Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 112
Filtrar
Más filtros

Intervalo de año de publicación
1.
Infect Immun ; 89(2)2021 01 19.
Artículo en Inglés | MEDLINE | ID: mdl-33139381

RESUMEN

Leishmania, the causative agent of leishmaniasis, is an intracellular pathogen that thrives in the insect gut and mammalian macrophages to complete its life cycle. Apart from temperature difference (26 to 37°C), it encounters several harsh conditions, including oxidative stress, inflammatory reactions, and low pH. Heat shock proteins (HSPs) play essential roles in cell survival by strategically reprogramming cellular processes and signaling pathways. HSPs assist cells in multiple functions, including differentiation, adaptation, virulence, and persistence in the host cell. Due to cyclical epidemiological patterns, limited chemotherapeutic options, drug resistance, and the absence of a vaccine, control of leishmaniasis remains a far-fetched dream. The essential roles of HSPs in parasitic differentiation and virulence and increased expression in drug-resistant strains highlight their importance in combating the disease. In this review, we highlighted the diverse physiological importance of HSPs present in Leishmania, emphasizing their significance in disease pathogenesis. Subsequently, we assessed the potential of HSPs as a chemotherapeutic target and underlined the challenges associated with it. Furthermore, we have summarized a few ongoing drug discovery initiatives that need to be explored further to develop clinically successful chemotherapeutic agents in the future.


Asunto(s)
Diferenciación Celular/fisiología , Proliferación Celular/fisiología , Supervivencia Celular/fisiología , Proteínas de Choque Térmico/efectos adversos , Proteínas de Choque Térmico/uso terapéutico , Leishmania/crecimiento & desarrollo , Leishmaniasis/fisiopatología , Leishmaniasis/terapia , Animales , Humanos , Insectos Vectores/crecimiento & desarrollo , Psychodidae/crecimiento & desarrollo
2.
Cytokine ; 147: 155310, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-33127256

RESUMEN

The blood vascular system of mammals is unique in nature; inhabited with a pool of tiny small cell fragments called platelets; attributed with the most important patrolling tasks to check integrity of the entire endothelial landscape. Their production is tightly coupled with hematopoietic system where everything starts from self renewable multipotent hematopoietic stem cells (HSCs) which eventually undergo dual step (megakaryopoiesis-thrombopoiesis) thrombocytes production. Several cytokines tune the fate of every progenitor cells during hematopoiesis through temporal activation of specific transcription factors. Though platelets generated through steady state hematopoiesis are involved in the regulation of vascular homeostasis, these cells can sense pathogens through its innate immune sensors and can mount crucial responses against the invading pathogen. For this, the primary aim of many infections including Leishmania is to induce thrombocytopenia within infected host. But the underlying mechanism of this induced thrombocytopenia in Leishmania infection has not been evaluated. Elucidation of these mechanisms will be fruitful to design new chemotherapeutic strategies.


Asunto(s)
Leishmaniasis/fisiopatología , Trombopoyesis/fisiología , Animales , Citocinas/metabolismo , Células Madre Hematopoyéticas/metabolismo , Células Madre Hematopoyéticas/fisiología , Humanos , Inmunidad Innata/fisiología , Leishmaniasis/metabolismo , Trombocitopenia/metabolismo , Trombocitopenia/fisiopatología
3.
Iran J Med Sci ; 46(1): 43-51, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33487791

RESUMEN

Background: Cutaneous leishmaniasis caused by Leishmania species (L. spp) is one of the most important parasitic diseases in humans. To gain information on the metabolite variations and biochemical pathways between L. spp, we used the comparative metabolome of metacyclic promastigotes in the Iranian isolates of L. major and L. tropica by proton nuclear magnetic resonance (1H-NMR). Methods: L. tropica and L. major were collected from three areas of Iran, namely Gonbad, Mashhad, and Bam, between 2017 and 2018, and were cultured. The metacyclic promastigote of each species was separated, and cell metabolites were extracted. 1H-NMR spectroscopy was applied, and the data were processed using ProMatab in MATLAB (version 7.8.0.347). Multivariate statistical analyses, including the principal component analysis and the orthogonal projections to latent structures discriminant analysis, were performed to identify the discriminative metabolites between the two L. spp. Metabolites with variable influences in projection values of more than one and a P value of less than 0.05 were marked as significant differences. Results: A set of metabolites were detected, and 24 significantly differentially expressed metabolites were found between the metacyclic forms of L. major and L. tropica isolates. The top differential metabolites were methionine, aspartate, betaine, and acetylcarnitine, which were increased more in L. tropica than L. major (P<0.005), whereas asparagine, 3-hydroxybutyrate, L-proline, and kynurenine were increased significantly in L. major (P<0.01). The significantly altered metabolites were involved in eight metabolic pathways. Conclusion: Metabolomics, as an invaluable technique, yielded significant metabolites, and their biochemical pathways related to the metacyclic promastigotes of L. major and L. tropica. The findings offer greater insights into parasite biology and how pathogens adapt to their hosts.


