RESUMO
Cocaine-induced sensitization induces long-term neuroplastic changes in the striatum. Among these, extracellular signal-regulated kinase (ERK) is a fundamental component in striatal gene and epigenetic regulation and plays an important role in reward processes. As previous studies suggested that the chemokine CCL2 enhanced striatal dopamine release and as its cognate CCR2 receptor was located in brain structures implicated in cocaine reward, we tested the hypothesis that CCR2/CCL2 could be involved in cocaine-induced behavioral response. We used CCR2 knockout mice (CCR2(-/-)) and studied two crucial steps in cocaine sensitization: locomotor activity in sensitized mice and ERK activation in the striatum. We show that locomotor sensitization is significantly reduced in CCR2(-/-) mice as well as the dopamine transporter regulation and the cocaine-induced p-ERK striatal activation. Taken together, our results suggest that CCR2 receptor is involved in cocaine sensitization.
Assuntos
Cocaína/farmacologia , Corpo Estriado/efeitos dos fármacos , Receptores CCR2/metabolismo , Animais , Comportamento Animal/efeitos dos fármacos , Quimiocina CCL2/genética , Quimiocina CCL2/metabolismo , Corpo Estriado/anatomia & histologia , Corpo Estriado/metabolismo , Dopamina/metabolismo , Ativação Enzimática , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Atividade Motora/efeitos dos fármacos , Atividade Motora/fisiologia , Plasticidade Neuronal/efeitos dos fármacos , Receptores CCR2/genéticaRESUMO
Mononuclear phagocytes have been attributed a crucial role in the host defense toward influenza virus (IV), but their contribution to influenza-induced lung failure is incompletely understood. We demonstrate for the first time that lung-recruited "exudate" macrophages significantly contribute to alveolar epithelial cell (AEC) apoptosis by the release of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in a murine model of influenza-induced pneumonia. Using CC-chemokine receptor 2-deficient (CCR2(-/-)) mice characterized by defective inflammatory macrophage recruitment, and blocking anti-CCR2 antibodies, we show that exudate macrophage accumulation in the lungs of influenza-infected mice is associated with pronounced AEC apoptosis and increased lung leakage and mortality. Among several proapoptotic mediators analyzed, TRAIL messenger RNA was found to be markedly up-regulated in alveolar exudate macrophages as compared with peripheral blood monocytes. Moreover, among the different alveolar-recruited leukocyte subsets, TRAIL protein was predominantly expressed on macrophages. Finally, abrogation of TRAIL signaling in exudate macrophages resulted in significantly reduced AEC apoptosis, attenuated lung leakage, and increased survival upon IV infection. Collectively, these findings demonstrate a key role for exudate macrophages in the induction of alveolar leakage and mortality in IV pneumonia. Epithelial cell apoptosis induced by TRAIL-expressing macrophages is identified as a major underlying mechanism.
Assuntos
Apoptose/imunologia , Influenza Humana/imunologia , Pulmão , Macrófagos/imunologia , Orthomyxoviridae/imunologia , Pneumonia/imunologia , Ligante Indutor de Apoptose Relacionado a TNF/imunologia , Animais , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/imunologia , Líquido da Lavagem Broncoalveolar/citologia , Líquido da Lavagem Broncoalveolar/imunologia , Quimera , Humanos , Leucócitos Mononucleares/imunologia , Pulmão/imunologia , Pulmão/fisiologia , Pulmão/virologia , Macrófagos/citologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Orthomyxoviridae/patogenicidade , Fagócitos/imunologia , Pneumonia/mortalidade , Pneumonia/virologia , Receptores CCR2/genética , Receptores CCR2/metabolismo , Mucosa Respiratória/imunologia , Mucosa Respiratória/patologia , Mucosa Respiratória/virologia , Ligante Indutor de Apoptose Relacionado a TNF/genéticaRESUMO
The MCP-1 (monocyte chemoattractant protein-1)/CCR2 (CC motif chemokine receptor-2) pathway may play a role in macrophage infiltration into obese adipose tissue. Here we investigated the role of CCR2 in the recruitment of bone marrow-derived macrophages into obese adipose tissue in vitro and in vivo. Using the TAXIScan device, which can measure quantitatively the directionality and velocity of cell migration at time lapse intervals in vitro, we demonstrated that bone marrow cells (BMCs) from wild type mice migrate directly toward MCP-1 or culture medium conditioned by adipose tissue explants of genetically obese ob/ob mice, which are efficiently suppressed by pharmacological blockade of CCR2 signaling. The number of F4/80-positive macrophages was reduced in the adipose tissue from high fat diet-fed obese KKAy or ob/ob mice treated with a CCR2 antagonist propagermanium relative to vehicle-treated groups. We also found that the number of macrophages is reduced in the adipose tissue from ob/ob mice reconstituted with CCR2(-/-) BMCs (ob/ob + CCR2(-/-) BMCs) relative to those with CCR2+/+ BMCs (ob/ob + CCR2+/+ BMCs). Expression of mRNAs for CD11c and TLR4 (Toll-like receptor 4) markers of proinflammatory M1 macrophages was also decreased in the adipose tissue from ob/ob + CCR2(-/-) BMCs relative to ob/ob + CCR2+/+ BMCs, whereas mannose receptor and CD163, markers of anti-inflammatory M2 macrophages, were unchanged. This study provides in vivo and in vitro evidence that CCR2 in bone marrow cells plays an important role in the recruitment of macrophages into obese adipose tissue.
