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1.
PLoS Pathog ; 19(3): e1011230, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36940219

RESUMEN

In Brazil, Leishmania braziliensis is the main causative agent of the neglected tropical disease, cutaneous leishmaniasis (CL). CL presents on a spectrum of disease severity with a high rate of treatment failure. Yet the parasite factors that contribute to disease presentation and treatment outcome are not well understood, in part because successfully isolating and culturing parasites from patient lesions remains a major technical challenge. Here we describe the development of selective whole genome amplification (SWGA) for Leishmania and show that this method enables culture-independent analysis of parasite genomes obtained directly from primary patient skin samples, allowing us to circumvent artifacts associated with adaptation to culture. We show that SWGA can be applied to multiple Leishmania species residing in different host species, suggesting that this method is broadly useful in both experimental infection models and clinical studies. SWGA carried out directly on skin biopsies collected from patients in Corte de Pedra, Bahia, Brazil, showed extensive genomic diversity. Finally, as a proof-of-concept, we demonstrated that SWGA data can be integrated with published whole genome data from cultured parasite isolates to identify variants unique to specific geographic regions in Brazil where treatment failure rates are known to be high. SWGA provides a relatively simple method to generate Leishmania genomes directly from patient samples, unlocking the potential to link parasite genetics with host clinical phenotypes.


Asunto(s)
Genoma de Protozoos , Leishmaniasis Cutánea , Parasitología , Piel , Genoma de Protozoos/genética , Humanos , Genética de Población , Piel/parasitología , Brasil , Leishmaniasis Cutánea/parasitología , Parasitología/métodos , Leishmania braziliensis/genética
2.
Emerg Infect Dis ; 30(3): 510-518, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38407142

RESUMEN

Disseminated leishmaniasis (DL) is an emergent severe disease manifesting with multiple lesions. To determine the relationship between immune response and clinical and therapeutic outcomes, we studied 101 DL and 101 cutaneous leishmaniasis (CL) cases and determined cytokines and chemokines in supernatants of mononuclear cells stimulated with leishmania antigen. Patients were treated with meglumine antimoniate (20 mg/kg) for 20 days (CL) or 30 days (DL); 19 DL patients were instead treated with amphotericin B, miltefosine, or miltefosine and meglumine antimoniate. High levels of chemokine ligand 9 were associated with more severe DL. The cure rate for meglumine antimoniate was low for both DL (44%) and CL (60%), but healing time was longer in DL (p = 0.003). The lowest cure rate (22%) was found in DL patients with >100 lesions. However, meglumine antimoniate/miltefosine treatment cured all DL patients who received it; therefore, that combination should be considered as first choice therapy.


Asunto(s)
Leishmania braziliensis , Leishmania , Leishmaniasis Cutánea , Fosforilcolina/análogos & derivados , Humanos , Antimoniato de Meglumina/uso terapéutico , Leishmaniasis Cutánea/diagnóstico , Leishmaniasis Cutánea/tratamiento farmacológico
3.
Eur J Neurosci ; 56(12): 6258-6268, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36300719

RESUMEN

To compare cell adhesion molecules levels in cerebrospinal fluid (CSF) between Zika virus (ZIKV)-exposed neonates with/without microcephaly (cases) and controls, 16 neonates (cases), 8 (50%) with and 8 (50%) without microcephaly, who underwent lumbar puncture (LP) during the ZIKV epidemic (2015-2016) were included. All mothers reported ZIKV clinical symptoms during gestation, all neonates presented with congenital infection findings, and other congenital infections were ruled out. Fourteen control neonates underwent LP in the same laboratory (2017-2018). Five cell adhesion proteins were measured in the CSF using mass spectrometry. Neurexin-1 (3.50 [2.00-4.00] vs. 7.5 [5.00-10.25], P = 0.001), neurexin-3 (0.00 [0.00-0.00] vs. 3.00 [1.50-4.00], P = 0.001) and neural cell adhesion molecule 2 (NCAM2) (0.00 [0.00-0.75] vs. 1.00 [1.00-2.00], P = 0.001) were significantly lower in microcephalic and non-microcephalic cases than in controls. When these two sub-groups of prenatally ZIKA-exposed children were compared to controls separately, the same results were found. When cases with and without microcephaly were compared, no difference was found. Neurexin-3 (18.8% vs. 78.6%, P = 0.001) and NCAM2 (25.0% vs. 85.7%, P = 0.001) were less frequently found among the cases. A positive correlation was found between cephalic perimeter and levels of these two proteins. Neurexin-2 and neurexin-2b presented no significant differences. Levels of three cell adhesion proteins were significantly lower in CSF of neonates exposed to ZIKV before birth than in controls, irrespective of presence of congenital microcephaly. Moreover, the smaller the cephalic perimeter, the lower CSF cell adhesion protein levels. These findings suggest that low CSF levels of neurexin-1, neurexin-3 and NCAM2 may reflect the effects of ZIKV on foetal brain development.