Asunto(s)
Leishmaniasis/fisiopatología , Metabolómica/métodos , Humanos , Irán/epidemiología , Leishmania major/efectos de los fármacos , Leishmania major/patogenicidad , Leishmania tropica/efectos de los fármacos , Leishmania tropica/patogenicidad , Leishmaniasis/diagnóstico , Leishmaniasis/epidemiología , Espectroscopía de Resonancia Magnética/métodos , Metabolómica/estadística & datos numéricos
4.
Parasite Immunol ; 40(11): e12586, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30187512

RESUMEN

Mammalian target of rapamycin (mTOR) is a central regulator of growth and immunity of host cells. It's involvement in cancer and tuberculosis is well documented but least explored in Leishmania donovani invasion of host cells. Therefore, in the present study, we aimed to investigate the role of mTOR in M2 macrophage polarization for Leishmania survival. We observed that Leishmania infection activated host mTOR pathway characterized by phosphorylation of mTOR, 70S6K and 4-EBP1. Inhibition of mTOR resulted in decreased parasite load and percent infectivity. Moreover, Leishmania infection triggered cell proliferation as was evidenced by increased expression of cyclin A and p-RPS6. mTOR activation during Leishmania infection resulted in reduced expression of M1 macrophage markers (eg, ROS, NO, iNOS, NOX-1, IL-12, IL-1ß and TNF-α), and increased expression of M2 macrophage markers (eg, arginase-1, IL-10, TGF-ß, CD206 and CD163). Furthermore, we observed that in case of Leishmania infection, mTOR inhibition increased the translocation of NF-κB to nucleus and deactivation of STAT-3. Eventually, we observed that inhibition of M2 macrophage polarization reduced Leishmania survival inside macrophages. Therefore, our findings suggest that mTOR plays a crucial role in regulation of M2 macrophage polarization and direct the innate immune homeostasis towards parasite survival inside host.


Asunto(s)
Leishmaniasis/inmunología , Macrófagos/citología , Macrófagos/inmunología , Serina-Treonina Quinasas TOR/inmunología , Animales , Polaridad Celular , Supervivencia Celular , Femenino , Humanos , Interleucina-12/genética , Interleucina-12/inmunología , Interleucina-1beta/genética , Interleucina-1beta/inmunología , Leishmania donovani/inmunología , Leishmania donovani/fisiología , Leishmaniasis/genética , Leishmaniasis/parasitología , Leishmaniasis/fisiopatología , Ratones , Ratones Endogámicos BALB C , FN-kappa B/genética , FN-kappa B/inmunología , Transducción de Señal , Serina-Treonina Quinasas TOR/genética , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/inmunología
5.
Parasitology ; 143(11): 1347-57, 2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-27221985

RESUMEN

Iron is an essential cofactor for many basic metabolic pathways in pathogenic microbes and their hosts. It is also dangerous as it can catalyse the production of reactive free radicals. This dual character makes the host can either limit iron availability to invading microbes or exploit iron to induce toxicity to pathogens. Successful pathogens, including Leishmania species, must possess mechanisms to circumvent host's iron limitation and iron-induced toxicity in order to survive. In this review, we discuss the regulation of iron metabolism in the setting of infection and delineate the iron acquisition strategies used by Leishmania parasites and their subversions to host iron metabolism to overcome host's iron-related defences.


Asunto(s)
Hierro/metabolismo , Leishmania/metabolismo , Leishmaniasis/metabolismo , Leishmaniasis/parasitología , Animales , Interacciones Huésped-Parásitos , Humanos , Leishmania/patogenicidad , Leishmaniasis/fisiopatología , Ratones
6.
Parasite Immunol ; 37(8): 385-93, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25983042

RESUMEN

Leishmaniasis is a vectorborne disease caused by Leishmania protozoa, which is a major health problem and a neglected disease common in many regions of the world. Leishmania is an intracellular parasite transmitted by sand flies that causes clinical manifestations ranging from a severe and potentially fatal disease named visceral leishmaniasis to less severe but in many cases disfiguring diseases that mainly affect the skin or mucosal tissues, known as cutaneous leishmaniasis. Despite the detection of Leishmania parasites in the brain and cerebrospinal fluid of human patients and dogs, epidemiological data, as well as information about the mechanisms of central and peripheral nervous system alterations, are poorly described. This review is focused on the current knowledge about the neurological manifestations and immunopathogenic mechanisms in human patients and animals infected with Leishmania.


