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
18 resultados
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- 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.
- 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.
- Th17 lymphocytes in atypical cutaneous leishmaniasis caused byLeishmania (L.) infantum chagasiin Central America(2020) FLORES, Gabriela Venicia Araujo; PACHECO, Carmen Maria Sandoval; OCHOA, Wilfredo Humberto Sosa; GOMES, Claudia Maria Castro; ZUNIGA, Concepcion; CORBETT, Carlos P.; LAURENTI, Marcia DalastraSkin lesions in nonulcerated cutaneous leishmaniasis (NUCL) caused byLeishmania (L.) infantum chagasiare characterized by a mononuclear inflammatory infiltrate in the dermis, which is composed mainly of lymphocytes, followed by macrophages, few plasma cells and epithelioid granulomas with mild tissue parasitism. Previous studies have shown that the main population of lymphocytes present in the dermal infiltrate is CD8(+)T cells, followed by CD4(+)T cells, which are correlated with IFN-gamma(+)cells. To improve the knowledge of cellular immune responses in NUCL, skin biopsies were submitted to immunohistochemistry using anti-ROR-gamma t, anti-IL-17, anti-IL-6, anti-TGF-beta, and anti-IL-23 antibodies to characterize the involvement of Th17 cells in the skin lesions of patients affected by NUCL. ROR-gamma t(+), IL-17(+), IL-6(+), TGF-beta(+)and IL-23(+)cells were observed in the dermal inflammatory infiltrate of NUCL skin lesions. A positive correlation between CD4(+)T-lymphocytes and ROR-gamma t(+)and IL-17(+)cells suggests that some of the CD4(+)T-lymphocytes in NUCL could be Th17 lymphocytes. Moreover, a positive correlation between ROR-gamma t(+)cells and TGF-beta(+), IL-6(+), IL-17(+)and IL-23(+)cells could indicate the role of these cytokines in the differentiation and maintenance of Th17 lymphocytes. Our findings improve knowledge of the pathogenesis of this rare and atypical clinical form of leishmaniasis.
- Detection of Pintomyia fischeri (Diptera: Psychodidae) With Leishmania infantum (Trypanosomatida: Trypanosomatidae) Promastigotes in a Focus of Visceral Leishmaniasis in Brazil(2021) GALVIS-OVALLOS, Fredy; UETA, Adriele Eiko; MARQUES, Gabriella de Oliveira; SARMENTO, Ana Maria Casagrande; ARAUJO, Gabriela; SANDOVAL, Carmen; TOMOKANE, Thaise Yumie; MATTA, Vania Lucia Ribeiro da; LAURENTI, Marcia Dalastra; GALATI, Eunice Aparecida BianchiVisceral leishmaniasis is spreading in Brazil where the main vector of its agent, Leishmania infantum Nicolle, 1908, is the Lutzomyia longipalpis (Lutz & Neiva, 1912) species complex (Diptera: Psychodidae: Phlebotominae), on which many of the activities of the visceral leishmaniasis surveillance program are based. However, there are areas where canine, and/or human cases have been occurring without the presence of this species complex as in the western part of the Greater Sao Paulo Metropolitan region, where Embu das Artes municipality is situated. In this area, Pintomyia fischeri (Pinto, 1926) has been implicated as potential vector of Le. infantum but so far its natural infection with this parasite has not yet been ascertained. Therefore, the present study sought to investigate the natural infection in sand flies of a CVL focus in Embu das Artes. The sand fly collections were undertaken with Shannon and CDC traps, monthly, between 1800 and 2100 hours from November 2018 to October 2019, inclusive. A total of 951 sand flies (457 males and 494 females), belonging to 10 species, were captured. Pintomyia fischeri was the predominant species (89.5%); of which 426 females were dissected and one of them (0.23%) was found to be harboring flagellates in its midgut. A sample of these flagellates was isolated in culture and characterized by a 234 base pair fragment of Leishmania heat-shock protein 70 gene (hsp70) and restriction fragment length polymorphism with Hae III restriction enzyme as Le. infantum. This finding reinforces previous evidence of Pi. fischeri as a vector of Le. infantum in foci of visceral leishmaniasis and highlights the importance of vector surveillance in areas where this species occurs.
