ABSTRACT
Chagas disease is a neglected tropical disease in Latin America and an imported emerging disease worldwide. Chronic Chagas disease cardiomyopathy (CCC) is the most prominent clinical form and can lead to heart failure, thromboembolism, and sudden death. While previous reports have supported a role for CD4+ T lymphocytes in the pathogenesis of CCC a comprehensive analysis of these cells during different clinical forms is lacking. Here, we used high-dimensional flow cytometry to assess the diversity of circulating CD4+ T cells in patients with distinct clinical forms. We found increased frequencies of CD4+CD69+ T cells in patients compared to controls. CD39+ regulatory T cells, represented by mesocluster 6 were reduced in mild CCC patients compared to controls. Cytotoxic CD4+ T cells co-expressing granzyme B and perforin were expanded in patients with Chagas disease and were higher in patients with mild CCC compared to controls. Furthermore, patients with mild CCC displayed higher frequencies of multifunctional effector memory CD4+ T cells. Our results demonstrate an expansion in activated CD4+ T cells and a decrease in a functional subset of regulatory T cells associated with the onset of Chagas cardiomyopathy, suggesting their role in the establishment of cardiac lesions and as potential biomarkers for disease aggravation.
Subject(s)
Cardiomyopathies , Chagas Disease , Heart Failure , Humans , Lymphocyte Count , T-Lymphocytes, Regulatory , Chagas Disease/complicationsABSTRACT
The Apicomplexa protozoan Toxoplasma gondii is a mandatory intracellular parasite and the causative agent of toxoplasmosis. This illness is of medical importance due to its high prevalence worldwide and may cause neurological alterations in immunocompromised persons. In chronically infected immunocompetent individuals, this parasite forms tissue cysts mainly in the brain. In addition, T. gondii infection has been related to mental illnesses such as schizophrenia, bipolar disorder, depression, obsessive-compulsive disorder, as well as mood, personality, and other behavioral changes. In the present study, we evaluated the kinetics of behavioral alterations in a model of chronic infection, assessing anxiety, depression and exploratory behavior, and their relationship with neuroinflammation and parasite cysts in brain tissue areas, blood-brain-barrier (BBB) integrity, and cytokine status in the brain and serum. Adult female C57BL/6 mice were infected by gavage with 5 cysts of the ME-49 type II T. gondii strain, and analyzed as independent groups at 30, 60 and 90 days postinfection (dpi). Anxiety, depressive-like behavior, and hyperactivity were detected in the early (30 dpi) and long-term (60 and 90 dpi) chronic T. gondii infection, in a direct association with the presence of parasite cysts and neuroinflammation, independently of the brain tissue areas, and linked to BBB disruption. These behavioral alterations paralleled the upregulation of expression of tumor necrosis factor (TNF) and CC-chemokines (CCL2/MCP-1, CCL3/MIP-1α, CCL4/MIP-1ß and CCL5/RANTES) in the brain tissue. In addition, increased levels of interferon-gamma (IFNγ), TNF and CCL2/MCP-1 were detected in the peripheral blood, at 30 and 60 dpi. Our data suggest that the persistence of parasite cysts induces sustained neuroinflammation, and BBB disruption, thus allowing leakage of cytokines of circulating plasma into the brain tissue. Therefore, all these factors may contribute to behavioral changes (anxiety, depressive-like behavior, and hyperactivity) in chronic T. gondii infection.