Asunto(s)
Microcefalia , Complicaciones Infecciosas del Embarazo , Infección por el Virus Zika , Virus Zika , Recién Nacido , Embarazo , Femenino , Niño , Humanos , Infección por el Virus Zika/diagnóstico , Infección por el Virus Zika/epidemiología , Microcefalia/epidemiología , Estudios de Casos y Controles , Adhesión Celular , Complicaciones Infecciosas del Embarazo/epidemiología , Moléculas de Adhesión Celular , Moléculas de Adhesión de Célula Nerviosa
4.
J Infect Dis ; 223(3): 527-535, 2021 02 13.
Artículo en Inglés | MEDLINE | ID: mdl-32620011

RESUMEN

BACKGROUND: Leishmania skin test (LST) evaluates the delayed type hypersensitivity to Leishmania antigens (LA) and has been used for diagnosis of cutaneous leishmaniasis (CL). In CL patients LST is usually positive but a small percentage have negative LST. The aim of this study was to determine the clinical and immunologic features and response to antimony therapy in LST-negative CL patients. METHODS: We compare the clinical presentation, response to therapy, and immune response of CL patients with negative vs positive LST. RESULTS: The clinical presentation was similar in both groups but LST-negative patients had a lower cure rate. In the lesions, LST-negative patients displayed less inflammation and necrosis, and higher frequency of CD8+ T cells. Mononuclear cells from LST-negative patients had a poor T helper 1 cell (Th1) response but levels of interleukin-1ß (IL-1ß), IL-6, IL-17, granzyme B, and metalloproteinase-9 (MMP-9) were similar to the LST-positive group upon stimulation with LA. Leishmania internalization and killing by macrophages were similar in both groups. Cure of disease was associated with restoration of Th1 response. CONCLUSIONS: In LST-negative patients, impaired Th1 response is associated with therapeutic failure. Increased frequency of CD8+ T cells and high production of inflammatory cytokines, granzyme B, and MMP-9 contributes to immunopathology.


Asunto(s)
Leishmania braziliensis/inmunología , Leishmaniasis Cutánea/parasitología , Células TH1/inmunología , Adolescente , Adulto , Anciano , Antimonio , Brasil , Linfocitos T CD8-positivos/inmunología , Citocinas/metabolismo , Femenino , Granzimas , Humanos , Inflamación , Leishmania/inmunología , Leishmaniasis Cutánea/patología , Masculino , Metaloproteinasa 9 de la Matriz , Persona de Mediana Edad , Necrosis , Piel/parasitología , Piel/patología , Adulto Joven
5.
Clin Infect Dis ; 73(6): 1020-1026, 2021 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-33725723

RESUMEN

BACKGROUND: Cutaneous leishmaniasis (CL) caused by Leishmania braziliensis is characterized by a single ulcer or multiple cutaneous lesions with raised borders. Cure rates <60% are observed in response to meglumine antimoniate therapy. We investigated the impact of obesity on CL clinical presentation and therapeutic response. METHODS: A total of 90 age-matched patients with CL were included (30 obese, 30 overweight, and 30 with normal body mass index [BMI]). CL was diagnosed through documentation of L. braziliensis DNA by polymerase chain reaction or identification of amastigotes in biopsied skin-lesion samples. Serum cytokine levels were determined by chemiluminescence. Antimony therapy with Glucantime (Sanofi-Aventis; 20 mg/kg/day) was administered for 20 days. RESULTS: Obese CL patients may present hypertrophic ulcers rather than typical oval, ulcerated lesions. A direct correlation between BMI and healing time was noted. After 1 course of antimony, cure was achieved in 73% of patients with normal BMI, 37% of overweight subjects, yet just 18% of obese CL patients (P < .01). Obese CL cases additionally presented higher leptin levels than overweight patients or those with normal BMI (P < .05). CONCLUSIONS: Obesity modifies the clinical presentation of CL and host immune response and is associated with greater failure to therapy.


