RESUMO
Increasing evidence suggests that free haem and iron exert vasculo-toxic and pro-inflammatory effects by activating endothelial and immune cells. In the present retrospective study, we compared serum samples from transfusion-dependent patients with ß-thalassaemia major and intermedia, hereditary spherocytosis and sickle cell disease (SCD). Haemolysis, transfusions and ineffective erythropoiesis contribute to haem and iron overload in haemolytic patients. In all cohorts we observed increased systemic haem and iron levels associated with scavenger depletion and toxic 'free' species formation. Endothelial dysfunction, oxidative stress and inflammation markers were significantly increased compared to healthy donors. In multivariable logistic regression analysis, oxidative stress markers remained significantly associated with both haem- and iron-related parameters, while soluble vascular cell adhesion molecule 1 (sVCAM-1), soluble endothelial selectin (sE-selectin) and tumour necrosis factor α (TNFα) showed the strongest association with haem-related parameters and soluble intercellular adhesion molecule 1 (sICAM-1), sVCAM-1, interleukin 6 (IL-6) and vascular endothelial growth factor (VEGF) with iron-related parameters. While hereditary spherocytosis was associated with the highest IL-6 and TNFα levels, ß-thalassaemia major showed limited inflammation compared to SCD. The sVCAM1 increase was significantly lower in patients with SCD receiving exchange compared to simple transfusions. The present results support the involvement of free haem/iron species in the pathogenesis of vascular dysfunction and sterile inflammation in haemolytic diseases, irrespective of the underlying haemolytic mechanism, and highlight the potential therapeutic benefit of iron/haem scavenging therapies in these conditions.
Assuntos
Anemia Falciforme/sangue , Heme/metabolismo , Hemoglobinas/metabolismo , Ferro/sangue , Esferocitose Hereditária/sangue , Talassemia beta/sangue , Adolescente , Adulto , Anemia Falciforme/terapia , Transfusão de Sangue , Criança , Pré-Escolar , Endotélio Vascular/metabolismo , Feminino , Humanos , Inflamação/sangue , Molécula 1 de Adesão Intercelular/sangue , Interleucina-6/sangue , Masculino , Esferocitose Hereditária/terapia , Fator de Necrose Tumoral alfa/sangue , Molécula 1 de Adesão de Célula Vascular/sangue , Fator A de Crescimento do Endotélio Vascular/sangue , Talassemia beta/terapiaRESUMO
AIMS: Whether and how iron affects the progression of atherosclerosis remains highly debated. Here, we investigate susceptibility to atherosclerosis in a mouse model (ApoE-/- FPNwt/C326S), which develops the disease in the context of elevated non-transferrin bound serum iron (NTBI). METHODS AND RESULTS: Compared with normo-ferremic ApoE-/- mice, atherosclerosis is profoundly aggravated in iron-loaded ApoE-/- FPNwt/C326S mice, suggesting a pro-atherogenic role for iron. Iron heavily deposits in the arterial media layer, which correlates with plaque formation, vascular oxidative stress and dysfunction. Atherosclerosis is exacerbated by iron-triggered lipid profile alterations, vascular permeabilization, sustained endothelial activation, elevated pro-atherogenic inflammatory mediators, and reduced nitric oxide availability. NTBI causes iron overload, induces reactive oxygen species production and apoptosis in cultured vascular cells, and stimulates massive MCP-1-mediated monocyte recruitment, well-established mechanisms contributing to atherosclerosis. NTBI-mediated toxicity is prevented by transferrin- or chelator-mediated iron scavenging. Consistently, a low-iron diet and iron chelation therapy strongly improved the course of the disease in ApoE-/- FPNwt/C326S mice. Our results are corroborated by analyses of serum samples of haemochromatosis patients, which show an inverse correlation between the degree of iron depletion and hallmarks of endothelial dysfunction and inflammation. CONCLUSION: Our data demonstrate that NTBI-triggered iron overload aggravates atherosclerosis and unravel a causal link between NTBI and the progression of atherosclerotic lesions. Our findings support clinical applications of iron restriction in iron-loaded individuals to counteract iron-aggravated vascular dysfunction and atherosclerosis.
