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1.
Proc Natl Acad Sci U S A ; 117(40): 25159-25168, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-32958676

RESUMO

The tropical Andes are an important natural laboratory to understand speciation in many taxa. Here we examined the evolutionary history of parasites of the Leishmania braziliensis species complex based on whole-genome sequencing of 67 isolates from 47 localities in Peru. We first show the origin of Andean Leishmania as a clade of near-clonal lineages that diverged from admixed Amazonian ancestors, accompanied by a significant reduction in genome diversity and large structural variations implicated in host-parasite interactions. Within the Andean species, patterns of population structure were strongly associated with biogeographical origin. Molecular clock and ecological niche modeling suggested that the history of diversification of the Andean lineages is limited to the Late Pleistocene and intimately associated with habitat contractions driven by climate change. These results suggest that changes in forestation over the past 150,000 y have influenced speciation and diversity of these Neotropical parasites. Second, genome-scale analyses provided evidence of meiotic-like recombination between Andean and Amazonian Leishmania species, resulting in full-genome hybrids. The mitochondrial genome of these hybrids consisted of homogeneous uniparental maxicircles, but minicircles originated from both parental species. We further show that mitochondrial minicircles-but not maxicircles-show a similar evolutionary pattern to the nuclear genome, suggesting that compatibility between nuclear-encoded mitochondrial genes and minicircle-encoded guide RNA genes is essential to maintain efficient respiration. By comparing full nuclear and mitochondrial genome ancestries, our data expand our appreciation on the genetic consequences of diversification and hybridization in parasitic protozoa.


Assuntos
Genoma Mitocondrial/genética , Interações Hospedeiro-Parasita/genética , Leishmania braziliensis/genética , Leishmaniose Cutânea/genética , Ecossistema , Florestas , Especiação Genética , Humanos , Leishmania braziliensis/patogenicidade , Leishmaniose Cutânea/epidemiologia , Leishmaniose Cutânea/parasitologia , Peru/epidemiologia , Filogeografia
2.
Immunology ; 159(4): 355-356, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32182636

RESUMO

Both CD8+ T cells and NK cells contribute to the immune response against the protozoan Leishmania parasite. Both are able to generate IFN-γ and both display cytotoxic features. These features may enable them to not only contribute to parasite clearance but also to cause immune-mediated pathology. This pathology is evident, for example, in the Leismania-induced skin lesions found in patients with cutaneous leismaniasis (CL). Here we highlight new data demonstrating that CD8+ T cells and NK cells in CL display a highly cytotoxic senescent phenotype, and that the senescent T cells play a major role in mediating skin pathology. This is the first demonstration that senescent CD8 T cells contribute to immunopathology in vivo.


Assuntos
Citotoxicidade Imunológica , Leishmania braziliensis/patogenicidade , Leishmaniose Cutânea/patologia , Pele/patologia , Linfócitos T Citotóxicos/patologia , Antígenos CD57/genética , Antígenos CD57/imunologia , Senescência Celular/imunologia , Expressão Gênica , Interações Hospedeiro-Parasita/genética , Interações Hospedeiro-Parasita/imunologia , Humanos , Interferon gama/genética , Interferon gama/imunologia , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/parasitologia , Células Matadoras Naturais/patologia , Leishmania braziliensis/imunologia , Leishmaniose Cutânea/imunologia , Leishmaniose Cutânea/parasitologia , Oligossacarídeos/genética , Oligossacarídeos/imunologia , Antígeno Sialil Lewis X/análogos & derivados , Antígeno Sialil Lewis X/genética , Antígeno Sialil Lewis X/imunologia , Pele/imunologia , Pele/parasitologia , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/parasitologia
3.
Immunology ; 159(4): 429-440, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31925782

RESUMO

Cytotoxic activity mediated by CD8+ T cells is the main signature of the immunopathogenesis of cutaneous leishmaniasis (CL). Here, we performed a broad evaluation of natural killer (NK) cell phenotypic and functional features during cutaneous leishmaniasis. We demonstrate for the first time that CL patients present the accumulation of circulating NK cells with multiple features of replicative senescence including low proliferative capacity and shorter telomeres, elevated expression of CD57, KLRG1 but diminished CD27 stimulatory receptor expression. Moreover, they exhibited higher cytotoxic and inflammatory potential than age-matched controls. The accumulation of circulating senescent NK cells (CD56dim  CD57bright ) correlated positively with skin lesion size in the same patients, suggesting that they, like circulating senescent CD8+ T cells, may contribute to the immunopathology of CL. However, this senescent population had lower cutaneous lymphocyte antigen expression and so had diminished skin-homing potential compared with total or senescent CD8+ T cells. This was confirmed in CL skin lesions where we found a predominance of CD8+ T cells (both senescent and non-senescent) that correlated with the severity of the disease. Although there was also a correlation between the proportions of senescent NK cells (CD56+  CD57+ ) in the skin and lesion size, this was less evident. Collectively our results demonstrate first-hand that senescent cytotoxic cells may mediate skin pathology during human cutaneous leishmaniasis. However, as senescent cytotoxic CD8+ T cells predominate in the skin lesions, they may have a greater role than NK cells in mediating the non-specific skin damage in CL.