Assuntos
Tecido Adiposo/metabolismo , Células da Medula Óssea/metabolismo , Movimento Celular , Macrófagos/metabolismo , Obesidade/metabolismo , Receptores CCR2/metabolismo , Tecido Adiposo/patologia , Animais , Antígenos CD/genética , Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/genética , Antígenos de Diferenciação Mielomonocítica/metabolismo , Células da Medula Óssea/patologia , Antígeno CD11c/genética , Antígeno CD11c/metabolismo , Quimiocina CCL2/genética , Quimiocina CCL2/metabolismo , Humanos , Células Jurkat , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Macrófagos/patologia , Receptor de Manose , Lectinas de Ligação a Manose/genética , Lectinas de Ligação a Manose/metabolismo , Camundongos , Camundongos Knockout , Camundongos Obesos , Obesidade/genética , Obesidade/patologia , Receptores CCR2/genética , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismoRESUMO
Myeloid cell recruitment is a characteristic feature of bacterial meningitis. However, the cellular mechanisms important for the control of Streptococcus pneumoniae infection remain largely undefined. Previous pharmacological or genetic studies broadly depleted many myeloid cell types within the meninges, which did not allow defining the function of specific myeloid subsets. Herein we show that besides CD11b(+)Ly-6G(+)CCR2(-) granulocytes, also CD11b(+)Ly-6C(high)CCR2(+) but not Ly-6C(low)CCR2(-) monocytes were recruited in high numbers to the brain as early as 12 h after bacterial challenge. Surprisingly, CD11b(+)Ly-6C(high)CCR2(+) inflammatory monocytes modulated local CXCL2 and IL-1beta production within the meninges but did not provide protection against bacterial infection. Consistent with these results, CCR2 deficiency strongly impaired monocyte recruitment to the infected brains but was redundant for disease pathogenesis. In contrast, specific depletion of polymorphonuclear granulocytes caused elevated local bacterial titer within the brains, led to an aggravated clinical course, and enhanced mortality. These findings demonstrate that Ly-6C(high)CCR2(+) inflammatory monocytes play a redundant role for the host defense during bacterial meningitis and that predominantly CD11b(+)Ly-6G(+)CCR2(-) myeloid cells are involved in the restriction of the extracellular bacteria.
Assuntos
Antígenos Ly/biossíntese , Meningite Pneumocócica/imunologia , Meningite Pneumocócica/prevenção & controle , Monócitos/imunologia , Células Mieloides/imunologia , Receptores CCR2/deficiência , Animais , Diferenciação Celular/imunologia , Quimiotaxia de Leucócito/imunologia , Granulócitos/imunologia , Granulócitos/metabolismo , Granulócitos/microbiologia , Imunofenotipagem , Masculino , Meningite Pneumocócica/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Monócitos/microbiologia , Monócitos/patologia , Células Mieloides/microbiologia , Células Mieloides/patologia , Receptores CCR2/biossíntese , Receptores CCR2/fisiologiaRESUMO
Angiotensin II (Ang II)-induced hypertension is associated with an inflammatory response that may contribute to the development of target organ damage. We tested the hypothesis that, in Ang II-induced hypertension, CC chemokine receptor 2 (CCR2) activation plays an important role in the development of renal fibrosis, damage, and dysfunction by causing oxidative stress, macrophage infiltration, and cell proliferation. To test this hypothesis, we used CCR2 knockout mice (CCR2-/-). The natural ligand of CCR2 is monocyte chemoattractant protein-1, a chemokine important for macrophage recruitment and activation. CCR2-/- and age-matched wild-type (CCR2+/+) C57BL/6J mice were infused continuously with either Ang II (5.2 ng/10 g per minute) or vehicle via osmotic minipumps for 2 or 4 weeks. Ang II infusion caused similar increases in systolic blood pressure and left ventricular hypertrophy in both strains of mice. However, in CCR2-/- mice with Ang II-induced hypertension, oxidative stress, macrophage infiltration, albuminuria, and renal damage were significantly decreased, and glomerular filtration rate was significantly higher than in CCR2+/+ mice. We concluded that, in Ang II-induced hypertension, CCR2 activation plays an important role in the development of hypertensive nephropathy via increased oxidative stress and inflammation.