Asunto(s)
Enfermedades de los Perros/fisiopatología , Leishmania/parasitología , Leishmaniasis/fisiopatología , Animales , Enfermedades de los Perros/inmunología , Perros , Humanos , Leishmaniasis/inmunología
7.
Public Health Nurs ; 32(6): 680-701, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25229995

RESUMEN

Although Neglected Tropical Diseases (NTDs) are largely endemic in the developing nations of Africa, Asia, and South and Central America, they are reemerging with increasing frequency in developed countries. Their diagnosis, treatment, and control are an increasing public health concern that requires a different awareness by health care providers. Neglected tropical diseases (NTDs) are chronic infectious diseases which disproportionately burden poor, rural, and marginalized populations with significant mortality and high morbidity (disability, disfigurement, impaired childhood growth and cognitive development, increased vulnerability to coinfection) that reinforces their poverty. What can we learn from the nurses in developing countries already battling NTD's that could be useful in the developed world? This article provides an overview of distribution, pathophysiology, symptoms, and management of 13 NTDs, with particular attention to the role of nurses in delivering cost-effective integrated interventions. Case studies of schistosomiasis, Chagas disease, and leishmaniasis address recognition and treatment of infected individuals in developed nations where NTD infection is limited primarily to immigrants and travelers.


Asunto(s)
Enfermedades Desatendidas/enfermería , Enfermeras de Salud Pública , Medicina Tropical , Enfermedad de Chagas/enfermería , Enfermedad de Chagas/fisiopatología , Países Desarrollados , Países en Desarrollo , Emigrantes e Inmigrantes , Humanos , Leishmaniasis/enfermería , Leishmaniasis/fisiopatología , Enfermedades Desatendidas/fisiopatología , Esquistosomiasis/enfermería , Esquistosomiasis/fisiopatología , Viaje
8.
Mem Inst Oswaldo Cruz ; 109(1): 61-9, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24626303

RESUMEN

Fibrocytes are important for understanding the progression of many diseases because they are present in areas where pathogenic lesions are generated. However, the morphology of fibrocytes and their interactions with parasites are poorly understood. In this study, we examined the morphology of peripheral blood fibrocytes and their interactions with Leishmania (L.) amazonensis . Through ultrastructural analysis, we describe the details of fibrocyte morphology and how fibrocytes rapidly internalise Leishmania promastigotes. The parasites differentiated into amastigotes after 2 h in phagolysosomes and the infection was completely resolved after 72 h. Early in the infection, we found increased nitric oxide production and large lysosomes with electron-dense material. These factors may regulate the proliferation and death of the parasites. Because fibrocytes are present at the infection site and are directly involved in developing cutaneous leishmaniasis, they are targets for effective, non-toxic cell-based therapies that control and treat leishmaniasis.


Asunto(s)
Fibroblastos/parasitología , Leishmania/fisiología , Leishmaniasis/fisiopatología , Leucocitos Mononucleares/parasitología , Análisis de Varianza , Animales , Fibroblastos/ultraestructura , Citometría de Flujo , Interacciones Huésped-Parásitos/fisiología , Mesodermo/citología , Ratones Endogámicos BALB C/parasitología , Microscopía Electrónica de Rastreo , Microscopía Electrónica de Transmisión , Óxido Nítrico/análisis , Óxido Nítrico/biosíntesis , Cultivo Primario de Células , Estadísticas no Paramétricas , Factores de Tiempo
9.
PLoS One ; 16(6): e0252419, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34101727