Assuntos
Citotoxicidade Imunológica , Células Matadoras Naturais/patologia , Leishmania braziliensis/patogenicidade , Leishmaniose Cutânea/patologia , Pele/patologia , Linfócitos T Citotóxicos/patologia , Antígeno CD56/genética , Antígeno CD56/imunologia , Antígenos CD57/genética , Antígenos CD57/imunologia , Estudos de Casos e Controles , Senescência Celular/imunologia , Feminino , Regulação da Expressão Gênica , Interações Hospedeiro-Parasita/genética , Interações Hospedeiro-Parasita/imunologia , Humanos , Interferon gama/genética , Interferon gama/imunologia , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/parasitologia , Lectinas Tipo C/genética , Lectinas Tipo C/imunologia , Leishmania braziliensis/imunologia , Leishmaniose Cutânea/imunologia , Leishmaniose Cutânea/parasitologia , Masculino , Oligossacarídeos/genética , Oligossacarídeos/imunologia , Receptores Imunológicos/genética , Receptores Imunológicos/imunologia , Índice de Gravidade de Doença , Antígeno Sialil Lewis X/análogos & derivados , Antígeno Sialil Lewis X/genética , Antígeno Sialil Lewis X/imunologia , Transdução de Sinais , Pele/imunologia , Pele/parasitologia , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/parasitologia
4.
Curr Opin Microbiol ; 52: 110-115, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31306995

RESUMO

The outcome of Leishmania infection depends on the parasite species and the host immune response. Virulence factors have been extensively studied over the years in an effort to find efficient vaccines and/or treatments for Leishmania infection. Arginase activity in Leishmania has been described as an essential player for the polyamines pathway, impacting parasite replication and infectivity. Considering previous studies showing that the absence of arginase activity leads to low infectivity of Leishmania amazonensis, we reanalyzed transcriptomic data comparing both promastigotes and axenic amastigotes from L. amazonensis wild type (La-WT) and L. amazonensis arginase knockout (La-arg-) backgrounds. The analysis produced a new compilation of modulated transcripts that indicated the role of arginase not only in the polyamines pathway but also in the modulation of virulence factors involved in parasite recognition, growth and differentiation.


Assuntos
Arginase/metabolismo , Leishmania braziliensis/enzimologia , Leishmania braziliensis/patogenicidade , Fatores de Virulência/metabolismo , Animais , Perfilação da Expressão Gênica , Interações Hospedeiro-Patógeno/imunologia , Humanos , Leishmania braziliensis/genética , Leishmaniose/imunologia , Macrófagos/parasitologia , Proteínas de Protozoários/metabolismo , Transcriptoma
5.
ACS Infect Dis ; 5(8): 1295-1305, 2019 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-31094195

RESUMO

Cutaneous leishmaniasisis is the most common clinical form of leishmaniasis and one of the most relevant neglected diseases. It is known that the progress of the disease is species specific and the host's immune response plays an important role in its outcome. However, the pathways that lead to parasite clearance or survival remain unknown. In this work, skin tissue from mice experimentally infected with L. amazonensis, one of the causative agents of cutaneous leishmaniasis in the Amazon region, L. major, another causative agent of cutaneous leishmaniasis in Africa, the Middle East, China, and India, or lipopolysaccharides from Escherichia coli as an inflammation model were investigated using label-free proteomics to unveil Leishmania-specific protein alterations. Proteomics is a powerful tool to investigate host-pathogen relationships to address biological questions. In this work, proteins from mice skin biopsies were identified and quantified using nano-LC coupled with tandem mass spectrometry analyses. Integrated Proteomics Pipeline was used for peptide/protein identification and quantification. Western blot was used for validation of protein quantification by mass spectrometry, and protein pathways were predicted using Ingenuity Pathway Analysis. In this proteomics study, several proteins were pointed out as hypothetical targets to guide future studies on Leishmania-specific modulation of proteins in the host. We identified hundreds of exclusively modulated proteins after Leishmania spp. infection and 17 proteins that were differentially modulated in the host after L. amazonensis or L. major infection.


Assuntos
Interações Hospedeiro-Patógeno , Leishmania braziliensis/patogenicidade , Leishmania major/patogenicidade , Leishmaniose Cutânea/metabolismo , Proteômica , Pele/metabolismo , Animais , Biópsia , Feminino , Inflamação , Leishmaniose Cutânea/patologia , Camundongos , Camundongos Endogâmicos BALB C , Mapas de Interação de Proteínas , Proteínas/análise , Pele/parasitologia , Pele/patologia , Espectrometria de Massas em Tandem
6.
Cell Immunol ; 341: 103920, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31078283