Subject(s)
Behavior, Animal , Blood-Brain Barrier/pathology , Blood-Brain Barrier/parasitology , Inflammation/parasitology , Toxoplasma/physiology , Toxoplasmosis, Cerebral/parasitology , Animals , Anxiety/complications , Anxiety/physiopathology , Brain Edema/complications , Brain Edema/physiopathology , Chronic Disease , Cytokines/metabolism , Depression/complications , Depression/physiopathology , Female , Inflammation/physiopathology , Locomotion , Mice, Inbred C57BL , Muscle Strength , Parasites/physiology , Time Factors , Toxoplasmosis, Cerebral/physiopathology , Up-RegulationABSTRACT
Toxoplasmosis is highly endemic worldwide. In Brazil, depending on the geographical region and socioeconomic status, 40-70% of individuals become seropositive at some point in their lives. A significant proportion of Toxoplasma gondii-chronically infected individuals who are otherwise immunocompetent develop recurrent ocular lesions. The inflammatory/immune mechanisms involved in development of ocular lesion are still unknown and, despite previous investigation, there are no reliable immune biomarkers to predict/follow disease outcome. To better understand the impact of the immune response on parasite control and immunopathology of ocular toxoplasmosis, and to provide insights on putative biomarkers for disease monitoring, we assessed the production of a large panel of circulating immune mediators in a longitudinal study of patients with postnatally acquired toxoplasmosis stratified by the presence of ocular involvement, both at the early acute stage and 6 months later during chronic infection, correlating them with presence of ocular involvement. We found that T. gondii-infected patients, especially during the acute stage of the disease, display high levels of chemokines, cytokines, and growth factors involved in the activation, proliferation, and migration of inflammatory cells to injured tissues. In particular, major increases were found in the IFN-induced chemokines CXCL9 and CXCL10 in T. gondii-infected patients regardless of disease stage or clinical manifestations. Moreover, a specific subgroup of circulating cytokines and chemokines including GM-CSF, CCL25, CCL11, CXCL12, CXCL13, and CCL2 was identified as potential biomarkers that accurately distinguish different stages of infection and predict the occurrence of ocular toxoplasmosis. In addition to serving as predictors of disease development, these host inflammatory molecules may offer promise as candidate targets for therapeutic intervention.
Subject(s)
Cytokines/immunology , Inflammation Mediators/immunology , Toxoplasma/immunology , Toxoplasmosis, Ocular/immunology , Acute Disease , Adolescent , Adult , Child , Chronic Disease , Female , Humans , Male , Middle AgedABSTRACT
The infection with the protozoan parasite Trypanosoma cruzi causes Chagas disease, a neglected tropical disease in Latin America and an imported emerging disease worldwide. Chronic Chagasic cardiomyopathy (CCC), a progressive inflammatory and fibrosing disease, is the most prominent clinical form of Chagas disease, culminating in heart failure and high rates of sudden death. CCC pathogenesis is influenced by both host and parasite factors and is proposed to be mostly immune-driven. Chemokines are crucial players in orchestrating immune cell recruitment to infected tissues and inflammation. Herein, we investigated inflammatory chemokine receptor expression on circulating T cells in patients stratified by CCC severity. Compared to asymptomatic individuals, we found increased percentages of effector CD4+ T cells and central memory CD4+ and CD8+ T cells expressing CCR5 in patients with structural cardiopathy, but normal global ventricular function and no symptoms of chronic heart failure. Even naïve T cells expressed CCR5 in these patients. In contrast, reduced frequencies of CD4+ and CD8+ effector T cells expressing CXCR3 were observed in patients presenting with severe heart disease. Patients with increased left ventricular diameter, heart enlargement, and insufficiency had higher frequencies of CCR5+ effector and effector memory CD8+ T cells. Moreover, the percentage of effector CCR5+ CD8+ T cells was increased in patients with a reduced ejection fraction. Our results show that high expression CCR5 and low expression of CXCR3 on circulating T cells are associated with worse prognosis, possibly reflecting immune-mediated cardiac remodeling of CCC.
