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1.
Exp Dermatol ; 30(3): 304-318, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33131073

RESUMO

Dipeptidyl peptidase-4 (DPP4) is a multifunctional, transmembrane glycoprotein present on the cell surface of various tissues. It is present in multiple molecular forms including cell surface and soluble. The role of DPP4 and its inhibition in cutaneous dermatoses have been a recent point of investigation. DPP4 exerts a notable influence on T-cell biology, the induction of skin-specific lymphocytes, and the homeostasis between regulatory and effector T cells. Moreover, DPP4 interacts with a broad range of molecules, including adenosine deaminase, caveolin-1, CXCR4 receptor, M6P/insulin-like growth factor II-receptor and fibroblast activation protein-α, triggering downstream effects that modulate the immune response, cell adhesion and chemokine activity. DPP4 expression on melanocytes, keratinocytes and fibroblasts further alters cell function and, thus, has crucial implications in cutaneous pathology. As a result, DPP4 plays a significant role in bullous pemphigoid, T helper type 1-like reactions, cutaneous lymphoma, melanoma, wound healing and fibrotic disorders. This review illustrates the multifactorial role of DPP4 expression, regulation, and inhibition in cutaneous diseases.


Assuntos
Dipeptidil Peptidase 4/imunologia , Dipeptidil Peptidase 4/metabolismo , Inibidores da Dipeptidil Peptidase IV/efeitos adversos , Dermatopatias/enzimologia , Dermatopatias/etiologia , Animais , Biomarcadores Tumorais/metabolismo , Dermatite Atópica/genética , Dermatite Atópica/imunologia , Dipeptidil Peptidase 4/genética , Humanos , Imunidade , Queratinócitos/metabolismo , Leishmaniose Cutânea/enzimologia , Linfócitos/metabolismo , Linfoma Cutâneo de Células T/enzimologia , Penfigoide Mucomembranoso Benigno/induzido quimicamente , Penfigoide Bolhoso/induzido quimicamente , Psoríase/enzimologia , Neoplasias Cutâneas/enzimologia , Cicatrização
2.
Parasitology ; 145(12): 1499-1509, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29530102

RESUMO

This is a systematic review on the role of metalloproteases in the pathogenicity of the American tegumentary leishmaniasis (ATL) caused by New World Leishmania species. The review followed the PRISMA method, searching for articles in PubMed, EMBASE, LILACS and ISI Web of Science, by employing the following terms: 'leishmaniasis', 'cutaneous leishmaniasis', 'mucocutaneous leishmaniasis', 'diffuse cutaneous leishmaniasis', 'Leishmania' and 'metalloproteases'. GP63 of New World Leishmania species is a parasite metalloproteases involved in the degradation and cleavage of many biological molecules as kappa-B nuclear factor, fibronectin, tyrosine phosphatases. GP63 is capable of inhibiting the activity of the complement system and reduces the host's immune functions, allowing the survival of the parasite and its dissemination. High serological/tissue levels of host matrix metalloproteases (MMP)-9 have been associated with tissue damage during the infection, while high transcriptional levels of MMP-2 related with a satisfactory response to treatment. Host MMPs serological and tissue levels have been investigated using Western Blot, zymography, and Real Time polymerase chain reaction. GP63 detection characterizes species and virulence in promastigotes isolated from lesions samples using techniques mentioned previously. The monitoring of host MMPs levels and GP63 in Leishmania isolated from host samples could be used on the laboratory routine to predict the prognostic and treatment efficacy of ATL.


Assuntos
Leishmania/enzimologia , Leishmaniose Cutânea/enzimologia , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Metaloendopeptidases/metabolismo , Metaloproteases/metabolismo , Humanos , Leishmania/imunologia , Leishmania/patogenicidade , Leishmaniose Cutânea/diagnóstico , Leishmaniose Cutânea/parasitologia , Prognóstico , Virulência
3.
Parasitol Res ; 116(8): 2159-2166, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28560572

RESUMO

Apoptosis of infected host macrophages by Leishmania spp. is mainly addressed as one of the survival mechanisms of the parasite. However, there is no eligible data about whether tumor suppressor p53 could induce the apoptosis of host lymphocytes-treated Leishmania major via the mitochondrial intrinsic pathway. In this study, the amastigotes of L. major obtained from ten cutaneous leishmaniases (CL) patients were separately isolated and cultured in N.N.N and RPMI 1640 media. L. major was definitely confirmed by targeting Cyt b gene following sequencing. Subsequently, 2-3 × 106 lymphocytes obtained from ten healthy individuals were isolated and co-cultured with 1-2 × 106 L. major promastigotes. Following 6 h of exposure time, the enzymatic activity of caspase-3 was determined by fluorometric assay in each L. major-treated lymphocytes and cell control (only lymphocyte). The mRNA expressions of Bax, Bcl-2, p53, and caspase-3 genes were assessed by quantitative real-time-PCR analysis following 6 to 9 h of exposure times. The Bcl-2 mRNA expression in L. major-treated lymphocytes was 100-fold down-regulated relative to cell control. The mRNA expressions of p53 and caspase-3 were over-expressed 1.8- and 3.2-fold up-regulated relative to control lymphocytes, respectively. The Bax/Bcl-2 ratio and caspase-3 activity were higher than the control group (Pv <0.05). The current new findings indicate that the apoptotic effects of L. major-treated host lymphocytes dependent on p53 tumor suppressor via mitochondrial pathway may probably address as an auxiliary survival mechanism of L. major in CL patients. However, here is much work ahead to figure out the multiple functions played by apoptosis in the evasion of L. major.