RESUMO

Localized cutaneous leishmaniasis (LCL) can ultimately progress to chronic ulcerated lesions with strong local inflammatory reactions. The functional role of certain inflammasomes in mediating inflammation caused by Leishmania braziliensis needs to be addressed. By combining PCR-array, quantitative real-time PCR and immunohistochemical analysis, we identified inflammasome genes, such as IL-1ß, NLRP3, NLRP1, NLRC5, AIM2 and P2RX7, that were upregulated in LCL patients. Temporal gene expression studies showed that the early phase of LCL displayed increased NLRP3 and reduced AIM2 and NLRP1 expression, while the late stages showed increased AIM2 and NLRP1 and lower NLRP3 expression. Our findings also showed that AIM2, NLRP1, and P2RX7 promoted susceptibility to experimental L. braziliensis infection. These results highlight the importance of inflammasome machinery in human LCL and suggest that inflammasome machinery plays a role in the acute and chronic phases of the disease.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Reguladoras de Apoptose/genética , Proteínas de Ligação a DNA/genética , Inflamassomos/genética , Leishmaniose Cutânea/genética , Receptores Purinérgicos P2X7/genética , Pele/imunologia , Proteínas Adaptadoras de Transdução de Sinal/imunologia , Adulto , Animais , Proteínas Reguladoras de Apoptose/imunologia , Proteínas de Ligação a DNA/imunologia , Progressão da Doença , Suscetibilidade a Doenças , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Humanos , Inflamassomos/imunologia , Interleucina-1beta/genética , Interleucina-1beta/imunologia , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/imunologia , Leishmania braziliensis/imunologia , Leishmania braziliensis/patogenicidade , Leishmaniose Cutânea/imunologia , Leishmaniose Cutânea/parasitologia , Leishmaniose Cutânea/patologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/imunologia , Receptores Purinérgicos P2X7/imunologia , Transdução de Sinais , Pele/parasitologia , Pele/patologia
7.
BMC Genomics ; 20(1): 118, 2019 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-30732584

RESUMO

BACKGROUND: The leishmaniasis are parasitic diseases caused by protozoans of the genus Leishmania, highly divergent eukaryotes, characterized by unique biological features. To survive in both the mammalian hosts and insect vectors, these pathogens make use of a number of mechanisms, many of which are associated with parasite specific proteases. The metalloprotease GP63, the major Leishmania surface antigen, has been found to have multiple functions required for the parasite's survival. GP63 is encoded by multiple genes and their copy numbers vary considerably between different species and are increased in those from the subgenus Viannia, including L. braziliensis. RESULTS: By comparing multiple sequences from Leishmania and related organisms this study sought to characterize paralogs in silico, evaluating their differences and similarities and the implications for the GP63 function. The Leishmania GP63 genes are encoded on chromosomes 10, 28 and 31, with the genes from the latter two chromosomes more related to genes found in insect or plant parasites. Those from chromosome 10 have experienced independent expansions in numbers in Leishmania, especially in L. braziliensis. These could be clustered in three groups associated with different mRNA 3' untranslated regions as well as distinct C-terminal ends for the encoded proteins, with presumably distinct expression patterns and subcellular localizations. Sequence variations between the chromosome 10 genes were linked to intragenic recombination events, mapped to the external surface of the proteins and predicted to be immunogenic, implying a role against the host immune response. CONCLUSIONS: Our results suggest a greater role for the sequence variation found among the chromosome 10 GP63 genes, possibly related to the pathogenesis of L. braziliensis and closely related species within the mammalian host. They also indicate different functions associated to genes mapped to different chromosomes. For the chromosome 10 genes, variable subcellular localizations were found to be most likely associated with multiple functions and target substrates for this versatile protease.


Assuntos
Simulação por Computador , Variação Genética , Evasão da Resposta Imune/genética , Leishmania braziliensis/genética , Leishmania braziliensis/imunologia , Metaloendopeptidases/genética , Sequência de Aminoácidos , Cromossomos/genética , Epitopos de Linfócito B/imunologia , Evolução Molecular , Leishmania braziliensis/patogenicidade , Metaloendopeptidases/química , Recombinação Genética , Homologia de Sequência do Ácido Nucleico , Virulência/genética
8.
Am J Trop Med Hyg ; 100(2): 306-310, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30628567

RESUMO

Local therapies have been proposed as safe and effective alternatives to systemic drugs in cutaneous leishmaniasis (CL), especially among less severe cases. However, they are not widely available and used in endemic places, including Colombia, which has a high burden of disease. Further complicating the uptake of local therapies is that different treatment guidelines have been established by the World Health Organization (WHO) and Pan American Health Organization (PAHO). Using data from a large referral center in Colombia, we determined the proportion of patients who would be eligible for and potentially benefit from local therapies according to both international guidelines. The sample included 1,891 confirmed cases of CL aged ≥ 12 years, mostly infected with Leishmania Viannia panamensis (91%, n = 601/660), between 2004 and 2014. Overall, 57% of the sample had one lesion, whereas another 31% had two to three lesions. For 74% of patients, all lesions were in an area other than head or neck. The maximum lesion size was ≤ 3 cm for 58% and < 5 cm for 88% of the sample. Based on our data, up to 56% of patients could have been eligible for local therapies according to the WHO criteria. By contrast, only 23% were eligible according to the more restrictive PAHO criteria. Regardless, these data suggest that a substantial proportion of CL patients in Colombia may benefit from local therapies given their relatively mild presentation of disease and low risk of complications. Individualized risk-benefit assessment and guideline adjustments may increase local therapy eligibility and benefit a large number of patients.