Subject(s)
CD8-Positive T-Lymphocytes/immunology , Cardiomyopathies/immunology , Cell Movement , Chagas Disease/immunology , Disease Progression , Immunologic Memory , Receptors, CCR5/metabolism , Adult , Aged , Cardiomyopathies/blood , Cardiomyopathies/pathology , Cell Movement/immunology , Cell Proliferation , Chagas Disease/blood , Chagas Disease/pathology , Chemokines/blood , Humans , Middle Aged , Severity of Illness Index , Young AdultABSTRACT
Several antigens from Trypanosoma cruzi, the causative agent of Chagas disease (CD), contain amino acid repeats identified as targets of the host immune response. Ribosomal proteins containing an Ala, Lys, Pro-rich repeat domain are among the T. cruzi antigens that are strongly recognized by antibodies from CD patients. Here we investigated the role of amino acid repeats present in the T. cruzi ribosomal protein L7a, by immunizing mice with recombinant versions of the full-length protein (TcRpL7a), as well as with truncated versions containing only the repetitive (TcRpL7aRep) or the non-repetitive domains (TcRpL7aΔRep). Mice immunized with full-length TcRpL7a produced high levels of IgG antibodies against the complete protein as well as against the repeat domain, whereas mice immunized with TcRpL7aΔRep or TcRpL7aRep produced very low levels or did not produce IgG antibodies against this antigen. Also in contrast to mice immunized with the full-length TcRpL7a, which produced high levels of IFN-γ, only low levels of IFN-γ or no IFN-γ were detected in cultures of splenocytes derived from mice immunized with truncated versions of the protein. After challenging with trypomastigotes, mice immunized with the TcRpL7a were partially protected against the infection whereas immunization with TcRpL7aΔRep did not alter parasitemia levels compared to controls. Strikingly, mice immunized with TcRpL7aRep displayed an exacerbated parasitemia compared to the other groups and 100% mortality after infection. Analyses of antibody production in mice that were immunized with TcRpL7aRep prior to infection showed a reduced humoral response to parasite antigens as well as against an heterologous antigen. In vitro proliferation assays with mice splenocytes incubated with different mitogens in the presence of TcRpL7aRep resulted in a drastic inhibition of B-cell proliferation and antibody production. Taken together, these results indicate that the repeat domain of TcRpL7a acts as an immunosuppressive factor that down regulates the host B-cell response against parasite antigens favoring parasite multiplication in the mammalian host.
ABSTRACT
The inflammatory cytokine interferon-gamma (IFNγ) is crucial for immunity against intracellular pathogens such as the protozoan parasite Trypanosoma cruzi, the causative agent of Chagas disease (CD). IFNγ is a pleiotropic cytokine which regulates activation of immune and non-immune cells; however, the effect of IFNγ in the central nervous system (CNS) and astrocytes during CD is unknown. Here we show that parasite persists in the CNS of C3H/He mice chronically infected with the Colombian T. cruzi strain despite the increased expression of IFNγ mRNA. Furthermore, most of the T. cruzi-bearing cells were astrocytes located near IFNγ+ cells. Surprisingly, in vitro experiments revealed that pretreatment with IFNγ promoted the infection of astrocytes by T. cruzi increasing uptake and proliferation of intracellular forms, despite inducing increased production of nitric oxide (NO). Importantly, the effect of IFNγ on T. cruzi uptake and growth is completely blocked by the anti-tumor necrosis factor (TNF) antibody Infliximab and partially blocked by the inhibitor of nitric oxide synthesis L-NAME. These data support that IFNγ fuels astrocyte infection by T. cruzi and critically implicate IFNγ-stimulated T. cruzi-infected astrocytes as sources of TNF and NO, which may contribute to parasite persistence and CNS pathology in CD.
Subject(s)
Astrocytes/drug effects , Astrocytes/parasitology , Chagas Disease/physiopathology , Interferon-gamma/pharmacology , Animals , Astrocytes/metabolism , Cells, Cultured , Chagas Disease/immunology , Chagas Disease/parasitology , Cytokines/metabolism , Female , Immunohistochemistry , Infliximab/pharmacology , Interferon-gamma/genetics , Interferon-gamma/metabolism , Mice , Mice, Inbred C3H , Mice, Inbred C57BL , NG-Nitroarginine Methyl Ester/pharmacology , Nitric Oxide/metabolism , Trypanosoma cruzi/growth & developmentABSTRACT
PI3Kγ is central in signaling diverse arrays of cellular functions and inflammation. Pulmonary fibrosis is associated with pulmonary inflammation, angiogenesis, and deposition of collagen and is modeled by instillation of bleomycin. The role of PI3Kγ in mediating bleomycin-induced pulmonary inflammation and fibrosis in mice and potential mechanisms involved was investigated here. WT or PI3Kγ KO mice were instilled with bleomycin and leukocyte subtype influx, cytokine and chemokine levels, and angiogenesis and tissue fibrosis evaluated. The activation of lung-derived leukocytes and fibroblasts was evaluated in vitro. The relevance of PI3Kγ for endothelial cell function was evaluated in HUVECs. PI3Kγ KO mice had greater survival and weight recovery and less fibrosis than WT mice after bleomycin instillation. This was associated with decreased production of TGF-ß(1) and CCL2 and increased production of IFN-γ and IL-10. There was reduced expression of collagen, fibronectin, α-SMA, and von Willebrand factor and decreased numbers and activation of leukocytes and phosphorylation of AKT and IκB-α. PI3Kγ KO mice had a reduced number and area of blood vessels in the lungs. In vitro, treatment of human endothelial cells with the PI3Kγ inhibitor AS605240 decreased proliferation, migration, and formation of capillary-like structures. AS605240 also decreased production of collagen by murine lung-derived fibroblasts. PI3Kγ deficiency confers protection against bleomycin-induced pulmonary injury, angiogenesis, and fibrosis through the modulation of leukocyte, fibroblast, and endothelial cell functions. Inhibitors of PI3Kγ may be beneficial for the treatment of pulmonary fibrosis.
