Inflammasome activation and CCR2-mediated monocyte-derived dendritic cell recruitment restrict Legionella pneumophila infection.

Flagellin-induced NAIP/NLRC4 inflammasome activation and pyroptosis are critical events restricting Legionella pneumophila infection. However, the cellular and molecular dynamics of the in vivo responses against this bacterium are still unclear. We have found temporal coordination of two independent innate immunity pathways in controlling Legionella infection, the inflammasome activation and the CCR2-mediated Mo-DC recruitment. Inflammasome activation was an important player at the early stage of infection by lowering the numbers of bacteria for an efficient bacterial clearance conferred by the Mo-DC at the late stage of the infection. Mo-DC emergence highly depended on CCR2-signaling and dispensed inflammasome activation and pyroptosis. Also, Mo-DC compartment did not rely on the inflammasome machinery to deliver proper immune responses and was the most abundant cytokine-producing among the monocyte-derived cells in the infected lung. Importantly, when the CCR2- and NLRC4-dependent axes of response were simultaneously ablated, we observed an aggravated bacterial burden in the lung of infected mice. Taken together, we showed that inflammasome activation and CCR2-mediated immune response interplay in distinct pathways to restrict pulmonary bacterial infection. These findings extend our understanding of the in vivo integration and cooperation of different innate immunity arms in controlling infectious agents.

Green propolis extract attenuates acute kidney injury and lung injury in a rat model of sepsis.

Sepsis is the leading cause of acute kidney injury (AKI) and lung injury worldwide. Despite therapeutic advances, sepsis continues to be associated with high mortality. Because Brazilian green propolis (GP) has promising anti-inflammatory, antioxidant, and immunomodulatory properties, we hypothesized that it would protect kidneys and lungs in rats induced to sepsis by cecal ligation and puncture (CLP). Male Wistar rats were divided into groups-control (sham-operated); CLP (CLP only); and CLP + GP (CLP and treatment with GP at 6 h thereafter)-all receiving volume expansion and antibiotic therapy at 6 h after the procedures. By 24 h after the procedures, treatment with GP improved survival, attenuated sepsis-induced AKI, and restored renal tubular function. Whole-blood levels of reduced glutathione were higher in the CLP + GP group. Sepsis upregulated the Toll-like receptor 4/nuclear factor-kappa B axis in lung and renal tissues, as well as increasing inflammatory cytokine levels and macrophage infiltration; all of those effects were attenuated by GP. Treatment with GP decreased the numbers of terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling-positive cells in renal and lung tissue, as well as protecting the morphology of the renal mitochondria. Our data open the prospect for clinical trials of the use of GP in sepsis.

CCR2-deficient mice are protected to sepsis by the disruption of the inflammatory monocytes emigration from the bone marrow.

Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. Inflammatory monocytes are recruited to both the infection site and vital organs during sepsis; however, the mechanisms that orchestrate their migration, as well as the participation of these cells in systemic inflammation and vital organ damage, are still not fully elucidated. In this context, we described that CCR2-deficient mice had diminished migration of inflammatory monocytes from bone marrow to the circulation and subsequently to the site of infection and vital organs during cecal ligation and puncture (CLP)-induced polymicrobial sepsis. The reduction in the migration of inflammatory monocytes to the infection site was accompanied by a significant increase in the number of neutrophils in the same compartment, which seemed to counterbalance the absence of inflammatory monocytes in controlling microbial growth. Indeed, wild-type (WT) and CCR2-deficient mice under CLP presented similar control of infection. However, the CCR2-deficient mice were more resistant to sepsis, which was associated with a decrease in inflammatory mediators and organ damage biomarkers. Furthermore, the systemic adoptive transfer of CCR2-WT or CCR2-deficient inflammatory monocytes into CCR2-deficient mice equally increased the susceptibility to sepsis, demonstrating the deleterious role of these cells in the periphery even when CCR2 is absent. Thus, despite the host-protective role of inflammatory monocytes in controlling infection, our results demonstrated that the mechanism by which CCR2 deficiency shows protection to CLP-induced sepsis is due to a decrease of inflammatory monocytes emigration from bone marrow to the circulation and vital organs, resulting in the reduction of organ damage and systemic cytokine production.

NFAT1 Regulates Ly6Chi Monocyte Recruitment to the CNS and Plays an Essential Role in Resistance to Toxoplasma gondii Infection.