Assuntos
Hipertensão/complicações , Nefroesclerose/etiologia , Nefroesclerose/patologia , Espécies Reativas de Oxigênio/análise , Receptores de Quimiocinas/análise , Albuminúria/diagnóstico , Angiotensina II , Animais , Western Blotting , Movimento Celular , Proliferação de Células , Modelos Animais de Doenças , Taxa de Filtração Glomerular , Hipertensão/induzido quimicamente , Hipertensão/fisiopatologia , Imuno-Histoquímica , Inflamação/fisiopatologia , Macrófagos/citologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Probabilidade , Distribuição Aleatória , Valores de Referência , Sensibilidade e EspecificidadeRESUMO
Prion diseases are caused by conversion of a normally folded, non-pathogenic isoform of the prion protein (PrP(C)) to a misfolded, pathogenic isoform (PrP(Sc)). Prion inoculation experiments in mice expressing homologous PrP(C) molecules on different genetic backgrounds displayed different incubation times, indicating that the conversion reaction may be influenced by other gene products. To identify genes that contribute to prion pathogenesis, we analysed incubation times of prions in mice in which the gene product was inactivated, knocked out or overexpressed. We tested 20 candidate genes, because their products either colocalize with PrP, are associated with Alzheimer's disease, are elevated during prion disease, or function in PrP-mediated signalling, PrP glycosylation, or protein maintenance. Whereas some of the candidates tested may have a role in the normal function of PrP(C), our data show that many genes previously implicated in prion replication have no discernible effect on the pathogenesis of prion disease. While most genes tested did not significantly affect survival times, ablation of the amyloid beta (A4) precursor protein (App) or interleukin-1 receptor, type I (Il1r1), and transgenic overexpression of human superoxide dismutase 1 (SOD1) prolonged incubation times by 13, 16 and 19 %, respectively.
Assuntos
Doenças Priônicas/genética , Príons/metabolismo , Precursor de Proteína beta-Amiloide/genética , Animais , Dosagem de Genes , Inativação Gênica , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Príons/genética , Receptores Tipo I de Interleucina-1/genética , Superóxido Dismutase/genética , Superóxido Dismutase-1 , Análise de SobrevidaRESUMO
The means by which the chemokine CCL2 produced in the brain parenchyma can recruit leukocytes lying behind the highly impervious endothelium of the blood-brain barrier (BBB) has remained a paradox. As other chemokines have been evidenced to stimulate their own synthesis and release by peripheral microvascular endothelial cells, and/or undergo transcytosis in the abluminal-to-luminal direction, we determined whether CCL2 experiences similar fates across brain microvascular endothelial cells (BMEC). Using cultured BMEC as a paradigm of the BBB, it was observed that exogenous unlabeled CCL2 actually depressed the release of endogenous CCL2, and further caused diminished CCL2 mRNA levels in these cells. On the other hand, exogenous (125)I-labeled CCL2 exhibited transport across BMEC in a manner that was sensitive to temperature, competition by excess unlabeled CCL2 but not unlabeled CCL3, knockdown of caveolin-1/caveolae, and elimination of the cognate CCL2 receptor CCR2. These results implied a facet of CCL2 transport by a transcellular mechanism partly involving binding of CCL2 to CCR2, and subsequent transfer to caveolae vesicles for transcytosis. This notion was supported by double-label immuno-electronmicroscopy, which revealed co-localization of caveolin-1 with exogenous CCL2, during this chemokine's transit across BMEC. Collectively, these findings provide a rationale by which CCL2, deposited on the abluminal side of the brain microvasculature during inflammatory episodes, can be relayed across the BBB to foster leukocyte recruitment.
Assuntos
Encéfalo/irrigação sanguínea , Encéfalo/metabolismo , Permeabilidade Capilar/fisiologia , Membrana Celular/metabolismo , Quimiocina CCL2/metabolismo , Endotélio Vascular/metabolismo , Animais , Transporte Biológico Ativo/fisiologia , Barreira Hematoencefálica/metabolismo , Encéfalo/citologia , Encéfalo/efeitos dos fármacos , Células Cultivadas , Quimiocina CCL2/farmacologia , Quimiotaxia de Leucócito/fisiologia , Endotélio Vascular/citologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microcirculação/citologia , Microcirculação/metabolismo , Microcirculação/fisiologiaRESUMO
Members of the chemokine system, play a central role in inflammatory processes that underlie the pathogenesis of atherosclerosis and possibly, aortic valve sclerosis. Here we show that genetic inactivation of CC chemokine receptor 5 (CCR5) in the atherosclerosis-prone Apoe-/- mice (Apoe-/- Ccr5-/-) fed a normal chow or a high-fat diet (HFD) are protected against advanced atherosclerosis as well as age-associated aortic valve thickening (AAAVT)--a murine correlate of aortic valve sclerosis. Notably, human sclerotic valves contained CCR5+ cells. We confirm that Apoe-/- Ccr5-/- mice does not influence early-atherosclerotic stage. Adoptive transfer studies showed that the atheroprotective effect of CCR5 inactivation resided in the bone marrow compartment, but was not dependent on T-cells. The CCR5-null state was associated with phenotypes postulated to be atheroprotective such as reduced macrophage accumulation in the plaque, and lower circulating levels of IL-6 and MCP-5. The lack of CCR5 expression in Apoe-/- mice was also associated with higher numbers of endothelial progenitor cells (EPCs)--another postulated athero-protective factor. Compared with controls, carriers of a polymorphism in the Ccr5 gene that leads to the lack of CCR5 in the cell surface had an increased mean percentage of EPCs, but this difference did not reach statistical significance. Collectively, these findings underscore a critical role of CCR5 in age-associated cardiovascular diseases, and highlight that the effects of the chemokine system can be temporally constrained to distinct stages of these disease processes.