Assuntos
Apoptose , Caspase 3/metabolismo , Leishmania major/fisiologia , Leishmaniose Cutânea/parasitologia , Linfócitos/parasitologia , Proteína Supressora de Tumor p53/metabolismo , Proteína X Associada a bcl-2/metabolismo , Adolescente , Adulto , Animais , Apoptose/efeitos dos fármacos , Criança , Ativação Enzimática , Feminino , Humanos , Leishmaniose Cutânea/enzimologia , Masculino , Mitocôndrias/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Adulto Jovem , Proteína X Associada a bcl-2/genética
4.
Arch Biochem Biophys ; 535(2): 163-76, 2013 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-23583962

RESUMO

Arginase from parasitic protozoa belonging to the genus Leishmania is a potential drug target for the treatment of leishmaniasis because this binuclear manganese metalloenzyme catalyzes the first committed step in the biosynthesis of polyamines that enable cell growth and survival. The high resolution X-ray crystal structures of the unliganded form of Leishmania mexicana arginase (LmARG) and four inhibitor complexes are now reported. These complexes include the reactive substrate analogue 2(S)-amino-6-boronohexanoic acid (ABH) and the hydroxylated substrate analogue nor-N(ω)-hydroxy-l-arginine (nor-NOHA), which are the most potent arginase inhibitors known to date. Comparisons of the LmARG structure with that of the archetypal arginase, human arginase I, reveal that all residues important for substrate binding and catalysis are strictly conserved. However, three regions of tertiary structure differ between the parasitic enzyme and the human enzyme corresponding to the G62 - S71, L161 - C172, and I219 - V230 segments of LmARG. Additionally, variations are observed in salt link interactions that stabilize trimer assembly in LmARG. We also report biological studies in which we demonstrate that localization of LmARG to the glycosome, a unique subcellular organelle peculiar to Leishmania and related parasites, is essential for robust pathogenesis.


Assuntos
Arginase/química , Leishmania mexicana/enzimologia , Proteínas de Protozoários/química , Aminocaproatos/química , Aminocaproatos/farmacologia , Animais , Antiparasitários/farmacologia , Arginase/antagonistas & inibidores , Arginina/análogos & derivados , Arginina/química , Arginina/farmacologia , Compostos de Boro/química , Compostos de Boro/farmacologia , Cristalografia por Raios X , Feminino , Humanos , Leishmania mexicana/efeitos dos fármacos , Leishmaniose Cutânea/enzimologia , Leishmaniose Cutânea/parasitologia , Camundongos , Camundongos Endogâmicos BALB C , Modelos Moleculares , Ornitina/química , Poliaminas/antagonistas & inibidores , Poliaminas/metabolismo , Conformação Proteica , Multimerização Proteica , Proteínas de Protozoários/antagonistas & inibidores
5.
J Infect Dis ; 205(1): 152-61, 2012 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-21990421

RESUMO

Recent studies have underscored physiological and pathophysiological roles for the tryptophan-degrading enzyme indolamine 2,3-dioxygenase (IDO) in immune counterregulation. However, IDO was first recognized as an antimicrobial effector, restricting tryptophan availability to Toxoplasma gondii and other pathogens in vitro. The biological relevance of these findings came under question when infectious phenotypes were not forthcoming in IDO-deficient mice. The recent discovery of an IDO homolog, IDO-2, suggested that the issue deserved reexamination. IDO inhibition during murine toxoplasmosis led to 100% mortality, with increased parasite burdens and no evident effects on the immune response. Similar studies revealed a counterregulatory role for IDO during leishmaniasis (restraining effector immune responses and parasite clearance), and no evident role for IDO in herpes simplex virus type 1 (HSV-1) infection. Thus, IDO plays biologically important roles in the host response to diverse intracellular infections, but the dominant nature of this role--antimicrobial or immunoregulatory--is pathogen-specific.