RESUMEN

BACKGROUND: Visceral Leishmaniasis (VL) is a neglected tropical disease endemic to several countries including Ethiopia. Outside of Africa, kidney involvement in VL is frequent and associated with increased mortality. There is however limited data on acute kidney injury (AKI) in VL patients in East-Africa, particularly in areas with high rates of HIV co-infection. This study aims to determine the prevalence, characteristics and associated factors of AKI in VL patients in Northwest Ethiopia. METHODS: A hospital based retrospective patient record analysis was conducted including patients treated for VL from January 2019 to December 2019 at the Leishmaniasis Research and Treatment Center (LRTC), Gondar, Ethiopia. Patients that were enrolled in ongoing clinical trials at the study site and those with significant incomplete data were excluded. Data was analyzed using SPSS version 20. P values were considered significant if < 0.05. RESULTS: Among 352 VL patients treated at LRTC during the study period, 298 were included in the study. All were male patients except two; the median age was 23 years (IQR: 20-27). The overall prevalence of AKI among VL patients was 17.4% (confidence interval (CI): 13.6%-22.2%). Pre-renal azotemia (57%) and drug-induced AKI (50%) were the main etiologies of AKI at admission and post-admission respectively. Proteinuria and hematuria occurred in 85% and 42% of AKI patients respectively. Multivariate logistic regression revealed HIV co-infection (adjusted odds ratio (AOR): 6.01 95% CI: 1.99-18.27, p = 0.001) and other concomitant infections (AOR: 3.44 95% CI: 1.37-8.65, p = 0.009) to be independently associated with AKI. CONCLUSION: AKI is a frequent complication in Ethiopian VL patients. Other renal manifestations included proteinuria, hematuria, and pyuria. HIV co-infection and other concomitant infections were significantly associated with AKI. Further studies are needed to quantify proteinuria and evaluate the influence of AKI on the treatment course, morbidity and mortality in VL patients.


Asunto(s)
Leishmaniasis Visceral/fisiopatología , Lesión Renal Aguda/patología , Lesión Renal Aguda/fisiopatología , Adolescente , Adulto , Coinfección/patología , Coinfección/fisiopatología , Etiopía , Infecciones por VIH/patología , Infecciones por VIH/fisiopatología , Humanos , Leishmaniasis/patología , Leishmaniasis/fisiopatología , Leishmaniasis Visceral/patología , Persona de Mediana Edad , Oportunidad Relativa , Estudios Retrospectivos , Factores de Riesgo , Adulto Joven
10.
PLoS Negl Trop Dis ; 15(10): e0009224, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34710089

RESUMEN

Leishmaniasis is a neglected tropical disease with diverse outcomes ranging from self-healing lesions, to progressive non-healing lesions, to metastatic spread and destruction of mucous membranes. Although resolution of cutaneous leishmaniasis is a classic example of type-1 immunity leading to self-healing lesions, an excess of type-1 related inflammation can contribute to immunopathology and metastatic spread. Leishmania genetic diversity can contribute to variation in polarization and robustness of the immune response through differences in both pathogen sensing by the host and immune evasion by the parasite. In this study, we observed a difference in parasite chemokine suppression between the Leishmania (L.) subgenus and the Viannia (V.) subgenus, which is associated with severe immune-mediated pathology such as mucocutaneous leishmaniasis. While Leishmania (L.) subgenus parasites utilize the virulence factor and metalloprotease glycoprotein-63 (gp63) to suppress the type-1 associated host chemokine CXCL10, L. (V.) panamensis did not suppress CXCL10. To understand the molecular basis for the inter-species variation in chemokine suppression, we used in silico modeling to identify a putative CXCL10-binding site on GP63. The putative CXCL10 binding site is in a region of gp63 under significant positive selection, and it varies from the L. major wild-type sequence in all gp63 alleles identified in the L. (V.) panamensis reference genome. Mutating wild-type L. (L.) major gp63 to the L. (V.) panamensis sequence at the putative binding site impaired cleavage of CXCL10 but not a non-specific protease substrate. Notably, Viannia clinical isolates confirmed that L. (V.) panamensis primarily encodes non-CXCL10-cleaving gp63 alleles. In contrast, L. (V.) braziliensis has an intermediate level of activity, consistent with this species having more equal proportions of both alleles. Our results demonstrate how parasite genetic diversity can contribute to variation in immune responses to Leishmania spp. infection that may play critical roles in the outcome of infection.


Asunto(s)
Quimiocina CXCL10/metabolismo , Leishmania major/enzimología , Leishmaniasis/metabolismo , Metaloendopeptidasas/metabolismo , Sitios de Unión , Quimiocina CXCL10/química , Quimiocina CXCL10/genética , Interacciones Huésped-Parásitos , Humanos , Leishmania major/química , Leishmania major/genética , Leishmaniasis/genética , Leishmaniasis/parasitología , Leishmaniasis/fisiopatología , Metaloendopeptidasas/química , Metaloendopeptidasas/genética , Unión Proteica , Factores de Virulencia/química , Factores de Virulencia/genética , Factores de Virulencia/metabolismo
11.
PLoS One ; 16(11): e0260022, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34797863

