MARCIA DALASTRA LAURENTI
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Patologia, Faculdade de Medicina - Docente
LIM/50 - Laboratório de Patologia das Moléstias Infecciosas, Hospital das Clínicas, Faculdade de Medicina - Líder
LIM/50 - Laboratório de Patologia das Moléstias Infecciosas, Hospital das Clínicas, Faculdade de Medicina - Líder
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- Leishmania enriettii visceralises in the trachea, lungs, and spleen of Cavia porcellus(2022) ALVES-SOBRINHO, Edneia Venancio; PINHEIRO, Lucelia de Jesus; PARANAIBA, Larissa Ferreira; FONTES, Igor Campos; PARREIRAS, Patricia Martins; GONTIJO, Nelder Figueiredo; TAFURI, Wagner Luiz; LAURENTI, Marcia Dalastra; SOARES, Rodrigo PedroBACKGROUND Leishmania (Mundinia) enriettii is a species commonly found in the guinea pig, Cavia porcellus. Although it is a dermotropic species, there is still an uncertainty regarding its ability to visceralise during Leishmania life cycle. OBJECTIVE Here, we investigated the ability of L. enriettii (strain L88) to visceralise in lungs, trachea, spleen, and liver of C. porcellus, its natural vertebrate host. METHODS Animals were infected sub-cutaneously in the nose and followed for 12 weeks using histological (hematoxilin-eosin) and molecular tools (polymerase chain reaction-restriction fragment length polymorphism - PCR-RFLP). To isolate parasite from C. porcellus, animals were experimentally infected for viscera removal and PCR typing targeting hsp70 gene. FINDINGS Histological analysis revealed intense and diffuse inflammation with the presence of amastigotes in the trachea, lung, and spleen up to 12 weeks post-infection (PI). Molecular analysis of paraffin-embedded tissues detected parasite DNA in the trachea and spleen between the 4th and 8th weeks PI. At the 12th PI, no parasite DNA was detected in any of the organs. To confirm that the spleen could serve as a temporary site for L. enriettii, we performed additional in vivo experiments. During 6th week PI, the parasite was isolated from the spleen confirming previous histopathological and PCR observations. MAIN CONCLUSION Leishmania enriettii (strain L88) was able to visceralise in the trachea, lung, and spleen of C. porcellus.
- SUSCEPTIBILITY OF PERITONEAL MACROPHAGE FROM DIFFERENT SPECIES OF NEOTROPICAL PRIMATES TO EX VIVO Leishmania (L.) infantum chagasi-INFECTION(2012) CARNEIRO, Liliane Almeida; LAURENTI, Marcia Dalastra; CAMPOS, Marliane Batista; GOMES, Claudia Maria de Castro; CORBETT, Carlos Eduardo Pereira; SILVEIRA, Fernando TobiasThis study examined the susceptibility of peritoneal macrophage (PM) from the Neotropical primates: Callithrix jacchus, Callithrix penicillata, Saimiri sciureus, Aotus azarae infulatus and Callimico goeldii to ex vivo Leishmania (L.) infantum chagasi-infection, the etiological agent of American visceral leishmaniasis (AVL), as a screening assay for evaluating the potential of these non-human primates as experimental models for studying AVL. The PM-susceptibility to infection was accessed by the PM-infection index (PMI) at 24, 72 h and by the mean of these rates (FPMI), as well as by the TNF-alpha, IL-12 (Capture ELISA) and Nitric oxide (NO) responses (Griess method). At 24h, the PMI of A. azarae infulatus (128) was higher than those of C. penicillata (83), C. goeldii (78), S. sciureus (77) and C. jacchus (55). At 72h, there was a significant PMI decrease in four monkeys: A. azarae infulatus (128/37), C. penicillata (83/38), S. sciureus (77/38) and C. jacchus (55/12), with exception of C. goeldii (78/54). The FPMI of A. azarae infulatus (82.5) and C. goeldii (66) were higher than C. jacchus (33.5), but not higher than those of C. penicillata (60.5) and S. sciureus (57.5). The TNF-alpha response was more regular in those four primates which decreased their PMI at 24/72 h: C. jacchus (145/122 pg/mu L), C. penicillata (154/130 pg/mu L), S. sciureus (164/104 pg/mu L) and A. azarae infulatus (154/104 pg/mu L), with exception of C. goeldii (38/83 pg/mu L). The IL-12 response was mainly prominent in A. infulatus and C. goeldii which presented the highest FPMI and, the NO response was higher in C. goeldii, mainly at 72 h. These findings strongly suggest that these New World primates have developed a resistant innate immune response mechanism capable of controlling the macrophage intracellular growth of L. (L.) i. chagasi-infection, which do not encourage their use as animal model for studying AVL.