Assuntos
Aterosclerose/metabolismo , Regulação da Expressão Gênica , Receptores CCR5/metabolismo , Receptores CCR5/fisiologia , Fatores Etários , Animais , Valva Aórtica/metabolismo , Células da Medula Óssea/metabolismo , Transplante de Medula Óssea , Humanos , Inflamação , Interleucina-6/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Células-Tronco/metabolismoRESUMO
Increased numbers of pulmonary dendritic cells (DCs) are recruited to the lungs during allergic airway inflammation and contribute to the maintenance of the inflammatory immune response. The chemokine receptors that directly control DC accumulation into the lungs are largely unknown. To explore this issue, we generated mixed bone marrow chimeric mice containing both wild-type and knockout cells for a given chemokine receptor. After induction of allergic airway inflammation, we specifically tracked and compared chemokine receptor knockout vs wild-type DC populations through various lung compartments. Using this approach, we show that CCR2, but not CCR5 or CCR6, directly controls the accumulation of DCs into allergic lungs. Furthermore, the size of inflammatory monocyte populations in peripheral blood was strikingly CCR2 dependent, suggesting that CCR2 primarily mediates the release of monocytic DC precursors into the bloodstream.
Assuntos
Asma/imunologia , Células Dendríticas/fisiologia , Pulmão/imunologia , Receptores CCR5/fisiologia , Receptores de Quimiocinas/fisiologia , Animais , Apoptose , Movimento Celular , Camundongos , Camundongos Endogâmicos C57BL , Monócitos/fisiologia , Receptores CCR2 , Receptores CCR6RESUMO
Following genital herpes simplex virus type 2 (HSV-2) exposure, NK cells and T cells are mobilized to sites of infection to control viral replication and spread. The present investigation sought to determine the role of the chemokine receptor CCR5 in this process. Mice deficient in CCR5 (CCR5-/-) displayed a significant reduction in cumulative survival following infection in comparison to wild-type, HSV-2-infected controls. Associated with decreased resistance to viral infection, CCR5-/- mice yielded significantly more virus and expressed higher levels of tumor necrosis factor alpha, CXCL1, CCL2, CCL3, and CCL5 in the vagina, spinal cord, and/or brain stem than did wild-type mice. Whereas there was no difference in absolute number of leukocytes (CD45high), CD4 T cells, or CD8 T cells residing in the draining lymph nodes, spleen, spinal cord, or brain stem comparing HSV-2-infected wild-type to CCR5-/- mice prior to or after infection, there were significantly more NK cells (NK1.1+ CD3-) residing in the brain stem and spleen of infected wild-type mice. Functionally, NK activity from cells isolated from the brain stem of HSV-2-infected wild-type mice was greater than that from HSV-2-infected CCR5-/- mice. In addition, antibody-mediated depletion of NK cells resulted in an increase in HSV-2 levels in the vaginal, spinal cord, and brain stem tissue of wild-type but not CCR5-/- mice. Collectively, the absence of CCR5 expression significantly impacts the ability of the host to control genital HSV-2 infection, inflammation, and spread associated with a specific reduction in NK cell expansion, infiltration, and activity in the nervous system.