Asunto(s)
Antiprotozoarios , Leishmania braziliensis , Leishmaniasis Cutánea , Antiprotozoarios/uso terapéutico , Humanos , Leishmaniasis Cutánea/tratamiento farmacológico , Antimoniato de Meglumina/uso terapéutico , Obesidad/complicaciones
6.
J Infect Dis ; 221(6): 973-982, 2020 03 02.
Artículo en Inglés | MEDLINE | ID: mdl-31748808

RESUMEN

BACKGROUND: Skin lesions from patients infected with Leishmania braziliensis has been associated with inflammation induced by cytotoxic CD8+ T cells. In addition, CD8+ T cell-mediated cytotoxicity has not been linked to parasite killing. Meanwhile, the cytotoxic role played by natural killer (NK) cells in cutaneous leishmaniasis (CL) remains poorly understood. METHODS: In this study, we observed higher frequencies of NK cells in the peripheral blood of CL patients compared with healthy subjects, and that NK cells expressed more interferon-γ, tumor necrosis factor (TNF), granzyme B, and perforin than CD8+ T cells. RESULTS: We also found that most of the cytotoxic activity in CL lesions was triggered by NK cells, and that the high levels of granzyme B produced in CL lesions was associated with larger lesion size. Furthermore, an in vitro blockade of granzyme B was observed to decrease TNF production. CONCCLUSIONS: Our data, taken together, suggest an important role by NK cells in inducing inflammation in CL, thereby contributing to disease immunopathology.


Asunto(s)
Regulación Enzimológica de la Expresión Génica/inmunología , Granzimas/metabolismo , Inflamación/metabolismo , Células Asesinas Naturales/enzimología , Leishmaniasis Cutánea/inmunología , Leishmaniasis Cutánea/patología , Linfocitos T CD4-Positivos , Estudios de Casos y Controles , Granzimas/genética , Humanos , Interferón gamma/genética , Interferón gamma/metabolismo , Subfamilia K de Receptores Similares a Lectina de Células NK/genética , Subfamilia K de Receptores Similares a Lectina de Células NK/metabolismo , Perforina/genética , Perforina/metabolismo , Linfocitos T Citotóxicos , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/metabolismo
7.
PLoS Pathog ; 13(2): e1006196, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-28192528

RESUMEN

Deregulated CD8+ T cell cytotoxicity plays a central role in enhancing disease severity in several conditions. However, we have little understanding of the mechanisms by which immunopathology develops as a consequence of cytotoxicity. Using murine models of inflammation induced by the protozoan parasite leishmania, and data obtained from patients with cutaneous leishmaniasis, we uncovered a previously unrecognized role for NLRP3 inflammasome activation and IL-1ß release as a detrimental consequence of CD8+ T cell-mediated cytotoxicity, ultimately resulting in chronic inflammation. Critically, pharmacological blockade of NLRP3 or IL-1ß significantly ameliorated the CD8+ T cell-driven immunopathology in leishmania-infected mice. Confirming the relevance of these findings to human leishmaniasis, blockade of the NLRP3 inflammasome in skin biopsies from leishmania-infected patients prevented IL-1ß release. Thus, these studies link CD8+ T cell cytotoxicity with inflammasome activation and reveal novel avenues of treatment for cutaneous leishmaniasis, as well as other of diseases where CD8+ T cell-mediated cytotoxicity induces pathology.


Asunto(s)
Linfocitos T CD8-positivos/inmunología , Inflamasomas/inmunología , Interleucina-1beta/biosíntesis , Leishmaniasis Cutánea/inmunología , Leishmaniasis Cutánea/patología , Animales , Citotoxicidad Inmunológica/inmunología , Citometría de Flujo , Humanos , Interleucina-1beta/inmunología , Leishmania braziliensis , Leishmaniasis Cutánea/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Proteína con Dominio Pirina 3 de la Familia NLR/inmunología , Reacción en Cadena en Tiempo Real de la Polimerasa , Linfocitos T Citotóxicos/inmunología
8.
J Infect Dis ; 217(5): 840-850, 2018 02 14.
Artículo en Inglés | MEDLINE | ID: mdl-29216363

RESUMEN

Background: Early cutaneous leishmaniasis (ECL) is characterized by a nonulcerated papular lesion and illness duration less than 30 days. Approximately 4 weeks later, the cutaneous leishmaniasis (CL) ulcers appear. We were surprised to find that failure after antimony therapy (Sb5) is higher in ECL than CL. We hypothesize that the inflammatory response in ECL patients may increase during Sb5 therapy, which leads to treatment failure. Methods: A cohort of 44 ECL patients infected by Leishmania braziliensis was established to evaluate the response to Sb5 and to compare immunologic responses in ECL patients with CL and healthy subjects. Results: A hierarchical clustering based on cytokine levels showed a weak positive correlation between proinflammatory cytokine levels and those patients that failed Sb5 treatment. Although Sb5 therapy decreased interferon-γ and tumor necrosis factor levels in CL patients, we were surprised to find that an increase in these cytokines was observed in ECL patients. Moreover, interleukin (IL)-10 was less able to down-modulate immune responses in ECL. Conclusions: The enhanced production of proinflammatory cytokines, due in part to the decreased ability of IL-10 to down-modulate immune response during therapy in ECL, promotes the development and persistence of leishmania ulcer despite antimony therapy.