- Thymic alterations resulting from experimental visceral leishmaniasis in a Syrian hamster (Mesocricetus auratus)(2023) MARCO, Karen Santos; BOREGIO, Jaqueline da Silva; JUSSIANI, Giulia Goncalves; FERREIRA, Laura Flavia Esperanca de Souza; FLORES, Gabriela Venicia Araujo; PACHECO, Carmen Maria Sandoval; LAURENTI, Marcia Dalastra; MACHADO, Gisele FabrinoBackground: The thymus is a lymphoid organ responsible for the development and maturation of T cells, which are part of the Th1, Th2, Th17, and Treg immune responses triggered by visceral leishmaniasis. The maturation and immunological development of T lymphocytes require a bidirectional interaction between the thymic microenvironment of epithelial cells, dendritic cells, and macrophages and the extracellular matrix with differentiating lymphocytes.Objectives: We evaluated the morphological characteristics and tissue distribution of hematopoietic and stromal cells in the thymuses of hamsters experimentally infected with Leishmania infantum, aiming to gain an insight into the pathophysiology of the disease.Methods: Fifteen hamsters were subjected to intraperitoneal experimental infection with 107 L. infantum pro-mastigotes (MHOM/BR/1972/BH46). The animals were divided into three groups, each comprising five infected hamsters, and were then euthanized 15, 60, and 120 days postinfection. The control groups consisted of three groups of five healthy hamsters euthanized simultaneously with the infected ones. Thymic morphology was evaluated through histopathology and the cell composition through immunohistochemistry. We used antibodies to mark mesenchymal cells (anti-vimentin), epithelial cells (anti-cytokeratin), macrophages (anti-MAC387), B lymphocytes (anti-CD79a), and T lymphocytes (anti-CD3). Immunohistochemistry was also used to mark the parasite in the thymus.Results: Infected and control hamsters showed no difference in thymic morphology and degree of atrophy. After 15 days of infection, CD3 + T lymphocytes in the thymus showed an increase that stabilized over time. At 120 days of infection, we detected a significant decrease in CD79a+ B lymphocytes. The parasite was present in the medullary and corticomedullary regions of 9 out of 15 hamsters. These findings confirm that the presence of a parasite can cause changes in a thymus cell population. However, further studies are needed to evaluate these changes' effects on the immune response of infected animals.
- Evaluation of Leishmania (Leishmania) infantum excreted-secreted antigens for detection of canine leishmaniasis(2016) PINEDO-CANCINO, Viviana; LAURENTI, Marcia Dalastra; KESPER, Norival; UMEZAWA, Eufrosina SetsuThe efficacy of tests with L (L.) infantum excreted-secreted antigens (ESA) to detect canine leishmaniasis (CanL) was evaluated using immunoblotting (ESA-blot), ELISA (ESA-ELISA) and ELISA with alkaline extract from promastigotes (PAE). Of one hundred fifty-five domestic dogs tested, 100 were suspected of CanL, 23 had other diseases and 32 were healthy. Sera from the dogs suspected of CanL were tested by immunohistochemistry (IHC), and 54% were confirmed to be infected by L (L.) infantum (38 symptomatic and 16 asymptomatic). Of these, 100% were positive by ESA-blot, ESA-ELISA and PAE-ELISA. In the ESA blot their sera recognized polypeptides in the 26.5-31.5 kDa region. Of the 46% of dogs with negative IHC, 44-53% tested positive in all three tests irrespective of clinical status. The twenty-three dogs with other diseases were negative by ESA-blot, but sera from 9% and 26% of them reacted with ESA-ELISA and PAE-ELISA, respectively. The 32 healthy dogs were negative in all the tests. ESA-blot showed good correlation with IHC in the detection of CanL and a high specificity index.