Assuntos
Herpes Simples/enzimologia , Herpesvirus Humano 1 , Indolamina-Pirrol 2,3,-Dioxigenase/imunologia , Leishmaniose Cutânea/imunologia , Toxoplasmose Animal/imunologia , Animais , Feminino , Herpes Simples/imunologia , Indolamina-Pirrol 2,3,-Dioxigenase/antagonistas & inibidores , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Leishmaniose Cutânea/enzimologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Toxoplasmose Animal/enzimologia , Triptofano/análogos & derivados , Triptofano/metabolismo
6.
Eur J Immunol ; 41(3): 706-15, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21287553

RESUMO

The protein kinase C (PKC) family is involved in the regulation of many intracellular signalling pathways. Here, we report that the PKCδ isoform regulates IL-12p40/p70 production in macrophages and DC and that PKCδ deficiency in mice transforms the 129/Sv healer to a non-healer strain during cutaneous leishmaniasis. Leishmania major-infected PKCδ(-/-) 129/Sv mice developed a rapid increase in footpad swelling and parasite burden with disease progression, leading to necrosis and ulceration similar to non-healer BALB/c mice. Moreover, PKCδ(-/-) mice failed to develop delayed-type hypersensitivity responses against Leishmania antigen. PKCδ(-/-) macrophages were fully functional with normal MHC class II surface expression and GM-CSF production, recruitment to the draining lymph node and killing effector functions by NO production. In contrast, macrophages and DC produced significantly reduced IL-12p40 and IL-12p70 compared to the WT cells. Decreased IL-12 production resulted in diminished Th1 differentiation, as determined by a striking reduction in IFN-γ by antigen-specific stimulated CD4(+) T cells isolated from popliteal lymph nodes of L. major-infected PKCδ(-/-) mice, explaining the "non-healer" phenotype. We conclude from these data that PKCδ is a regulator of IL-12p40/p70 production by DC and macrophages, driving the healer phenotype during cutaneous leishmaniasis.


Assuntos
Subunidade p40 da Interleucina-12/biossíntese , Interleucina-12/biossíntese , Leishmaniose Cutânea/enzimologia , Leishmaniose Cutânea/imunologia , Proteína Quinase C-delta/imunologia , Animais , Antígenos de Protozoários , Células Dendríticas/enzimologia , Células Dendríticas/imunologia , Modelos Animais de Doenças , Hipersensibilidade Tardia , Leishmania major/imunologia , Macrófagos/enzimologia , Macrófagos/imunologia , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos BALB C , Camundongos Knockout , Fenótipo , Proteína Quinase C-delta/deficiência , Proteína Quinase C-delta/genética , Especificidade da Espécie , Células Th1/enzimologia , Células Th1/imunologia
7.
FASEB J ; 25(12): 4162-73, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21846836

RESUMO

We 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-ß on induction of PKR-promoter activity. The observed effects required the engagement of TLR2. TLR2-KO macrophages expressed low IFN-ß 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/IFN-1-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.


Assuntos
Interferon Tipo I/metabolismo , Leishmania mexicana , Leishmaniose Cutânea/enzimologia , Leishmaniose Cutânea/imunologia , Receptor 2 Toll-Like/metabolismo , eIF-2 Quinase/metabolismo , Animais , Glicoesfingolipídeos/imunologia , Interações Hospedeiro-Parasita , Humanos , Leishmania mexicana/imunologia , Leishmania mexicana/patogenicidade , Leishmaniose Cutânea/genética , Leishmaniose Tegumentar Difusa/enzimologia , Leishmaniose Tegumentar Difusa/genética , Leishmaniose Tegumentar Difusa/imunologia , Macrófagos Peritoneais/enzimologia , Macrófagos Peritoneais/imunologia , Macrófagos Peritoneais/parasitologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Modelos Biológicos , Regiões Promotoras Genéticas , Transdução de Sinais , Superóxido Dismutase/genética , Superóxido Dismutase-1 , Receptor 2 Toll-Like/deficiência , Receptor 2 Toll-Like/genética , Transfecção , eIF-2 Quinase/genética
8.
J Immunol ; 184(6): 3098-105, 2010 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-20154209

RESUMO

We showed previously that mice with an inactivating knockin mutation in the p110delta isoform of PI3K (referred to as p110delta(D910A) mice) displayed enhanced primary resistance to Leishmania major despite mounting paradoxically impaired T cell responses. In this study, we show that p110delta(D910A) mice are impaired in their secondary (memory) anti-Leishmania responses in vitro and in vivo. Following secondary L. major challenge, p110delta(D910A) mice exhibited reduced delayed-type hypersensitivity response and weaker parasite control compared to wild-type mice. Using adoptive transfer experiments, we show that immune T cells from healed p110delta(D910A) mice were impaired in their proliferation and effector cytokine (IFN-gamma) responses upon L. major challenge. Interestingly, Leishmania-reactive T cells from healed p110delta(D910A) mice contain severalfold lower numbers of CD62L(lo) and CD62(hi) T cells than those from healed wild-type mice. The reduction in numbers of CD62L(lo) T cells in p110delta(D910A) mice is due to failure of their CD62L(hi) T cells to downregulate CD62L expression in response to L. major. Furthermore, although CD62L(lo) cells from p110delta(D910A) mice could home efficiently to lymphoid organs, their ability to exit these tissues and emigrate to cutaneous sites of infection was greatly impaired. Collectively, our data identify PI3K signaling as important events that control memory T cell subset differentiation, generation, effector function, and recruitment to cutaneous tissues and suggest that manipulating this pathway could provide means of enhancing desired memory T cell subset, response during vaccination, or both.