Asunto(s)
Antimonio/administración & dosificación , Antiprotozoarios/administración & dosificación , Inflamación/patología , Leishmaniasis Cutánea/tratamiento farmacológico , Leishmaniasis Cutánea/patología , Adulto , Estudios Transversales , Citocinas/sangre , Femenino , Humanos , Leishmania braziliensis/aislamiento & purificación , Leishmaniasis Cutánea/parasitología , Leucocitos Mononucleares/inmunología , Masculino , Prevención Secundaria , Insuficiencia del Tratamiento , Adulto Joven
9.
Mem Inst Oswaldo Cruz ; 112(11): 733-740, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29091132

RESUMEN

Cutaneous leishmaniasis (CL) is a chronic disease caused by species of the protozoan Leishmania and characterised by the presence of ulcerated skin lesions. Both parasite and host factors affect the clinical presentation of the disease. The development of skin ulcers in CL is associated with an inflammatory response mediated by cells that control parasite growth but also contribute to pathogenesis. CD8+ T cells contribute to deleterious inflammatory responses in patients with CL through cytotoxic mechanisms. In addition, natural killer cells also limit Leishmania infections by production of interferon-γ and cytotoxicity. In this review, we focus on studies of cytotoxicity in CL and its contribution to the pathogenesis of this disease.


Asunto(s)
Linfocitos T CD8-positivos/parasitología , Citotoxicidad Inmunológica/inmunología , Células Asesinas Naturales/parasitología , Leishmaniasis Cutánea/inmunología , Linfocitos T Citotóxicos/parasitología , Animales , Linfocitos T CD8-positivos/inmunología , Modelos Animales de Enfermedad , Humanos , Células Asesinas Naturales/inmunología , Leishmaniasis Cutánea/patología , Linfocitos T Citotóxicos/inmunología
10.
J Infect Dis ; 214(4): 570-6, 2016 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-27190181

RESUMEN

BACKGROUND: The control of Leishmania braziliensis by individuals with subclinical infection (SC) are unknown. METHODS: A cohort of 308 household contacts (HCs) of patients with cutaneous leishmaniasis (CL) was established in 2010 in an endemic area and followed up for 5 years. Whole-blood cultures stimulated with soluble Leishmania antigen and a Leishmania skin test (LST) were performed in years 0, 2, and 4. The identification of the lymphocyte subsets secreting interferon (IFN) γ and the ability of monocytes to control Leishmania were determined. RESULTS: During follow-up, 118 subjects (38.3%) had evidence of L. braziliensis infection. Of the HCs, CL was documented in 45 (14.6%), 101 (32.8%) had SC infection, and 162 (52.6%) did not have evidence of exposure to L. braziliensis The ratio of infection to disease was 3.2:1. IFN-γ production, mainly by natural killer cells, was associated with protection, and a positive LST result did not prevent development of disease. Moreover, monocytes from subjects with SC infection were less permissive to parasite penetration and had a greater ability to control L. braziliensis than cells from patients with CL. CONCLUSIONS: Protection against CL was associated with IFN-γ production, negative LST results, impaired ability of Leishmania to penetrate monocytes, and increased ability to control Leishmania growth.


Asunto(s)
Biomarcadores , Leishmania braziliensis/inmunología , Leishmaniasis Cutánea/inmunología , Leishmaniasis Cutánea/prevención & control , Adolescente , Adulto , Sangre/inmunología , Niño , Femenino , Estudios de Seguimiento , Humanos , Interferón gamma/metabolismo , Leucocitos Mononucleares/inmunología , Masculino , Pruebas Cutáneas , Adulto Joven
11.
Microb Pathog ; 91: 155-60, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26718098

