RESUMO
The most severe manifestation of Herpes Simplex Type 1 virus (HSV-1) infection is encephalitis characterized by arousal impairment and seizures that can evolve to coma and death. Previous studies reported the involvement of suppressor of cytokine signaling (SOCS) proteins, specifically SOCS1 and SOCS3, in HSV-1 infection, suggesting that other members of this family could be involved in the immune response against HSV-1. No previous study has reported the role of SOCS2 in HSV-1 infection. In the current study, C57BL/6 wild-type mice (WT) and mice deficient in SOCS2 gene (SOCS2-/-) were subjected to intracranial inoculation with 102 plaque forming units (PFU) of HSV-1. Survival curve, neuroinflammatory parameters and neuropathology were evaluated. Infected SOCS2-/- mice had increased survival in comparison with infected WT animals. This better outcome was associated with reduced leukocyte infiltration, concentration of cytokines, and structural changes in the brain. SOCS2 seems to play a detrimental role in HSV-1 encephalitis. Moreover, the control of neuroinflammatory response in HSV-1 infection was of paramount importance to clinical outcome.
Assuntos
Encefalite por Herpes Simples/imunologia , Herpes Simples/imunologia , Herpesvirus Humano 1 , Proteínas Supressoras da Sinalização de Citocina/deficiência , Animais , Encéfalo/imunologia , Encéfalo/patologia , Quimiocinas/metabolismo , Chlorocebus aethiops , Citocinas/metabolismo , Modelos Animais de Doenças , Encefalite por Herpes Simples/patologia , Herpes Simples/patologia , Leucócitos/imunologia , Leucócitos/patologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Supressoras da Sinalização de Citocina/genética , Análise de Sobrevida , Células Vero , Carga ViralRESUMO
Herpes simplex virus type 1 (HSV-1) is a human pathogen that may cause severe encephalitis. The exacerbated immune response against the virus contributes to the disease severity and death. Platelet activating factor (PAF) is a mediator capable of inducing increase in vascular permeability, production of cytokines on endothelial cells and leukocytes. We aimed to investigate the activation of PAF receptor (PAFR) and its contribution to the severity of the inflammatory response in the brain following HSV-1 infection. C57BL/6 wild-type (WT) and PAFR deficient (PAFR-/-) mice were inoculated intracranially with 104 plaque-forming units (PFU) of HSV-1. Visualization of leukocyte recruitment was performed using intravital microscopy. Cells infiltration in the brain tissue were analyzed by flow cytometry. Brain was removed for chemokine assessment by ELISA and for histopathological analysis. The pharmacological inhibition by the PAFR antagonist UK-74,505 was also analyzed. In PAFR-/- mice, there was delayed lethality but no difference in viral load. Histopathological analysis of infected PAFR-/- mice showed that brain lesions were less severe when compared to their WT counterparts. Moreover, PAFR-/- mice showed less TCD4+, TCD8+ and macrophages in brain tissue. This reduction of the presence of leukocytes in parenchyma may be mechanistically explained by a decrease in leukocytes rolling and adhesion. PAFR-/- mice also presented a reduction of the chemokine CXCL9 in the brain. In addition, by antagonizing PAFR, survival of C57BL/6 infected mice increased. Altogether, our data suggest that PAFR plays a role in the pathogenesis of experimental HSV-1 meningoencephalitis, and its blockade prevents severe disease manifestation.