- First report of putative Leishmania RNA virus 2 (LRV2) in Leishmania infantum strains from canine and human visceral leishmaniasis cases in the southeast of Brazil(2023) REGO, Felipe Dutra; SILVA, Eduardo Sergio da; LOPES, Valeriana Valadares; TEIXEIRA-NETO, Rafael Goncalves; BELO, Vinicius Silva; JR, Antonio Augusto Fonseca; PEREIRA, Diego Andrade; PENA, Heber Paulino; LAURENTI, Marcia Dalastra; V, Gabriela Araujo; MATTA, Vania Lucia Ribeiro da; CHOUMAN, Islam Hussein; BURRIN, Thaina Bergantin; SANDOVAL, Carmen M.; BARROUIN-MELO, Stella Maria; PINHO, Flaviane Alves de; ANDRADE, Helida Monteiro de; NUNES, Ramon Vieira; GONTIJO, Celia Maria Ferreira; SOCCOL, Vanete Thomaz; KLOCEK, Donnamae; GRYBCHUK, Danyil; MACEDO, Diego Henrique; MONTE-NETO, Rubens Lima do; YURCHENKO, Vyacheslav; SOARES, Rodrigo PedroBACKGROUND Leishmania RNA virus 1 (LRV1) is commonly found in South American Leishmania parasites belonging to the subgenus Viannia, whereas Leishmania RNA virus 2 (LRV2) was previously thought to be restricted to the Old-World pathogens of the subgenus Leishmania. OBJECTIVES In this study, we investigated the presence of LRV2 in strains of Leishmania (L.) infantum, the causative agent of visceral leishmaniasis (VL), originating from different hosts, clinical forms, and geographical regions. METHODS A total of seventy-one isolates were screened for LRV2 using semi-nested reverse transcription-polymerase chain reaction (RT-PCR) targeting the RNA-dependent RNA polymerase (RdRp) gene. FINDINGS We detected LRV2 in two L. infantum isolates (CUR268 and HP-EMO) from canine and human cases, respectively. MAIN CONCLUSIONS To the best of our knowledge, this is the first detection of LRV2 in the New World.
- Macrophage Polarization in the Skin Lesion Caused by Neotropical Species of Leishmania sp(2021) PACHECO, Carmen M. Sandoval; V, Gabriela Araujo Flores; GONZALEZ, Kadir; GOMES, Claudia M. de Castro; PASSERO, Luiz F. D.; TOMOKANE, Thaise Y.; SOSA-OCHOA, Wilfredo; ZUNIGA, Concepcion; CALZADA, Jose; SALDANA, Azael; CORBETT, Carlos E. P.; SILVEIRA, Fernando T.; LAURENTI, Marcia D.Macrophages play important roles in the innate and acquired immune responses against Leishmania parasites. Depending on the subset and activation status, macrophages may eliminate intracellular parasites; however, these host cells also can offer a safe environment for Leishmania replication. In this sense, the fate of the parasite may be influenced by the phenotype of the infected macrophage, linked to the subtype of classically activated (M1) or alternatively activated (M2) macrophages. In the present study, M1 and M2 macrophage subsets were analyzed by double-staining immunohistochemistry in skin biopsies from patients with American cutaneous leishmaniasis (ACL) caused by L. (L.) amazonensis, L. (V.) braziliensis, L. (V.) panamensis ,and L. (L.) infantum chagasi. High number of M1 macrophages was detected in nonulcerated cutaneous leishmaniasis (NUCL) caused by L. (L.) infantum chagasi (M1=112 +/- 12, M2=43 +/- 12 cells/mm(2)). On the other side, high density of M2 macrophages was observed in the skin lesions of patients with anergic diffuse cutaneous leishmaniasis (ADCL) (M1=195 +/- 25, M2=616 +/- 114), followed by cases of localized cutaneous leishmaniasis (LCL) caused by L. (L.) amazonensis (M1=97 +/- 24, M2=219 +/- 29), L. (V.) panamensis (M1=71 +/- 14, M2=164 +/- 14), and L. (V.) braziliensis (M1=50 +/- 13, M2=53 +/- 10); however, low density of M2 macrophages was observed in NUCL. The data presented herein show the polarization of macrophages in skin lesions caused by different Leishmania species that may be related with the outcome of the disease.