Assuntos
Antimônio/uso terapêutico , Antiprotozoários/uso terapêutico , Leishmania braziliensis/efeitos dos fármacos , Leishmania guyanensis/efeitos dos fármacos , Leishmaniose Cutânea/terapia , Paromomicina/uso terapêutico , Pentamidina/uso terapêutico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Colômbia/epidemiologia , Estudos Transversais , Crioterapia/métodos , Feminino , Humanos , Hipertermia Induzida/métodos , Leishmania braziliensis/crescimento & desenvolvimento , Leishmania braziliensis/patogenicidade , Leishmania guyanensis/crescimento & desenvolvimento , Leishmania guyanensis/patogenicidade , Leishmaniose Cutânea/epidemiologia , Leishmaniose Cutânea/parasitologia , Masculino , Pessoa de Meia-Idade , Guias de Prática Clínica como Assunto , Índice de Gravidade de Doença
9.
Bull Math Biol ; 81(11): 4447-4469, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-30569327

RESUMO

We propose and analyze a mathematical model of a vector-borne disease that includes vector feeding preference for carrier hosts and intrinsic incubation in hosts. Analysis of the model reveals the following novel results. We show theoretically and numerically that vector feeding preference for carrier hosts plays an important role for the existence of both the endemic equilibria and backward bifurcation when the basic reproduction number [Formula: see text] is less than one. Moreover, by increasing the vector feeding preference value, backward bifurcation is eliminated and endemic equilibria for hosts and vectors are diminished. Therefore, the vector protects itself and this benefits the host. As an example of these phenomena, we present a case of Andean cutaneous leishmaniasis in Peru. We use parameter values from previous studies, primarily from Peru to introduce bifurcation diagrams and compute global sensitivity of [Formula: see text] in order to quantify and understand the effects of the important parameters of our model. Global sensitivity analysis via partial rank correlation coefficient shows that [Formula: see text] is highly sensitive to both sandflies feeding preference and mortality rate of sandflies.


Assuntos
Modelos Biológicos , Doenças Transmitidas por Vetores/epidemiologia , Doenças Transmitidas por Vetores/transmissão , Animais , Número Básico de Reprodução/estatística & dados numéricos , Simulação por Computador , Vetores de Doenças , Doenças Endêmicas/estatística & dados numéricos , Especificidade de Hospedeiro , Interações Hospedeiro-Parasita , Humanos , Leishmania braziliensis/patogenicidade , Leishmaniose Cutânea/epidemiologia , Leishmaniose Cutânea/parasitologia , Leishmaniose Cutânea/transmissão , Conceitos Matemáticos , Peru/epidemiologia , Psychodidae/parasitologia
10.
Int J Biol Macromol ; 120(Pt A): 431-439, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30118767

RESUMO

Leishmania amazonensis and Leishmania braziliensis are the main causative agents of American Tegumentary Leishmaniasis (ATL) in Brazil. As intracellular parasites, the infection by Leishmania species is dependent on the host immune response and the immunotherapy could be promissory for the development of new strategies to combat ATL. In this work we investigated the leishmanicidal potential of a galactose-binding lectin from the snake venom of Bothrops leucurus (BLL) during the infection with L. amazonensis and L. braziliensis. BLL inhibited the promastigote growth and viability of both species in a mechanism dependent on galactose and calcium. The treatment with BLL also decreases the survival of intracellular parasites for both species and induced profound ultrastructural changes on amastigotes without apparent damage to the host cells. The analysis of the cytokine profile revealed that BLL induced an increase in the proinflammatory cytokines IL-6 and TNF-α by infected macrophages in both species, but differed in relation to IL-1ß and IL-10 response. Future works using in vitro and in vivo models are necessary to support the use of these lectins as biotechnological tool in immunological studies.


Assuntos
Galectinas/farmacologia , Leishmania braziliensis/efeitos dos fármacos , Leishmaniose Cutânea/tratamento farmacológico , Venenos de Serpentes/química , Animais , Bothrops , Brasil , Galectinas/química , Humanos , Leishmania braziliensis/patogenicidade , Leishmaniose Cutânea/parasitologia , Macrófagos/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Venenos de Serpentes/farmacologia
11.
Biomed Pharmacother ; 106: 1624-1632, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30119238

RESUMO

AIM: The present study compared and evaluated morphological and quantitative alterations in the ileum of hamsters infected by two L. (V.) braziliensis strains isolated from patients with different lesion aspects and treatment responses. MAIN METHODS: Hamsters were infected in the left hindpaw with a suspension of promastigotes (2 × 107/100 µl) of two different strains of L. (V.) braziliensis. After 90 or 120 days, the animals were euthanized. Samples of the ileum and mesenteric lymph node were collected for histological examination and quantitative polymerase chain reaction. KEY FINDINGS: All infected animals developed similar profile of paw lesions. In peripheral blood there was an increase in the number of mononuclear cells which contributed to elevated global leukocytes count. Increases in the width and height of villi and width and depth of crypts were observed. The thickness of the muscular layers, submucosa, and intestinal wall also increased. Histopathological alterations were observed, including inflammatory infiltrate in crypts and a large number of immune cells in the lamina propria, submucosa, and muscular layer. Immune cells were found inside myenteric ganglia, with an increase in the number of intraepithelial lymphocytes. Leishmania DNA was detected in the ileum and mesenteric lymph node at both times of infection. The presence of amastigotes in the ileum was revealed by immunohistochemistry. SIGNIFICANCE: The infection with different strains of L. (V.) braziliensis causes morphological and quantitative alterations in the ileum of hamsters and the parasite can migrate to the mesenteric lymph node and intestine.