Assuntos
Aterosclerose , Sobrecarga de Ferro , Animais , Aterosclerose/tratamento farmacológico , Aterosclerose/etiologia , Aterosclerose/prevenção & controle , Dieta , Humanos , Ferro/metabolismo , Sobrecarga de Ferro/complicações , Sobrecarga de Ferro/tratamento farmacológico , Camundongos , TransferrinaRESUMO
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.
Assuntos
Antimônio/administração & dosagem , Antiprotozoários/administração & dosagem , Inflamação/patologia , Leishmaniose Cutânea/tratamento farmacológico , Leishmaniose Cutânea/patologia , Adulto , Estudos Transversais , Citocinas/sangue , Feminino , Humanos , Leishmania braziliensis/isolamento & purificação , Leishmaniose Cutânea/parasitologia , Leucócitos Mononucleares/imunologia , Masculino , Prevenção Secundária , Falha de Tratamento , Adulto JovemRESUMO
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.
Assuntos
Linfócitos T CD8-Positivos/parasitologia , Citotoxicidade Imunológica/imunologia , Células Matadoras Naturais/parasitologia , Leishmaniose Cutânea/imunologia , Linfócitos T Citotóxicos/parasitologia , Animais , Linfócitos T CD8-Positivos/imunologia , Modelos Animais de Doenças , Humanos , Células Matadoras Naturais/imunologia , Leishmaniose Cutânea/patologia , Linfócitos T Citotóxicos/imunologiaRESUMO
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.
Assuntos
Leishmania braziliensis/imunologia , Leishmaniose Cutânea/imunologia , Leishmaniose Cutânea/patologia , Monócitos/imunologia , Adolescente , Adulto , Quimiocina CCL2/metabolismo , Feminino , Proteínas Ligadas por GPI/análise , Humanos , Masculino , Pessoa de Meia-Idade , Monócitos/química , Receptores CCR2/análise , Receptores de IgG/análise , Fator de Necrose Tumoral alfa/metabolismo , Úlcera/imunologia , Úlcera/patologia , Adulto JovemRESUMO
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.
Assuntos
Interleucina-17/imunologia , Leishmania major/fisiologia , Leishmaniose Cutânea/imunologia , Leishmaniose Cutânea/patologia , Animais , Modelos Animais de Doenças , Regulação para Baixo , Feminino , Humanos , Interferon gama/sangue , Interferon gama/imunologia , Interleucina-10/deficiência , Interleucina-10/genética , Interleucina-17/sangue , Interleucina-1beta/metabolismo , Leishmania major/patogenicidade , Leishmaniose Cutânea/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Monócitos/imunologia , Infiltração de NeutrófilosRESUMO
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.
Assuntos
Leishmania braziliensis/fisiologia , Leishmaniose Cutânea/prevenção & controle , Monócitos/parasitologia , Espécies Reativas de Oxigênio/metabolismo , Animais , Citometria de Fluxo , Perfilação da Expressão Gênica , Humanos , Leishmaniose Cutânea/metabolismo , Monócitos/metabolismo , Óxido Nítrico/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , PennsylvaniaRESUMO
Cutaneous leishmaniasis (CL) is the most frequent clinical form of tegumentary leishmaniasis and is characterised by a single or a few ulcerated skin lesions that may disseminate into multiple ulcers and papules, which characterise disseminated leishmaniasis (DL). In this study, cells were quantified using immunohistochemistry and haematoxylin and eosin staining (CD4+, CD68+, CD20+, plasma cells and neutrophils) and histopathology was used to determine the level of inflammation in biopsies from patients with early CL, late CL and DL (ulcers and papules). The histopathology showed differences in the epidermis between the papules and ulcers from DL. An analysis of the cells present in the tissues showed similarities between the ulcers from localised CL (LCL) and DL. The papules had fewer CD4+ T cells than the DL ulcers. Although both CD4+ cells and macrophages contribute to inflammation in early CL, macrophages are the primary cell type associated with inflammation intensity in late ulcers. The higher frequency of CD20+ cells and plasma cells in lesions demonstrates the importance of B cells in the pathogenesis of leishmaniasis. The number of neutrophils was the same in all of the analysed groups. A comparison between the ulcers from LCL and DL and the early ulcers and papules shows that few differences between these two clinical forms can be distinguished by observing only the tissue.