- Infectious Diseases in Free-Ranging Blonde Capuchins, Sapajus flavius, in Brazil(2017) BUENO, Marina Galvao; CATO-DIAS, Jose Luiz; LAROQUE, Plautino de Oliveira; VASCONCELLOS, Silvio Arruda; FERREIRA NETO, Jose Soares; GENNARI, Solange Maria; FERREIRA, Fernando; LAURENTI, Marcia Dalastra; UMEZAWA, Eufrosina Setsu; KESPER, Norival; KIRCHGATTER, Karin; GUIMARES, Lilian Oliveira; PAVANATO, Heloise Juliao; VALENCA-MONTENEGRO, Monica MafraThe main threats to primates worldwide are the degradation, fragmentation, and loss of their habitats; hunting (especially for bushmeat); and illegal trade. For many species, the most important threat is forest fragmentation, resulting in small populations that are restricted to isolated forest patches. In this situation, primates are particularly vulnerable to disease. The Endangered blonde capuchin (Sapajus flavius) is now restricted to a few forest patches in Northeast Brazil. We investigated the occurrence of parasites and bacterial diseases in one of three free-ranging groups of S. flavius in a small forest patch in Paraiba state, Northeast Brazil. We tested for antibodies against Leishmania spp., Trypanosoma cruzi, Toxoplasma gondii, Leptospira spp. (24 strains), and Brucella spp.. We used molecular analysis to detect Plasmodium spp., and evaluated blood smears for the presence of hemoparasites. All individuals tested negative for Leptospira spp. and B. abortus, but 8 of 48 (16%) presented antibodies for both Leishmania spp. and T. cruzi. We identified antibodies to T. gondii in 12% of the individuals tested. Plasmodium brasilianum infection was present in 4% of the individuals tested, and blood smears showed microfilariae parasites in 46% of the individuals tested. The occurrence of these infectious diseases in S. flavius may pose a significant threat in terms of reduced recruitment and poor survival rates, and an understanding of the influence of pathogens is crucial for the management of small populations of primates.
- In situ study of cellular immune response in human cutaneous lesions caused by Leishmania (Viannia) panamensis in Panama(2021) GONZALEZ, Kadir; CALZADA, Jose Eduardo; TOMOKANE, Thaise Yumie; PACHECO, Carmen Maria Sandoval; FLORES, Gabriela Venicia Araujo; GOMES, Claudia Maria Castro; CORBETT, Carlos Eduardo Pereira; SALDANA, Azael; LAURENTI, Marcia DalastraAims: Leishmaniasis is considered a disease with multiple clinical/immunopathological characteristics, depending on the immunity of the host and the species of the parasite. In Panama, the most prevalent species that causes localized cutaneous leishmaniasis (LCL) is Leishmania (Viannia) panamensis, and its immune response is poorly studied. Therefore, we evaluated by immunohistochemistry, the in situ immune response during this infection. Methods and Results: Biopsies from Panamanian patients with LCL were collected and processed by histological techniques. Infection by L. (V.) panamensis was demonstrated by isolation in culture and molecular characterization by Hsp70-RFLP. The in situ immune response was assessed by immunohistochemistry. The immune response was characterized by predominance of T cells, mainly CD8 cells that showed positive correlation with IFN-gamma and Granzyme B. CD4 cells presented positive correlation with both IFN-gamma and IL-13, pointed by mixed cellular immune response. Regulatory response was characterized by FoxP3 cells, which showed positive correlation to IL-10 but not with TGF-beta. Conclusions: L. (V.) panamensis infection triggers a mixed cellular immune response, characterized by the presence of pro-inflammatory, anti-inflammatory and regulatory elements in the skin lesion of Panamanian patients. These data contribute to a better understanding of the immunopathogenesis of Leishmania Viannia infection in Panama.