Assuntos
Herpes Genital/imunologia , Herpesvirus Humano 2/imunologia , Imunidade Inata , Células Matadoras Naturais/imunologia , Receptores CCR5/imunologia , Animais , Tronco Encefálico/citologia , Tronco Encefálico/imunologia , Tronco Encefálico/virologia , Quimiocinas/biossíntese , Modelos Animais de Doenças , Feminino , Expressão Gênica , Granzimas/biossíntese , Procedimentos de Redução de Leucócitos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Citotóxicas Formadoras de Poros/biossíntese , Receptores CCR5/deficiência , Medula Espinal/imunologia , Medula Espinal/virologia , Baço/citologia , Baço/imunologia , Análise de Sobrevida , Vagina/imunologia , Vagina/virologia , Replicação Viral , VírusRESUMO
Chemokines recruit inflammatory cells to sites of injury, but the role of the CC chemokine receptor 2 (CCR2) during regenerative processes following ischemia is poorly understood. We studied injury, inflammation, perfusion, capillary formation, monocyte chemotactic protein-1 (MCP-1) levels, muscle regeneration, fat accumulation, and transcription factor activation in hindlimb muscles of CCR2-/- and wild-type (WT) mice following femoral artery excision (FAE). In both groups, muscle injury and restoration of vascular perfusion were similar. Nevertheless, edema and neutrophil accumulation were significantly elevated in CCR2-/- compared with WT mice at day 1 post-FAE and fewer macrophages were present at day 3. MCP-1 levels in post-ischemic calf muscle of CCR2-/- animals were significantly elevated over baseline through 14 days post-FAE and were higher than WT mice at days 1, 7, and 14. In addition, CCR2-/- mice exhibited impaired muscle regeneration, decreased muscle fiber size, and increased intermuscular adipocytes with similar capillaries/mm(2) postinjury. Finally, the transcription factors, MyoD and signal transducers of and activators of transcription-3 (STAT3), were significantly increased above baseline but did not differ significantly between groups at any time point post-FAE. These findings suggest that increases in MCP-1, and possibly, MyoD and STAT3, may modulate molecular signaling in CCR2-/- mice during inflammatory and regenerative events. Furthermore, alterations in neutrophil and macrophage recruitment in CCR2-/- mice may critically alter the normal progression of downstream regenerative events in injured skeletal muscle and may direct myogenic precursor cells in the regenerating milieu toward an adipogenic phenotype.
Assuntos
Adipócitos/patologia , Isquemia/patologia , Músculo Esquelético/fisiopatologia , Receptores de Quimiocinas/metabolismo , Regeneração , Animais , Capilares/fisiopatologia , Quimiocina CCL2/metabolismo , Membro Posterior , Inflamação/metabolismo , Inflamação/patologia , Isquemia/metabolismo , Macrófagos/imunologia , Camundongos , Camundongos Knockout , Fibras Musculares Esqueléticas/metabolismo , Fibras Musculares Esqueléticas/patologia , Músculo Esquelético/irrigação sanguínea , Músculo Esquelético/patologia , Proteína MyoD/metabolismo , Neutrófilos/imunologia , Receptores CCR2 , Receptores de Quimiocinas/genética , Fator de Transcrição STAT3/metabolismoRESUMO
Influenza A virus pneumonia is characterized by severe lung injury and high mortality. Early infection elicits a strong recruitment of monocytes from the peripheral blood across the endo-/epithelial barrier into the alveolar air space. However, it is currently unclear which of the infected resident lung cell populations, alveolar epithelial cells or alveolar macrophages, elicit monocyte recruitment during influenza A virus infection. In the current study, we investigated whether influenza A virus infection of primary alveolar epithelial cells and resident alveolar macrophages would elicit a basal-to-apical monocyte transepithelial migration in vitro. We found that infection of alveolar epithelial cells with the mouse-adapted influenza A virus strain PR/8 strongly induced the release of monocyte chemoattractants CCL2 and CCL5 followed by a strong monocyte transepithelial migration, and this monocytic response was strictly dependent on monocyte CCR2 but not CCR5 chemokine receptor expression. Analysis of the adhesion molecule pathways demonstrated a role of ICAM-1, VCAM-1, integrin-associated protein (CD47), and junctional adhesion molecule-c on the epithelial cell surface interacting with monocyte beta(1) and beta(2) integrins and integrin-associated protein in the monocyte transmigration process. Importantly, addition of influenza A virus-infected alveolar macrophages further enhanced monocyte transmigration across virus-infected epithelium in a TNF-alpha-dependent manner. Collectively, the data show an active role for virus-infected alveolar epithelium in the regulation of CCL2/CCR2-dependent monocyte transepithelial migration during influenza infection that is essentially dependent on both classical beta(1) and beta(2) integrins but also junctional adhesion molecule pathways.
Assuntos
Moléculas de Adesão Celular/fisiologia , Movimento Celular/imunologia , Quimiocinas/fisiologia , Células Epiteliais/imunologia , Vírus da Influenza A Subtipo H1N1/imunologia , Monócitos/imunologia , Alvéolos Pulmonares/citologia , Alvéolos Pulmonares/imunologia , Animais , Moléculas de Adesão Celular/biossíntese , Comunicação Celular/imunologia , Células Cultivadas , Quimiocina CCL2/deficiência , Quimiocina CCL2/genética , Quimiocina CCL2/fisiologia , Quimiocinas/deficiência , Quimiocinas/genética , Células Epiteliais/química , Células Epiteliais/virologia , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Monócitos/química , Monócitos/virologia , Proteínas do Nucleocapsídeo , Nucleoproteínas/análise , Alvéolos Pulmonares/virologia , Proteínas de Ligação a RNA/análise , Receptores CCR2 , Receptores de Quimiocinas/deficiência , Receptores de Quimiocinas/genética , Receptores de Quimiocinas/fisiologia , Regulação para Cima/imunologia , Proteínas do Core Viral/análiseRESUMO
The CC chemokine ligand 2 (CCL2) and CC chemokine receptor 2 (CCR2) are expressed in the heart after infection with Trypanosoma cruzi, suggesting that they play an important role in host defense. Infection of CCR2-deficient (CCR2(-/-)) mice with T. cruzi resulted in increased cardiac parasitism, yet the severity of cardiac inflammation was not affected. In addition, expression of interferon- gamma and inducible NO synthase in the heart, which are associated with effective killing of trypomastigotes, was not affected in CCR2(-/-) mice. These observations reveal that CCR2 signaling plays a distinct role that is separate from that of influencing either chemotaxis or previously defined anti-trypomastigote mechanisms for the control of T. cruzi's replication in the heart.