Assuntos
Linfócitos B/parasitologia , Leishmaniose Cutânea/patologia , Macrófagos/parasitologia , Neutrófilos/parasitologia , Pele/patologia , Adolescente , Adulto , Antígenos de Protozoários/análise , Biópsia , Derme/patologia , Progressão da Doença , Amarelo de Eosina-(YS) , Epiderme/patologia , Feminino , Hematoxilina , Humanos , Imuno-Histoquímica , Inflamação/patologia , Leishmaniose Cutânea/imunologia , Leishmaniose Tegumentar Difusa/imunologia , Leishmaniose Tegumentar Difusa/patologia , Masculino , Pessoa de Meia-Idade , Plasmócitos/parasitologia , Úlcera Cutânea/parasitologia , Adulto JovemRESUMO
IL-6 and IL-27 are closely related cytokines that play critical but distinct roles during infection with Toxoplasma gondii. Thus, IL-6 is required for the development of protective immunity to this pathogen, whereas IL-27 is required to limit infection-induced pathology. Paradoxically, these factors both signal through gp130, but little is known about how the signals downstream of gp130 are integrated to coordinate the immune response to infection. To better understand these events, gp130 Y757F mice that have a mutation in gp130 at the binding site for suppressor of cytokine signaling 3, a critical negative regulator of gp130 signaling, were infected with T. gondii. These mutant mice were acutely susceptible to this challenge, characterized by an early defect in the production of IL-12 and IFN-γ and increased parasite burdens. Consistent with the reduced IL-12 levels, IL-6, but not other gp130 cytokines, was a potent antagonist of IL-12 production by gp130 Y757F macrophages and dendritic cells in vitro. Moreover, in gp130 Y757F mice, blocking IL-6 in vivo, or administration of rIL-12, during infection restored IFN-γ production and protective immunity. Collectively, these studies highlight that a failure to abbreviate IL-6-mediated gp130 signaling results in a profound anti-inflammatory signal that blocks the generation of protective immunity to T. gondii.
Assuntos
Receptor gp130 de Citocina/antagonistas & inibidores , Mediadores da Inflamação/antagonistas & inibidores , Interleucina-6/fisiologia , Transdução de Sinais/imunologia , Toxoplasma/crescimento & desenvolvimento , Toxoplasma/imunologia , Animais , Células Cultivadas , Receptor gp130 de Citocina/fisiologia , Predisposição Genética para Doença , Imunidade Inata/genética , Mediadores da Inflamação/fisiologia , Interleucina-6/antagonistas & inibidores , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Camundongos Knockout , Transdução de Sinais/genética , Toxoplasma/patogenicidade , Toxoplasmose/genética , Toxoplasmose/imunologia , Toxoplasmose/parasitologiaRESUMO
Previous studies have implicated T cell production of IL-17 in resistance to Toxoplasma gondii as well as the development of immune-mediated pathology during this infection. Analysis of C57BL/6 and C57BL/6 RAG(-/-) mice challenged with T. gondii-identified NK cells as a major innate source of IL-17. The ability of soluble Toxoplasma Ag to stimulate NK cells to produce IL-17 was dependent on the presence of accessory cells and the production of IL-6, IL-23, and TGF-beta. In contrast, these events were inhibited by IL-2, IL-15, and IL-27. Given that IL-6 was one of the most potent enhancers of NK cell production of IL-17, further studies revealed that only a subset of NK cells expressed both chains of the IL-6R, IL-6 upregulated expression of the Th17-associated transcription factor RORgammat, and that IL-6(-/-) mice challenged with T. gondii had a major defect in NK cell production of IL-17. Together, these data indicate that many of the same cytokines that regulate Th17 cells are part of a conserved pathway that also control innate production of IL-17 and identify a major role for IL-6 in the regulation of NK cell responses.