Monocytes play key roles in the maintenance of homeostasis and in the control of the infection. Monocytes are recruited from the bone marrow to inflammatory sites and are essential for antimicrobial activity to limit tissue damage and promote adaptive T cell responses. Here, we investigated the role of Nuclear Factor of Activated T cells 1 (NFAT1) in the regulation of Ly6Chi inflammatory monocyte recruitment to the CNS upon T. gondii infection. We show that NFAT-1-deficient monocytes are unable to migrate to the CNS of T. gondii-infected mice. Moreover, NFAT1-/- mice are highly susceptible to chronic T. gondii infection due to a failure to control parasite replication in the CNS. The inhibition of Ly6Chi inflammatory monocyte recruitment to the CNS severely blocked CXCL10 production and consequently the migration of IFN-γ-producing CD4+ T cells. Moreover, the transfer of Ly6Chi monocytes to infected NFAT1-/- mice favored CD4+ T cell migration to the CNS and resulted in the inhibition of parasite replication and host defense. Together, these results demonstrated for the first time the contribution of NFAT1 to the regulation of Ly6Chi monocyte recruitment to the CNS and to resistance during chronic T. gondii infection.

Phosphatidyl-Inositol-3 Kinase Inhibitors Regulate Peptidoglycan-Induced Myeloid Leukocyte Recruitment, Inflammation, and Neurotoxicity in Mouse Brain.

Acute brain injury leads to the recruitment and activation of immune cells including resident microglia and infiltrating peripheral myeloid cells (MC), which contribute to the inflammatory response involved in neuronal damage. We previously reported that TLR2 stimulation by peptidoglycan (PGN) from Staphylococcus aureus, in vitro and in vivo, induced microglial cell activation followed by autophagy induction. In this report, we evaluated if phosphatidyl-inositol-3 kinase (PI3K) pharmacological inhibitors LY294200 and 3-methyladenine (3-MA) can modulate the innate immune response to PGN in the central nervous system. We found that injection of PGN into the mouse brain parenchyma (caudate putamen) triggered an inflammatory reaction, which involved activation of microglial cells, recruitment of infiltrating MC to injection site, production of pro-inflammatory mediators, and neuronal injury. In addition, we observed the accumulation of LC3B+ CD45+ cells and colocalization of LC3B and lysosomal-associated membrane protein 1 in brain cells. Besides, we found that pharmacological inhibitors of PI3K, including the classical autophagy inhibitor 3-MA, reduced the recruitment of MC, microglial cell activation, and neurotoxicity induced by brain PGN injection. Collectively, our results suggest that PI3K pathways and autophagic response may participate in the PGN-induced microglial activation and MC recruitment to the brain. Thus, inhibition of these pathways could be therapeutically targeted to control acute brain inflammatory conditions.

Macrophage Populations in Visceral Adipose Tissue from Pregnant Women: Potential Role of Obesity in Maternal Inflammation.

Obesity is associated with inflammatory changes and accumulation and phenotype polarization of adipose tissue macrophages (ATMs). Obese pregnant women have alterations in adipose tissue composition, but a detailed description of macrophage population is not available. In this study, we characterized macrophage populations in visceral adipose tissue (VAT) from pregnant women with normal, overweight, and obese pregestational weight. Immunophenotyping of macrophages from VAT biopsies was performed by flow cytometry using CD45 and CD14 as markers of hematopoietic and monocyte linage, respectively, while HLA-DR, CD11c, CD163, and CD206 were used as pro- and anti-inflammatory markers. Adipocyte number and size were evaluated by light microscopy. The results show that pregnant women that were overweight and obese during the pregestational period had adipocyte hypertrophy. Two different macrophage populations in VAT were identified: recruited macrophages (CD45⁺CD14⁺), and a novel population lacking CD45, which was considered to be a resident macrophages subset (CD45−CD14⁺). The number of resident HLA−DRlow/− macrophages showed a negative correlation with body mass index (BMI). Both resident and recruited macrophages from obese women expressed higher CD206 levels. CD11c expression was higher in resident HLA-DR⁺ macrophages from obese women. A strong correlation between CD206 and CD11c markers and BMI was observed. Our findings show that being overweight and obese in the pregestational period is associated with adipocyte hypertrophy and specific ATMs populations in VAT.

Ovariectomy Modifies TH2, and TH17 Balance in BALB/C Allergic Mice.

