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
9 resultados
Resultados de Busca
Agora exibindo 1 - 9 de 9
- Validation of ELISA with recombinant antigens in serological diagnosis of canine Leishmania infantum infection(2021) FUJIMORI, Mahyumi; ALMEIDA, Arleana do Bom Parto Ferreira de; BARROUIN-MELO, Stella Maria; CORTEZ, Luiz Ricardo Paes de Barros; DUTHIE, Malcolm Scott; HIRAMOTO, Roberto Mitsuyoshi; PINHO, Flaviane Alves de; REED, Steven Gregory; SOUSA, Valeria Regia Franco; SOUZA, Nazare Fonseca; SOARES, Rodrigo Martins; TOLEZANO, Jose Eduardo; SANCHEZ, Maria Carmen Arroyo; GOTO, HiroBACKGROUND Dogs are the main peridomiciliary reservoir of Leishmania infantum thus the correct diagnosis of infection is essential for the control of the transmission and treatment as well. However, the diagnosis is based on serological assays that are not fully effective. OBJECTIVE We aimed to establish an effective serological assay for the diagnosis of L. infantum infected dogs using Leishmania-derived recombinant antigens. METHODS Leishmania derived rK39-, rK28-, rKR95-based enzyme-linked immunosorbent assay (ELISA) was standardized using symptomatic and asymptomatic L. infantum-infected dogs. Then 2,530 samples from inquiry in endemic areas for VL were evaluated and the results compared with recommended assays by the Brazilian Ministry of Health (MH algorithm). Further samples from a cohort of 30 dogs were searched. FINDINGS For rK39-, rK28- and rKR95-ELISA the sensitivity was around 97% and specificity 100%. The positivity of these three ELISA in the inquiry samples was 27-28%, around 10% higher than the assays currently in use. When cohort samples were searched, we observed likely false-negative results (> 65%) with supposedly negative samples that turned positive six months later with the assays in use (MH algorithm). MAIN CONCLUSIONS For the diagnosis of L. infantum-infected dogs, rK39-based ELISA showed better diagnostic performance than other assays in use in Brazil and worldwide.
- 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.
- The interactions and essential effects of intrinsic insulin-like growth factor-I on Leishmania (Leishmania) major growth within macrophages(2013) REIS, L. C.; RAMOS-SANCHEZ, E. M.; GOTO, H.Previously, we showed in Leishmania infections that extrinsic insulin-like growth factor (IGF)-I favored Leishmania proliferation and leishmaniasis development. In this study, the interaction of intrinsically expressed IGF-I and Leishmania (Leishmania) major in macrophages was addressed, and a key finding was the observation, using confocal microscopy, of the co-localization of IGF-I and parasites within macrophages. Following stimulation with interferon-gamma (IFN-gamma), which is known to inhibit IGF-I production in macrophages, we observed a reduction in the expression of both IGF-I mRNA and protein. This reduced expression was accompanied by a reduction in the cellular parasite load that was completely recovered with the addition of extrinsic IGF-I, which suggests an essential role for IGF-I in Leishmania growth.