Assuntos
Íleo/parasitologia , Leishmania braziliensis/patogenicidade , Leishmaniose Cutânea/parasitologia , Animais , DNA de Protozoário/genética , Modelos Animais de Doenças , Feminino , Interações Hospedeiro-Parasita , Íleo/imunologia , Íleo/patologia , Leishmania braziliensis/genética , Leishmania braziliensis/imunologia , Leishmaniose Cutânea/imunologia , Leishmaniose Cutânea/patologia , Linfonodos/parasitologia , Mesocricetus , Carga Parasitária , Fatores de Tempo
12.
Mol Immunol ; 93: 173-183, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29197260

RESUMO

Coinfection with leishmaniasis and schistosomiasis has been associated with increased time to healing of cutaneous lesions of leishmaniasis. The objective of this study was to evaluate the effect of Leishmania braziliensis infection on co-cultures of monocyte-derived dendritic cells (MoDCs) with autologous lymphocytes from patients with schistosomiasis and patients with cutaneous leishmaniasis. MoDCs were differentiated from peripheral blood monocytes, isolated by magnetic beads, infected with L. braziliensis, and co-cultured with autologous lymphocytes. Expression of HLA-DR, CD1a, CD83, CD80, CD86, CD40, and the IL-10 receptor (IL-10R) on MoDCs as well as CD28, CD40L, CD25, and CTLA-4 on lymphocytes were evaluated by flow cytometry. The production of the cytokines IL-10, TNF, IL-12p40, and IFN-γ were evaluated by sandwich ELISA of the culture supernatant. The infectivity evaluation was performed by light microscopy after concentration of cells by cytospin and Giemsa staining. It was observed that the frequency of MoDCs expressing CD83, CD80, and CD86 as well as the MFI of HLA-DR were smaller in the group of patients with schistosomiasis compared to the group of patients with leishmaniasis. On the other hand, the frequency of IL-10R on MoDCs was higher in patients with schistosomiasis than in patients with leishmaniasis. CD4+ and CD8+ T lymphocytes from patients with schistosomiasis presented a lower frequency of CD28 and a higher frequency of CTLA-4 compared to lymphocytes from patients with leishmaniasis. Levels of IL-10 were higher in the supernatants of co-cultures from individuals with schistosomiasis compared to those with leishmaniasis. However, levels of TNF, IL-12p40, and IFN-γ were lower in the group of individuals with schistosomiasis. Regarding the frequency of MoDCs infected by L. braziliensis after 72h in culture, it was observed that higher frequencies of cells from patients with schistosomiasis were infected compared to cells from patients with leishmaniasis. It was concluded that MoDCs from patients with schistosomiasis are more likely to be infected by L. braziliensis, possibly due to a lower degree of activation and a regulatory profile.


Assuntos
Células Dendríticas/parasitologia , Leishmania braziliensis/patogenicidade , Leishmaniose Cutânea/imunologia , Esquistossomose mansoni/imunologia , Adolescente , Adulto , Ligante de CD40 , Técnicas de Cocultura , Coinfecção , Citocinas/biossíntese , Células Dendríticas/imunologia , Feminino , Humanos , Imunoglobulina E/sangue , Leishmaniose Cutânea/parasitologia , Ativação Linfocitária , Masculino , Pessoa de Meia-Idade , Esquistossomose mansoni/sangue , Esquistossomose mansoni/parasitologia , Linfócitos T Citotóxicos/imunologia , Células Th1/imunologia , Células Th2/imunologia , Adulto Jovem
13.
Cell Host Microbe ; 22(1): 13-24.e4, 2017 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-28669672

RESUMO

Skin microbiota can impact allergic and autoimmune responses, wound healing, and anti-microbial defense. We investigated the role of skin microbiota in cutaneous leishmaniasis and found that human patients infected with Leishmania braziliensis develop dysbiotic skin microbiota, characterized by increases in the abundance of Staphylococcus and/or Streptococcus. Mice infected with L. major exhibit similar changes depending upon disease severity. Importantly, this dysbiosis is not limited to the lesion site, but is transmissible to normal skin distant from the infection site and to skin from co-housed naive mice. This observation allowed us to test whether a pre-existing dysbiotic skin microbiota influences disease, and we found that challenging dysbiotic naive mice with L. major or testing for contact hypersensitivity results in exacerbated skin inflammatory responses. These findings demonstrate that a dysbiotic skin microbiota is not only a consequence of tissue stress, but also enhances inflammation, which has implications for many inflammatory cutaneous diseases.