Asthma is a chronic inflammation of the airways affecting over 300 million people worldwide. As in the autoimmune diseases, it is well described that women are the most affected by asthma. The higher number of women presenting this pathology suggests the involvement of female sex hormones in the construction of the allergic immune response. Female Balb / c mice were used for the experiments. Thirty-eight animals were separated into four groups: OVX-Ova; Sham-Ova; OVX-Sal; Sham-Sal. Then animals underwent acute allergic induction protocol by Ovalbulmin (OVA). Ovariectomized animals showed greater number of leukocytes in bronchoalveolar lavage (BAL) and elevated white blood cells recruitment to the lung environment observed by histological analysis. There was a significant increase of eosinophils and mast cells in inflammatory sites at pulmonary tissue. The relative uterine and body weight were lower in ovariectomized animals and higher in Sham mice, respectively. Moreover, the lack of the sex hormones induced an increase in interleukin (IL)-4 and titers of immunoglobulin G1 (IgG1) antibodies. However, increased production of IL-17A was only observed in Sham animals. Altogether, data this study suggest that ovariectomy induces the formation of a stronger Th2 response in allergic animal. However, the immune processes involved in the allergic response in females currently remain unclear.

Tolerogenic Plasmacytoid Dendritic Cells Control Paracoccidioides brasiliensis Infection by Inducting Regulatory T Cells in an IDO-Dependent Manner.

Plasmacytoid dendritic cells (pDCs), considered critical for immunity against viruses, were recently associated with defense mechanisms against fungal infections. However, the immunomodulatory function of pDCs in pulmonary paracoccidiodomycosis (PCM), an endemic fungal infection of Latin America, has been poorly defined. Here, we investigated the role of pDCs in the pathogenesis of PCM caused by the infection of 129Sv mice with 1 x 106 P. brasiliensis-yeasts. In vitro experiments showed that P. brasiliensis infection induces the maturation of pDCs and elevated synthesis of TNF-α and IFN-ß. The in vivo infection caused a significant influx of pDCs to the lungs and increased levels of pulmonary type I IFN. Depletion of pDCs by a specific monoclonal antibody resulted in a less severe infection, reduced tissue pathology and increased survival time of infected mice. An increased influx of macrophages and neutrophils and elevated presence of CD4+ and CD8+ T lymphocytes expressing IFN-γ and IL-17 in the lungs of pDC-depleted mice were also observed. These findings were concomitant with decreased frequency of Treg cells and reduced levels of immunoregulatory cytokines such as IL-10, TGF-ß, IL-27 and IL-35. Importantly, P. brasilienis infection increased the numbers of pulmonary pDCs expressing indoleamine 2,3-dioxygenase-1 (IDO), an enzyme with immunoregulatory properties, that were reduced following pDC depletion. In agreement, an increased immunogenic activity of infected pDCs was observed when IDO-deficient or IDO-inhibited pDCs were employed in co-cultures with lymphocytes Altogether, our results suggest that in pulmonary PCM pDCs exert a tolerogenic function by an IDO-mediated mechanism that increases Treg activity.

Role of P2 Receptors as Modulators of Rat Eosinophil Recruitment in Allergic Inflammation.

ATP and other nucleotides are released from cells through regulated pathways or following the loss of plasma membrane integrity. Once outside the cell, these compounds can activate P2 receptors: P2X ionotropic receptors and G protein-coupled P2Y receptors. Eosinophils represent major effector cells in the allergic inflammatory response and they are, in fact, associated with several physiological and pathological processes. Here we investigate the expression of P2 receptors and roles of those receptors in murine eosinophils. In this context, our first step was to investigate the expression and functionality of the P2X receptors by patch clamping, our results showed a potency ranking order of ATP>ATPγS> 2meSATP> ADP> αßmeATP> ßγmeATP>BzATP> UTP> UDP>cAMP. This data suggest the presence of P2X1, P2X2 and P2X7. Next we evaluate by microfluorimetry the expression of P2Y receptors, our results based in the ranking order of potency (UTP>ATPγS> ATP > UDP> ADP >2meSATP > αßmeATP) suggests the presence of P2Y2, P2Y4, P2Y6 and P2Y11. Moreover, we confirmed our findings by immunofluorescence assays. We also did chemotaxis assays to verify whether nucleotides could induce migration. After 1 or 2 hours of incubation, ATP increased migration of eosinophils, as well as ATPγS, a less hydrolysable analogue of ATP, while suramin a P2 blocker abolished migration. In keeping with this idea, we tested whether these receptors are implicated in the migration of eosinophils to an inflammation site in vivo, using a model of rat allergic pleurisy. In fact, migration of eosinophils has increased when ATP or ATPγS were applied in the pleural cavity, and once more suramin blocked this effect. We have demonstrated that rat eosinophils express P2X and P2Y receptors. In addition, the activation of P2 receptors can increase migration of eosinophils in vitro and in vivo, an effect blocked by suramin.