Assuntos
Diferenciação Celular/imunologia , Imunização Secundária/métodos , Memória Imunológica , Leishmania major/imunologia , Leishmaniose Cutânea/enzimologia , Leishmaniose Cutânea/imunologia , Fosfatidilinositol 3-Quinases/fisiologia , Subpopulações de Linfócitos T/enzimologia , Subpopulações de Linfócitos T/imunologia , Animais , Diferenciação Celular/genética , Classe I de Fosfatidilinositol 3-Quinases , Citocinas/biossíntese , Citocinas/deficiência , Regulação para Baixo/genética , Regulação para Baixo/imunologia , Epitopos de Linfócito T/genética , Epitopos de Linfócito T/imunologia , Técnicas de Introdução de Genes , Inativação Gênica/imunologia , Hipersensibilidade Tardia/enzimologia , Hipersensibilidade Tardia/imunologia , Hipersensibilidade Tardia/parasitologia , Memória Imunológica/genética , Isoenzimas/deficiência , Isoenzimas/genética , Isoenzimas/fisiologia , Leishmaniose Cutânea/patologia , Camundongos , Camundongos Endogâmicos C57BL , Fosfatidilinositol 3-Quinases/deficiência , Fosfatidilinositol 3-Quinases/genética , Vacinas Protozoárias/administração & dosagem , Vacinas Protozoárias/imunologia , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Subpopulações de Linfócitos T/parasitologia
9.
Clin Exp Immunol ; 163(2): 207-14, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21091666

RESUMO

Cutaneous lesions caused by Leishmania braziliensis infection occasionally heal spontaneously, but with antimonials therapy heal rapidly in approximately 3 weeks. However, about 15% of the cases require several courses of therapy. Matrix metalloproteinase-2 (MMP-2) and MMP-9 are gelatinases that have been implicated in other chronic cutaneous diseases and skin re-epithelialization. These enzymes are controlled by their natural inhibitors [tissue inhibitors of metalloproteinase (TIMPs)] and by some cytokines. Uncontrolled gelatinase activity may result in intense tissue degradation and, consequently, poorly healing wounds. The present study correlates gelatinase activity to therapeutic failure of cutaneous leishmaniasis (CL) lesions. Our results demonstrate an association between gelatinase activity and increased numbers of cells making interferon (IFN)-γ, interleukin (IL)-10 and transforming growth factor (TGF)-ß in lesions from poor responders. Conversely, high levels of MMP-2 mRNA and enhanced MMP-2 : TIMP-2 ratios were associated with a satisfactory response to antimonials treatment. Additionally, high gelatinolytic activity was found in the wound beds, necrotic areas in the dermis and within some granulomatous infiltrates. These results indicate the importance of gelatinase activity in the skin lesions caused by CL. Thus, we hypothesize that the immune response profile may be responsible for the gelatinase activity pattern and may ultimately influence the persistence or cure of CL lesions.


Assuntos
Antimônio/uso terapêutico , Antiprotozoários/uso terapêutico , Citocinas/imunologia , Leishmaniose Cutânea/tratamento farmacológico , Leishmaniose Cutânea/enzimologia , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Meglumina/uso terapêutico , Compostos Organometálicos/uso terapêutico , Pele/enzimologia , Adulto , Feminino , Humanos , Interferon gama/imunologia , Interleucina-10/imunologia , Leishmaniose Cutânea/imunologia , Masculino , Antimoniato de Meglumina , Regeneração , Pele/patologia , Fator de Crescimento Transformador beta/imunologia , Falha de Tratamento
10.
PLoS Pathog ; 5(6): e1000494, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19557162

RESUMO

Leishmania major parasites reside and multiply in late endosomal compartments of host phagocytic cells. Immune control of Leishmania growth absolutely requires expression of inducible Nitric Oxide Synthase (iNOS/NOS2) and subsequent production of NO. Here, we show that CD11b+ CD11c+ Ly-6C+ MHC-II+ cells are the main iNOS-producing cells in the footpad lesion and in the draining lymph node of Leishmania major-infected C57BL/6 mice. These cells are phenotypically similar to iNOS-producing inflammatory DC (iNOS-DC) observed in the mouse models of Listeria monocytogenes and Brucella melitensis infection. The use of DsRed-expressing parasites demonstrated that these iNOS-producing cells are the major infected population in the lesions and the draining lymph nodes. Analysis of various genetically deficient mouse strains revealed the requirement of CCR2 expression for the recruitment of iNOS-DC in the draining lymph nodes, whereas their activation is strongly dependent on CD40, IL-12, IFN-gamma and MyD88 molecules with a partial contribution of TNF-alpha and TLR9. In contrast, STAT-6 deficiency enhanced iNOS-DC recruitment and activation in susceptible BALB/c mice, demonstrating a key role for IL-4 and IL-13 as negative regulators. Taken together, our results suggest that iNOS-DC represent a major class of Th1-regulated effector cell population and constitute the most frequent infected cell type during chronic Leishmania major infection phase of C57BL/6 resistant mice.