Assuntos
Cardiomiopatia Chagásica/imunologia , Coração/parasitologia , Receptores de Quimiocinas/imunologia , Trypanosoma cruzi/imunologia , Animais , Cardiomiopatia Chagásica/parasitologia , Cardiomiopatia Chagásica/patologia , Modelos Animais de Doenças , Feminino , Interferon gama/biossíntese , Camundongos , Camundongos Knockout , Miocárdio/imunologia , Miocárdio/patologia , Óxido Nítrico/biossíntese , Receptores CCR2RESUMO
BACKGROUND: Acute peritonitis developing in response to gram-negative bacterial infection is known to act as a trigger for the development of acute lung injury which is often complicated by the development of nosocomial pneumonia. We hypothesized that endotoxin-induced peritonitis provokes recruitment of monocytes into the lungs, which amplifies lung inflammatory responses to a second hit intra-alveolar challenge with endotoxin. METHODS: Serum and lavage cytokines as well as bronchoalveolar lavage fluid cells were analyzed at different time points after intraperitoneal or intratracheal application of LPS. RESULTS: We observed that mice challenged with intraperitoneal endotoxin developed rapidly increasing serum and bronchoalveolar lavage fluid (BALF) cytokine and chemokine levels (TNFalpha, MIP-2, CCL2) and a nearly two-fold expansion of the alveolar macrophage population by 96 h, but this was not associated with the development of neutrophilic alveolitis. In contrast, expansion of the alveolar macrophage pool was not observed in CCR2-deficient mice and in wild-type mice systemically pretreated with the anti-CD18 antibody GAME-46. An intentional two-fold expansion of alveolar macrophage numbers by intratracheal CCL2 following intraperitoneal endotoxin did not exacerbate the development of acute lung inflammation in response to intratracheal endotoxin compared to mice challenged only with intratracheal endotoxin. CONCLUSION: These data, taken together, show that intraperitoneal endotoxin triggers a CCR2-dependent de novo recruitment of monocytes into the lungs of mice but this does not result in an accentuation of neutrophilic lung inflammation. This finding represents a previously unrecognized novel inflammatory component of lung inflammation that results from endotoxin-induced peritonitis.
Assuntos
Monócitos/imunologia , Peritonite/imunologia , Peritonite/patologia , Alvéolos Pulmonares/imunologia , Alvéolos Pulmonares/patologia , Receptores de Quimiocinas/imunologia , Animais , Movimento Celular/efeitos dos fármacos , Feminino , Lipopolissacarídeos , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Monócitos/efeitos dos fármacos , Peritonite/induzido quimicamente , Pneumonia/imunologia , Pneumonia/patologia , Alvéolos Pulmonares/efeitos dos fármacos , Receptores CCR2RESUMO
The host factors that influence autoimmune arthritides such as rheumatoid arthritis have not been fully elucidated. We previously found that genetic inactivation of CC chemokine receptor 2 (CCR2) in the arthritis-prone DBA/1j mouse strain significantly increases the susceptibility of this strain to autoimmune arthritis induced by immunization with collagen type II (CII) and complete Freund's adjuvant (CFA). Here, we show that following intradermal infection with Mycobacterium avium, a similar arthritis phenotype was detected in Ccr2-null mice in the DBA/1j, but not in the BALB/c background. The failure to develop arthritis in Ccr2-null BALB/c mice occurred in the face of high bacterial burdens and low interferon gamma (IFNgamma) production. By contrast, Ccr2-null DBA/1j mice had low bacterial burdens, produced normal amounts of IFNgamma, and had high titers of autoantibodies against CII. Thus, the Ccr2-null state in an arthritic-prone genetic background leads to increased arthritis susceptibility following infectious (M. avium) and noninfectious (CII/CFA) challenges. Because CCR2 serves as a negative regulator of murine arthritis, caution might need to be exercised while testing CCR2 blockers in human arthritis or other diseases. These findings also indicate that Ccr2-null DBA/1j mice might serve as a valuable model system to uncover the immunological determinants of arthritis and to test novel antiarthritic agents.