RESUMEN

Chronic infection with hepatitis C virus (HCV) causes a quantitative and functional alteration in innate and adaptative immunity. In the present work, we determined by flow-cytometry the profile of blood lymphocyte of untreated HCV patients and in subjects of this group that achieved or not an early virologic response at 12-weeks of treatment with interferon-α plus ribavirin. Twenty-six untreated HCV patients and 20 control healthy individuals were enrolled in the study. Untreated HCV patients had a higher proportion of B cell and a lower proportion of CD8(+) T cell and NK cells than healthy individuals did, but the proportions of CD4(+) T cells and Treg cells (CD4(+)CD25(+)Foxp3(+)) were similar in these patients and controls. Untreated HCV patients presenting cryoglobulinemia had a lower proportion of Treg cells and a lower Treg/NK cell ratio when compared with those without cryoglobulins. Nineteen out of 26 untreated HCV patients remained in the study and were treated with Interferon-α plus ribavirin. At 12-weeks of treatment, 10 of them achieved early virologic response (EVR), whereas 9 were non-responders (NR). EVR patients differed from NR patients in the increase of their proportion of NK cells at 12 weeks of treatment. In conclusion, untreated HCV patients exhibit an altered profile of blood lymphocyte subsets, including a reduction in the proportion of CD4(+)CD25(+)FoxP3(+)T regulatory cells in patients that present cryoglobulinemia. An early virological response at 12-weeks of treatment with IFN-α plus ribavirin seems to be associated a significant improvement in the proportion of NK cells of HCV treated patients.


Asunto(s)
Antivirales/administración & dosificación , Hepacivirus/efectos de los fármacos , Hepatitis C Crónica/tratamiento farmacológico , Interferón-alfa/administración & dosificación , Ribavirina/administración & dosificación , Adulto , Anciano , Quimioterapia Combinada , Femenino , Hepacivirus/fisiología , Hepatitis C Crónica/inmunología , Hepatitis C Crónica/virología , Humanos , Masculino , Persona de Mediana Edad , Subgrupos de Linfocitos T/efectos de los fármacos , Subgrupos de Linfocitos T/inmunología , Resultado del Tratamiento
12.
J Infect Dis ; 212(1): 157-65, 2015 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-25596303

RESUMEN

BACKGROUND: Leishmaniasis is caused by parasites transmitted to the vertebrate host by infected sand flies. During transmission, the vertebrate host is also inoculated with sand fly saliva, which exerts powerful immunomodulatory effects on the host's immune response. METHODS: We conducted a prospective cohort analysis to characterize the human immune response to Lutzomyia intermedia saliva in 264 individuals, from an area for cutaneous leishmaniasis (CL) caused by Leishmania braziliensis. RESULTS: Antibodies were found in 150 individuals (56.8%); immunoglobulin G1 and G4 were the predominant subclasses. Recall responses to salivary gland sonicate showed elevated production of interleukin 10 (IL-10), interleukin 13, interferon γ, CXCL9, and CCL2 compared with controls. CD4(+)CD25(+) T cells, including Foxp3(+) cells, were the main source of IL-10. L. braziliensis replication was increased (P < .05) in macrophages cocultured with saliva-stimulated lymphocytes from exposed individuals and addition of anti-IL-10 reverted this effect. Positive correlation between antibody response to saliva and cellular response to Leishmania was not found. Importantly, individuals seropositive to saliva are 2.1 times more likely to develop CL (relative risk, 2.1; 95% confidence interval, 1.07-4.2; P < .05). CONCLUSIONS: Exposure to L. intermedia sand flies skews the human immune response, facilitating L. braziliensis survival in vitro, and increases the risk of developing CL.


Asunto(s)
Susceptibilidad a Enfermedades , Interleucina-10/metabolismo , Leishmania braziliensis/aislamiento & purificación , Leishmaniasis Cutánea/epidemiología , Leishmaniasis Cutánea/inmunología , Psychodidae/inmunología , Adolescente , Adulto , Animales , Anticuerpos/sangre , Linfocitos T CD4-Positivos/inmunología , Niño , Preescolar , Estudios de Cohortes , Citocinas/sangre , Femenino , Humanos , Inmunoglobulina G/sangre , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Medición de Riesgo , Saliva/inmunología , Adulto Joven
13.
J Infect Dis ; 211(2): 274-82, 2015 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-25139016

RESUMEN

Ulcer development in patients with cutaneous leishmaniasis (CL) caused by Leishmania braziliensis is associated with high levels of tumor necrosis factor (TNF). We found that early after infection, before ulcer development, the frequency of CD16(+) (both intermediate [CD14(+)CD16(+)] and nonclassical [CD14(dim)CD16(+)]) monocytes was increased in the peripheral blood of patients with L. braziliensis, compared with uninfected controls. These results suggest that CD16(+) monocytes might promote disease. Also, we found that intermediate monocytes expressed CCR2 and that increased levels of CCL2 protein were present in lesions from patients, suggesting that intermediate monocytes are more likely than nonclassical monocytes to migrate to the lesion site. Finally, we found that the intermediate monocytes produced TNF. Our results show that intermediate monocytes are increased in frequency soon after infection; express CCR2, which would promote their migration into the lesions; and, owing to their production of TNF, can enhance the inflammatory response.