Assuntos
Células Dendríticas/enzimologia , Leishmania major/imunologia , Leishmaniose Cutânea/imunologia , Óxido Nítrico Sintase Tipo II/biossíntese , Animais , Doença Crônica , Citocinas/metabolismo , Células Dendríticas/imunologia , Células Dendríticas/parasitologia , Citometria de Fluxo , Inflamação/enzimologia , Inflamação/parasitologia , Leishmaniose Cutânea/enzimologia , Leishmaniose Cutânea/parasitologia , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Linfonodos/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Óxido Nítrico Sintase Tipo II/metabolismo , Fenótipo , Receptores CCR2/metabolismo , Estatísticas não Paramétricas
11.
J Immunol ; 183(12): 8068-76, 2009 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-19923451

RESUMO

The balance between the products of L-arginine metabolism in macrophages regulates the outcome of Leishmania major infection. L-arginine can be oxidized by host inducible NO synthase to produce NO, which contributes to parasite killing. In contrast, L-arginine hydrolysis by host arginase blocks NO generation and provides polyamines, which can support parasite proliferation. Additionally, Leishmania encode their own arginase which has considerable potential to modulate infectivity and disease pathogenesis. In this study, we compared the infectivity and impact on host cellular immune response in vitro and in vivo of wild-type (WT) L. major with that of a parasite arginase null mutant (arg(-)) L. major. We found that arg(-) L. major are impaired in their macrophage infectivity in vitro independent of host inducible NO synthase activities. As with in vitro results, the proliferation of arg(-) L. major in animal infections was also significantly impaired in vivo, resulting in delayed onset of lesion development, attenuated pathology, and low parasite burden. Despite this attenuated pathology, the production of cytokines by cells from the draining lymph node of mice infected with WT and arg(-) L. major was similar at all times tested. Interestingly, in vitro and in vivo arginase levels were significantly lower in arg(-) than in WT-infected cases and were directly correlated with parasite numbers inside infected cells. These results suggest that Leishmania-encoded arginase enhances disease pathogenesis by augmenting host cellular arginase activities and that contrary to previous in vitro studies, the host cytokine response does not influence host arginase activity.


Assuntos
Arginase/metabolismo , Citocinas/fisiologia , Hiperargininemia/imunologia , Hiperargininemia/parasitologia , Leishmania major/enzimologia , Leishmania major/crescimento & desenvolvimento , Leishmaniose Cutânea/imunologia , Leishmaniose Cutânea/parasitologia , Adjuvantes Imunológicos/fisiologia , Animais , Arginase/genética , Arginase/fisiologia , Células da Medula Óssea/enzimologia , Células da Medula Óssea/imunologia , Células da Medula Óssea/patologia , Proliferação de Células , Células Cultivadas , Ativação Enzimática/genética , Ativação Enzimática/imunologia , Feminino , Hiperargininemia/enzimologia , Leishmania major/genética , Leishmaniose Cutânea/enzimologia , Macrófagos Peritoneais/enzimologia , Macrófagos Peritoneais/imunologia , Macrófagos Peritoneais/patologia , Camundongos , Camundongos Endogâmicos BALB C
12.
J Exp Med ; 183(4): 1501-14, 1996 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-8666908

RESUMO

Nitric oxide (NO) synthase (iNOS) is required for the resolution of acute cutaneous leishmaniasis in resistant C57BL/6 mice. As is the case in several other infections, the clinically cured host organism still harbors small amounts of live Leishmania major parasites. Here, we demonstrate lifelong expression of iNOS at the site of the original skin lesion and in the draining lymph node of long-term-infected C57BL/6 mice. iNOS activity in the lymph node was dependent on CD4+, but not on the CD8+ T cells. By double labeling techniques, iNOS and L. major were each found in macrophages (F4/80+, BM-8+, and/or MOMA-2+) and dendritic cells (NLDC-145+), but not in granulocytes or endothelial cells. In situ triple labeling of lymph node sections revealed that approximately 30-40% of the L. major foci were associated with iNOS-positive macrophages or dendritic cells. The majority of the L. major foci (60-70%), however, was located in areas that were negative for both iNOS and the macrophage and dendritic cell markers. In L. major-infected C57BL/6 mice, which had cured their cutaneous lesions, administration of L-N6-iminoethyl-lysine (L-NIL), a potent inhibitor of iNOS, led to a 10(4)-10(5)-fold increase of the parasite burden in the cutaneous and lymphoid tissue and caused clinical recrudescence of the disease. Persistent expression of iNOS and resumption of parasite replication after application of L-NIL was also observed in resistant C3H/HeN and CBA/J mice. We conclude that iNOS activity is crucial for the control of Leishmania persisting in immunocompetent hosts after resolution of the primary infection. Failure to maintain iNOS activity might be the mechanism underlying endogenous reactivation of latent infections with NO-sensitive microbes during phases of immunosuppression.