Subject(s)
Bleomycin/toxicity , Class Ib Phosphatidylinositol 3-Kinase/physiology , Pneumonia/enzymology , Pneumonia/pathology , Pulmonary Fibrosis/enzymology , Pulmonary Fibrosis/pathology , Animals , Cells, Cultured , Class Ib Phosphatidylinositol 3-Kinase/deficiency , Class Ib Phosphatidylinositol 3-Kinase/genetics , Disease Models, Animal , Endothelium, Vascular/cytology , Endothelium, Vascular/drug effects , Endothelium, Vascular/enzymology , Humans , Lung/blood supply , Lung/immunology , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Neovascularization, Physiologic/immunology , Pneumonia/chemically induced , Pulmonary Fibrosis/chemically inducedABSTRACT
Chagas' disease is caused by Trypanosoma cruzi infection and is characterized by chronic fibrogenic inflammation and heart dysfunction. Chemokines are produced during infection and drive tissue inflammation. In rats, acute infection is characterized by intense myocarditis and regression of inflammation after control of parasitism. We investigated the role of CCL3 and CCL5 during infection by using DNA vaccination encoding for each chemokine separately or simultaneously. MetRANTES treatment was used to evaluate the role of CCR1 and CCR5, the receptors for CCL3 and CCL5. Vaccination with CCL3 or CCL5 increased heart parasitism and decreased local IFN-gamma production, but did not influence intensity of inflammation. Simultaneous treatment with both plasmids or treatment with MetRANTES enhanced cardiac inflammation, fibrosis and parasitism. In conclusion, chemokines CCL3 and CCL5 are relevant, but not essential, for control of T. cruzi infection in rats. On the other hand, combined blockade of these chemokines or their receptors enhanced tissue inflammation and fibrosis, clearly contrasting with available data in murine models of T. cruzi infection. These data reinforce the important role of chemokines during T. cruzi infection but suggest that caution must be taken when expanding the therapeutic modulation of the chemokine system in mice to the human infection.
Subject(s)
Chagas Cardiomyopathy/immunology , Chemokine CCL3/immunology , Chemokine CCL5/immunology , Trypanosoma cruzi/immunology , Animals , Chagas Cardiomyopathy/pathology , Heart/parasitology , Myocardium/pathology , Rats , Rats, Sprague-Dawley , Trypanosoma cruzi/pathogenicity , Vaccines, DNA/administration & dosageABSTRACT
The comprehension of the molecular mechanisms leading to Trypanosoma cruzi-elicited heart dysfunction might contribute to design novel therapeutic strategies aiming to ameliorate chronic Chagas disease cardiomyopathy. In C3H/He mice infected with the low virulence T. cruzi Colombian strain, the persistent cardiac inflammation composed mainly of CCR5(+) T lymphocytes parallels the expression of CC-chemokines in a pro-inflammatory IFN-gamma and TNF-alpha milieu. The chronic myocarditis is accompanied by increased frequency of peripheral CCR5(+)LFA-1(+) T lymphocytes. The treatment of chronically T. cruzi-infected mice with Met-RANTES, a selective CCR1/CCR5 antagonist, led to a 20-30% decrease in CD4(+) cell numbers as well as IL-10, IL-13 and TNF-alpha expression. Further, Met-RANTES administration impaired the re-compartmentalization of the activated CD4(+)CCR5(+) lymphocytes. Importantly, Met-RANTES treatment resulted in significant reduction in parasite load and fibronectin deposition in the heart tissue. Moreover, Met-RANTES treatment significantly protected T. cruzi-infected mice against connexin 43 loss in heart tissue and CK-MB level enhancement, markers of heart dysfunction. Thus, our results corroborate that therapeutic strategies based on the modulation of CCR1/CCR5-mediated cell migration and/or effector function may contribute to cardiac tissue damage limitation during chronic Chagas disease.