Assuntos
Artrite Experimental/metabolismo , Mycobacterium avium , Receptores de Quimiocinas/fisiologia , Tuberculose Cutânea/complicações , Animais , Artrite Experimental/etiologia , Artrite Experimental/patologia , Colágeno Tipo II/imunologia , Interferon gama/biossíntese , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos DBA , Camundongos Knockout , Receptores CCR2 , Receptores de Quimiocinas/genéticaRESUMO
Ocular herpes simplex virus type 1 (HSV-1) infection elicits a strong inflammatory response that is associated with production of the beta chemokines CCL3 and CCL5, which share a common receptor, CCR5. To gain insight into the role of these molecules in ocular immune responses, the corneas of wild-type (WT) and CCR5-deficient (CCR5-/-) mice were infected with HSV-1 and inflammatory parameters were measured. In the absence of CCR5, the early infiltration of neutrophils into the cornea was diminished. Associated with this aberrant leukocyte recruitment, neutrophils in CCR5-/- mice were restricted to the stroma, whereas in WT mice, these cells trafficked to the stroma and epithelial layers of the infected cornea. Virus titres and cytokine/chemokine levels in the infected tissue of these mice were similar for the first 5 days after infection. However, by day 7 post-infection, the CCR5-/- mice showed a significant elevation in the chemokines CCL2, CCL5, CXCL9 and CXCL10 in the trigeminal ganglion and brainstem, as well as a significant increase in virus burden. The increase in chemokine expression was associated with an increase in the infiltration of CD4 and/or CD8 T cells into the trigeminal ganglion and brainstem of CCR5-/- mice. Surprisingly, even though infected CCR5-/- mice were less efficient at controlling the progression of virus replication, there was no difference in mortality. These results suggest that, although CCR5 plays a role in regulating leukocyte trafficking and control of virus burden, compensatory mechanisms are involved in preventing mortality following HSV-1 infection.
Assuntos
Herpesvirus Humano 1 , Ceratite Herpética/imunologia , Animais , Tronco Encefálico/imunologia , Tronco Encefálico/virologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Contagem de Células , Movimento Celular , Quimiocinas/biossíntese , Chlorocebus aethiops , Córnea/imunologia , Córnea/virologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neutrófilos/fisiologia , Receptores CCR5/deficiência , Receptores CCR5/genética , Gânglio Trigeminal/imunologia , Gânglio Trigeminal/virologia , Células VeroRESUMO
BACKGROUND: Monocyte chemoattractant protein-1 (MCP-1) and its major receptor, CC chemokine receptor 2 (CCR2), have been shown to contribute to left ventricular remodeling after myocardial infarction. However, it is unknown whether CCR2 deficiency protects the myocardium after myocardial ischemia-reperfusion. The purpose of the present study was to investigate the effects of CCR2 deficiency on myocardial ischemia-reperfusion injury in mice. METHODS AND RESULTS: Experiments were performed in CCR2(-/-) and wild-type mice subjected to 45 min of ischemia followed by reperfusion. Macrophage infiltration in ischemic lesions was markedly reduced in CCR2(-/-) mice compared with wild-type mice (p<0.01). The infarct size was significantly reduced in CCR2(-/-) mice compared with wild-type mice at 3 days after reperfusion (p<0.001). In situ zymography revealed augmented gelatinolytic activity at 3 days after reperfusion in wild-type mice, but significantly less activity in CCR2(-/-) mice. NADPH oxidase activity, the intensity of nitrotyrosine staining and expression of inducible nitric oxide synthase and thioredoxin-1 were significantly increased in ischemic myocardium in wild-type mice compared with CCR2(-/-) mice, indicating a role for CCR2 in oxidative stress after ischemia-reperfusion. CONCLUSIONS: Inhibition of the MCP-1/CCR2 pathway may be a useful strategy for attenuating myocardial ischemia-reperfusion injury.
Assuntos
Infarto do Miocárdio/etiologia , Infarto do Miocárdio/patologia , Traumatismo por Reperfusão Miocárdica/complicações , Estresse Oxidativo/fisiologia , Receptores de Quimiocinas/deficiência , Animais , Movimento Celular/genética , Movimento Celular/fisiologia , Quimiocina CCL2/genética , Quimiocina CCL2/fisiologia , Citocinas/genética , Citocinas/fisiologia , Regulação da Expressão Gênica/fisiologia , Imuno-Histoquímica , Macrófagos/química , Macrófagos/patologia , Macrófagos/fisiologia , Masculino , Metaloproteinases da Matriz/genética , Metaloproteinases da Matriz/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Monócitos/química , Monócitos/patologia , Monócitos/fisiologia , Infarto do Miocárdio/fisiopatologia , Traumatismo por Reperfusão Miocárdica/patologia , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Miocárdio/química , Miocárdio/patologia , Neutrófilos/química , Neutrófilos/patologia , Neutrófilos/fisiologia , RNA Mensageiro/análise , RNA Mensageiro/genética , Receptores CCR2 , Receptores de Quimiocinas/análise , Receptores de Quimiocinas/genética , Receptores de Quimiocinas/fisiologia , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
The chemokine RANTES has been implicated in neointimal hyperplasia after arterial injury. We analyzed the differential role of the RANTES receptors CCR1 and CCR5 by genetic deletion in apolipoprotein E-deficient mice. Deficiency in CCR5 significantly reduced neointimal area after arterial wire injury, associated with a decrease in macrophages, CD3(+) T lymphocytes, and CCR2(+) cells. In contrast, CCR1 deficiency did not affect neointimal area or cell content. Deletion of CCR5 entailed an up-regulation of the anti-inflammatory cytokine interleukin 10 (IL-10) in neointimal smooth muscle cells, and its antibody blockade reversed effects in CCR5(-/-) mice. Conversely, proinflammatory interferon gamma was increased in the neointima of CCR1(-/-) mice, and its blockade unmasked a reduction in macrophage recruitment. Our data indicate that CCR5 is more crucial than CCR1 for neointimal plaque formation, and that its attenuation in CCR5(-/-) mice is due to an atheroprotective immune response involving IL-10. This harbors important implications for targeting chemokine receptors in vascular remodeling.