Assuntos
Herpes Simples/metabolismo , Herpesvirus Humano 1 , Meningoencefalite/metabolismo , Glicoproteínas da Membrana de Plaquetas/antagonistas & inibidores , Glicoproteínas da Membrana de Plaquetas/deficiência , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Receptores Acoplados a Proteínas G/deficiência , Índice de Gravidade de Doença , Animais , Encéfalo/patologia , Encéfalo/virologia , Di-Hidropiridinas/farmacologia , Di-Hidropiridinas/uso terapêutico , Herpes Simples/patologia , Herpes Simples/prevenção & controle , Imidazóis/farmacologia , Imidazóis/uso terapêutico , Masculino , Meningoencefalite/patologia , Meningoencefalite/prevenção & controle , Camundongos , Camundongos Endogâmicos C57BL , Camundongos KnockoutRESUMO
Experimental cerebral malaria (ECM) is characterized by a strong immune response, with leukocyte recruitment, blood-brain barrier breakdown and hemorrhage in the central nervous system. Phosphatidylinositol 3-kinase γ (PI3Kγ) is central in signaling diverse cellular functions. Using PI3Kγ-deficient mice (PI3Kγ-/-) and a specific PI3Kγ inhibitor, we investigated the relevance of PI3Kγ for the outcome and the neuroinflammatory process triggered by Plasmodium berghei ANKA (PbA) infection. Infected PI3Kγ-/- mice had greater survival despite similar parasitemia levels in comparison with infected wild type mice. Histopathological analysis demonstrated reduced hemorrhage, leukocyte accumulation and vascular obstruction in the brain of infected PI3Kγ-/- mice. PI3Kγ deficiency also presented lower microglial activation (Iba-1+ reactive microglia) and T cell cytotoxicity (Granzyme B expression) in the brain. Additionally, on day 6 post-infection, CD3+CD8+ T cells were significantly reduced in the brain of infected PI3Kγ-/- mice when compared to infected wild type mice. Furthermore, expression of CD44 in CD8+ T cell population in the brain tissue and levels of phospho-IkB-α in the whole brain were also markedly lower in infected PI3Kγ-/- mice when compared with infected wild type mice. Finally, AS605240, a specific PI3Kγ inhibitor, significantly delayed lethality in infected wild type mice. In brief, our results indicate a pivotal role for PI3Kγ in the pathogenesis of ECM.
Assuntos
Classe Ib de Fosfatidilinositol 3-Quinase/genética , Classe Ib de Fosfatidilinositol 3-Quinase/metabolismo , Malária Cerebral/imunologia , Malária Cerebral/patologia , Plasmodium berghei/imunologia , Animais , Encéfalo/imunologia , Modelos Animais de Doenças , Matriz Extracelular/imunologia , Matriz Extracelular/parasitologia , Feminino , Humanos , Pulmão/enzimologia , Pulmão/parasitologia , Malária Cerebral/enzimologia , Malária Cerebral/parasitologia , Camundongos , Inibidores de Fosfoinositídeo-3 Quinase , Quinoxalinas/farmacologia , Análise de Sobrevida , Tiazolidinedionas/farmacologiaRESUMO
BACKGROUND: The neuroinflammatory response aimed at clearance of herpes simplex virus-1 (HSV-1) plays a key role in the pathogenesis of neuroaxonal damage in herpetic encephalitis. Leukocytes activated in an adaptive immune response access brain tissue by passing through the blood-brain barrier. The chemokine CCL5/RANTES is involved in recruitment of these cells to the brain acting via the receptors CCR1, CCR3 and mainly CCR5. Here, we evaluated the role of CCR5 on traffic of leukocytes in the brain microvasculature, cellular and cytokines profile in a severe form of herpetic encephalitis. RESULTS: Wild type and mice lacking CCR5 (CCR5-/-) were inoculated intracerebrally with 104 PFU of neurotropic HSV-1. We evaluated the traffic of leukocytes in the brain microvasculature using intravital microscopy and the profile of cytokines by Enzyme-Linked Immunosorbent Assay at 1 day post infection. Flow cytometry and histopathological analyses were also carried out in brain tissue. Absence of CCR5 leads to lower viral load and an increased leukocyte adhesion in brain microvasculature, predominantly of neutrophils (CD11+ Ly6G+ cells). Moreover, there was a significant increase in the levels of MIP-1/CCL2, RANTES/CCL5, KC/CXCL1 and MIG/CXCL9 in the brain of infected CCR5-/- mice. CONCLUSIONS: These results suggest that the absence of CCR5 may boost the immune response with a high neutrophil recruitment which most likely helps in viral clearance. Nonetheless, the elevated immune response may be detrimental to the host.