Subject(s)
CCR5 Receptor Antagonists , Chagas Disease/drug therapy , Chagas Disease/pathology , Chemokine CCL5/therapeutic use , Immunologic Factors/therapeutic use , Myocardium/pathology , Receptors, CCR1/antagonists & inhibitors , Trypanosoma cruzi/physiology , Animals , CD4-Positive T-Lymphocytes/immunology , Chagas Cardiomyopathy/drug therapy , Chagas Cardiomyopathy/pathology , Chemokine CCL5/pharmacology , Connexin 43/analysis , Female , Heart/parasitology , Immunologic Factors/pharmacology , Interleukin-10/biosynthesis , Interleukin-13/biosynthesis , Mice , Mice, Inbred C3H , Myocardium/chemistry , Tumor Necrosis Factor-alpha/biosynthesisABSTRACT
Pulmonary fibrosis is characterized by chronic inflammation and excessive collagen deposition. Neutrophils are thought to be involved in the pathogenesis of lung fibrosis. We hypothesized that CXCR2-mediated neutrophil recruitment is essential for the cascade of events leading to bleomycin-induced pulmonary fibrosis. CXCL1/KC was detected as early as 6 hours after bleomycin instillation and returned to basal levels after Day 8. Neutrophils were detected in bronchoalveolar lavage and interstitium from 12 hours and peaked at Day 8 after instillation. Treatment with the CXCR2 receptor antagonist, DF2162, reduced airway neutrophil transmigration but led to an increase of neutrophils in lung parenchyma. There was a significant reduction in IL-13, IL-10, CCL5/RANTES, and active transforming growth factor (TGF)-beta(1) levels, but not on IFN-gamma and total TGF-beta(1,) and enhanced granulocyte macrophage-colony-stimulating factor production in DF2162-treated animals. Notably, treatment with the CXCR2 antagonist led to an improvement of the lung pathology and reduced collagen deposition. Using a therapeutic schedule, DF2162 administered from Days 8 to 16 after bleomycin reduced pulmonary fibrosis and levels of active TGF-beta(1) and IL-13. DF2162 treatment reduced bleomycin-induced expression of von Willebrand Factor, a marker of angiogenesis, in the lung. In vitro, DF2162 reduced the angiogenic activity of IL-8 on human umbilical vein endothelial cells. In conclusion, we show that CXCR2 plays an important role in mediating fibrosis after bleomycin instillation. The compound blocks angiogenesis and the production of pro-angiogenic cytokines, and decreases IL-8-induced endothelial cell activation. An effect on neutrophils does not appear to account for the major effects of the blockade of CXCR2 in the system.
Subject(s)
Pneumonia/complications , Pneumonia/metabolism , Pulmonary Fibrosis/complications , Pulmonary Fibrosis/metabolism , Receptors, Interleukin-8B/metabolism , Animals , Benzeneacetamides/administration & dosage , Benzeneacetamides/pharmacology , Bleomycin , Bronchoalveolar Lavage Fluid , Cell Movement/drug effects , Chemokines/biosynthesis , Dose-Response Relationship, Drug , Humans , Kinetics , Male , Mesylates/administration & dosage , Mesylates/pharmacology , Mice , Mice, Inbred C57BL , Neovascularization, Pathologic/metabolism , Neutrophils/cytology , Neutrophils/drug effects , Pneumonia/chemically induced , Pneumonia/pathology , Pulmonary Fibrosis/chemically induced , Pulmonary Fibrosis/pathology , Receptors, Interleukin-8B/antagonists & inhibitors , Time FactorsABSTRACT
BACKGROUND: Kinins are important mediators of inflammation and act through stimulation of two receptor subtypes, B1 and B2. Leukocyte infiltration contributes to the pathogenesis of autoimmune inflammation in the central nervous system (CNS), occurring not only in multiple sclerosis (MS) but also in experimental autoimmune encephalomyelitis (EAE). We have previously shown that the chemokines CCL2 and CCL5 play an important role in the adhesion of leukocytes to the brain microcirculation in EAE. The aim of the present study was to evaluate the relevance of B2 receptors to leukocyte-endothelium interactions in the cerebral microcirculation, and its participation in CNS inflammation in the experimental model of myelin-oligodendrocyte-glycoprotein (MOG)(35-55)-induced EAE in mice. METHODS: In order to evaluate the role of B2 receptor in the cerebral microvasculature we used wild-type (WT) and kinin B2 receptor knockout (B2-/-) mice subjected to MOG(35-55)-induced EAE. Intravital microscopy was used to investigate leukocyte recruitment on pial matter vessels in B2-/- and WT EAE