- Insulin-like growth factor-I serum levels and their biological effects on Leishmania isolates from different clinical forms of American tegumentary leishmaniasis(2016) SOUZA, Luana Dias de; VENDRAME, Celia Maria Vieira; JESUS, Amelia Ribeiro de; CARVALHO, Marcia Dias Teixeira; MAGALHAES, Andrea Santos; SCHRIEFER, Albert; GUIMARAES, Luiz Henrique; CARVALHO, Edgar Marcelino de; GOTO, HiroBackground: American tegumentary leishmaniasis (ATL) in Brazil is mostly caused by Leishmania (Viannia) braziliensis, with known forms of the disease being cutaneous (CL), mucosal (ML) and disseminated (DL) leishmaniasis. The development of the lesion in ATL is related both to the persistence of the Leishmania in the skin and to the parasite-triggered immune and inflammatory responses that ensue lesions. In this context one factor with expected role in the pathogenesis is insulin-like growth factor (IGF)-I with known effects on parasite growth and healing and inflammatory processes. In the present study, we addressed the effect of IGF-I on intracellular amastigote isolates from CL, ML and DL patients within human macrophage and we evaluated the IGF-I and IGF-binding protein-3 (IGFBP3) serum levels in patients presenting different clinical forms and controls from the endemic area. Methods: We evaluated biological variability in the responses of intracellular amastigotes of Leishmania isolates derived from CL, ML, and DL patients from an area for ATL in response to IGF-I. Intracellular amastigote growth was evaluated using the human macrophage cell line THP-1. Arginase activity in infected cells was evaluated quantifying the generated urea concentration. Serum samples from patients and controls were assayed using chemiluminescent immunometric assay to determine IGF-I and IGFBP3 levels. Results: We observed an increase in intracellular parasitism upon IGF-I stimulus in 62.5 % of isolates from CL, in 85.7 % from ML and only 42.8 % from DL cases. In DL, the basal arginase activity was lower than that of CL. We then evaluated the IGF-I and IGFBP3 serum levels in patients, and we observed significantly lower levels in ML and DL than in CL and control samples. Conclusions: The data suggest that IGF-I is modulated distinctly in different clinical forms of tegumentary leishmaniasis. IGF-I seemingly exerts effect on parasite growth likely contributing to its persistence in the skin in earlier phase. In addition the decreased IGF-I serum levels may affect the modulation of inflammation and lesion healing in chronic phase. In view of potential role of IGF-I in the pathogenesis of ATL we can speculate on therapeutic procedures taking into account the local IGF-I level.
- Spatial distribution of canine Leishmania infantum infection in a municipality with endemic human leishmaniasis in Eastern Bahia, Brazil(2021) VARJAO, Bruno Milen; PINHO, Flaviane Alves de; SOLCA, Manuela da Silva; SILVESTRE, Ricardo; FUJIMORI, Mahyumi; GOTO, Hiro; VARJAO, Natasha Milen; DIAS, Roberta Costa; BARROUIN-MELO, Stella MariaEfforts to control a zoonotic disease such as visceral leishmaniasis (VL) caused by Leishmania infantum can be successful if they rely on comprehensive data on animal infection. In Bahia state, Brazil, human VL is endemic, yet some areas have no epidemiological data on canine L. infantum infection and canine leishmaniasis (CanL) to date. We aimed to perform an epidemiological study describing the spatial distribution and characterizing canine L. infantum infection in two districts of the municipality of Muritiba, where human cases have occurred. Brazilian official serodiagnostic protocol (ELISA and immunochromatographic tests), PCR and clinical examination were performed in 351 owned dogs. A seroprevalence of 15.7% (55/351) was found, and L. infantum identified in 88.8% (32/36) of PCR tested samples. Spatial distribution of positive dogs indicated infection in both urban and rural districts. There was no association between seropositivity and sex or breed, but dogs older than 2 years were 3.8 times more likely to be seropositive (95% CI 1.57 - 9.18) than younger dogs. Among seropositive dogs, 80% (44/55) had clinical manifestations of CanL: 75% (33/44) presented dermatopathy, 50% (22/44) emaciation, and 29.5% (13/44) ophthalmopathy. This is the first report on canine seroprevalence and natural L. infantum infection in Muritiba, Bahia.
- In vivo assessment of antiretroviral therapy-associated side effects(2014) RAMOS-SANCHEZ, Eduardo Milton; GOTO, Hiro; RIVERO, Dolores Helena Rodriguez Ferreira; MAUAD, Thais; SOUZA, Fernando Nogueira de; MONTEIRO, Andrea Moreira; GIDLUND, MagnusAntiretroviral therapy has been associated with side effects, either from the drug itself or in conjunction with the effects of human immunodeficiency virus infection. Here, we evaluated the side effects of the protease inhibitor (PI) indinavir in hamsters consuming a normal or high-fat diet. Indinavir treatment increased the hamster death rate and resulted in an increase in triglyceride, cholesterol and glucose serum levels and a reduction in anti-oxLDL auto-antibodies. The treatment led to histopathological alterations of the kidney and the heart. These results suggest that hamsters are an interesting model for the study of the side effects of antiretroviral drugs, such as PIs.