RESUMEN

BACKGROUND: Visceral leishmaniasis (VL) is one of the major public health burden, mainly distributed throughout tropical and subtropical regions of the world. Among the Sub-Saharan African countries, Ethiopia is the second most affected country with VL. An Alteration of liver function is a typical manifestation of the disease. OBJECTIVE: The purpose of conducting this study was to assess liver function tests and associated risk factors among VL patients at Leishmaniasis Research and Treatment Center of University of Gondar Comprehensive Specialized Hospital, North West Ethiopia. METHOD: Hospital based comparative cross-sectional study design was conducted. A total of 102 study participants were involved in this study. Newly diagnosed VL patients who were attended at Leishmaniasis Research and Treatment Center of University of Gondar Comprehensive Specialized Hospital from 21st February 2020 to 30th September 2020 were included under case group category. On the other hand, age-sex matched apparently healthy study subjects were categorized as control group. Written consent was obtained willingness of patients to participate after ethical clearance was obtained from the Institutional Review Board of School of Medicine, University of Gondar. After overnight fasting, 5ml venous blood was drawn from both VL patients and controls to evaluate liver function tests, including AST, ALT, total bilirubin, albumin, and total protein. Thus, senior health professionals (laboratory technologist) investigate the results using Cobas Integra 400 Plus clinical chemistry analyzer. Data was entered into Epi-data version 4.6 and exported to STATA 14 for analysis of liver function tests and associated risk factors. RESULT: The result of this study showed that significant mean difference was exhibited in aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin, serum albumin, and total protein level among VL patients and controls. It showed that there was a statistically significant elevation in the level of AST, ALT, and total bilirubin among cases as compared to control. The serum AST level was significantly (p<0.001) elevated among cases as compared to controls. Serum ALT was significantly (p<0.001) elevated among cases compared to controls. Additionally, the total serum bilirubin level was significantly increased (P<0.001) among cases as compared to controls. There was a statistically significant (P<0.001) reduction of serum albumin level among VL patients as compared to controls. Similarly, serum total protein was significantly (P<0.001) reduced in VL patients than control groups. CONCLUSION: There were significantly higher mean levels of serum AST, ALT, and total bilirubin among VL patients as compared to controls. On the other hand, VL patients showed significantly lowered level of albumin and total protein as compared to controls.


Asunto(s)
Leishmaniasis Visceral/fisiopatología , Pruebas de Función Hepática/métodos , Adulto , Alanina Transaminasa/análisis , Alanina Transaminasa/sangre , Aspartato Aminotransferasas/análisis , Aspartato Aminotransferasas/sangre , Bilirrubina/análisis , Bilirrubina/sangre , Estudios Transversales , Etiopía/epidemiología , Hospitales Especializados , Humanos , Leishmaniasis/fisiopatología , Hígado/citología , Hígado/metabolismo , Masculino , Factores de Riesgo , Albúmina Sérica/análisis , Adulto Joven
12.
J Exp Med ; 169(1): 59-72, 1989 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-2521244

RESUMEN

We purified poly(A)+ mRNA from the spleen and lymph nodes at designated times after infection with Leishmania major in genetically susceptible BALB/c and resistant C57BL/6 mice. The steady-state levels of IL-2, IFN-gamma, IL-4, and IL-1 beta mRNA were determined using Northern hybridizations. IL-2 mRNA levels in the infected organs of BALB/c and C57BL/6 mice were comparable after infection, but IFN-gamma and IL-4 mRNA levels were reciprocally expressed. Levels of IFN-gamma mRNA in C57BL/6 draining nodes and spleen were significantly greater than in BALB/c mice except at 4 and 6 wk of infection, when splenic IFN-gamma mRNA levels were transiently comparable. In contrast, IL-4 mRNA was apparent only in BALB/c and not in C57BL/6 nodes and spleen. Tissue levels of IL-1 beta mRNA were 10-20-fold greater in BALB/c mice. BALB/c mice were pretreated with GK1.5 mAb, a manipulation that promotes healing of subsequent infection by transiently depleting L3T4+ cells. At 8 wk of infection, by which time lymphoid organs were repopulated with L3T4+ cells, GK1.5-pretreated BALB/c mice produced IFN-gamma, but not IL-4 message. Serum levels of IgE were markedly elevated in infected BALB/c, but not in infected C57BL/6 or GK1.5-pretreated BALB/c mice, consistent with in vivo biologic activity of IL-4 in nonhealing mice. Treatment of infected BALB/c mice with neutralizing anti-IL-4 antibody abolished the elevation of serum IgE and significantly attenuated the progression of disease as assessed by size and ulceration of the lesion, and by reduction in the number of tissue parasites. Both protective and deleterious responses to Leishmania infection have previously been shown to be L3T4+ cell dependent. Our findings are consistent with the differential expansion of protective, IFN-gamma-producing Th1 cells in healing mice, and the expansion of deleterious, IL-4-producing Th2 cells in nonhealing mice. The inverse relationship of IFN-gamma and IL-4 gene expression during leishmaniasis may underlie the divergence of cellular and humoral immunity that occurs during chronic infection with Leishmania and possibly other intracellular parasites.