Asunto(s)
Leishmania braziliensis/inmunología , Leishmaniasis Cutánea/inmunología , Leishmaniasis Cutánea/patología , Monocitos/inmunología , Adolescente , Adulto , Quimiocina CCL2/metabolismo , Femenino , Proteínas Ligadas a GPI/análisis , Humanos , Masculino , Persona de Mediana Edad , Monocitos/química , Receptores CCR2/análisis , Receptores de IgG/análisis , Factor de Necrosis Tumoral alfa/metabolismo , Úlcera/inmunología , Úlcera/patología , Adulto Joven
14.
Infect Immun ; 83(3): 898-906, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25534940

RESUMEN

Cutaneous leishmaniasis (CL) caused by Leishmania braziliensis is characterized by a strong Th1 response that leads to skin lesion development. In areas where L. braziliensis transmission is endemic, up to 15% of healthy subjects have tested positive for delayed-type hypersensitivity to soluble leishmania antigen (SLA) and are considered to have subclinical (SC) infection. SC subjects produce less gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α) than do CL patients, but they are able to control the infection. The aim of this study was to characterized the role of CD8(+) T cells in SC infection and in CL. Peripheral blood mononuclear cells (PBMC) were stimulated with SLA to determine the frequencies of CD4(+) IFN-γ(+) and CD8(+) IFN-γ(+) T cells. Monocytes from PBMC were infected with L. braziliensis and cocultured with CD8(+) T cells, and the frequencies of infected monocytes and levels of cytotoxicity markers, target cell apoptosis, and granzyme B were determined. The frequency of CD8(+) IFN-γ(+) cells after SLA stimulation was higher for SC individuals than for CL patients. The frequency of infected monocytes in SC cells was lower than that in CL cells. CL CD8(+) T cells induced more apoptosis of infected monocytes than did SC CD8(+) T cells. Granzyme B production in CD8(+) T cells was higher in CL than in SC cells. While the use of a granzyme B inhibitor decreased the number of apoptotic cells in the CL group, the use of z-VAD-FMK had no effect on the frequency of these cells. These results suggest that CL CD8(+) T cells are more cytotoxic and may be involved in pathology.


Asunto(s)
Linfocitos T CD4-Positivos/patología , Leishmania braziliensis/patogenicidad , Leishmaniasis Cutánea/patología , Linfocitos T Citotóxicos/patología , Clorometilcetonas de Aminoácidos/farmacología , Antígenos de Protozoos/inmunología , Antígenos de Protozoos/farmacología , Apoptosis/efectos de los fármacos , Enfermedades Asintomáticas , Linfocitos T CD4-Positivos/efectos de los fármacos , Linfocitos T CD4-Positivos/inmunología , Enfermedad Crónica , Técnicas de Cocultivo , Citotoxicidad Inmunológica , Inhibidores Enzimáticos/farmacología , Granzimas/antagonistas & inhibidores , Granzimas/metabolismo , Humanos , Interferón gamma/biosíntesis , Interferón gamma/metabolismo , Leishmania braziliensis/inmunología , Leishmaniasis Cutánea/inmunología , Leishmaniasis Cutánea/parasitología , Recuento de Linfocitos , Monocitos/inmunología , Monocitos/parasitología , Cultivo Primario de Células , Linfocitos T Citotóxicos/efectos de los fármacos , Linfocitos T Citotóxicos/inmunología , Factor de Necrosis Tumoral alfa/biosíntesis , Factor de Necrosis Tumoral alfa/metabolismo
15.
PLoS Pathog ; 9(3): e1003243, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23555256