Assuntos
Disbiose/etiologia , Disbiose/imunologia , Inflamação , Leishmania braziliensis/patogenicidade , Leishmaniose Cutânea/complicações , Leishmaniose Cutânea/microbiologia , Microbiota/fisiologia , Pele/imunologia , Animais , Modelos Animais de Doenças , Humanos , Hipersensibilidade , Inflamação/imunologia , Inflamação/microbiologia , Leishmania major/imunologia , Leishmania major/patogenicidade , Camundongos , Camundongos Endogâmicos C57BL , Microbiota/imunologia , Pele/microbiologia , Pele/parasitologia , Staphylococcus/imunologia , Staphylococcus/patogenicidade , Streptococcus/imunologia , Streptococcus/patogenicidade
14.
Sci Rep ; 7(1): 3149, 2017 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-28600554

RESUMO

Sand flies inject saliva while feeding in the vertebrate host and anti-saliva antibodies can be used as biomarkers of exposure to Leishmania vectors. We expressed recombinant salivary proteins from Lutzomyia intermedia, a vector of Leishmania braziliensis, and evaluated the seroreactivity in exposed individuals in search for exposure markers. We found a strong correlation among positive serology to recombinant proteins LinB-13, 26, 15, 21 and to salivary proteins: rLinB-13 was the top performing molecule; IgG4 was the most predominant antibody subclass and antibodies to rLinB-13 did not cross react with Lu. longipalpis salivary proteins. By evaluating a cohort of contacts of CL patients, we confirmed that rLinB-13, an antigen 5-related protein, is a marker of exposure to Lu. intermedia with high degree of accuracy. In a 5-year follow up, we determined that individuals who developed CL presented higher anti-rLinB13 IgG responses, before the appearance of clinical symptoms. They also presented a lower frequency of cellular responses to the parasite (DTH). Our results show that seroconversion to a salivary molecule, rLinB-13, is a marker of risk for CL development caused by Leishmania braziliensis. This highlight the possibility of developing tools based on vector molecules to manage the disease in endemic areas.


Assuntos
Doenças Endêmicas , Imunoglobulina G/sangue , Proteínas de Insetos/sangue , Insetos Vetores/química , Leishmaniose Cutânea/diagnóstico , Psychodidae/química , Proteínas e Peptídeos Salivares/sangue , Animais , Biomarcadores/sangue , Brasil/epidemiologia , Diagnóstico Precoce , Humanos , Soros Imunes/química , Immunoblotting/métodos , Proteínas de Insetos/genética , Proteínas de Insetos/imunologia , Insetos Vetores/imunologia , Leishmania braziliensis/patogenicidade , Leishmania braziliensis/fisiologia , Leishmaniose Cutânea/sangue , Leishmaniose Cutânea/epidemiologia , Leishmaniose Cutânea/imunologia , Psychodidae/imunologia , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas e Peptídeos Salivares/genética , Proteínas e Peptídeos Salivares/imunologia , Soroconversão
15.
Am J Trop Med Hyg ; 96(5): 1155-1159, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28500815

RESUMO

AbstractCutaneous leishmaniasis (CL) by Leishmania braziliensis is associated with decreasing cure rates in Brazil. Standard treatment with pentavalent antimony (Sbv) cures only 50-60% of the cases. The immunopathogenesis of CL ulcer is associated with high interferon-γ and tumor necrosis factor (TNF) production. Pentoxifylline, a TNF inhibitor, has been successfully used in association with Sbv in mucosal and cutaneous leishmaniasis. This randomized, double-blind, and placebo-controlled trial aimed to evaluate the efficacy and safety of oral pentoxifylline plus Sbv versus placebo plus Sbv in patients with CL in Bahia, Brazil. A total of 164 patients were randomized in two groups to receive the combination or the monotherapy. Cure rate 6 months after treatment was 45% in the pentoxifylline group and 43% in the control group. There was also no difference between the groups regarding the healing time (99.7 ± 66.2 days and 98.1 ± 72.7 days, respectively). Adverse events were more common in the pentoxifylline group (37.8%), versus 23% in the placebo group. This trial shows that Sbv combined therapy with pentoxifylline is not more effective than Sbv monotherapy in the treatment of CL caused by L. braziliensis.


Assuntos
Antimônio/uso terapêutico , Antiprotozoários/uso terapêutico , Leishmania braziliensis/efeitos dos fármacos , Leishmaniose Cutânea/tratamento farmacológico , Pentoxifilina/uso terapêutico , Adolescente , Adulto , Brasil , Método Duplo-Cego , Quimioterapia Combinada , Feminino , Humanos , Interferon gama/antagonistas & inibidores , Interferon gama/biossíntese , Interferon gama/imunologia , Leishmania braziliensis/crescimento & desenvolvimento , Leishmania braziliensis/patogenicidade , Leishmaniose Cutânea/imunologia , Leishmaniose Cutânea/parasitologia , Leishmaniose Cutânea/patologia , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Fator de Necrose Tumoral alfa/biossíntese , Fator de Necrose Tumoral alfa/imunologia
16.
Artigo em Inglês | MEDLINE | ID: mdl-28461312