Asunto(s)
Interferón gamma/fisiología , Interleucinas/fisiología , Leishmaniasis/fisiopatología , Linfocitos T Colaboradores-Inductores/inmunología , Animales , Reacciones Antígeno-Anticuerpo , Antígenos de Diferenciación de Linfocitos T/inmunología , Regulación de la Expresión Génica , Inmunoglobulina E/sangre , Interleucina-4 , Leishmaniasis/parasitología , Ganglios Linfáticos/fisiopatología , Ratones , Ratones Endogámicos , ARN Mensajero/genética , Bazo/fisiopatología
13.
J Exp Med ; 172(5): 1359-65, 1990 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-2146362

RESUMEN

Leishmaniasis provides a biologically relevant model to analyze the heterogeneity of CD4+ T cells and may lead to answering the major question of the mechanism for the preferential induction of T helper type 1 (Th1) and Th2 cells. Using synthetic peptides corresponding to the tandemly repeating regions of Leishmania proteins, we have identified an epitope that can preferentially induce the disease-exacerbating Th2 cells in susceptible BALB/c mice. Lymph node cells from BALB/c mice immunized subcutaneously with the octamer (p183) of the repeating 10-mer peptide EAEEAARLQA proliferated strongly against the peptide as well as the soluble antigen extract (SolAg) of Leishmania major. The proliferative T cells are CD4+, major histocompatibility complex class II restricted, and secrete interleukin 4 (IL-4) but little or no IL-2 and interferon gamma when stimulated with the peptide in vitro. T cells from BALB/c mice with progressive disease, but not from BALB/c mice cured of the infection, recognized this epitope. BALB/c mice injected subcutaneously with p183 developed significantly exacerbated disease when subsequently challenged with L. major. Furthermore, subcutaneous injection with p183 prevented the subsequent induction of resistance against L. major by intravenous immunization with soluble antigen. The T cell response to p183 is H-2d restricted. Immunization of the genetically resistant B10.D2 mice with p183 also produced strong T cell responses and exacerbated disease when challenged with L. major.


Asunto(s)
Leishmania tropica/análisis , Leishmaniasis/fisiopatología , Activación de Linfocitos/efectos de los fármacos , Péptidos/fisiología , Secuencias Repetitivas de Ácidos Nucleicos/fisiología , Linfocitos T Colaboradores-Inductores/efectos de los fármacos , Secuencia de Aminoácidos , Animales , Susceptibilidad a Enfermedades , Femenino , Leishmaniasis/genética , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Endogámicos CBA , Datos de Secuencia Molecular , Péptidos/genética , Péptidos/inmunología , Secuencias Repetitivas de Ácidos Nucleicos/genética , Secuencias Repetitivas de Ácidos Nucleicos/inmunología , Linfocitos T Colaboradores-Inductores/inmunología , Linfocitos T Colaboradores-Inductores/fisiología
14.
Exp Dermatol ; 19(8): 760-71, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20590820

RESUMEN

Dendritic cells (DC) are key elements of the immune system. In peripheral tissues, they function as sentinels taking up and processing antigens. After migration to the draining lymph nodes, the DC either present antigenic peptides by themselves or transfer them to lymph node-resident DC. The skin is the primary interface between the body and the environment and host's various DC subsets, including dermal DC (dDC) and Langerhans cells (LC). Because of their anatomical position in the epidermis, LC are believed to be responsible for induction of adaptive cutaneous immune responses. The functions of LC and dDC in the skin immune system in vivo are manifold, and it is still discussed controversially whether the differentiation of T-cell subtypes (e.g. effector T cells and regulatory T cells) may be initiated by distinct DC subtypes. As skin DC are able to promote or downmodulate immune responses, we chose different skin diseases (cutaneous leishmaniasis, contact hypersensitivity, UV radiation-induced suppression, and graft-versus-host disease) to describe the biological interactions between different DC subtypes and T cells that lead to the development of efficient or unwanted immune responses. A detailed knowledge about the immune modulatory capacity of different cutaneous DC subsets might be helpful to specifically target these cells through the skin during therapeutic interventions.