- Evaluation of Rhamnetin as an Inhibitor of the Pharmacological Effect of Secretory Phospholipase A2(2017) BELCHOR, Mariana Novo; GAETA, Henrique Hessel; RODRIGUES, Caroline Fabri Bittencourt; COSTA, Caroline Ramos da Cruz; TOYAMA, Daniela de Oliveira; PASSERO, Luiz Felipe Domingues; LAURENTI, Marcia Dalastra; TOYAMA, Marcos HikariRhamnetin (Rhm), 3-O-methylquercetin (3MQ), and Rhamnazin (Rhz) are methylated derivatives of quercetin commonly found in fruits and vegetables that possess antioxidant and anti-inflammatory properties. Phospholipase A2 (PLA2) displays several important roles during acute inflammation; therefore, this study aimed at investigating new compounds able to inhibit this enzyme, besides evaluating creatine kinase (CK) levels and citotoxicity. Methylated quercetins were compared with quercetin (Q) and were incubated with secretory PLA2 (sPLA2) from Bothrops jararacussu to determine their inhibitory activity. Cytotoxic studies were performed by using the J774 cell lineage incubated with quercertins. In vivo tests were performed with Swiss female mice to evaluate decreasing paw edema potential and compounds' CK levels. Structural modifications on sPLA2 were made with circular dichroism (CD). Despite Q and Rhz showing greater enzymatic inhibitory potential, high CK was observed. Rhm exhibited sPLA2 inhibitory potential, no toxicity and, remarkably, it decreased CK levels. The presence of 3OH on the C-ring of Rhm may contribute to both its anti-inflammatory and enzymatic inhibition of sPLA2, and the methylation of ring A may provide the increase in cell viability and low CK level induced by sPLA2. These results showed that Rhm can be a candidate as a natural compound for the development of new anti-inflammatory drugs.
- Value of the oral swab for the molecular diagnosis of dogs in different stages of infection with Leishmania infantum(2016) ASCHAR, Mariana; OLIVEIRA, Eveline Tozzi Braga de; LAURENTI, Marcia Dalastra; MARCONDES, Mary; TOLEZANO, Jose Eduardo; HIRAMOTO, Roberto Mitsuyoshi; CORBETT, Carlos Eduardo P.; MATTA, Vania Lucia Ribeiro daThis study was based on the need to employ a sensitive and specific method with samples that could be easily collected for diagnosing dogs infected with Leishmania infantum. To this end, we used real time-PCR (qPCR) to assess the value of the oral swab (OS) in detecting infected sick dogs (SD; n = 62), including, for the first time, the analysis of apparently healthy infected dogs (AD; n =30), both from endemic areas for visceral leishmaniasis (VL). For comparison, we also evaluated the performance of the conjunctival swab (CS), blood (BL), lymph node (LN) and serology. We detected the presence of Leishmania DNA in the oral cavity in 62 out of the 92 dogs studied. The OS positivity (67.4%) was equivalent to the CS (68.5%) (p > 0.05), higher than BL (52.2%) (p <= 0.05), and lower than LN (84.8%) (p <= 0.05). OS and CS performed well in SD dogs (82.3% and 83.9%, respectively) but not in AD dogs (36.7% for both samples). BL showed the lowest positivity (52.2%) and provided equivalent results between AD (60.0%) and SD (48.4%) dogs (p > 0.05). LN yielded the highest positivity (84.8%), and it was also higher in the SD population (93.5%) compared to the AD population (66.7%) (p <= 0.05). Parasite load was high in LN, moderate in OS and CS, and low in BL, showing the relationship between the levels of parasitism and the positivity rates found in these samples. Serology was positive in 82.2% of the SD group and in 70% of the AD dogs (p > 0.05). Among the 20 seronegative dogs, seven (35%) were positive in either OS or CS, and 12 (60%) were positive when both noninvasive samples were jointly considered. The OS/CS combination resulted in a significant increase of positivity (p <= 0.05) for the AD dogs (from 36.7% to 63.4%), as well as OS/serology (80%) and OS/CS/serology (83.4%). For the SD population, positivity reached up to 95.2% with the same combinations, showing that combination of samples and/or tests is required for the identification of dogs infected with L. infantum and that the OS and CS combination based on qPCR notably improves the detection of both AD and SD dogs. In conclusion, OS proved to be a suitable sample for the molecular diagnosis of infected dogs with clinical signs of VL, but not for dogs with inapparent infection. For these, we recommend the combination of OS results with CS and/or serology in order to reach relevant positivity for L infantum. Finally, another advantage of using OS or both noninvasive samples is the increased likelihood of diagnosing seronegative dogs.