RESUMEN

Leishmaniasis, resulting from infection with the protozoan parasite Leishmania, consists of a wide spectrum of clinical manifestations, from healing cutaneous lesions to fatal visceral infections. A particularly severe form of cutaneous leishmaniasis, termed mucosal leishmaniasis, exhibits decreased IL-10 levels and an exaggerated inflammatory response that perpetuates the disease. Using a mouse model of leishmaniasis, we investigated what cytokines contribute to increased pathology when IL-10-mediated regulation is absent. Leishmania major infected C57BL/6 mice lacking IL-10 regulation developed larger lesions than controls, but fewer parasites. Both IFN-γ and IL-17 levels were substantially elevated in mice lacking the capacity to respond to IL-10. IFN-γ promoted an increased infiltration of monocytes, while IL-17 contributed to an increase in neutrophils. Surprisingly, however, we found that IFN-γ did not contribute to increased pathology, but instead regulated the IL-17 response. Thus, blocking IFN-γ led to a significant increase in IL-17, neutrophils and disease. Similarly, the production of IL-17 by cells from leishmaniasis patients was also regulated by IL-10 and IFN-γ. Additional studies found that the IL-1 receptor was required for both the IL-17 response and increased pathology. Therefore, we propose that regulating IL-17, possibly by downregulating IL-1ß, may be a useful approach for controlling immunopathology in leishmaniasis.


Asunto(s)
Interleucina-17/inmunología , Leishmania major/fisiología , Leishmaniasis Cutánea/inmunología , Leishmaniasis Cutánea/patología , Animales , Modelos Animales de Enfermedad , Regulación hacia Abajo , Femenino , Humanos , Interferón gamma/sangre , Interferón gamma/inmunología , Interleucina-10/deficiencia , Interleucina-10/genética , Interleucina-17/sangre , Interleucina-1beta/metabolismo , Leishmania major/patogenicidad , Leishmaniasis Cutánea/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Monocitos/inmunología , Infiltración Neutrófila
16.
PLoS Pathog ; 9(7): e1003504, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23874205

RESUMEN

Disease progression in response to infection can be strongly influenced by both pathogen burden and infection-induced immunopathology. While current therapeutics focus on augmenting protective immune responses, identifying therapeutics that reduce infection-induced immunopathology are clearly warranted. Despite the apparent protective role for murine CD8⁺ T cells following infection with the intracellular parasite Leishmania, CD8⁺ T cells have been paradoxically linked to immunopathological responses in human cutaneous leishmaniasis. Transcriptome analysis of lesions from Leishmania braziliensis patients revealed that genes associated with the cytolytic pathway are highly expressed and CD8⁺ T cells from lesions exhibited a cytolytic phenotype. To determine if CD8⁺ T cells play a causal role in disease, we turned to a murine model. These studies revealed that disease progression and metastasis in L. braziliensis infected mice was independent of parasite burden and was instead directly associated with the presence of CD8⁺ T cells. In mice with severe pathology, we visualized CD8⁺ T cell degranulation and lysis of L. braziliensis infected cells. Finally, in contrast to wild-type CD8⁺ T cells, perforin-deficient cells failed to induce disease. Thus, we show for the first time that cytolytic CD8⁺ T cells mediate immunopathology and drive the development of metastatic lesions in cutaneous leishmaniasis.


Asunto(s)
Citotoxicidad Inmunológica , Modelos Animales de Enfermedad , Leishmania braziliensis/inmunología , Leishmaniasis Cutánea/inmunología , Piel/inmunología , Linfocitos T Citotóxicos/inmunología , Animales , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Brasil , Progresión de la Enfermedad , Perfilación de la Expresión Génica , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Humanos , Leishmania braziliensis/aislamiento & purificación , Leishmaniasis Cutánea/parasitología , Leishmaniasis Cutánea/patología , Leishmaniasis Cutánea/fisiopatología , Leishmaniasis Cutánea Difusa/etiología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Piel/parasitología , Piel/patología , Organismos Libres de Patógenos Específicos , Linfocitos T Citotóxicos/parasitología , Linfocitos T Citotóxicos/patología
17.
J Infect Dis ; 209(8): 1288-96, 2014 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-24403561

RESUMEN

Leishmania braziliensis are intracellular parasites that cause unique clinical forms of cutaneous leishmaniasis. Previous studies with other leishmania species demonstrated that reactive oxygen species (ROS) control promastigotes, the infective stage of the parasite, but not the amastigote form that exists in the mammalian host. Here we show that ROS inhibits growth of L. braziliensis amastigotes in resting monocytes, and that classical monocytes are primarily responsible for this control. ROS, but not nitric oxide, also contributed to killing of L. braziliensis by IFN-γ activated monocytes. Furthermore, by gene expression profiling of human lesions we found greater expression of genes associated with ROS, but not nitric oxide, compared to normal skin. This study shows that ROS are important for control of L. braziliensis both at the initial stages of infection, as well as at later time points, and highlights that monocyte subsets may play different roles during leishmaniasis.


Asunto(s)
Leishmania braziliensis/fisiología , Leishmaniasis Cutánea/prevención & control , Monocitos/parasitología , Especies Reactivas de Oxígeno/metabolismo , Animales , Citometría de Flujo , Perfilación de la Expresión Génica , Humanos , Leishmaniasis Cutánea/metabolismo , Monocitos/metabolismo , Óxido Nítrico/metabolismo , Análisis de Secuencia por Matrices de Oligonucleótidos , Pennsylvania
18.
J Immunol ; 188(3): 1394-401, 2012 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-22205030

RESUMEN

Control of the protozoan parasite Leishmania major is dependent on establishing a robust T cell response. An early event in the development of an effective T cell response is the expansion (or hypertrophy) of the lymph node draining the site of infection, although the mechanisms involved in this response are not completely understood. In this study, we show that lymph node hypertrophy following L. major infection in mice is associated with increased recruitment of lymphocytes to the lymph node from the blood, and that CD62L-deficient mice, which are unable to recruit cells to the lymph node, develop a chronic infection with L. major. Injection of L. major-activated dendritic cells promoted lymph node hypertrophy, and this correlated with an increase in the expression of CCR7 on dendritic cells, although the upregulation of CCR7 occurred on the bystander (uninfected) dendritic cells rather than those containing parasites. We found that increased CCR7 expression was TLR9-dependent, that TLR9(-/-) dendritic cells migrated less efficiently to the draining lymph node, and that TLR9(-/-) mice exhibited a deficit in lymph node expansion following L. major infection, as well as increased susceptibility. Taken together, to our knowledge, these results are the first to demonstrate that activation of dendritic cells via TLR9 is essential for the induction of lymph node hypertrophy in leishmaniasis.


Asunto(s)
Hipertrofia/parasitología , Leishmaniasis Cutánea/patología , Ganglios Linfáticos/parasitología , Receptor Toll-Like 9/inmunología , Animales , Células Dendríticas , Hipertrofia/inmunología , Leishmania major , Leishmaniasis Cutánea/inmunología , Ganglios Linfáticos/inmunología , Ratones , Ratones Noqueados , Receptor Toll-Like 9/deficiencia
19.
Pathogens ; 13(4)2024 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-38668256

RESUMEN

Cutaneous leishmaniasis (CL), caused by Leishmania braziliensis, in recent decades has shown decreasing cure rates after treatment with meglumine antimoniate (MA). Granulocyte colony-stimulating factor (G-CSF) is a cytokine associated with epithelialization and healing processes. METHODS: This study compares the effectiveness of G-CSF associated with MA in the treatment of CL. A total of 32 patients aged between 18 and 50 years with CL confirmed for L. braziliensis were included in this study. G-CSF or placebo (0.9% saline) was applied by intralesional infiltration at four equidistant points on the edges of the largest ulcer on days 0 and 15 of treatment associated with intravenous MA. RESULTS: Males predominated in the G-CSF group (59%), while females predominated in the control group (53%). Injuries to the lower limbs predominated in both study groups. The cure rate in the G-CSF group was 65% and in the control group it was 47%, 90 days after initiation of therapy. CONCLUSIONS: Our data indicate that the association of G-CSF with MA is not superior to MA monotherapy. Although not significant, the potential benefit of this combination deserves further investigation. The use of higher doses or other routes of application of G-CSF in a greater number of patients should contribute to a definitive response.

20.
Pathogens ; 13(3)2024 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-38535542

RESUMEN

The role of the immune response in the pathogenesis of cutaneous leishmaniasis (CL) due to Leishmania (Viannia) braziliensis is predominantly carried out via blood cells. Here, we evaluate whether cytokine production by peripheral blood mononuclear cells (PBMCs) reflects what has been documented at the lesion site. The participants included 22 CL patients diagnosed with a positive PCR. PBMCs were stimulated for 72 h with a soluble leishmania antigen (SLA). Biopsies obtained from the edge of the ulcers were incubated for the same period. Cytokines in supernatants were assessed via ELISA. TNF, IL-1ß, IL-6, IL-17, and granzyme B (GzmB) were higher in the supernatants of biopsies than in PBMCs, but IFN-γ was higher in the supernatants of PBMCs than in biopsies. There was a positive correlation between IFN-γ and TNF in PBMCs, and an inverse correlation between TNF and IL-10 in the cells from the lesion site. A strong correlation between IL-1ß, IL-17, and GzmB was observed in the biopsies, and a positive correlation was detected between these cytokines and the lesion size. Our results indicate that the immune response in L. braziliensis lesions is different from that observed in peripheral blood, and our data suggest that in addition to IL-1ß and GzmB, IL-17 participates in the pathology of CL.

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