Assuntos
Inibidores Enzimáticos/farmacologia , Leishmania major/patogenicidade , Leishmaniose Cutânea/parasitologia , Óxido Nítrico Sintase/antagonistas & inibidores , Animais , Feminino , Interações Hospedeiro-Parasita , Leishmaniose Cutânea/enzimologia , Leishmaniose Cutânea/patologia , Lisina/análogos & derivados , Lisina/farmacologia , Camundongos , Camundongos Endogâmicos , Recidiva , Pele/enzimologia , Pele/parasitologia , Pele/patologia
13.
Am J Dermatopathol ; 32(1): 15-8, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19770631

RESUMO

Dendritic cells belong to a family of antigen-presenting cells that are localized at the entry sites, such as skin and mucosa. Dendritic cells are related to immune surveillance function. The role of Langerhans cells in the pathogenesis of skin infectious diseases is well studied; however, there are few articles addressing involvement of factor XIIIa-positive dermal dendrocytes (FXIIIa+ DD) in such processes. FXIIIa+ DDs are bone marrow-monocytic lineage-derived cells and members of the skin immune system. Due to their immune phenotype and functional characteristics, they are considered complementary cells to Langerhans cells in the process of antigen presentation and inducing immune response. To verify the interaction between FXIIIa+ DD and Leishmania amastigotes, 22 biopsies of American tegumentary leishmaniasis (ATL) skin lesions were subjected to double staining technique with anti-factor XIIIa and anti-Leishmania antibodies. FXIIIa+ DDs were hypertrophic and abundant in the cutaneous reaction of ATL. FXIIIa+ DDs harboring parasites were observed in 11 of 22 skin biopsies. The data obtained suggest that FXIIIa+ DD plays a role in the pathogenesis of ATL skin lesion as host cell, immune effector, and/or antigen-presenting cell.


Assuntos
Biomarcadores/metabolismo , Células Dendríticas/enzimologia , Derme/enzimologia , Fator XIIIa/metabolismo , Leishmaniose Cutânea/enzimologia , Derme/patologia , Granuloma/enzimologia , Granuloma/parasitologia , Granuloma/patologia , Interações Hospedeiro-Parasita , Humanos , Técnicas Imunoenzimáticas , Leishmania/isolamento & purificação , Leishmania/fisiologia , Leishmaniose Cutânea/patologia
14.
Biochem Pharmacol ; 180: 114191, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32777278

RESUMO

The protozoan parasite Leishmania braziliensis is a major causative agent of the neglected tropical diseases Cutaneous and Mucocutaneous Leishmaniases in the New World. There are no vaccines to prevent the infection and the treatment relies on few drugs that often display high toxicity and costs. Thus, chemotherapeutic alternatives are required. Histone Deacetylases (HDACs) are epigenetic enzymes involved in the control of chromatin structure. In this work, we tested an in-house library of 78 hydroxamic acid derivatives as putative inhibitors of L. braziliensis HDACs (HDACi). The compounds were evaluated in relation to the toxicity to the host cell macrophage and to the leishmanicidal effect against L. braziliensis during in vitro infection. Eight HDACi showed significant leishmanicidal effects and the top 5 compounds showed effective concentrations (EC50) in the range of 4.38 to 10.21 µM and selectivity indexes (SI) from of 6 to 21.7. Analyses by Transmission Electron Microscopy (TEM) indicated induction of apoptotic cell death of L. braziliensis amastigotes with a necrotic phenotype. An altered chromatin condensation pattern and cellular disorganization of intracellular amastigotes was also observed. A tight connection between the mitochondrion and nuclear protrusions, presumably of endoplasmic reticulum origin, was found in parasites but not in the host cell. In flow cytometry (FC) analyses, HDACi promoted parasite cell cycle arrest in the G2-M phase and no changes were found in macrophages. In addition, the direct effect of HDACi against the promastigotes showed apoptosis as the main mechanism of cell death. The FC results corroborate the TEM analyses indicating that the HDACi lead to changes in the cell cycle and induction of apoptosis of L. braziliensis. The production of nitric oxide by the infected macrophages was not altered after treatment with the top 5 compounds. Taken together, our results evidenced new HDACi as promising agents for the development of new treatments for American Tegumentary Leishmaniasis caused by L. braziliensis.