- Leishmania infantum INFECTION IN DOGS FROM THE SOUTHERN REGION OF MINAS GERAIS STATE, BRAZIL(2016) NUNES, Juliana Barbosa; LAURENTI, Marcia Dalastra; KANAMURA, Herminia Yohko; PEREIRA, Alessandro Antonio Costa; COLOMBO, Fabio Antonio; MARQUES, Marcos JoseVisceral leishmaniasis is a systemic and chronic disease and dogs are the main reservoir of the etiologic agent, Leishmania infantum (syn L. chagasi). A serological and molecular investigation of canine visceral leishmaniasis (CVL) was performed in the municipality of Alfenas, located in the southern region of Minas Gerais, where the disease is not endemic. Samples from 87 dogs were submitted to serological tests including the Dual Path Platform (DPP (R)) CVL Bio-Manguinhos rapid test, an in-house enzyme-linked immunosorbent assay (ELISA) and an immunofluorescence antibody test (IFAT), as well as molecular techniques such as a conventional polymerase chain reaction (PCR) with the RV1/RV2 primers and a quantitative PCR (qPCR) with the LinJ31, Ldon and DNApol primers. Of the 87 serum samples, eight (9.2%) were positive for Leishmania using the DPP rapid test, but only four (4.6%) were confirmed by ELISA and two (2.3%) by IFAT. In these two serologically confirmed cases, spleen and liver samples were positive by all the employed molecular and parasitological procedures performed on spleen samples. When whole blood samples were used in the molecular assays, two samples (2.3%) were positive only by qPCR. DNA extracted and amplified from the spleens of seropositive dogs was sequenced, showing 100% of similarity with the Leishmania infantum (syn L. chagasi) sequence. Thus, the first cases of CVL have been confirmed in the Alfenas region, suggesting the importance of canine surveys in non-endemic municipalities for CVL to monitor disease progression and to prevent outbreaks.
- Human cutaneous leishmaniasis: interferon-dependent expression of double-stranded RNA-dependent protein kinase (PKR) via TLR2(2011) VIVARINI, Aislan de Carvalho; PEREIRA, Renata de Meirelles Santos; TEIXEIRA, Karina Luiza Dias; CALEGARI-SILVA, Teresa Cristina; BELLIO, Maria; LAURENTI, Marcia Dalastra; CORBETT, Carlos Eduardo Pereira; GOMES, Claudia Maria de Castro; SOARES, Rodrigo Pedro; SILVA, Aristobolo Mendes; SILVEIRA, Fernando Tobias; LOPES, Ulisses GazosWe investigated the type I interferon (IFN-1)/PKR axis in the outcome of the Leishmania (Leishmania) amazonensis infection, along with the underlying mechanisms that trigger and sustain this signaling pathway. Reporter assays of cell extracts from RAW-264.7 macrophages infected with L. (L.) amazonensis or HEK-293T cells cotransfected with TLR2 and PKR promoter constructions were employed. Primary macrophages of TLR2-knockout (KO) or IFNR-KO mice were infected, and the levels of PKR, IFN-1, and superoxide dismutase 1 (SOD1) transcript levels were investigated and compared. Immunohistochemical analysis of human biopsy lesions was evaluated for IFN-1 and PKR-positive cells. Leishmania infection increased the expression of PKR and IFN-beta on induction of PKR-promoter activity. The observed effects required the engagement of TLR2. TLR2-KO macrophages expressed low IFN-beta and PKR levels postinfection with a reduced parasite load. We also revealed the requirement of PKR signaling for Leishmania-induced IFN-1 expression, responsible for sustaining PKR expression and enhancing infection. Moreover, during infection, SOD1 transcripts increased and were also enhanced when IFN-1 was added to the cultures. Remarkably, SOD1 expression was abrogated in infected, dominant-negative PKR-expressing cells. Finally, lesions of patients with anergic diffuse cutaneous leishmaniasis exhibited higher levels of PKR/IFN1-expressing cells compared to those with single cutaneous leishmaniasis. In summary, we demonstrated the mechanisms and relevance of the IFN-1/PKR axis in the Leishmania infection.-De Carvalho Vivarini, A., Pereira, R. M. S., Dias Teixeira, K. L., Calegari-Silva, T. C., Bellio, M., Laurenti, M. D., Corbett, C. E. P., de Castro Gomes, C. M., Soares, R. P., Mendes Silva, A., Silveira, F. T., Lopes, U. G. Human cutaneous leish-maniasis: interferon-dependent expression of double-stranded RNA-kinase (PKR) via TLR2. FASEB J. 25, 4162-4173 (2011). www.fasebj.org