- Can domestic dogs be considered a good reservoir of Leishmania (L.) infantum chagasi in an endemic area of nonulcerated cutaneous leishmaniasis in Southern Honduras?(2023) SEGURA, Gabriela Beatriz Rodriguez; OCHOA, Wilfredo Humberto Sosa; MATTA, Vania Lucia Ribeiro da; MARTINEZ, Mercedes; TERCERO, Carol Rodriguez; GONZALEZ, Raquel Romero; PACHECO, Carmen M. Sandoval; FLORES, Gabriela V. Araujo; SILVEIRA, Fernando Tobias; HENRIQUEZ, Maria Mercedes Rueda; LAURENTI, Marcia DalastraDogs are considered to be the main domestic reservoir associated with the transmission of Leishmania (L.) infantum chagasi to humans in endemic areas of visceral leishmaniasis in America. However, little is known about the role of canines as a source of infection in endemic areas of nonulcerated cutaneous leishmaniasis (NUCL). Therefore, the objective of the present study was to investigate the role of dogs as a possible reservoir of the parasite in Southern Honduras. Dogs (n = 107) living with individuals affected by NUCL were clinically examined and biological material was collected for parasitological and immunological diagnosis. Most animals showed a healthy appearance and a few presented slight weight loss (64%), alopecia (7%), onychogryphosis (5%) and skin lesions (1%). The overall seroprevalence of Leishmania infection based on the DDP (R) quick test and/or in-house ELISA serological test was 41%. The presence of the parasite's DNA was confirmed in 94% of the dogs; however, the average parasite load in the buffy coat was low at 6.09 parasites/mu L, ranging between 0.221 and 50.2. The skin of seropositive dogs examined by histopathology using paraffin sections stained by hematoxylin and immunohistochemistry did not show cutaneous lesions or parasite amastigotes. Based on the absence of parasites in the skin and the low parasite load detected in the buffy coat, it seems that the dog does not represent a good source of infection for the vector in the endemic area of NUCL transmission in Southern Honduras. Other domestic and/or wild animals should be investigated.
- Histopathological features of skin lesions in patients affected by non-ulcerated or atypical cutaneous leishmaniasis in Honduras, Central America(2018) PACHECO, Carmen Maria Sandoval; FLORES, Gabriela Venicia Araujo; FERREIRA, Aurea Favero; OCHOA, Wilfredo Sosa; MATTA, Vania Lucia Ribeiro da; VALERIANO, Concepcion Zuniga; CORBETT, Carlos Eduardo Pereira; LAURENTI, Marcia DalastraIn Honduras visceral leishmaniasis and non-ulcerated or atypical cutaneous leishmaniasis (NUCL) are caused by the species Leishmania (L.) infantum chagasi. NUCL is the most common clinical form in the southern regions of the country, mainly affecting the young. In view of the lack of knowledge about the pathogenesis of the disease pattern caused by L. (L) infantum chagasi in individuals affected by NUCL, the aim of the present study was to describe in detail the histopathological features of the skin lesion caused by the parasite. Biopsies from human NUCL lesions with a positive parasitological diagnosis were collected and processed using standard histological techniques. Paraffin sections stained by haematoxylin and eosin were used to examine the histopathological alterations seen in the skin. The lesions varied between 3 and 5 mm, and the majority of the patients (60%) had a single lesion. Lesions were more frequently seen in females (65%), with an average age of 33.4 years. Microscopically, the skin lesions were characterized by mononuclear inflammatory infiltrate in the dermis composed of lymphocytes, macrophages and a few plasma cells. The intensity of the infiltration varied from discrete to intense. In both cases, the parasitic infection was discrete. Granulomas were present in 60% of cases and were associated with intense inflammation. The data revealed by the histopathological alterations in the skin of individuals affected by NUCL suggest activation of a cellular immune response that potentially controls parasite spreading.