Assuntos
Interleucina-17/biossíntese , Interleucina-6/fisiologia , Células Matadoras Naturais/imunologia , Toxoplasmose Animal/imunologia , Doença Aguda , Animais , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Células Cultivadas , Proteínas de Homeodomínio/genética , Imunidade Inata/genética , Células Matadoras Naturais/metabolismo , Células Matadoras Naturais/parasitologia , Células Matadoras Naturais/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Toxoplasma/imunologia , Toxoplasmose Animal/metabolismo , Toxoplasmose Animal/patologiaRESUMO
The article presents a perspective on the Brazilian scientific production on the health of the black population (SPN) published in scientific journals. We performed a rapid scoping review combined with thematic and bibliometric analysis. Our search included four indexed databases. We retrieved 519 studies in line with the thematic axes and strategic underlying themes of the Agenda of Research Priorities of the Ministry of Health and the guidelines of the National Policy for the Comprehensive Health of the Black Population. The data mainly returned quantitative studies published from 1969 to 2022. Sixty-five of the selected studies were explicitly about the black population and 54 about the quilombola population. The analysis of the most recurrent terms in the titles of the selected studies evidenced that epidemiological aspects and health and disease conditions prevailed. We observed limitations in the currently available indexing descriptors, which do not cover the most conceptually appropriate terminology. This paper consolidates knowledge about the SPN-related scientific production. It supports the discussion on a propositional priority research agenda to improve health policies for this population, overcome racism, and denounce rights violations.
O artigo apresenta uma prospecção da produção científica brasileira sobre a saúde da população negra (SPN) publicada em periódicos científicos. Trata-se de uma revisão de escopo rápida, combinada com análise temática e bibliométrica. As buscas foram realizadas em quatro bases indexadas. Foram selecionados 519 trabalhos em consonância com os eixos temáticos e subtemas estratégicos da Agenda de Prioridades de Pesquisa do Ministério da Saúde e das diretrizes da Política Nacional de Saúde Integral da População Negra. Os dados mostraram estudos publicados entre 1969 e 2022, a maioria deles com abordagem quantitativa. Entre os selecionados, 65 foram especificamente sobre a população negra e 54 sobre a população quilombola. A análise dos termos mais recorrentes nos títulos dos trabalhos selecionados mostrou que prevaleceram aspectos epidemiológicos e condições de saúde e doença. Observou-se limitações nos descritores de indexação hoje disponíveis, que não abrangem a terminologia mais adequada conceitualmente. O artigo contribui para consolidar o conhecimento sobre a produção científica relacionada com a SPN, subsidiando também a discussão em torno de uma agenda prioritária propositiva para pesquisas com vistas a aprimorar as políticas de saúde para essa população, superar o racismo e denunciar as violações de direitos.
Assuntos
Indexação e Redação de Resumos , Bibliometria , Brasil , Bases de Dados Factuais , HumanosRESUMO
Understanding host immune pathways associated with tissue damage during reactions are of upmost importance to the development of immune intervention strategies. The participation of monocytes in leprosy reactions was evaluated by determining the frequency of monocyte subsets and the degree of cellular activation through the expression of MHCII and the co-stimulatory molecules CD40, CD80, CD86. Leprosy subjects with or without reactions were included in this cross-sectional study. Peripheral blood mononuclear cell were isolated and stained ex vivo to determine monocyte subsets and the degree of cellular activation by flow cytometry. Intermediate monocytes were increased in leprosy patients with reactions when compared to patients without reactions. Although no difference was detected in the frequency of monocyte subsets between type 1 and 2 reactions, the expression of CD80 was increased in monocytes from patients with type 1 reactions and CD40 was higher in paucibacillary subjects presenting type 1 reactions. Moreover, CD86 and MHC II expression were higher in intermediate monocytes when compared to the other subsets in leprosy reaction types 1 and 2. Intermediate monocyte activation with CD86 and MHCII expression is involved with both type 1 and 2 reactions, whereas CD80 and CD40 expression is related to type 1 reactions.