- Unusual manifestation of genital cutaneous leishmaniasis in an immunocompetent patient from Sao Paulo, Brazil: A case report(2021) REIS, Luiza Campos; LINDOSO, Jose Angelo Lauletta; CELESTE, Beatriz Julieta; BRAZ, Lucia Maria Almeida; RAMOS-SANCHEZ, Eduardo Milton; YAMASHIRO-KANASHIRO, Edite Hatsumi; GOTO, Hiro; OYAFUSO, Luiza Keiko MatsukaA 31-year-old male patient developed an ulcer on the glans penis that evolved for three months without healing. We diagnosed it as leishmaniasis using polymerase chain reaction. No immunosuppression or associated diseases were observed. The patient was treated with meglumine antimoniate that cured the lesion in a month post-treatment. Here, we report this case of cutaneous leishmaniasis lesion at the unusual location of glans penis in an immunocompetent individual. The lesion likely developed due to the bite of a vector, highlighting the need for considering cutaneous leishmaniasis among differential diagnosis of sexually transmitted diseases in areas endemic for leishmaniasis.
- Visceral Leishmaniasis and HIV Coinfection in Latin America(2014) LINDOSO, Jose Angelo; COTA, Glaucia Fernandes; CRUZ, Alda Maria da; GOTO, Hiro; MAIA-ELKHOURY, Ana Nilce Silveira; ROMERO, Gustavo Adolfo Sierra; SOUSA-GOMES, Marcia Leite de; SANTOS-OLIVEIRA, Joanna Reis; RABELLO, AnaVisceral leishmaniasis (VL) is an endemic zoonotic disease in Latin America caused by Leishmania (Leishmania) infantum, which is transmitted by sand flies from the genus Lutzomyia. VL occurs in 12 countries of Latin America, with 96% of cases reported in Brazil. Recently, an increase in VL, primarily affecting children and young adults, has been observed in urban areas of Latin America. The area in which this spread of VL is occurring overlaps regions with individuals living with HIV, the number of whom is estimated to be 1.4 million people by the World Health Organization. This overlap is suggested to be a leading cause of the increased number of reported VL-HIV coinfections. The clinical progression of HIV and L. infantum infections are both highly dependent on the specific immune response of an individual. Furthermore, the impact on the immune system caused by either pathogen and by VL-HIV coinfection can contribute to an accelerated progression of the diseases. Clinical presentation of VL in HIV positive patients is similar to patients without HIV, with symptoms characterized by fever, splenomegaly, and hepatomegaly, but diarrhea appears to be more common in coinfected patients. In addition, VL relapses are higher in coinfected patients, affecting 10% to 56.5% of cases and with a lethality ranging from 8.7% to 23.5% in Latin America, depending on the study. With regards to the diagnosis of VL, parasitological tests of bone marrow aspirates have proven to be the most sensitive test in HIV-infected patients. Serologic tests have demonstrated a variable sensitivity according to the method and antigens used, with the standard tests used for diagnosing VL in Latin America displaying lower sensitivity. For this review, few articles were identified that related to VL-HIV coinfections and originated from Latin America, highlighting the need for improving research within the regions most greatly affected. We strongly support the formation of a Latin American network for coinfections of Leishmania and HIV to improve the consistency of research on the current situation of VL-HIV coinfections. Such a network would improve the collection of vital data and samples for better understanding of the clinical manifestations and immunopathogenic aspects of VL in immunosuppressed patients. Ultimately, a concerted effort would improve trials for new diagnostic methodologies and therapeutics, which could accelerate the implementation of more specific and effective diagnosis as well as public policies for treatments to reduce the impact of VL-HIV coinfections on the Latin American population.