RESUMO

Leishmaniasis is a neglected tropical disease that affects millions of people worldwide and represents a major public health problem. Information on protein expression patterns and functional roles within the context of Leishmania-infected human monocyte-derived macrophages (MDMs) under drug treatment conditions is essential for understanding the role of these cells in leishmaniasis treatment. We analyzed functional changes in the expression of human MDM genes and proteins during in vitro infection by Leishmania braziliensis and treatment with Glucantime (SbV), using quantitative PCR (qPCR) arrays, Western blotting, confocal microscopy, and small interfering RNA (siRNA) human gene inhibition assays. Comparison of the results from gene transcription and protein expression analyses revealed that glutathione S-transferase π1 (GSTP1), glutamate-cysteine ligase modifier subunit (GCLM), glutathione reductase (GSR), glutathione synthetase (GSS), thioredoxin (TRX), and ATP-binding cassette, subfamily B, member 5 (ABCB5), were strongly upregulated at both the mRNA and protein levels in human MDMs that were infected and treated, compared to the control group. Subcellular localization studies showed a primarily phagolysosomal location for the ABCB5 transporter, indicating that this protein may be involved in the transport of SbV By inducing a decrease in L. braziliensis intracellular survival in THP-1 macrophages, siRNA silencing of GSTP1, GSS, and ABCB5 resulted in an increased leishmanicidal effect of SbV exposure in vitro Our results suggest that human MDMs infected with L. braziliensis and treated with SbV express increased levels of genes participating in antioxidant defense, whereas our functional analyses provide evidence for the involvement of human MDMs in drug detoxification. Therefore, we conclude that GSS, GSTP1, and ABCB5 proteins represent potential targets for enhancing the leishmanicidal activity of Glucantime.


Assuntos
Leishmania braziliensis/efeitos dos fármacos , Leishmania braziliensis/patogenicidade , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Meglumina/farmacologia , Compostos Organometálicos/farmacologia , Subfamília B de Transportador de Cassetes de Ligação de ATP , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Antioxidantes/metabolismo , Glutamato-Cisteína Ligase/metabolismo , Glutationa Redutase/metabolismo , Glutationa S-Transferase pi/metabolismo , Glutationa Sintase/metabolismo , Interações Hospedeiro-Patógeno , Humanos , Antimoniato de Meglumina , Reação em Cadeia da Polimerase
17.
Infect Genet Evol ; 49: 212-220, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28119029

RESUMO

FLI1 (Friend leukemia virus integration 1) and IL6 (interleukin 6; IL-6) are associated with Leishmania braziliensis susceptibility. Cutaneous lesions show exaggerated matrix metalloproteinase 1 (MMP1). In other skin diseases, FLI1 promoter methylation reduces FLI1 expression, and low FLI1 down-regulates MMP1. IL-6 increases FLI1 expression. We hypothesized that epigenetic regulation of FLI1 in cutaneous leishmaniasis, together with IL-6, might determine MMP1 expression. While generally low (<10%), percent FLI1 promoter methylation was lower (P=0.001) in lesion biopsies than normal skin. Contrary to expectation, a strong positive correlation occurred between FLI1 methylation and gene expression in lesions (r=0.98, P=0.0005) and in IL-6-treated L. braziliensis-infected macrophages (r=0.99, P=0.0004). In silico analysis of the FLI1 promoter revealed co-occurring active H3K27ac and repressive DNA methylation marks to enhance gene expression. FLI1 expression was enhanced between 3 and 24hour post infection in untreated (P=0.0002) and IL-6-treated (P=0.028) macrophages. MMP1 was enhanced in lesion biopsies (P=0.0002), induced (P=0.007) in infected macrophages, but strongly inhibited by IL-6. No correlations occurred between FLI1 and MMP1 expression in lesions or infected macrophages (with/without IL-6). We conclude that MMP1 is regulated by factors other than FLI1, and that the influence of IL-6 on MMP1 was independent of its effect on FLI1.


Assuntos
Epigênese Genética , Interações Hospedeiro-Patógeno , Interleucina-6/genética , Leishmaniose Cutânea/genética , Metaloproteinase 1 da Matriz/genética , Proteína Proto-Oncogênica c-fli-1/genética , Adolescente , Adulto , Criança , Metilação de DNA , Feminino , Regulação da Expressão Gênica , Histonas/genética , Histonas/imunologia , Humanos , Interleucina-6/imunologia , Leishmania braziliensis/patogenicidade , Leishmania braziliensis/fisiologia , Leishmaniose Cutânea/imunologia , Leishmaniose Cutânea/patologia , Macrófagos/imunologia , Macrófagos/patologia , Masculino , Metaloproteinase 1 da Matriz/imunologia , Regiões Promotoras Genéticas , Proteína Proto-Oncogênica c-fli-1/imunologia , Pele/imunologia , Pele/patologia
18.
J Microbiol Methods ; 131: 45-50, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27713019

RESUMO

Galleria mellonella is an excellent invertebrate model for the study of diseases that involve interactions with cells from the innate immune system, since they have an innate immune system capable of recognizing the pathogens. Here we present for the first time, an alternative model for an in vitro phagocytic assay using hemocytes of G. mellonella larvae to study infection by Leishmania (Viannia) braziliensis. We showed that the insect phagocytic cells were able to engulf promastigotes. Furthermore, this infective form differentiated into the amastigote form inside those cells. However, the cells in this model seem resistant to the parasite, since amastigotes were depleted after 24h and NO levels were maintained after infection. Our model opens an avenue of possibilities for new investigations regarding other Leishmania species, mechanisms of invasion and evasion, receptors involved, release of signaling molecules and, above all, it is a novel infection model using invertebrate animals.