Assuntos
Antígeno B7-1/análise , Antígeno B7-2/análise , Antígenos CD40/análise , Hanseníase/imunologia , Adolescente , Adulto , Idoso , Apresentação de Antígeno , Biomarcadores/análise , Estudos Transversais , Feminino , Citometria de Fluxo , Humanos , Leucócitos Mononucleares/imunologia , Masculino , Pessoa de Meia-Idade , Monócitos/imunologia , Adulto JovemRESUMO
[This corrects the article DOI: 10.1371/journal.pntd.0004992.].
RESUMO
O artigo apresenta uma prospecção da produção científica brasileira sobre a saúde da população negra (SPN) publicada em periódicos científicos. Trata-se de uma revisão de escopo rápida, combinada com análise temática e bibliométrica. As buscas foram realizadas em quatro bases indexadas. Foram selecionados 519 trabalhos em consonância com os eixos temáticos e subtemas estratégicos da Agenda de Prioridades de Pesquisa do Ministério da Saúde e das diretrizes da Política Nacional de Saúde Integral da População Negra. Os dados mostraram estudos publicados entre 1969 e 2022, a maioria deles com abordagem quantitativa. Entre os selecionados, 65 foram especificamente sobre a população negra e 54 sobre a população quilombola. A análise dos termos mais recorrentes nos títulos dos trabalhos selecionados mostrou que prevaleceram aspectos epidemiológicos e condições de saúde e doença. Observou-se limitações nos descritores de indexação hoje disponíveis, que não abrangem a terminologia mais adequada conceitualmente. O artigo contribui para consolidar o conhecimento sobre a produção científica relacionada com a SPN, subsidiando também a discussão em torno de uma agenda prioritária propositiva para pesquisas com vistas a aprimorar as políticas de saúde para essa população, superar o racismo e denunciar as violações de direitos.
Assuntos
População Negra , Saúde das Minorias Étnicas , BibliometriaRESUMO
Resumo O artigo apresenta uma prospecção da produção científica brasileira sobre a saúde da população negra (SPN) publicada em periódicos científicos. Trata-se de uma revisão de escopo rápida, combinada com análise temática e bibliométrica. As buscas foram realizadas em quatro bases indexadas. Foram selecionados 519 trabalhos em consonância com os eixos temáticos e subtemas estratégicos da Agenda de Prioridades de Pesquisa do Ministério da Saúde e das diretrizes da Política Nacional de Saúde Integral da População Negra. Os dados mostraram estudos publicados entre 1969 e 2022, a maioria deles com abordagem quantitativa. Entre os selecionados, 65 foram especificamente sobre a população negra e 54 sobre a população quilombola. A análise dos termos mais recorrentes nos títulos dos trabalhos selecionados mostrou que prevaleceram aspectos epidemiológicos e condições de saúde e doença. Observou-se limitações nos descritores de indexação hoje disponíveis, que não abrangem a terminologia mais adequada conceitualmente. O artigo contribui para consolidar o conhecimento sobre a produção científica relacionada com a SPN, subsidiando também a discussão em torno de uma agenda prioritária propositiva para pesquisas com vistas a aprimorar as políticas de saúde para essa população, superar o racismo e denunciar as violações de direitos.
Abstract The article presents a perspective on the Brazilian scientific production on the health of the black population (SPN) published in scientific journals. We performed a rapid scoping review combined with thematic and bibliometric analysis. Our search included four indexed databases. We retrieved 519 studies in line with the thematic axes and strategic underlying themes of the Agenda of Research Priorities of the Ministry of Health and the guidelines of the National Policy for the Comprehensive Health of the Black Population. The data mainly returned quantitative studies published from 1969 to 2022. Sixty-five of the selected studies were explicitly about the black population and 54 about the quilombola population. The analysis of the most recurrent terms in the titles of the selected studies evidenced that epidemiological aspects and health and disease conditions prevailed. We observed limitations in the currently available indexing descriptors, which do not cover the most conceptually appropriate terminology. This paper consolidates knowledge about the SPN-related scientific production. It supports the discussion on a propositional priority research agenda to improve health policies for this population, overcome racism, and denounce rights violations.