Assuntos
Inibidores de Histona Desacetilases/farmacologia , Histona Desacetilases/metabolismo , Leishmania braziliensis/efeitos dos fármacos , Leishmania braziliensis/enzimologia , Leishmaniose Cutânea/enzimologia , Animais , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Inibidores de Histona Desacetilases/uso terapêutico , Humanos , Leishmania braziliensis/ultraestrutura , Leishmaniose Cutânea/tratamento farmacológico , Leishmaniose Cutânea/patologia , Macrófagos/efeitos dos fármacos , Macrófagos/enzimologia , Macrófagos/ultraestrutura , Camundongos , Óxido Nítrico/antagonistas & inibidores , Óxido Nítrico/metabolismo , Células RAW 264.7
15.
Trop Med Int Health ; 14(9): 1071-85, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19624480

RESUMO

A series of 1048 Leishmania strains from Old World cutaneous leishmaniasis foci, isolated between 1981 and 2005, were studied by isoenzyme analysis. The strains were obtained from humans, rodents, dogs and sandflies from 33 countries. The four typically dermotropic species, Leishmania major, L. tropica, L. aethiopica and L. killicki, were found. The viscerotropic species L. donovani and L. infantum, which can occasionally be responsible for cutaneous leishmaniasis, are not considered in this paper. Leishmania major was the least polymorphic species (12 zymodemes, 638 strains). Leishmania tropica was characterized by a complex polymorphism varying according to focus (35 zymodemes, 329 strains). Leishmania aethiopica, a species restricted to East Africa, showed a high polymorphism, in spite of a limited number of strains (23 zymodemes, 40 strains). Leishmania killicki, mainly restricted to Tunisia had a single zymodeme for 39 strains. Recently a parasite close to L. killicki (one zymodeme, two strains) was isolated in Algeria, which lead us to revise the taxonomic status of this taxon.


Assuntos
Leishmania/enzimologia , Leishmaniose Cutânea/epidemiologia , África/epidemiologia , Animais , Ásia Central/epidemiologia , Ásia Ocidental/epidemiologia , Técnicas de Laboratório Clínico , Análise por Conglomerados , Cães , Humanos , Isoenzimas/análise , Leishmaniose Cutânea/enzimologia , Leishmaniose Cutânea/parasitologia , Psychodidae , Ratos , Especificidade da Espécie
16.
J Leukoc Biol ; 106(3): 631-640, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31063608

RESUMO

The NLRP3 inflammasome is activated in response to multiple stimuli and triggers activation of caspase-1 (CASP1), IL-1ß production, and inflammation. NLRP3 activation requires two signals. The first leads to transcriptional regulation of specific genes related to inflammation, and the second is triggered when pathogens, toxins, or specific compounds damage cellular membranes and/or trigger the production of reactive oxygen species (ROS). Here, we assess the requirement of the first signal (priming) for the activation of the NLRP3 inflammasome in bone marrow-derived macrophages (BMDMs) infected with Leishmania amazonensis. We found that BMDMs express the inflammasome components NLRP3, ASC, and CASP1 at sufficient levels to enable the assembly and activation of NLRP3 inflammasome in response to infection. Therefore, priming was not required for the formation of ASC specks, CASP1 activation (measured by fluorescent dye FAM-YVAD), and restriction of L. amazonensis replication via the NLRP3 inflammasome. By contrast, BMDM priming was required for CASP1 cleavage (p20) and IL-1ß secretion, because priming triggers robust up-regulation of pro-IL-1ß and CASP11 that are important for efficient processing of CASP1 and IL-1ß. Taken together, our data shed light into the cellular and molecular processes involved in activation of the NLRP3 in macrophages by Leishmania, a process that is important for the outcome of Leishmaniasis.


Assuntos
Inflamassomos/metabolismo , Leishmania mexicana/fisiologia , Macrófagos/parasitologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Animais , Proteínas Adaptadoras de Sinalização CARD/metabolismo , Ativação Enzimática , Interleucina-1alfa/metabolismo , Interleucina-1beta/metabolismo , Leishmania mexicana/crescimento & desenvolvimento , Leishmaniose Cutânea/enzimologia , Leishmaniose Cutânea/imunologia , Leishmaniose Cutânea/parasitologia , Ligantes , Lipopolissacarídeos , Macrófagos/metabolismo , Camundongos Endogâmicos C57BL , Parasitos/crescimento & desenvolvimento , Receptores de Interleucina-1/metabolismo , Receptores Toll-Like/agonistas , Receptores Toll-Like/metabolismo , Regulação para Cima
17.
Exp Parasitol ; 120(3): 275-9, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18682252

RESUMO

Protozoan parasites of the genus Leishmania escape from the immune response by interfering with signal transduction pathways of its host cell, the macrophage, thereby establishing permissive conditions for intracellular survival. Inhibition of macrophage activation after Leishmania infection has been suggested to require activation of the host cell phosphatase SHP-1. However, by utilizing infections of SHP-1 deficient (me(v)) and CD45 null mutant mice or macrophages, we provide evidence that intracellular survival of Leishmania major is not generally dependent on these cellular phosphatases.