mice. Histological documentation of inflammatory infiltrates in brain and spinal cords was correlated with intravital findings. The expression of CCL5 and CCL2 in cerebral tissue was assessed by ELISA. RESULTS: Clinical parameters of disease were reduced in B2-/- mice in comparison to wild type EAE mice. At day 14 after EAE induction, there was a significant decrease in the number of adherent leukocytes, a reduction of cerebral CCL5 and CCL2 expressions, and smaller inflammatory and degenerative changes in B2-/- mice when compared to WT. CONCLUSION: Our results suggest that B2 receptors have two major effects in the control of EAE severity: (i) B2 regulates the expression of chemokines, including CCL2 and CCL5, and (ii) B2 modulates leukocyte recruitment and inflammatory lesions in the CNS.
Subject(s)
Chemokine CCL2/immunology , Chemokine CCL5/immunology , Encephalomyelitis, Autoimmune, Experimental/immunology , Leukocytes/immunology , Receptor, Bradykinin B2/immunology , Animals , Brain/blood supply , Brain/metabolism , Brain/pathology , Chemokines/metabolism , Cytokines/metabolism , Encephalomyelitis, Autoimmune, Experimental/pathology , Female , Glycoproteins/immunology , Leukocyte Rolling , Mice , Mice, Inbred C57BL , Mice, Knockout , Microvessels/metabolism , Microvessels/pathology , Myelin-Oligodendrocyte Glycoprotein , Peptide Fragments/immunology , Receptor, Bradykinin B2/geneticsABSTRACT
Encephalitis rarely occurs during acute Trypanosoma cruzi infection. However, the central nervous system (CNS) is the major site of infection reactivation in immunocompromised patients. We show that the acute T. cruzi-triggered CD8-enriched meningoencephalitis paralleled the in situ expression of CCL3/MIP-1alpha and CCL5/RANTES mRNA. The frequency of CCR5-bearing cells was increased among peripheral blood mononuclear cells (PBMC) of infected mice. Further, CCL5/RANTES-driven in vitro PBMC migration was partially abrogated by the CCR1/CCR5 antagonist Met-RANTES. However, Met-RANTES treatment of infected mice altered neither parasitism nor intensity and nature of the CNS inflammation, indicating that T. cruzi-elicited meningoencephalitis is a CCR1/CCR5 independent process.
Subject(s)
Inflammation/etiology , Meningoencephalitis/etiology , Receptors, CCR5/physiology , Receptors, Chemokine/physiology , Trypanosoma cruzi/pathogenicity , Animals , CD8 Antigens/metabolism , Cell Movement/drug effects , Chemokine CCL5/analogs & derivatives , Chemokine CCL5/pharmacology , Enzyme Inhibitors/pharmacology , Female , Gene Expression , Immunohistochemistry , Inflammation/drug therapy , Meningoencephalitis/complications , Meningoencephalitis/drug therapy , Meningoencephalitis/metabolism , Mice , Mice, Inbred C3H , Mice, Inbred C57BL , Receptors, CCR1ABSTRACT
Chagas' disease, caused by Trypanosoma cruzi, is a major cause of cardiovascular disease in Latin America. Exacerbated inflammation disproportional to parasite load characterizes chronic myocardial lesions in chagasic patients. Chemokines and their receptors are expected to account for the renewed inflammatory processes after the inoculation of the parasite, but their potential unique functions are far from being clear. Herein, we evaluated the effect of a DNA vaccine encoding CCL4/MIP-1beta, a CC-chemokine, in T. cruzi-elicited myocarditis in rats. Holtzman rats were given intramuscularly cardiotoxin and the CCL4/MIP-1beta DNA-containing plasmid (100microg) was delivered in this muscular site four times. Fourteen days after last immunization, animals were inoculated with a myotropical CL-Brener T. cruzi clone. Peak of parasitism was observed at day 15 after infection, preceding the peak of myocardial inflammation at day 20. Myocarditis was still intense at day 30, but the inflammatory infiltrates showed a more focal distribution. The expression of CCL2/MCP-1 and CCL4/MIP-1beta correlated closely with the kinetics of myocardial inflammation. The CCL4/MIP-1beta DNA vaccine induced an increase of the levels of the anti-CCL4/MIP-1beta observed in T. cruzi-infected animals. This was associated with an exacerbation of myocardial inflammation and fibrosis, although alterations in parasitemia and myocardial parasitism were not observed. Our data suggest that CCL4/MIP-1beta plays a role in preventing excessive inflammation and pathology rather than in controlling parasite replication.