Assuntos
Encefalite por Herpes Simples/imunologia , Encefalite por Herpes Simples/patologia , Regulação da Expressão Gênica/genética , Infiltração de Neutrófilos/fisiologia , Receptores CCR5/deficiência , Animais , Antígenos Ly/metabolismo , Encéfalo/imunologia , Encéfalo/patologia , Encéfalo/virologia , Adesão Celular/genética , Adesão Celular/imunologia , Citocinas/metabolismo , Modelos Animais de Doenças , Encefalite por Herpes Simples/genética , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Leucócitos/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores CCR5/genéticaRESUMO
Malaria-associated lung pathology has been a neglected area in the study of malaria complications. Platelet-activating factor (PAF) is an inflammatory mediator involved in lung inflammation. Using mice lacking the PAF receptor (PAFR(-/-)) we investigated the relevance of signaling through the PAFR for the lung inflammatory process triggered by Plasmodium berghei ANKA (PbA) strain infection. In PAFR(-/-) mice, pulmonary inflammation was markedly reduced as demonstrated by histology, production of certain pro-inflammatory mediators, accumulation of macrophage and CD8+ T cells in the lung parenchyma and the virtual absence of changes in vascular permeability. Therefore, PAFR activation is crucial in the pathogenesis of pulmonary damage associated with PbA infection in C57Bl/6 mice.
Assuntos
Pulmão/patologia , Malária/patologia , Plasmodium berghei/patogenicidade , Glicoproteínas da Membrana de Plaquetas/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Animais , Modelos Animais de Doenças , Histocitoquímica , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Glicoproteínas da Membrana de Plaquetas/deficiência , Receptores Acoplados a Proteínas G/deficiênciaRESUMO
The article discusses the historical, scientific and literary aspects of malaria, with an emphasis on images of the disease in the work of the writer João Guimarães Rosa. The main reference for this study is the short story "Sarapalha," which is featured in the book entitled Sagarana. The author's medical training together with his experiences in the hinterlands of the country is the subject matter for the work, with stories of the harsh reality of life in the outback. A highlight of the story is the narrative of malaria in the language of the outback, though with absolute medical and scientific precision.
RESUMO
O artigo aborda fatores históricos, científicos e literários da malária, com ênfase nas imagens da doença na obra do escritor João Guimarães Rosa. A principal referência para este estudo é o conto "Sarapalha", presente no livro Sagarana. A formação médica do autor somada a suas experiências no interior do país serve de subsídio para a obra, com histórias vivenciadas na rudeza do sertão. Um ponto de destaque no conto é a narrativa da malária na linguagem do sertão, mas com absoluta fidedignidade médico-científica.
The article discusses the historical, scientific and literary aspects of malaria, with an emphasis on images of the disease in the work of the writer João Guimarães Rosa. The main reference for this study is the short story "Sarapalha," which is featured in the book entitled Sagarana. The author's medical training together with his experiences in the hinterlands of the country is the subject matter for the work, with stories of the harsh reality of life in the outback. A highlight of the story is the narrative of malaria in the language of the outback, though with absolute medical and scientific precision.
Assuntos
Humanos , Literatura , Malária/história , Medicina na Literatura , Brasil , História Natural das Doenças , FolcloreRESUMO
Dengue virus is a human pathogen that may cause meningoencephalitis and other neurological syndromes. The current study investigated anxiety-like behavior and expression of proinflammatory cytokines and pro-apoptotic caspase-3 in the hippocampus of C57BL/6 mice infected with non-adapted Dengue virus 3 genotype I (DENV-3) inoculated intracranially with 4×10(3) (plaque-forming unit) PFU. Anxiety-like behavior was assessed in control and DENV-3 infected mice using the elevated plus maze. The open field test was performed to evaluate locomotor activity. Histopathological changes in CA regions of the hippocampus were assessed by haematoxylin and eosin staining. Immunoreactive and protein levels of cleaved caspase-3 were also analyzed in the hippocampus. The mRNA expression of IL-6 and TNF-α in the hippocampus were estimated by quantitative real time (polymerase chain reaction) PCR. All procedures were conducted on day 5 post-infection. We found that DENV-3 infected mice presented higher levels of anxiety in comparison with controls (p≤0.05). No difference in motor activity was found between groups (p=0.77). The infection was followed by a significant increase of TNF-α and IL-6 mRNA expression in the hippocampus (p≤0.05). Histological analysis demonstrated meningoencephalitis with formation of perivascular cuffs, infiltration of immune cells and loss of neurons at CA regions of hippocampus. Numerous caspase-3 positive neurons were visualized at CA areas in DENV-3 infected mice. Marked increase of cleaved caspase-3 levels were observed after infection. This study described anxiety-like behavior, hippocampal inflammation and neuronal apoptosis associated with DENV-3 infection in the central nervous system.