Assuntos
Aterosclerose/etiologia , Interleucina-10/fisiologia , Receptores CCR5/deficiência , Receptores de Quimiocinas/deficiência , Túnica Íntima/patologia , Animais , Complexo CD3 , Contagem de Células , Regulação da Expressão Gênica , Interferon gama/análise , Interferon gama/genética , Interleucina-10/análise , Interleucina-10/genética , Macrófagos/citologia , Camundongos , Camundongos Knockout , Miócitos de Músculo Liso/patologia , Receptores CCR1 , Receptores CCR2 , Receptores CCR5/fisiologia , Receptores de Quimiocinas/fisiologia , Linfócitos T/citologiaRESUMO
To clarify the role of the monocyte chemoattractant protein-1 (MCP-1)/C-C chemokine receptor 2 (CCR2) signalling pathway in hyperoxia-induced acute lung injury, CCR2-deficient (CCR2-/-) and wild-type (CCR2+/+) mice were exposed to 85% O(2) for up to 6 days. At day 3, body weight significantly decreased and total protein concentration in bronchoalveolar lavage fluid (BALF) was higher in CCR2-/- mice compared with CCR2+/+ mice. Cumulative survivals were significantly lower in CCR2-/- mice than in CCR2+/+ mice. However, the two groups showed no significant differences in both histological changes and number of macrophages in BALF. Real-time reverse transcriptase-polymerase chain reaction revealed increased mRNA levels of MCP-1, interleukin-1beta thioredoxin-1, and inducible nitric oxide synthase (iNOS) in lung tissues in CCR2-/- mice compared with CCR2+/+ mice. Increased iNOS mRNA levels in alveolar macrophages exposed to 85% O(2) for 48 h in vivo or in vitro were significantly higher in CCR2-/- mice than in CCR2+/+ mice. These results suggest that the MCP-1/CCR2 signalling pathway is protective against hyperoxia-induced tissue injury by suppressing induction of iNOS and consequent production of reactive oxygen species by activated alveolar macrophages.
Assuntos
Quimiocina CCL2/metabolismo , Hiperóxia/metabolismo , Óxido Nítrico/metabolismo , Receptores de Quimiocinas/metabolismo , Síndrome do Desconforto Respiratório/metabolismo , Transdução de Sinais , Doença Aguda , Animais , Líquido da Lavagem Broncoalveolar/química , Quimiocina CCL2/genética , Interleucina-1beta/genética , Macrófagos Alveolares/enzimologia , Camundongos , Camundongos Knockout , Modelos Animais , Óxido Nítrico Sintase Tipo II/genética , RNA Mensageiro/análise , Receptores de Quimiocinas/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Tiorredoxinas/genéticaRESUMO
The liver parenchyma is populated by hepatocytes and several nonparenchymal cell types, including Kupffer cells and hepatic stellate cells. Both Kupffer cells and hepatic stellate cells are responsive to the chemokine CCL2, but the precise roles of CCL2 and these cells in liver tumor formation remain undefined. Hence, we investigated the effects of the lack of the major CCL2 receptor, CCR2, on liver tumor formation induced by intraportal injection of the murine colon adenocarcinoma cell line, colon 26. Wild-type mice showed macroscopic tumor foci in the liver 10 days after injection of colon 26 cells. After 10 days, CCL2 proteins were detected predominantly in tumor cells, coincident with increased intratumoral macrophage and hepatic stellate cell numbers. Although tumor formation occurred at similar rates in wild-type and CCR2-deficient mice up to 10 days after tumor cell injection, the number and size of tumor foci were significantly attenuated in CCR2-deficient mice relative to wild-type mice thereafter. Moreover, neovascularization and matrix metalloproteinase 2 expression were diminished in CCR2-deficient mice with a concomitant reduction in the accumulation of macrophages and hepatic stellate cells. Furthermore, matrix metalloproteinase 2 was detected predominantly in hepatic stellate cells but not in macrophages. We provided the first definitive evidence that the absence of CCR2-mediated signals can reduce the trafficking of hepatic stellate cells, a main source of matrix metalloproteinase 2, and consequently can diminish neovascularization during liver tumor formation.