Assuntos
Leishmania major/fisiologia , Leishmaniose Cutânea/parasitologia , Antígenos Comuns de Leucócito/deficiência , Macrófagos Peritoneais/parasitologia , Proteína Tirosina Fosfatase não Receptora Tipo 6/deficiência , Animais , Células Cultivadas , Feminino , Leishmania major/imunologia , Leishmania major/patogenicidade , Leishmaniose Cutânea/enzimologia , Leishmaniose Cutânea/imunologia , Ativação de Macrófagos/fisiologia , Macrófagos Peritoneais/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Óxido Nítrico/metabolismo , Transdução de Sinais/fisiologia , Virulência
18.
Bioorg Med Chem Lett ; 17(23): 6563-6, 2007 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-17936625

RESUMO

The synthesis of novel dipeptidyl alpha-fluorovinyl sulfones using a Horner-Wadsworth-Emmons approach on N-Boc-l-phenylalaninal is described. Inhibitory assays against a Leishmania mexicana cysteine protease (CPB2.8DeltaCTE) revealed low biological activity. Relative rates of Michael additions of 2'-(phenethyl)thiol with vinyl sulfone and alpha-fluorovinyl sulfone were determined, and ab initio calculations on several Michael acceptor model structures were performed; both were in agreement with the biological testing results.


Assuntos
Cisteína Endopeptidases , Inibidores de Cisteína Proteinase/síntese química , Dipeptídeos/síntese química , Animais , Sítios de Ligação/efeitos dos fármacos , Cisteína Endopeptidases/metabolismo , Inibidores de Cisteína Proteinase/farmacologia , Dipeptídeos/farmacologia , Leishmania mexicana/efeitos dos fármacos , Leishmania mexicana/enzimologia , Leishmania mexicana/crescimento & desenvolvimento , Leishmaniose Cutânea/tratamento farmacológico , Leishmaniose Cutânea/enzimologia , Leishmaniose Cutânea/parasitologia , Modelos Moleculares
19.
Biomed Res Int ; 2017: 1309485, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29181385

RESUMO

Leishmaniasis is an infectious disease caused by protozoan parasites of the genus Leishmania. There is no vaccine against human leishmaniasis and the treatment of the disease would benefit from a broader spectrum and a higher efficacy of leishmanicidal compounds. We analyzed the leishmanicidal activity and the mechanism of action of the calcium ionophore, calcimycin. L. major promastigotes were coincubated with calcimycin and the viability of the cells was assessed using resazurin assay. Calcimycin displayed dose-dependent effect with IC50 = 0.16 µM. Analysis of propidium iodide/LDS-751 stained promastigotes revealed that lower concentrations of calcimycin had cytostatic effect and higher concentrations had cytotoxic effect. To establish the mechanism of action of calcimycin, which is known to stimulate activity of mammalian constitutive nitric oxide synthase (NOS), we coincubated L. major promastigotes with calcimycin and selective NOS inhibitors ARL-17477 or L-NNA. Addition of these inhibitors substantially decreased the toxicity of calcimycin to Leishmania promastigotes. In doing so, we demonstrated for the first time that calcimycin has a direct leishmanicidal effect on L. major promastigotes. Also, we showed that Leishmania constitutive Ca2+/calmodulin-dependent nitric oxide synthase is involved in the parasite cell death. These data suggest activation of Leishmania nitric oxide synthase as a new therapeutic approach.


Assuntos
Calcimicina/farmacologia , Ionóforos de Cálcio/farmacologia , Leishmania major/enzimologia , Óxido Nítrico Sintase/metabolismo , Proteínas de Protozoários/metabolismo , Ativação Enzimática , Leishmaniose Cutânea/tratamento farmacológico , Leishmaniose Cutânea/enzimologia
20.
FASEB J ; 19(8): 1000-2, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15811879

RESUMO

Arginase 1, an enzyme induced by Th2 cytokines, is a hallmark of alternatively activated macrophages and is responsible for the hydrolysis of L-arginine into ornithine, the building block for the production of polyamines. Upregulation of arginase 1 has been observed in a variety of diseases, but the mechanisms by which arginase contributes to pathology are not well understood. We reveal here a unique role for arginase 1 in the pathogenesis of nonhealing leishmaniasis, a prototype Th2 disease, and demonstrate that the activity of this enzyme promotes pathology and uncontrolled growth of Leishmania parasites in vivo. Inhibition of arginase activity during the course of infection has a clear therapeutic effect, as evidenced by markedly reduced pathology and efficient control of parasite replication. Despite the clear amelioration of the disease, this treatment does not alter the Th2 response. To address the underlying mechanisms, the arginase-induced L-arginine catabolism was investigated and the results demonstrate that arginase regulates parasite growth directly by affecting the polyamine synthesis in macrophages.


Assuntos
Arginase/fisiologia , Leishmania major/crescimento & desenvolvimento , Leishmaniose Cutânea/enzimologia , Poliaminas/metabolismo , Animais , Arginase/antagonistas & inibidores , Arginase/genética , Arginina/metabolismo , Células da Medula Óssea , Inibidores Enzimáticos/farmacologia , Leishmania major/enzimologia , Leishmaniose Cutânea/parasitologia , Leishmaniose Cutânea/terapia , Ativação de Macrófagos , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Reação em Cadeia da Polimerase , RNA Mensageiro/análise , Células Th1/imunologia , Células Th2/imunologia
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