Assuntos
Transtornos de Ansiedade/etiologia , Transtornos de Ansiedade/virologia , Dengue/complicações , Encefalite/complicações , Encefalite/etiologia , Animais , Apoptose/fisiologia , Vírus da Dengue/genética , Vírus da Dengue/patogenicidade , Vírus da Dengue/fisiologia , Modelos Animais de Doenças , Encefalite/patologia , Comportamento Exploratório/fisiologia , Hipocampo/metabolismo , Hipocampo/virologia , Interleucina-6/genética , Interleucina-6/metabolismo , Masculino , Aprendizagem em Labirinto/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , RNA Mensageiro/metabolismo , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo , Proteínas Virais/genética , Proteínas Virais/metabolismoRESUMO
Cerebral malaria is a severe form of the disease that may result, in part, from an overt inflammatory response during infection by Plasmodium falciparum. The understanding of the pathogenesis of cerebral malaria may aid in the development of better therapeutic strategies for patients. The immune response in cerebral malaria involves elevation of circulating levels of cytokines and chemokines associated with leukocyte accumulation and breakdown of the blood-brain barrier in the central nervous system. Platelet-activating factor (PAF) is a mediator of inflammation shown to orchestrate inflammatory processes, including recruitment of leukocytes and increase of vascular permeability. Using mice lacking the PAF receptor (PAFR(-/-)), we investigated the relevance of this molecule for the outcome and the neuroinflammatory process triggered by P. berghei ANKA, an experimental model of cerebral malaria. In PAFR(-/-) mice, lethality was markedly delayed and brain inflammation was significantly reduced, as demonstrated by histology, accumulation, and activation of CD8(+) T cells, changes in vascular permeability and activation of caspase-3 on endothelial cells and leukocytes. Similarly, treatment with the PAFR antagonist UK-74,505 delayed lethality. Taken together, the results suggest that PAFR signaling is crucial for the development of experimental cerebral malaria. Mechanistically, PAFR activation is crucial for the cascade of events leading to changes in vascular permeability, accumulation, and activation of CD8(+) T cells and apoptosis of leukocytes and endothelial cells.
Assuntos
Malária Cerebral/etiologia , Glicoproteínas da Membrana de Plaquetas/fisiologia , Receptores Acoplados a Proteínas G/fisiologia , Animais , Química Encefálica , Caspase 3/metabolismo , Quimiocinas/metabolismo , Citocinas/biossíntese , Citocinas/metabolismo , Di-Hidropiridinas/farmacologia , Imidazóis/farmacologia , Leucócitos/fisiologia , Ativação Linfocitária , Malária Cerebral/prevenção & controle , Camundongos , Camundongos Endogâmicos C57BL , Inibidores da Agregação Plaquetária/farmacologia , Glicoproteínas da Membrana de Plaquetas/antagonistas & inibidores , Glicoproteínas da Membrana de Plaquetas/deficiência , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Receptores Acoplados a Proteínas G/deficiênciaRESUMO
O artigo aborda fatores históricos, científicos e literários da malária, com ênfase nas imagens da doença na obra do escritor João Guimarães Rosa. A principal referência para este estudo é o conto Sarapalha, presente no livro Sagarana. A formação médica do autor somada a suas experiências no interior do país serve de subsídio para a obra, com histórias vivenciadas na rudeza do sertão. Um ponto de destaque no conto é a narrativa da malária na linguagem do sertão, mas com absoluta fidedignidade médico-científica. (AU)