Subject(s)
Chagas Cardiomyopathy/pathology , Chemokines, CC/immunology , Trypanosoma cruzi/immunology , Vaccines, DNA/immunology , Animals , Chagas Cardiomyopathy/immunology , Chemokine CCL4 , Chemokines, CC/genetics , Disease Models, Animal , Gene Expression Regulation , Heart/parasitology , Histocytochemistry , Myocardium/pathology , Parasitemia , RNA, Messenger/analysis , RNA, Messenger/genetics , Rats , Rats, Sprague-Dawley , Trypanosoma cruzi/isolation & purification , Vaccines, DNA/geneticsABSTRACT
We investigated the role of the platelet activation factor (PAF) receptor (PAFR) in the outcome of infection with Leishmania amazonensis. PAFR deficient (PAFR(-/-)) mice were infected with L. amazonensis and the course of infection was followed. We found that PAFR(-/-) mice in the C57BL/6 background were more susceptible to infection with L. amazonensis than the wild-type controls, as seen both by lesion size and parasite number at the site of infection. Interferon (IFN)-gamma production was delayed in PAFR(-/-) mice, and lower levels of Ccl5 were found in lesions. Expression of nitric oxide synthase-2 mRNA was found impaired in PAFR(-/-) associated with higher levels of arginase-1 mRNA. Moreover, higher levels of antibodies were produced in response to L. amazonensis by PAFR(-/-) mice. We conclude that signaling through the PAFR is essential for the ability of the murine host to control L. amazonensis infection by driving an adequate immune response.
Subject(s)
Interferon-gamma/biosynthesis , Leishmania mexicana/immunology , Leishmaniasis, Cutaneous/immunology , Platelet Membrane Glycoproteins/deficiency , Receptors, G-Protein-Coupled/deficiency , Animals , Antibodies, Protozoan/blood , Arginase/biosynthesis , Chemokine CCL1 , Chemokine CCL5 , Chemokines, CC/analysis , Disease Models, Animal , Disease Susceptibility , Gene Expression , Histocytochemistry , Immunoglobulin G/blood , Interleukin-10/analysis , Leishmaniasis, Cutaneous/parasitology , Leishmaniasis, Cutaneous/pathology , Mice , Mice, Inbred C57BL , Mice, Knockout , Nitric Oxide Synthase Type II/biosynthesis , Platelet Membrane Glycoproteins/genetics , RNA, Messenger/analysis , RNA, Messenger/genetics , Receptors, G-Protein-Coupled/genetics , Tumor Necrosis Factor-alpha/analysis , Up-RegulationABSTRACT
Statins exert favorable effects on lipoprotein metabolism but may also possess anti-inflammatory effects. Here, we explored the effects of atorvastatin in a model of adjuvant-induced arthritis in rat. Oral treatment with atorvastatin (1-10 mg/kg) from days 10 to 15 after arthritis induction caused inhibition of the increase in paw volume. Maximal inhibition occurred at a dose of 10 mg/kg. At this dose, atorvastatin markedly ameliorated the histopathological findings of joints obtained from day 16 of arthritic animals. This was mirrored by an effective blockade of neutrophil influx, as assessed by the tissue myeloperoxidase levels. The concentrations of the cytokines interleukin-1beta, interleukin-6 and tumor necrosis factor-alpha and the chemokines CCL5 and CCL2 were significantly decreased in arthritic rats treated with atorvastatin. In contrast, the levels of interleukin-10 were enhanced by the drug treatment. The drug also prevented the hypernociception observed in the inflamed joints. These data clearly illustrate the therapeutic potential of a statin-sensitive pathway in inflammatory arthritis.