- Lipophosphoglycans from dermotropic Leishmania infantum are more pro-inflammatory than those from viscerotropic strains(2020) CARDOSO, Camila A.; V, Gabriela Araujo; SANDOVAL, Carmen M.; NOGUEIRA, Paula M.; ZUNIGA, Concepcion; SOSA-OCHOA, Wilfredo H.; LAURENTI, Marcia D.; SOARES, Rodrigo P.Although Leishmania infantum is well-known as the aethiological agent of visceral leishmaniasis (VL), in some Central American countries it may cause atypical non-ulcerated cutaneous leishmaniasis ( NUCL). However, the mechanisms favoring its establishment in the skin are still unknown. Lipophosphoglycan (LPG) is the major Leishmania multivirulence factor involved in parasite-host interaction. In the case of viscerotropic L. infantum, it causes an immunosuppression during the interaction with macrophages. Here, we investigated the biochemical and functional roles of LPGs from four dermotropic L. infantum strains from Honduras during in vitro interaction with murine macrophages. LPGs were extracted, purified and their repeat units analysed. They did not have side chains consisting of Gal(beta 1,4)Man(alpha 1)-PO4 common to all LPGs. Peritoneal macrophages from BALB/c and C57BL/6 were exposed to LPG for nitric oxide (NO) and cytokine (TNF-alpha and, IL-6) production. LPGs from dermotropic strains from Honduras triggered higher NO and cytokine levels compared to those from viscerotropic strains. In conclusion, LPGs from dermotropic strains are devoid of side-chains and exhibit high pro-inflammatory activity.
- Evaluation of Regulatory Immune Response in Skin Lesions of Patients Affected by Nonulcerated or Atypical Cutaneous Leishmaniasis in Honduras, Central America(2018) FLORES, Gabriela Venicia Araujo; PACHECO, Carmen Maria Sandoval; TOMOKANE, Thaise Yumie; OCHOA, Wilfredo Sosa; VALERIANO, Concepcion Zuniga; GOMES, Claudia Maria Castro; CORBETT, Carlos Eduardo Pereira; LAURENTI, Marcia DalastraIn Honduras, Leishmania (L.) infantum chagasi causes both visceral leishmaniasis (LV) and nonulcerated or atypical cutaneous leishmaniasis (NUCL). NUCL is characterized by mononuclear inflammatory infiltration of the dermis, composed mainly of lymphocytes followed by macrophages with discrete parasitism. Considering that little is known about the pathogenesis of NUCL, the aim of this study was to evaluate the regulatory response in situ in skin lesions of patients affected by NUCL. Biopsies (n = 20) from human cutaneous nonulcerative lesions were collected and processed by usual histological techniques. The in situ regulatory immune response was evaluated by immunohistochemistry using antihuman CD4, FoxP3, IL-10, and TGF-beta antibodies. CD4(+), FoxP3(+), TGF-beta(+), and IL-10(+) cells were observed in the dermis with inflammatory infiltration in all studied cases and at higher densities compared to the normal skin controls. A positive and strong correlation was observed between CD4(+) and FoxP3(+) cells, and a positive and moderate correlation was observed between FoxP3(+) and TGF-beta(+) but not with IL-10(+) cells. The data suggest that T regulatory FoxP3(+) cells and the regulatory cytokines, especially TGF-beta, play an important role in the immunopathogenesis of NUCL, modulating a cellular immune response in the skin, avoiding tissue damage, and leading to low tissue parasitic persistence.