Assuntos
Modelos Animais de Doenças , Hemócitos/parasitologia , Larva/parasitologia , Leishmania braziliensis/patogenicidade , Leishmaniose Mucocutânea/parasitologia , Lepidópteros/parasitologia , Fagócitos/parasitologia , Animais , Hemócitos/citologia , Hemócitos/imunologia , Hemolinfa/parasitologia , Interações Hospedeiro-Patógeno/imunologia , Imunidade Celular , Larva/imunologia , Leishmania braziliensis/imunologia , Leishmania braziliensis/fisiologia , Leishmaniose Mucocutânea/imunologia , Lepidópteros/citologia , Lepidópteros/imunologia , Microscopia Eletrônica de Varredura , Óxido Nítrico/metabolismo , Fagócitos/citologia , Fagócitos/imunologia
19.
Proc Natl Acad Sci U S A ; 113(43): 11998-12005, 2016 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-27790981

RESUMO

Many Leishmania (Viannia) parasites harbor the double-stranded RNA virus Leishmania RNA virus 1 (LRV1), which has been associated with increased disease severity in animal models and humans and with drug treatment failures in humans. Remarkably, LRV1 survives in the presence of an active RNAi pathway, which in many organisms controls RNA viruses. We found significant levels (0.4 to 2.5%) of small RNAs derived from LRV1 in both Leishmania braziliensis and Leishmania guyanensis, mapping across both strands and with properties consistent with Dicer-mediated cleavage of the dsRNA genome. LRV1 lacks cis- or trans-acting RNAi inhibitory activities, suggesting that virus retention must be maintained by a balance between RNAi activity and LRV1 replication. To tilt this balance toward elimination, we targeted LRV1 using long-hairpin/stem-loop constructs similar to those effective against chromosomal genes. LRV1 was completely eliminated, at high efficiency, accompanied by a massive overproduction of LRV1-specific siRNAs, representing as much as 87% of the total. For both L. braziliensis and L. guyanensis, RNAi-derived LRV1-negative lines were no longer able to induce a Toll-like receptor 3-dependent hyperinflammatory cytokine response in infected macrophages. We demonstrate in vitro a role for LRV1 in virulence of L. braziliensis, the Leishmania species responsible for the vast majority of mucocutaneous leishmaniasis cases. These findings establish a targeted method for elimination of LRV1, and potentially of other Leishmania viruses, which will facilitate mechanistic dissection of the role of LRV1-mediated virulence. Moreover, our data establish a third paradigm for RNAi-viral relationships in evolution: one of balance rather than elimination.


Assuntos
Antiprotozoários/farmacologia , Leishmaniose Mucocutânea/tratamento farmacológico , Leishmaniavirus/efeitos dos fármacos , Oligorribonucleotídeos Antissenso/farmacologia , RNA de Cadeia Dupla/antagonistas & inibidores , RNA Viral/antagonistas & inibidores , Animais , Antiprotozoários/química , Antiprotozoários/metabolismo , Expressão Gênica , Sequências Repetidas Invertidas , Leishmania braziliensis/patogenicidade , Leishmania braziliensis/virologia , Leishmania guyanensis/patogenicidade , Leishmania guyanensis/virologia , Leishmaniose Mucocutânea/parasitologia , Leishmaniose Mucocutânea/virologia , Leishmaniavirus/genética , Leishmaniavirus/metabolismo , Macrófagos/parasitologia , Macrófagos/virologia , Camundongos , Oligorribonucleotídeos Antissenso/genética , Oligorribonucleotídeos Antissenso/metabolismo , Interferência de RNA/efeitos dos fármacos , RNA de Cadeia Dupla/genética , RNA de Cadeia Dupla/metabolismo , RNA Viral/genética , RNA Viral/metabolismo , Simbiose/genética , Receptor 3 Toll-Like/genética , Receptor 3 Toll-Like/metabolismo , Replicação Viral/efeitos dos fármacos
20.
Mediators Inflamm ; 2016: 7068287, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27073297

RESUMO

Leishmania (L.) amazonensis (La) and L. (V.) braziliensis (Lb) are responsible for a large clinical and immunopathological spectrum in human disease; while La may be responsible for anergic disease, Lb infection leads to cellular hypersensitivity. To better understand the dichotomy in the immune response caused by these Leishmania species, we evaluated subsets of dendritic cells (DCs) and T lymphocyte in draining lymph nodes during the course of La and Lb infection in BALB/c mice. Our results demonstrated a high involvement of DCs in La infection, which was characterized by the greater accumulation of Langerhans cells (LCs); conversely, Lb infection led to an increase in dermal DCs (dDCs) throughout the infection. Considering the T lymphocyte response, an increase of effector, activated, and memory CD4(+) T-cells was observed in Lb infection. Interleukin- (IL-) 4- and IL-10-producing CD4(+)and CD8(+) T-cells were present in both La and Lb infection; however, interferon- (IFN-) γ-producing CD4(+)and CD8(+) T-cells were detected only in Lb infection. The results suggest that during Lb infection, the dDCs were the predominant subset of DCs that in turn was associated with the development of Th1 immune response; in contrast La infection was associated with a preferential accumulation of LCs and total blockage of the development of Th1 immune response.


Assuntos
Células Dendríticas/metabolismo , Leishmania braziliensis/patogenicidade , Leishmania/patogenicidade , Linfonodos/metabolismo , Animais , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Células Dendríticas/imunologia , Citometria de Fluxo , Interferon gama/metabolismo , Interleucina-10/metabolismo , Interleucina-4/metabolismo , Leishmania/imunologia , Leishmania braziliensis/imunologia , Linfonodos/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C
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