RESUMO
Host and parasite gene expression in skin biopsies from Leishmania braziliensis-infected patients were simultaneously analyzed using high throughput RNA-sequencing. Biopsies were taken from 8 patients with early cutaneous leishmaniasis and 17 patients with late cutaneous leishmaniasis. Although parasite DNA was found in all patient lesions at the time of biopsy, the patients could be stratified into two groups: one lacking detectable parasite transcripts (PTNeg) in lesions, and another in which parasite transcripts were readily detected (PTPos). These groups exhibited substantial differences in host responses to infection. PTPos biopsies contained an unexpected increase in B lymphocyte-specific and immunoglobulin transcripts in the lesions, and an upregulation of immune inhibitory molecules. Biopsies without detectable parasite transcripts showed decreased evidence for B cell activation, but increased expression of antimicrobial genes and genes encoding skin barrier functions. The composition and abundance of L. braziliensis transcripts in PTPos lesions were surprisingly conserved among all six patients, with minimal meaningful differences between lesions from patients with early and late cutaneous leishmaniasis. The most abundant parasite transcripts expressed in lesions were distinct from transcripts expressed in vitro in human macrophage cultures infected with L. amazonensis or L. major. Therefore in vitro gene expression in macrophage monolayers may not be a strong predictor of gene expression in lesions. Some of the most highly expressed in vivo transcripts encoded amastin-like proteins, hypothetical genes, putative parasite virulence factors, as well as histones and tubulin. In summary, RNA sequencing allowed us to simultaneously analyze human and L. braziliensis transcriptomes in lesions of infected patients, and identify unexpected differences in host immune responses which correlated with active transcription of parasite genes.
Assuntos
Interações Hospedeiro-Parasita/imunologia , Leishmania braziliensis/genética , Leishmaniose Cutânea/genética , Macrófagos/imunologia , Pele/patologia , Estudos de Casos e Controles , DNA de Protozoário/isolamento & purificação , Expressão Gênica , Perfilação da Expressão Gênica , Humanos , Leishmania braziliensis/imunologia , Leishmaniose Cutânea/imunologia , Ativação Linfocitária , Pele/parasitologia , TranscriptomaRESUMO
Skin ulcer development in cutaneous leishmaniasis due to Leishmania braziliensis infection is associated with a mononuclear cell infiltrate and high levels of tumor necrosis factor (TNF). Herein, we show that despite the absence of Leishmania-driven TNF, a cutaneous leishmaniasis patient with acquired immunodeficiency syndrome developed a skin ulcer. The presence of mononuclear phagocytes and high levels of TNF, chemokine (C-C motif) ligand 2 (CCL2), and metalloproteinase-9 in tissue are identified as potential contributors to immunopathology observed in L. braziliensis-infected patients.
Assuntos
Coinfecção/complicações , Infecções por HIV/complicações , Leishmaniose Cutânea/complicações , Fagócitos/fisiologia , Úlcera Cutânea/etiologia , Adulto , Quimiocina CCL2/sangue , Coinfecção/parasitologia , Coinfecção/virologia , Feminino , Infecções por HIV/parasitologia , Humanos , Leishmania braziliensis , Leishmaniose Cutânea/patologia , Leishmaniose Cutânea/virologia , Metaloproteinase 9 da Matriz/sangue , Úlcera Cutânea/parasitologia , Úlcera Cutânea/virologia , Fator de Necrose Tumoral alfa/sangueRESUMO
The host immune response has a critical role not only in protection from human leishmaniasis but also in promoting disease severity. Although candidate gene approaches in mouse models of leishmaniasis have been extremely informative, a global understanding of the immune pathways active in lesions from human patients is lacking. To address this issue, genome-wide transcriptional profiling of Leishmania braziliensis-infected cutaneous lesions and normal skin controls was carried out. A signature of the L. braziliensis skin lesion was defined, which includes over 2,000 differentially regulated genes. Pathway-level analysis of this transcriptional response revealed key biological pathways present in cutaneous lesions, generating a testable 'metapathway' model of immunopathology and providing new insights for treatment of human leishmaniasis.