Asunto(s)
Células Dendríticas/fisiología , Dermatitis por Contacto/fisiopatología , Enfermedad Injerto contra Huésped/fisiopatología , Tolerancia Inmunológica/fisiología , Leishmaniasis/fisiopatología , Piel/inmunología , Animales , Diferenciación Celular/fisiología , Células Dendríticas/patología , Dermatitis por Contacto/patología , Modelos Animales de Enfermedad , Enfermedad Injerto contra Huésped/patología , Humanos , Sistema Inmunológico/fisiopatología , Células de Langerhans/patología , Células de Langerhans/fisiología , Leishmaniasis/patología , Ratones , Linfocitos T/patología , Linfocitos T/fisiología
15.
J Biomed Biotechnol ; 2010: 719361, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-19884987

RESUMEN

Neutrophils are rapidly and massively recruited to the site of Leishmania inoculation, where they phagocytose the parasites, some of which are able to survive within these first host cells. Neutrophils can thus provide a transient safe shelter for the parasites, prior to their entry into macrophages where they will replicate. In addition, neutrophils release and synthesize rapidly several factors including cytokines and chemokines. The mechanism involved in their rapid recruitment to the site of parasite inoculation, as well as the putative consequences of their massive presence on the microenvironment of the focus of infection will be discussed in the context of the development of the Leishmania-specific immune response.


Asunto(s)
Leishmania/metabolismo , Leishmaniasis/sangre , Leishmaniasis/fisiopatología , Neutrófilos/parasitología , Animales , Quimiocinas/metabolismo , Citocinas/metabolismo , Humanos , Sistema Inmunológico , Macrófagos/parasitología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Modelos Biológicos , Psychodidae , Especificidad de la Especie
16.
Science ; 239(4845): 1306-8, 1988 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-3344436

RESUMEN

Leishmaniasis is a parasitic disease transmitted by phlebotomine sand flies. The role of sand fly saliva in transmission of the disease was investigated by injecting mice with Leishmania major parasites in the presence of homogenized salivary glands from Lutzomyia longipalpis. This procedure resulted in cutaneous lesions of Leishmania major that were routinely five to ten times as large and contained as much as 5000 times as many parasites as controls. With inocula consisting of low numbers of Leishmania major, parasites were detected at the site of injection only when the inoculum also contained salivary gland material. This enhancing effect of sand fly salivary glands on cutaneous leishmaniasis occurred with as little as 10 percent of the contents of one salivary gland of one fly. Material obtained from other bloodsucking arthropods could not mediate the phenomenon.


Asunto(s)
Dípteros , Leishmania tropica/patogenicidad , Leishmaniasis/fisiopatología , Extractos de Tejidos/farmacología , Animales , Artrópodos , Ratones , Ratones Endogámicos CBA , Glándulas Salivales , Especificidad de la Especie
17.
Neuroimmunomodulation ; 16(2): 106-13, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19212130

RESUMEN

Sex-associated hormones such as estradiol, testosterone and progesterone have all been shown to modulate immune responses, which can result in differential disease outcomes between males and females, as well as between pregnant and nonpregnant females. Most parasitic diseases, including leishmaniasis, usually result in more severe disease in males compared with females. This review highlights our current knowledge concerning the role of sex hormones in modulating leishmaniasis in both clinical settings and experimental disease models.


Asunto(s)
Hormonas Esteroides Gonadales/fisiología , Leishmaniasis/fisiopatología , Animales , Cricetinae , Citocinas/fisiología , Susceptibilidad a Enfermedades , Femenino , Humanos , Leishmaniasis/inmunología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos DBA , Óxido Nítrico/fisiología , Embarazo , Complicaciones Infecciosas del Embarazo/inmunología , Complicaciones Infecciosas del Embarazo/parasitología , Complicaciones Infecciosas del Embarazo/fisiopatología , Factores Sexuales , Células Th2/inmunología
18.
Indian J Exp Biol ; 47(6): 412-23, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19634705

RESUMEN

Leishmaniasis is a parasitic disease caused by various species of Leishmania, a unicellular kinetoplastid protozoan flagellate. It manifests mainly in 3 clinical forms; visceral leishmaniasis (VL), cutaneous leishmaniasis (CL) and mucocutaneous leishmaniasis (MCL), of which VL is the most severe form of the disease. VL is lethal if untreated and spontaneous cure is extremely rare. Cutaneous leishmaniasis usually has milder course and often results into a self-healing of ulcers. Resolution of leishmanial infection is dependent on the coordinated interactions between components of cell mediated immune response, specifically the activation of targeted T-cell populations for appropriate cytokine production and activation of macrophages. In murine model, the development of Thl response is associated with control of infection, and Th2 response is associated with disease progression. However, Th1 and Th2 dichotomy in the human system is not as distinct as in mice and the murine model does not strictly apply to human leishmaniasis. This review focuses the dichotomy of immune response against various clinical forms of the disease. An in-depth knowledge of sequences involved in the immune response to the parasite would help in designing prophylactic and therapeutic strategies against leishmaniasis.


