer of IFN gamma-producing but not IFN gamma-deficient CD4(+) T cells, mimicking the expansion of IFN gamma-producing CD4(+) T cells that occurs during infection in wild type mice. Collectively, these data indicate that anemia during experimental murine visceral leishmaniasis can be driven by defects associated with the bone marrow erythropoietic niche, and that this represents a further example of CD4(+) T cell-mediated immunopathology affecting hematopoietic competence.
- Insulin-Like Growth Factor-I as an Effector Element of the Cytokine IL-4 in the Development of a Leishmania major Infection(2018) REIS, Luiza C.; RAMOS-SANCHEZ, Eduardo Milton; PETITTO-ASSIS, Fabricio; NERLAND, Audun H.; HERNANDEZ-VALLADARES, Maria; SELHEIM, Frode; FLOETER-WINTER, Lucile Maria; GOTO, HiroCertain cytokines modulate the expression of insulin-like growth factor-(IGF-) I. Since IL-4 and IGF-I promote growth of the protozoan Leishmania major, we here addressed their interaction in downregulating the expression of Igf-I mRNA using small interfering RNA (siRNA) in Leishmania major-infected macrophages. Parasitism was decreased in the siRNA-treated cells compared with the nontreated cells, reversed by the addition of recombinant IGF-I (rIGF-I). In IL-4-stimulated macrophages, parasitism and the Igf-I mRNA amount were increased, and the effects were nullified upon siRNA transfection. IGF-I downregulation inhibited both parasite and macrophage arginase activation even in IL-4-stimulated cells. Searching for intracellular signaling components shared by IL-4 and IGF-I, upon siRNA transfection, phosphorylated p44, p38, and Akt proteins were decreased, affecting the phosphatidylinositol-3-kinase (PI3K)/Akt pathway. In L. major-infected C57BL6-resistant mice, the preincubation of the parasite with rIGF-I changed the infection profile to be similar to that of susceptible mice. We conclude that IGF-I constitutes an effector element of IL-4 involving the PI3K/Akt pathway during L. major infection.
- Leishmania infection in blood donors: A new challenge in leishmaniasis transmission?(2018) FRANCA, Adriana de Oliveira; POMPILIO, Mauricio Antonio; PONTES, Elenir Rose Jardim Cury; OLIVEIRA, Marcia Pereira de; PEREIRA, Luiza Oliveira Ramos; LIMA, Rosimar Baptista; GOTO, Hiro; SANCHEZ, Maria Carmen Arroyo; FUJIMORI, Mahyumi; LIMA-JUNIORS, Manoel Sebastiao da Costa; MATOS, Maria de Fatima Cepa; DORVAL, Maria Elizabeth Moraes CavalheirosTransfusion-transmitted leishmaniasis has been a concern in regions endemic for the disease. Whether immediate or delayed, the risks posed by this mode of transmission call for careful assessment. The purpose of this study was to detect Leishmania infection in blood donors living in an endemic area and to investigate progression to the disease in these individuals. Immunofluorescent antibody test, enzyme-linked immunosorbent assay, leishmaniasis rapid test, and the polymerase chain reaction were applied to 430 donors in an initial evaluation. Of those donors with at least one positive test, 50 were reevaluated four years later by the same methods, as were 25 controls who had been negative on the same tests. In the first evaluation, Leishmania infection was detected in 41.4% (95% CI: 36.7-46.1) of donors (n = 430). None of the 75 reevaluated individuals had developed the disease, but retesting revealed positivity in at least one test in 36.0% (95% CI: 25.1-46.9) of donors. Of the 50 initially testing positive, 50% remained so on retesting. Of the 25 initially negative controls, two tested positive in the subsequent evaluation. The severity of the parasitosis and the risk of transfusion transmission warrant investigation of the potential inclusion of methods for Leishmania detection into blood banks for effective screening of infected donors.
conferenceObject EFFECTS OF INSULIN-LIKE GROWTH FACTOR-I AND IL-4 ON LEISHMANIA (L.) INFANTUM-INFECTED HUMAN MACROPHAGES(2018) GOTO, Hiro; SEVILLANO, Orlando; REIS, Luiza; RAMOS-SANCHEZ, EduardoconferenceObject INSULIN-LIKE GROWTH FACTOR-I AS EFFECTOR ELEMENT OF IL-4 EFFECT LEADING TO SUSCEPTIBILITY TO LEISHMANIA MAJOR INFECTION(2018) GOTO, Hiro; REIS, Luiza; RAMOS-SANCHEZ, Eduardo; PETITTO-ASSIS, Fabricio; NERLAND, Audun; HERNANDEZ-VALLADARES, Maria; SELHEIM, Frode; FLOETER-WINTER, Lucile