Subject(s)
Analgesics/pharmacology , Anti-Inflammatory Agents/pharmacology , Arthritis, Experimental/prevention & control , Heptanoic Acids/pharmacology , Pyrroles/pharmacology , Analgesics/therapeutic use , Animals , Anti-Inflammatory Agents/therapeutic use , Arthritis, Experimental/metabolism , Arthritis, Experimental/pathology , Atorvastatin , Chemokine CCL2/biosynthesis , Chemokine CCL5/biosynthesis , Chemokines, CC/biosynthesis , Dose-Response Relationship, Drug , Edema/complications , Edema/prevention & control , Female , Heptanoic Acids/therapeutic use , Hindlimb/drug effects , Hindlimb/pathology , Hydroxymethylglutaryl-CoA Reductase Inhibitors/pharmacology , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Hyperalgesia/etiology , Hyperalgesia/prevention & control , Interleukin-1/biosynthesis , Interleukin-10/biosynthesis , Interleukin-6/biosynthesis , Leukocytes/pathology , Neutrophils/pathology , Peroxidase/metabolism , Pyrroles/therapeutic use , Rats , Tarsal Joints/drug effects , Tarsal Joints/pathology , Time Factors , Tumor Necrosis Factor-alpha/biosynthesisABSTRACT
In human schistosomiasis, the concentrations of the chemokine macrophage inflammatory protein 1alpha (MIP-1alpha/CCL3) is greater in the plasma of patients with clinical hepatosplenic disease. The objective of the present study was to confirm the ability of CCL3 to detect severe disease in patients classified by ultrasonography (US) and to evaluate the potential role of CCL3 in Schistosoma mansoni-infected mice. CCL3 was measured by enzyme-linked immunosorbent assay in the plasma of S. mansoni-infected patients. CCL3-deficient mice were infected with 25 cercariae, and various inflammatory and infectious indices were evaluated. The concentration of CCL3 was higher in the plasma of S. mansoni-infected than noninfected patients. Moreover, CCL3 was greater in those with US-defined hepatosplenic than with the intestinal form of the disease. In CCL3-deficient mice, the size of the granuloma and the liver eosinophil peroxidase activity and collagen content were diminished compared to wild-type mice. In CCL3-deficient mice, the worm burden after 14 weeks of infection, but not after 9 weeks, was consistently smaller. The in vitro response of mesenteric lymph node cells to antigen stimulation was characterized by lower levels of interleukin-4 (IL-4) and IL-10. CCL3 is a marker of disease severity in infected humans, and experimental studies in mice suggest that CCL3 may be a causative factor in the development of severe schistosomiasis.
Subject(s)
Macrophage Inflammatory Proteins/physiology , Schistosomiasis mansoni/etiology , Animals , Chemokine CCL3 , Chemokine CCL4 , Chronic Disease , Collagen/biosynthesis , Cytokines/biosynthesis , Eosinophil Peroxidase/metabolism , Female , Humans , Intestines/pathology , Liver/pathology , Male , Mice , Mice, Inbred C57BL , Schistosomiasis mansoni/immunology , Schistosomiasis mansoni/pathologyABSTRACT
Central nervous system (CNS) damage can occur during Trypanosoma cruzi infection, especially in immunosuppressed patients. The enhanced susceptibility of C3H/He mice to CD8-mediated acute meningoencephalitis is associated with higher up-regulation of vascular cell adhesion molecule-1 (VCAM-1) on CNS vascular endothelia than in the less susceptible C57BL/6. Further, in vitro adhesion of activated peripheral blood cells to CNS blood vessels was abrogated by anti-VLA-4 antibodies that also inhibited cell migration into the CNS of T. cruzi-infected mice. Lastly, the reactivation of meningoencephalitis in immunosuppressed chronically infected mice was associated with VCAM-1 up-regulation. Therefore, we hypothesize that VLA-4/VCAM-1 pathway plays a pivotal role in the establishment of T. cruzi-elicited encephalitis.