Asunto(s)
Leishmaniasis/inmunología , Animales , Comorbilidad , Infecciones por VIH/inmunología , Humanos , Inmunidad Celular/inmunología , Leishmaniasis/fisiopatología , Leishmaniasis Visceral/inmunología , Células TH1/inmunología , Células Th2/inmunología
19.
Vet Parasitol ; 272: 44-52, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31395204

RESUMEN

In the present study, a quantitative proteomic approach to study changes in saliva proteins associated with canine leishmaniosis (CanL) was performed. For this, canine salivary proteins were analysed and compared between dogs before (T0) and after (T1) experimental infection with Leishmania infantum by high-throughput label-based quantitative LC-MS/MS proteomic approach and bioinformatic analysis of the in silico inferred interactome protein network was created from the initial list of differential proteins. More than 2000 proteins were identified, and of the 90 differentially expressed proteins between T0 and T1, 12 were down-regulated with log2 fold change lower than -0.5849, and 19 were up-regulated with log2 fold change greater than 0.5849. This study provides evidence of changes in salivary proteome that can occur in canine leishmaniosis and revealed biological pathways in saliva modulated in canine leishmaniosis with potential for further targeted research.


Asunto(s)
Enfermedades de los Perros/fisiopatología , Leishmaniasis/veterinaria , Saliva , Proteínas y Péptidos Salivales/genética , Proteínas y Péptidos Salivales/metabolismo , Animales , Cromatografía Liquida , Simulación por Computador , Perros , Regulación de la Expresión Génica , Leishmaniasis/fisiopatología , Proteoma/genética , Proteoma/metabolismo , Proteómica , Saliva/química , Saliva/metabolismo , Espectrometría de Masas en Tándem
20.
Biomedica ; 28(4): 597-606, 2008 Dec.
Artículo en Español | MEDLINE | ID: mdl-19462565

RESUMEN

INTRODUCTION: The analysis of the PCR-restriction fragment length polymorphism and random amplified polymorphic DNA have been useful tools for Leishmania identification. OBJECTIVES: Molecular procedures were demonstrated for identification and typing of reference strains of New World Leishmania and their applicability was validated for clinical samples. MATERIALS AND METHODS: DNA was extracted from 16 reference strains of Latin American Leishmania as well as from clinical samples of leishmaniasis patients. A sequence coding for cysteine proteinase B was amplified by PCR and subjected to restriction fragment length polymorphism analysis. The enzyme used was Taq1. For eight of the reference strains, the random amplified polymorphic desoxyribonucleic acid technique (RAPD) was applied. Band patterns for Leishmania species differentiation were established each each method. The sample size of the clinical sample was of 5. RESULTS: PCR products of the cysteine proteinase B gene were obtained for L. braziliensis, L. peruviana, L. panamensis and L. guyanensis. For the other species, L. mexicana, L. amazonensis, L. garnhami, L. lainsoni, L. chagasi, L. naiffi, no amplification occurred. The patterns of restriction fragments revealed band patterns in common for L. peruviana, L. guyanensis and L. panamensis, whereas L. braziliensis had a distinctive pattern. When human samples were examined, amplification occurred for all cases, and the profiles corresponded to the common profile of L. peruviana, L. guyanensis and L. panamensis. The RAPD technique demonstrated reproducible and distinctive patterns for each of the 8 reference strains, L. mexicana, L. amazonensis, L. garnhami, L. lainsoni, L. chagasi, L. naiffi, making possible to differentiate all them. The advantages and limitations of each procedure are discussed. CONCLUSIONS: The combination of RFP and RAPD methodologies provide useful tools to identify medical important species of Leishmania by recognizing DNA sequences characteristic of each species.


Asunto(s)
Leishmania , Reacción en Cadena de la Polimerasa/métodos , Polimorfismo de Longitud del Fragmento de Restricción , Técnica del ADN Polimorfo Amplificado Aleatorio , Animales , Humanos , Leishmania/clasificación , Leishmania/genética , Leishmaniasis/etiología , Leishmaniasis/fisiopatología , Clima Tropical
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA