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1.
Immunohorizons ; 4(2): 47-56, 2020 02 07.
Artículo en Inglés | MEDLINE | ID: mdl-32034084

RESUMEN

Erythema nodosum leprosum (ENL) is an inflammatory complication in leprosy. Yet, the involvement of ENL neutrophils in the inflammatory response against Mycobacterium leprae remains poorly explored. Our primary aim was to investigate the utility of the surface expression of neutrophil IL-10R1 as an ENL biomarker and, secondarily, to evaluate whether leprosy or healthy M. leprae-stimulated neutrophils produce cytokines and are able to respond to IL-10. We, in this study, describe a subpopulation of circulating neutrophils of ENL patients that exclusively expressed IL-10R1, providing evidence that IL-10R1+ neutrophils are present in ENL lesions. It was also found that ENL neutrophils, but not those of nonreactional leprosy controls, were able to secret detectable levels of TNF ex vivo and the addition of IL-10 blocked TNF release. It was likewise observed that M. leprae-stimulated, healthy neutrophils expressed IL-10R1 in vitro, and ENL-linked cytokines were released by M. leprae-cultured neutrophils in vitro. Moreover, consistent with the presence of a fully functional IL-10R, the addition of IL-10 prevented the release of M. leprae-induced cytokines. Most importantly, dead M. leprae revealed its superior capacity to induce CCL4 and IL-8 in primary neutrophils over live Mycobacterium, suggesting that M. leprae may hamper the inflammatory machinery as an immune escape mechanism.

2.
F1000Res ; 92020.
Artículo en Inglés | MEDLINE | ID: mdl-32051758

RESUMEN

Chronic infection by the obligate intracellular pathogen Mycobacterium leprae may lead to the development of leprosy. Of note, in the lepromatous clinical form of the disease, failure of the immune system to constrain infection allows the pathogen to reproduce to very high numbers with minimal clinical signs, favoring transmission. The bacillus can modulate cellular metabolism to support its survival, and these changes directly influence immune responses, leading to host tolerance, permanent disease, and dissemination. Among the metabolic changes, upregulation of cholesterol, phospholipids, and fatty acid biosynthesis is particularly important, as it leads to lipid accumulation in the host cells (macrophages and Schwann cells) in the form of lipid droplets, which are sites of polyunsaturated fatty acid-derived lipid mediator biosynthesis that modulate the inflammatory and immune responses. In Schwann cells, energy metabolism is also subverted to support a lipogenic environment. Furthermore, effects on tryptophan and iron metabolisms favor pathogen survival with moderate tissue damage. This review discusses the implications of metabolic changes on the course of M. leprae infection and host immune response and emphasizes the induction of regulatory T cells, which may play a pivotal role in immune modulation in leprosy.

3.
PLoS Negl Trop Dis ; 13(9): e0007368, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31504035

RESUMEN

Up to 50% of patients with the multibacillary form of leprosy are expected to develop acute systemic inflammatory episodes known as type 2 reactions (T2R), thus aggravating their clinical status. Thalidomide rapidly improves T2R symptoms. But, due to its restricted use worldwide, novel alternative therapies are urgently needed. The T2R triggering mechanisms and immune-inflammatory pathways involved in its pathology remain ill defined. In a recent report, we defined the recognition of nucleic acids by TLR9 as a major innate immunity pathway that is activated during T2R. DNA recognition has been described as a major inflammatory pathway in several autoimmune diseases, and neutrophil DNA extracellular traps (NETs) have been shown to be a prime source of endogenous DNA. Considering that neutrophil abundance is a marked characteristic of T2R lesions, the objective of this study was to investigate NETs production in T2R patients based on the hypothesis that the excessive NETs formation would play a major role in T2R pathogenesis. Abundant NETs were found in T2R skin lesions, and increased spontaneous NETs formation was observed in T2R peripheral neutrophils. Both the M. leprae whole-cell sonicate and the CpG-Hlp complex, mimicking a mycobacterial TLR9 ligand, were able to induce NETs production in vitro. Moreover, TLR9 expression was shown to be higher in T2R neutrophils, suggesting that DNA recognition via TLR9 may be one of the pathways triggering this process during T2R. Finally, treatment of T2R patients with thalidomide for 7 consecutive days resulted in a decrease in all of the evaluated in vivo and ex vivo NETosis parameters. Altogether, our findings shed light on the pathogenesis of T2R, which, it is hoped, will contribute to the emergence of novel alternative therapies and the identification of prognostic reactional markers in the near future.


Asunto(s)
Trampas Extracelulares/inmunología , Inmunidad Innata , Lepra/inmunología , Adulto , Anciano , Anciano de 80 o más Años , Enfermedades Autoinmunes/inmunología , Enfermedades Autoinmunes/microbiología , Femenino , Humanos , Inflamación/inmunología , Inflamación/patología , Lepra/tratamiento farmacológico , Lepra/patología , Masculino , Persona de Mediana Edad , Mycobacterium leprae/inmunología , Mycobacterium leprae/patogenicidad , Neutrófilos/patología , Talidomida/administración & dosificación , Talidomida/uso terapéutico
4.
Mem Inst Oswaldo Cruz ; 114: e180579, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30970080

RESUMEN

BACKGROUND: CD64 (FcγR1) is a high-affinity receptor for monomeric IgG1 and IgG3. Circulating neutrophils express very low amounts of CD64 on their surface. OBJECTIVES: Our primary aim was to investigate the utility of neutrophil CD64 surface expression as a biomarker of active pulmonary tuberculosis (TB). We hypothesised that elevated neutrophil CD64 expression in TB infection would be associated with interferon gamma (IFN-γ) as an inducer of CD64 expression. METHODS: The expression level of CD64 per neutrophil (PMN CD64 index) was quantitatively measured with flow cytometry using a Leuko64 kit in samples from patients with TB and latent TB infection (LTBI) as well as healthy controls, as part of a prospective cohort study in Brazil. FINDINGS: The PMN CD64 index in patients with TB was higher than that in healthy controls and LTBI. Receiver operating characteristic curve analyses determined that the PMN CD64 index could discriminate patients with TB from those with LTBI and healthy individuals. PMN CD64 index levels returned to baseline levels after treatment. CONCLUSIONS: The positive regulation of CD64 expression in circulating neutrophils of patients with active TB could represent an additional biomarker for diagnosis of active TB and could be used for monitoring individuals with LTBI before progression of TB disease.


Asunto(s)
Tuberculosis Latente/diagnóstico , Neutrófilos/inmunología , Receptores de IgG/inmunología , Adulto , Biomarcadores/análisis , Estudios de Casos y Controles , Femenino , Citometría de Flujo , Humanos , Ensayos de Liberación de Interferón gamma , Tuberculosis Latente/inmunología , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Curva ROC , Receptores de IgG/metabolismo , Sensibilidad y Especificidad
5.
Front Immunol ; 10: 495, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30949168

RESUMEN

Leprosy is an infectious disease caused by the intracellular bacillus Mycobacterium leprae that mainly affects the skin and peripheral nerves. One of the most intriguing aspects of leprosy is the diversity of its clinical forms. Paucibacillary patients are characterized as having less than five skin lesions and rare bacilli while the lesions in multibacillary patients are disseminated with voluminous bacilli. The chronic course of leprosy is often interrupted by acute episodes of an inflammatory immunological response classified as either reversal reaction or erythema nodosum leprosum (ENL). Although ENL is considered a neutrophilic immune-complex mediated condition, little is known about the direct role of neutrophils in ENL and leprosy disease overall. Recent studies have shown a renewed interest in neutrophilic biology. One of the most interesting recent discoveries was that the neutrophilic population is not homogeneous. Neutrophilic polarization leads to divergent phenotypes (e.g., a pro- and antitumor profile) that are dynamic subpopulations with distinct phenotypical and functional abilities. Moreover, there is emerging evidence indicating that neutrophils expressing CD64 favor systemic inflammation during ENL. In the present review, neutrophilic involvement in leprosy is discussed with a particular focus on ENL and the potential of neutrophils as clinical biomarkers and therapeutic targets.

6.
Mem. Inst. Oswaldo Cruz ; 114: e180579, 2019. tab, graf
Artículo en Inglés | LILACS | ID: biblio-1002686

RESUMEN

BACKGROUND CD64 (FcγR1) is a high-affinity receptor for monomeric IgG1 and IgG3. Circulating neutrophils express very low amounts of CD64 on their surface. OBJECTIVES Our primary aim was to investigate the utility of neutrophil CD64 surface expression as a biomarker of active pulmonary tuberculosis (TB). We hypothesised that elevated neutrophil CD64 expression in TB infection would be associated with interferon gamma (IFN-γ) as an inducer of CD64 expression. METHODS The expression level of CD64 per neutrophil (PMN CD64 index) was quantitatively measured with flow cytometry using a Leuko64 kit in samples from patients with TB and latent TB infection (LTBI) as well as healthy controls, as part of a prospective cohort study in Brazil. FINDINGS The PMN CD64 index in patients with TB was higher than that in healthy controls and LTBI. Receiver operating characteristic curve analyses determined that the PMN CD64 index could discriminate patients with TB from those with LTBI and healthy individuals. PMN CD64 index levels returned to baseline levels after treatment. CONCLUSIONS The positive regulation of CD64 expression in circulating neutrophils of patients with active TB could represent an additional biomarker for diagnosis of active TB and could be used for monitoring individuals with LTBI before progression of TB disease.


Asunto(s)
Humanos , Biomarcadores/análisis , Tuberculosis Latente/diagnóstico , Tuberculosis Latente/inmunología , Citometría de Flujo , Estudios de Casos y Controles , Estudios Prospectivos , Ensayos de Liberación de Interferón gamma , Neutrófilos/inmunología
7.
Front Immunol ; 9: 518, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29643852

RESUMEN

Leprosy is an infectious disease that may present different clinical forms depending on host immune response to Mycobacterium leprae. Several studies have clarified the role of various T cell populations in leprosy; however, recent evidences suggest that local innate immune mechanisms are key determinants in driving the disease to its different clinical manifestations. Leprosy is an ideal model to study the immunoregulatory role of innate immune molecules and its interaction with nervous system, which can affect homeostasis and contribute to the development of inflammatory episodes during the course of the disease. Macrophages, dendritic cells, neutrophils, and keratinocytes are the major cell populations studied and the comprehension of the complex networking created by cytokine release, lipid and iron metabolism, as well as antimicrobial effector pathways might provide data that will help in the development of new strategies for leprosy management.


Asunto(s)
Inmunidad Innata , Lepra/inmunología , Animales , Humanos , Lepra/patología , Lepra/transmisión , Mycobacterium leprae/fisiología
8.
J Infect Dis ; 216(12): 1635-1643, 2017 12 19.
Artículo en Inglés | MEDLINE | ID: mdl-29272525

RESUMEN

Background: Leprosy, the leading infectious cause of disability worldwide, remains a major public health challenge in the most severely affected countries despite the sharp decline in new cases in recent years. The search for biomarkers is essential to achieve a better understanding of the molecular and cellular mechanisms underlying the disease. Methods: Pentraxin-3 (PTX3) analyses of sera from 87 leprosy patients with or without reactions were conducted via enzyme-linked immunosorbent assay. In situ identification of PTX3 in skin lesion was confirmed by quantitative reverse-transcription polymerase chain reaction, immunohistochemistry, and immunofluorescence assays. Results: We found that PTX3 serum levels were higher in multibacillary patients when evaluated before the onset of acute erythema nodosum leprosum (ENL) and persistently elevated during reaction. Thalidomide treatment reduced PTX3 in the serum 7 days after starting treatment. In situ analyses have also demonstrated enhancement of PTX3 in ENL lesions and showed that treatment with thalidomide reduced its expression and the prominent neutrophilic infiltrate, a hallmark of the disease. Conclusions: In summary, our study provides in vivo evidence that PTX3 is enhanced during ENL but not in reversal reaction and provides a new molecular target in ENL pathogenesis.


Asunto(s)
Biomarcadores/análisis , Proteína C-Reactiva/análisis , Eritema Nudoso/diagnóstico , Eritema Nudoso/patología , Lepra Lepromatosa/diagnóstico , Lepra Lepromatosa/patología , Componente Amiloide P Sérico/análisis , Adolescente , Adulto , Anciano , Proteína C-Reactiva/genética , Estudios de Casos y Controles , Niño , Ensayo de Inmunoadsorción Enzimática , Femenino , Técnica del Anticuerpo Fluorescente , Humanos , Inmunohistoquímica , Leprostáticos/administración & dosificación , Masculino , Persona de Mediana Edad , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Componente Amiloide P Sérico/genética , Piel/patología , Talidomida/administración & dosificación , Adulto Joven
9.
Microbes Infect ; 19(11): 505-514, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-28684130

RESUMEN

Our previous study has demonstrated that IL-10 may modulate both indoleamine 2,3-dioxygenase (IDO) and CD163 expression in lepromatous leprosy (LL) cells, favoring Mycobacterium leprae persistence through induction of regulatory pathways and iron storage. Here, we observed that in LL lesion cells there is an increase in the expression of proteins involved in iron metabolism such as hemoglobin (Hb), haptoglobin, heme oxygenase 1 and transferrin receptor 1 (TfR1) when compared to tuberculoid leprosy (BT) cells. We also found increased iron deposits and diminished expression of the iron exporter ferroportin 1 in LL lesion cells. Hemin, but not FeSO4 stimulation, was able to enhance M. leprae viability by a mechanism that involves IDO. Analysis of cell phenotype in lesions demonstrated a predominance of M2 markers in LL when compared with BT lesion cells. A positive correlation between CD163 and PPARG with the bacillary index (BI) was observed. In contrast, TNF, STAT1 and CSF2 presented a negative correlation with the BI. In summary, this study demonstrates that iron may regulate IDO expression by a mechanism that involves IL-10, which may contribute for the predominance of M2-like phenotype in LL lesions that favors the phagocytosis and maintenance of M. leprae in host cells.


Asunto(s)
Indolamina-Pirrol 2,3,-Dioxigenasa/fisiología , Hierro/fisiología , Mycobacterium leprae/fisiología , Adulto , Femenino , Humanos , Immunoblotting , Técnicas para Inmunoenzimas , Indolamina-Pirrol 2,3,-Dioxigenasa/metabolismo , Hierro/metabolismo , Lepra Lepromatosa/metabolismo , Lepra Lepromatosa/microbiología , Masculino , Persona de Mediana Edad , Mycobacterium leprae/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
10.
J. Bras. Patol. Med. Lab. (Online) ; 53(2): 119-123, Jan.-Apr. 2017. graf
Artículo en Inglés | LILACS-Express | ID: biblio-1040201

RESUMEN

ABSTRACT Human cytomegalovirus (HCMV) infection is the main cause of morbidity in kidney transplant recipients. This study aims to investigate if CD64 expression on polymorphonuclear (PMN) cells is useful for the detection of HCMV infection in eleven kidney recipients during sixty days. From the total patients, nine were positive for both pp65 antigenemia and HCMV by quantitative polymerase chain reaction (qPCR), all of which had circulating neutrophils expressing CD64 3-4 weeks prior to pp65 antigenemia peak. These results suggest that quantification of PMN CD64 together with pp65 antigenemia could be useful for the early diagnosis of HCMV after transplantation.


RESUMO A infecção por citomegalovírus humano (CMVH) é a principal causa de morbidade em receptores de transplante renal. Este estudo pretende investigar se a expressão de CD64 em polimorfonucleares (PMN) é útil para a detecção de infecção por CMVH em 11 receptores renais durante 60 dias. Do total de pacientes, nove foram positivos para antigenemia pp65 e para CMVH por reação em cadeia da polimerase quantitativa (qPCR), todos apresentando neutrófilos circulantes que expressam CD64 3-4 semanas antes do pico de antigenemia pp65. Esses resultados sugerem que a quantificação de PMN CD64 em conjunto com a antigenemia pp65 pode ser útil para o diagnóstico precoce de HCMV no pós-transplante.

11.
s.l; Elsevier; 2017. 10 p. tab, graf.
No convencional en Inglés | Sec. Est. Saúde SP, HANSEN, SESSP-ILSLPROD, Sec. Est. Saúde SP, SESSP-ILSLACERVO, Sec. Est. Saúde SP | ID: biblio-1052567

RESUMEN

Our previous study has demonstrated that IL-10 may modulate both indoleamine 2,3-dioxygenase (IDO) and CD163 expression in lepromatous leprosy (LL) cells, favoring Mycobacterium leprae persistence through induction of regulatory pathways and iron storage. Here, we observed that in LL lesion cells there is an increase in the expression of proteins involved in iron metabolism such as hemoglobin (Hb), haptoglobin, heme oxygenase 1 and transferrin receptor 1 (TfR1) when compared to tuberculoid leprosy (BT) cells. We also found increased iron deposits and diminished expression of the iron exporter ferroportin 1 in LL lesion cells. Hemin, but not FeSO stimulation, was able to enhance M. leprae viability by a mechanism that involves IDO. Analysis of cell phenotype in lesions demonstrated a predominance of M2 markers in LL when compared with BT lesion cells. A positive correlation between CD163 and PPARG with the bacillary index (BI) was observed. In contrast, TNF, STAT1 and CSF2 presented a negative correlation with the BI. In summary, this study demonstrates that iron may regulate IDO expression by a mechanism that involves IL-10, which may contribute for the predominance of M2-like phenotype in LL lesions that favors the phagocytosis and maintenance of M. leprae in host cells.


Asunto(s)
Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Immunoblotting , Lepra Lepromatosa/metabolismo , Lepra Lepromatosa/microbiología , Técnicas para Inmunoenzimas , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Indolamina-Pirrol 2,3,-Dioxigenasa/fisiología , Indolamina-Pirrol 2,3,-Dioxigenasa/metabolismo , Hierro/fisiología , Hierro/metabolismo , Mycobacterium leprae/fisiología , Mycobacterium leprae/metabolismo
12.
PLoS Negl Trop Dis ; 10(8): e0004955, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27556927

RESUMEN

Erythema Nodosum Leprosum (ENL) is an immune reaction in leprosy that aggravates the patient´s clinical condition. ENL presents systemic symptoms of an acute infectious syndrome with high leukocytosis and intense malaise clinically similar to sepsis. The treatment of ENL patients requires immunosuppression and thus needs to be early and efficient to prevent both disabilities and permanent nerve damage. Some patients experience multiple episodes of ENL and prolonged use of immunosuppressive drugs may lead to serious adverse effects. Thalidomide treatment is extremely effective at ameliorating ENL symptoms. Several mechanisms have been proposed to explain the efficacy of thalidomide in ENL, including the inhibition of TNF production. Given its teratogenicity, thalidomide is prohibitive for women of childbearing age. A rational search for molecular targets during ENL episodes is essential to better understand the disease mechanisms involved, which may also lead to the discovery of new drugs and diagnostic tests. Previous studies have demonstrated that IFN-γ and GM-CSF, involved in the induction of CD64 expression, increase during ENL. The aim of the present study was to investigate CD64 expression during ENL and whether thalidomide treatment modulated its expression. Leprosy patients were allocated to one of five groups: (1) Lepromatous leprosy, (2) Borderline leprosy, (3) Reversal reaction, (4) ENL, and (5) ENL 7 days after thalidomide treatment. The present study demonstrated that CD64 mRNA and protein were expressed in ENL lesions and that thalidomide treatment reduced CD64 expression and neutrophil infiltrates-a hallmark of ENL. We also showed that ENL blood neutrophils exclusively expressed CD64 on the cell surface and that thalidomide diminished overall expression. Patient classification based on clinical symptoms found that severe ENL presented high levels of neutrophil CD64. Collectively, these data revealed that ENL neutrophils express CD64, presumably contributing to the immunopathogenesis of the disease.


Asunto(s)
Eritema Nudoso/inmunología , Leprostáticos/uso terapéutico , Neutrófilos/efectos de los fármacos , Neutrófilos/inmunología , Receptores de IgG/genética , Talidomida/uso terapéutico , Adolescente , Adulto , Anciano , Biopsia , Eritema Nudoso/diagnóstico , Eritema Nudoso/tratamiento farmacológico , Eritema Nudoso/microbiología , Femenino , Humanos , Lepra Dimorfa/tratamiento farmacológico , Lepra Dimorfa/inmunología , Lepra Dimorfa/microbiología , Lepra Lepromatosa/tratamiento farmacológico , Lepra Lepromatosa/inmunología , Lepra Lepromatosa/microbiología , Masculino , Persona de Mediana Edad , Receptores de IgG/inmunología , Piel/microbiología , Piel/patología , Adulto Joven
13.
J Immunol ; 193(7): 3613-23, 2014 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-25187655

RESUMEN

Complement and the kallikrein-kinin cascade system are both activated in injured tissues. Little is known about their partnership in the immunopathogenesis of Chagas disease, the chronic infection caused by the intracellular protozoan Trypanosoma cruzi. In this study, we show that pharmacological targeting of the C5a receptor (C5aR) or the bradykinin B2 receptor (B2R) inhibited plasma leakage in hamster cheek pouch topically exposed to tissue culture trypomastigotes (TCTs). Further, angiotensin-converting enzyme inhibitors potentiated TCT-evoked paw edema in BALB/c, C57BL/6, and C5-deficient A/J mice through activation of joint pathways between C5aR/B2R or C3aR/B2R. In addition to generation of C5a and kinins via parasite-derived cruzipain, we demonstrate that macrophages internalize TCTs more efficiently through joint activation of C5aR/B2R. Furthermore, we found that C5aR targeting markedly reduces NO production and intracellular parasitism in macrophages. We then studied the impact of C5aR/B2R cross-talk in TCT infection on the development of adaptive immunity. We found that IL-12p40/70 expression was blunted in splenic dendritic cells by blocking either C5aR or B2R, suggesting that codominant signaling via C5aR and B2R fuels production of the Th1-polarizing cytokine. Finally, we assessed the impact of kinins and C5a liberated in parasite-laden tissues on Th cell differentiation. As predicted, BALB/c mice pretreated with angiotensin-converting enzyme inhibitors potentiated IFN-γ production by Ag-specific T cells via C5aR/B2R cross-talk. Interestingly, we found that B2R targeting upregulated IL-10 secretion, whereas C5aR blockade vigorously stimulated IL-4 production. In summary, we describe a novel pathway by which C5aR/B2R cross-talk couples transendothelial leakage of plasma proteins to the cytokine circuitry that coordinates antiparasite immunity.


Asunto(s)
Inmunidad Adaptativa , Enfermedad de Chagas/inmunología , Inmunidad Innata , Receptor de Anafilatoxina C5a/inmunología , Receptor de Bradiquinina B2/inmunología , Células TH1/inmunología , Trypanosoma cruzi/inmunología , Animales , Antígenos de Protozoos/genética , Antígenos de Protozoos/inmunología , Enfermedad de Chagas/genética , Enfermedad de Chagas/patología , Complemento C5a/genética , Complemento C5a/inmunología , Cricetinae , Cisteína Endopeptidasas/genética , Cisteína Endopeptidasas/inmunología , Citocinas/genética , Citocinas/inmunología , Ratones , Ratones Endogámicos BALB C , Ratones Noqueados , Proteínas Protozoarias , Receptor de Anafilatoxina C5a/genética , Receptor de Bradiquinina B2/genética , Células TH1/patología , Trypanosoma cruzi/genética
14.
Eur J Immunol ; 42(11): 2925-36, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22851198

RESUMEN

Lepromatous macrophages possess a regulatory phenotype that contributes to the immunosuppression observed in leprosy. CD163, a scavenger receptor that recognizes hemoglobin-haptoglobin complexes, is expressed at higher levels in lepromatous cells, although its functional role in leprosy is not yet established. We herein demonstrate that human lepromatous lesions are microenvironments rich in IDO⁺CD163⁺. Cells isolated from these lesions were CD68⁺IDO⁺CD163⁺ while higher levels of sCD163 in lepromatous sera positively correlated with IL-10 levels and IDO activity. Different Myco-bacterium leprae (ML) concentrations in healthy monocytes likewise revealed a positive correlation between increased concentrations of the mycobacteria and IDO, CD209, and CD163 expression. The regulatory phenotype in ML-stimulated monocytes was accompanied by increased TNF, IL-10, and TGF-ß levels whereas IL-10 blockade reduced ML-induced CD163 expression. The CD163 blockade reduced ML uptake in human monocytes. ML uptake was higher in HEK293 cells transfected with the cDNA for CD163 than in untransfected cells. Simultaneously, increased CD163 expression in lepromatous cells seemed to be dependent on ML uptake, and contributed to augmented iron storage in lepromatous macrophages. Altogether, these results suggest that ML-induced CD163 expression modulates the host cell phenotype to create a favorable environment for myco-bacterial entry and survival.


Asunto(s)
Antígenos CD/inmunología , Antígenos de Diferenciación Mielomonocítica/inmunología , Lepra Lepromatosa/inmunología , Lepra Lepromatosa/microbiología , Macrófagos/inmunología , Mycobacterium leprae/inmunología , Receptores de Superficie Celular/inmunología , Antígenos CD/genética , Antígenos de Diferenciación Mielomonocítica/genética , Biopsia , Citometría de Flujo , Humanos , Indolamina-Pirrol 2,3,-Dioxigenasa/inmunología , Interleucina-10/inmunología , Lepra Lepromatosa/patología , Macrófagos/microbiología , ARN Mensajero/química , ARN Mensajero/genética , Receptores de Superficie Celular/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
15.
J Leukoc Biol ; 85(6): 1005-14, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19293401

RESUMEN

Previous analysis of the endogenous innate signals that steer T cell-dependent immunity in mice acutely infected by the protozoan Trypanosoma cruzi revealed that bradykinin (BK) or lysyl-BK, i.e., the short-lived peptides excised from plasma-borne kininogens through the activity of cruzipain, induces dendritic cell maturation via BK B(2) receptors (B(2)R). Here, we used the s.c. model of T. cruzi infection to study the functional interplay of TLR2, CXCR2, and B(2)R in edema development. Using intravital microscopy, we found that repertaxin (CXCR2 antagonist) blocked tissue-culture trypomastigotes (TCT)-induced plasma leakage and leukocyte accumulation in the hamster cheek pouch topically exposed to TCT. Furthermore, we found that TCT-evoked paw edema in BALB/c mice was blocked by repertaxin or HOE-140 (B(2)R antagonist), suggesting that CXCR2 propels the extravascular activation of the kinin/B(2)R pathway. We then asked if TLR2-mediated sensing of TCT by innate sentinel cells could induce secretion of CXC chemokines, which would then evoke neutrophil-dependent plasma leakage via the CXCR2/B(2)R pathway. Consistent with this notion, in vitro studies revealed that TCT induce robust secretion of CXC chemokines by resident macrophages in a TLR2-dependent manner. In contrast, TLR2(+/+) macrophages stimulated with insect-derived metacyclic trypomastigotes or epimastigotes, which lack the developmentally regulated TLR2 agonist displayed by TCT, failed to secrete keratinocyte-derived chemokine/MIP-2. Collectively, these results suggest that secretion of CXC chemokines by innate sentinel cells links TLR2-dependent recognition of TCT to the kinin system, a proteolytic web that potently amplifies vascular inflammation and innate immunity through the extravascular release of BK.


Asunto(s)
Quimiocinas CXC/metabolismo , Quininas/metabolismo , Activación de Macrófagos/inmunología , Macrófagos/metabolismo , Procesamiento Proteico-Postraduccional , Receptor Toll-Like 2/inmunología , Trypanosoma cruzi/fisiología , Animales , Cricetinae , Edema/complicaciones , Edema/inmunología , Edema/parasitología , Genotipo , Inflamación/complicaciones , Inflamación/inmunología , Inflamación/parasitología , Estadios del Ciclo de Vida , Macrófagos/parasitología , Ratones , Modelos Inmunológicos , Especificidad de Órganos , Parásitos/crecimiento & desarrollo , Fenotipo , Receptor de Bradiquinina B2/metabolismo , Receptores de Interleucina-8B/metabolismo , Transducción de Señal , Trypanosoma cruzi/crecimiento & desarrollo
16.
Biol Chem ; 389(8): 1015-24, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18979626

RESUMEN

Tissue injury by pathogens induces a stereotyped inflammatory response that alerts the innate immune system of the potential threat to host integrity. Here, we review knowledge emerging from investigations of the role of the kinin system in the mechanisms that link innate to the adaptive phase of immunity. Progress in this field started with results demonstrating that bradykinin is an endogenous danger signal that induces dendritic cell (DC) maturation via G protein-coupled bradykinin B2 receptors (B2R). The immunostimulatory role of kinins was recently confirmed in two different mouse models of Trypanosoma cruzi infection, a parasitic protozoan equipped with kinin-releasing cysteine proteases (cruzipain). Infection by the intraperitoneal route showed that DCs from B2R-/- mice (susceptible phenotype) failed to sense kinin 'danger' signals proteolytically released by parasites, explaining why these mutant mice display lower frequencies of interferon-gamma-producing effector T-cells. Studies of the dynamics of inflammation in the subcutaneous model of infection revealed that the balance between cruzipain and angiotensin-converting enzyme, respectively acting as kinin-generating and degrading enzymes, governs extent of DC maturation and TH1 development via the B2R-dependent innate pathway. Studies of the kinin role in immunity may shed light on the relationship between proteolytic networks and the cytokine circuits that guide T-cell development.


Asunto(s)
Adaptación Biológica/inmunología , Inmunidad Innata/inmunología , Quininas/inmunología , Quininas/metabolismo , Peptidil-Dipeptidasa A/metabolismo , Trypanosoma cruzi/enzimología , Trypanosoma cruzi/inmunología , Animales , Cisteína Endopeptidasas/metabolismo , Humanos
17.
PLoS Pathog ; 3(11): e185, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18052532

RESUMEN

Although the concept that dendritic cells (DCs) recognize pathogens through the engagement of Toll-like receptors is widely accepted, we recently suggested that immature DCs might sense kinin-releasing strains of Trypanosoma cruzi through the triggering of G-protein-coupled bradykinin B2 receptors (B2R). Here we report that C57BL/6.B2R-/- mice infected intraperitoneally with T. cruzi display higher parasitemia and mortality rates as compared to B2R+/+ mice. qRT-PCR revealed a 5-fold increase in T. cruzi DNA (14 d post-infection [p.i.]) in B2R-/- heart, while spleen parasitism was negligible in both mice strains. Analysis of recall responses (14 d p.i.) showed high and comparable frequencies of IFN-gamma-producing CD4+ and CD8+ T cells in the spleen of B2R-/- and wild-type mice. However, production of IFN-gamma by effector T cells isolated from B2R-/- heart was significantly reduced as compared with wild-type mice. As the infection continued, wild-type mice presented IFN-gamma-producing (CD4+CD44+ and CD8+CD44+) T cells both in the spleen and heart while B2R-/- mice showed negligible frequencies of such activated T cells. Furthermore, the collapse of type-1 immune responses in B2R-/- mice was linked to upregulated secretion of IL-17 and TNF-alpha by antigen-responsive CD4+ T cells. In vitro analysis of tissue culture trypomastigote interaction with splenic CD11c+ DCs indicated that DC maturation (IL-12, CD40, and CD86) is controlled by the kinin/B2R pathway. Further, systemic injection of trypomastigotes induced IL-12 production by CD11c+ DCs isolated from B2R+/+ spleen, but not by DCs from B2R-/- mice. Notably, adoptive transfer of B2R+/+ CD11c+ DCs (intravenously) into B2R-/- mice rendered them resistant to acute challenge, rescued development of type-1 immunity, and repressed TH17 responses. Collectively, our results demonstrate that activation of B2R, a DC sensor of endogenous maturation signals, is critically required for development of acquired resistance to T. cruzi infection.


Asunto(s)
Enfermedad de Chagas/inmunología , Células Dendríticas/inmunología , Quininas/metabolismo , Receptor de Bradiquinina B2/inmunología , Células TH1/inmunología , Traslado Adoptivo , Animales , Enfermedad de Chagas/metabolismo , Células Dendríticas/metabolismo , Citometría de Flujo , Interferón gamma/biosíntesis , Interleucina-12/biosíntesis , Interleucina-17/biosíntesis , Quininas/inmunología , Activación de Linfocitos/inmunología , Ratones , Ratones Mutantes , Reacción en Cadena de la Polimerasa , Receptor de Bradiquinina B2/metabolismo , Células TH1/metabolismo , Trypanosoma cruzi , Factor de Necrosis Tumoral alfa/biosíntesis
18.
J Immunol ; 177(9): 6325-35, 2006 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-17056563

RESUMEN

We have previously reported that exogenous bradykinin activates immature dendritic cells (DCs) via the bradykinin B(2) receptor (B(2)R), thereby stimulating adaptive immunity. In this study, we show that these premises are met in a model of s.c. infection by Trypanosoma cruzi, a protozoan that liberates kinins from kininogens through its major protease, cruzipain. Intensity of B(2)R-dependent paw edema evoked by trypomastigotes correlated with levels of IL-12 produced by CD11c(+) dendritic cells isolated from draining lymph nodes. The IL-12 response induced by endogenously released kinins was vigorously increased in infected mice pretreated with inhibitors of angiotensin converting enzyme (ACE), a kinin-degrading metallopeptidase. Furthermore, these innate stimulatory effects were linked to B(2)R-dependent up-regulation of IFN-gamma production by Ag-specific T cells. Strikingly, the trypomastigotes failed to up-regulate type 1 immunity in TLR2(-/-) mice, irrespective of ACE inhibitor treatment. Analysis of the dynamics of inflammation revealed that TLR2 triggering by glycosylphosphatidylinositol-anchored mucins induces plasma extravasation, thereby favoring peripheral accumulation of kininogens in sites of infection. Further downstream, the parasites generate high levels of innate kinin signals in peripheral tissues through the activity of cruzipain. The demonstration that the deficient type 1 immune responses of TLR2(-/-) mice are rescued upon s.c. injection of exogenous kininogens, along with trypomastigotes, supports the notion that generation of kinin "danger" signals is intensified through cooperative activation of TLR2 and B(2)R. In summary, we have described a s.c. infection model where type 1 immunity is vigorously up-regulated by bradykinin, an innate signal whose levels in peripheral tissues are controlled by an intricate interplay of TLR2, B(2)R, and ACE.


Asunto(s)
Enfermedad de Chagas/inmunología , Quininas/metabolismo , Receptor de Bradiquinina B2/agonistas , Receptor Toll-Like 2/agonistas , Trypanosoma cruzi , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Animales , Bradiquinina/farmacología , Antígeno CD11c/análisis , Diferenciación Celular , Cisteína Endopeptidasas/metabolismo , Células Dendríticas/química , Células Dendríticas/inmunología , Modelos Animales de Enfermedad , Inmunidad Innata , Interleucina-12/metabolismo , Quininógenos/administración & dosificación , Quininógenos/metabolismo , Ratones , Ratones Mutantes , Peptidil-Dipeptidasa A/metabolismo , Proteínas Protozoarias , Receptor de Bradiquinina B2/genética , Piel/inmunología , Piel/parasitología , Receptor Toll-Like 2/genética
19.
Microbes Infect ; 8(1): 206-20, 2006 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-16203170

RESUMEN

Kinins, the vasoactive peptides proteolytically liberated from kininogens, were recently recognized as signals alerting the innate immune system. Here we demonstrate that Leishmania donovani and Leishmania chagasi, two etiological agents of visceral leishmaniasis (VL), activate the kinin system. Intravital microscopy in the hamster cheek pouch showed that topically applied promastigotes induced macromolecular leakage (FITC-dextran) through postcapillary venules. Peaking at 15 min, the parasite-induced leakage was drastically enhanced by captopril (Cap), an inhibitor of angiotensin-converting enzyme (ACE), a kinin-degrading metallopeptidase. The enhanced microvascular responses were cancelled by HOE-140, an antagonist of the B2 bradykinin receptor (B2R), or by pre-treatment of promastigotes with the irreversible cysteine proteinase inhibitor N-methylpiperazine-urea-Phe-homoPhe-vinylsulfone-benzene (N-Pip-hF-VSPh). In agreement with the above-mentioned data, the promastigotes vigorously induced edema in the paw of Cap-treated J129 mice, but not Cap-B2R-/- mice. Analysis of parasite-induced breakdown of high molecular weight kininogens (HK), combined with active site-affinity-labeling with biotin-N-Pip-hF-VSPh, identified 35-40 kDa proteins as kinin-releasing cysteine peptidases. We then checked if macrophage infectivity was influenced by interplay between these kinin-releasing parasite proteases, kininogens, and kinin-degrading peptidases (i.e. ACE). Our studies revealed that full-fledged B2R engagement resulted in vigorous increase of L. chagasi uptake by resident macrophages. Evidence that inflammatory macrophages treated with HOE-140 became highly susceptible to amastigote outgrowth, assessed 72 h after initial macrophage interaction, further suggests that the kinin/B2R activation pathway may critically modulate inflammation and innate immunity in visceral leishmaniasis.


Asunto(s)
Permeabilidad Capilar/fisiología , Cisteína Endopeptidasas/metabolismo , Quininas/metabolismo , Leishmania donovani/enzimología , Leishmania infantum/enzimología , Macrófagos/metabolismo , Macrófagos/parasitología , Animales , Cricetinae , Eliminación de Gen , Masculino , Ratones , Ratones Endogámicos BALB C , Peptidil-Dipeptidasa A/metabolismo , Receptores de Bradiquinina/genética , Receptores de Bradiquinina/metabolismo , Factores de Tiempo
20.
J Biol Chem ; 277(8): 5875-81, 2002 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-11726662

RESUMEN

Trypanosoma cruzi activates the kinin pathway through the activity of its major cysteine proteinase, cruzipain. Because kininogen molecules may be displayed on cell surfaces by binding to glycosaminoglycans, we examined whether the ability of cruzipain to release kinins from high molecular weight kininogen (HK) is modulated by heparan sulfate (HS). Kinetic assays show that HS reduces the cysteine proteinase inhibitory activity (K(i app)) of HK about 10-fold. Conversely, the catalytic efficiency of cruzipain on kinin-related synthetic fluorogenic substrates is enhanced up to 6-fold in the presence of HS. Analysis of the HK breakdown products generated by cruzipain indicated that HS changes the pattern of HK cleavage products. Direct measurements of bradykinin demonstrated an up to 35-fold increase in cruzipain-mediated kinin liberation in the presence of HS. Similarly, kinin release by living trypomastigotes increased up to 10-fold in the presence of HS. These studies suggest that the efficiency of T. cruzi to initiate kinin release is potently enhanced by the mutual interactions between cruzipain, HK, and heparan sulfate proteoglycans.


Asunto(s)
Cisteína Endopeptidasas/metabolismo , Heparitina Sulfato/farmacología , Quininas/metabolismo , Trypanosoma cruzi/enzimología , Secuencias de Aminoácidos , Secuencia de Aminoácidos , Animales , Activación Enzimática/efectos de los fármacos , Cinética , Quininógenos/metabolismo , Fragmentos de Péptidos/química , Fragmentos de Péptidos/metabolismo , Proteínas Protozoarias , Especificidad por Sustrato , Trypanosoma cruzi/efectos de los fármacos
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