Assuntos
Genômica/métodos , Leishmania braziliensis/imunologia , Leishmaniose Cutânea , Úlcera Cutânea , Adolescente , Adulto , Feminino , Humanos , Inflamassomos/genética , Inflamassomos/imunologia , Leishmaniose Cutânea/genética , Leishmaniose Cutânea/imunologia , Leishmaniose Cutânea/parasitologia , Masculino , Pessoa de Meia-Idade , Psoríase/genética , Psoríase/imunologia , Pele/imunologia , Pele/parasitologia , Úlcera Cutânea/genética , Úlcera Cutânea/imunologia , Úlcera Cutânea/parasitologia , Transcrição Gênica/imunologia , Transcriptoma/imunologia , Adulto JovemRESUMO
Pentoxifylline is a tumor necrosis factor-α (TNF-α) inhibitor that also attenuates the immune response and decreases tissue inflammation. The association of pentoxifylline with antimony improves the cure rate of mucosal and cutaneous leishmaniasis. In this randomized and double blind pilot trial, cure rate was higher, although not significant, in patients who received antimony plus pentoxifylline than in those patients receiving antimony plus placebo. A significant decrease in TNF-α and interferon-γ (IFN-γ) levels during therapy was more pronounced in the antimony plus pentoxifylline group, whereas CCL-3 (Chemokine [C-C motif] ligand 3) decreased similarly in both groups. The increased levels of CXCL-9 (Chemokine [C-X-C motif] ligand 9) during therapy were lower in the antimony plus pentoxifylline group. Therapy with pentoxifylline modifies cytokines and chemokines production, which may be associated with therapeutic outcome.
Assuntos
Antimônio/uso terapêutico , Leishmaniose Cutânea/tratamento farmacológico , Pentoxifilina/uso terapêutico , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Adulto , Quimiocina CCL3/imunologia , Quimiocina CXCL10/imunologia , Quimiocina CXCL9/imunologia , Método Duplo-Cego , Quimioterapia Combinada/métodos , Feminino , Humanos , Interferon gama/imunologia , Interleucina-10/imunologia , Leishmaniose Cutânea/imunologia , Masculino , Projetos Piloto , Resultado do Tratamento , Fator de Necrose Tumoral alfa/imunologia , Adulto JovemRESUMO
INTRODUCTION: Cutaneous leishmaniasis (CL) due to L.braziliensis infection is characterized by a strong inflammatory response with high levels of TNF and ulcer development. Less attention has been given to the role of mononuclear phagocytes to this process. Monocytes constitute a heterogeneous population subdivided into classical, intermediate and non-classical, and are known to migrate to inflammatory sites and secrete inflammatory mediators. TNF participates in the induction of matrix metalloproteinases (MMPs). MMP-9 is an enzyme that degrades basal membrane and its activity is controlled by the tissue inhibitor of metalloproteinase. METHODS: Mononuclear cells were obtained from ex-vivo labeling sub-populations of monocytes and MMP-9, and the frequency was determined by flow cytometry. Culture was performed during 72 hours, stimulating the cells with SLA, levels of MMP-9 and TIMP-1 in the supernatants were determined by ELISA. RESULTS: We observed that cells from CL lesions secrete high amounts of MMP-9 when compared to healthy subjects. Although MMP-9 was produced by monocytes, non-classical ones were the main source of this enzyme. We also observed that TNF produced in high level during CL contributes to MMP-9 production. CONCLUSIONS: These observations emphasize the role of monocytes, TNF and MMP-9 in the pathogenesis of L. braziliensis infection.