IFN-γ-Dependent Recruitment of CD4(+) T Cells and Macrophages Contributes to Pathogenesis During Leishmania amazonensis Infection.

Interferon gamma (IFN-γ) is a key factor in the protection of hosts against intracellular parasites. This cytokine induces parasite killing through nitric oxide and reactive oxygen species production by phagocytes. Surprisingly, during Leishmania amazonensis infection, IFN-γ plays controversial roles. During in vitro infections, IFN-γ induces the proliferation of the amastigote forms of L. amazonensis. However, this cytokine is not essential at the beginning of an in vivo infection. It is not clear why IFN-γ does not mediate protection during the early stages of infection. Thus, the aim of our study was to investigate the role of IFN-γ during L. amazonensis infection. We infected IFN-γ(-/-) mice in the footpad and followed the development of leishmaniasis in these mice compared with that in WT mice. CD4(+) T lymphocytes and macrophages migrated earlier to the site of infection in the WT mice, and the earlier migration of these 2 cell types was associated with lesion development and parasite growth, respectively. These differences in the infiltrate populations were explained by the increased expression of chemokines in the lesions of the WT mice. Thus, we propose that IFN-γ plays a dual role during L. amazonensis infection; it is an important inducer of effector mechanisms, particularly through inducible nitric oxide synthase expression, and conversely, it is a mediator of inflammation and pathogenesis through the induction of the expression of chemokines. Our data provided evidence for a pathogenic effect of IFN-γ production during leishmaniasis that was previously unknown.

scFv from Antibody That Mimics gp43 Modulates the Cellular and Humoral Immune Responses during Experimental Paracoccidioidomycosis.

Paracoccidioidomycosis (PCM), caused by Paracoccidioides species is a prevalent systemic and progressive mycosis that occurs in Latin America. It is caused by Paracoccidioides species. Immunization with dendritic cells transfected with a plasmid encoding the scFv (pMAC/PS-scFv) that mimics the main antigen of P. brasiliensis (gp43) confers protection in experimental PCM. DCs link innate and adaptive immunity by recognizing invading pathogens and selecting the type of effector T cell to mediate the immune response. Here, we showed that DC-pMAC/PS-scFv induces the activation of CD4+ and CD8+ T cells. Moreover, our results demonstrated that BALB/c mice infected with P. brasiliensis and treated with DC-pMAC/PS-scFv showed the induction of specific IgG production against gp43 and IFN-γ, IL-12 and IL-4 cytokines. Analysis of regional lymph nodes revealed increases in the expression of clec7a, myd88, tlr2, gata3 and tbx21, which are involved in the immune response. Taken together, our results indicate that the scFv modulates the humoral and cellular immune responses and presents epitopes to CD4+ and CD8+ T cells.

Immunomodulatory effects mediated by serotonin.

Serotonin (5-HT) induces concentration-dependent metabolic effects in diverse cell types, including neurons, entherochromaffin cells, adipocytes, pancreatic beta-cells, fibroblasts, smooth muscle cells, epithelial cells, and leukocytes. Three classes of genes regulating 5-HT function are constitutively expressed or induced in these cells: (a) membrane proteins that regulate the response to 5-HT, such as SERT, 5HTR-GPCR, and the 5HT3-ion channels; (b) downstream signaling transduction proteins; and (c) enzymes controlling 5-HT metabolism, such as IDO and MAO, which can generate biologically active catabolites, including melatonin, kynurenines, and kynurenamines. This review covers the clinical and experimental mechanisms involved in 5-HT-induced immunomodulation. These mechanisms are cell-specific and depend on the expression of serotonergic components in immune cells. Consequently, 5-HT can modulate several immunological events, such as chemotaxis, leukocyte activation, proliferation, cytokine secretion, anergy, and apoptosis. The effects of 5-HT on immune cells may be relevant in the clinical outcome of pathologies with an inflammatory component. Major depression, fibromyalgia, Alzheimer disease, psoriasis, arthritis, allergies, and asthma are all associated with changes in the serotonergic system associated with leukocytes. Thus, pharmacological regulation of the serotonergic system may modulate immune function and provide therapeutic alternatives for these diseases.

Neutrophil migration in the activation of the innate immune response to different Flavobacterium psychrophilum vaccines in zebrafish (Danio rerio).

Flavobacterium psychrophilum is a Gram-negative bacterium, responsible for the bacterial cold-water disease and the rainbow trout fry syndrome in freshwater salmonid fish. At present, there is only one commercial vaccine in Chile, made with two Chilean F. psychrophilum isolates and another licensed in Europe. The present study analyzed neutrophil migration, as a marker of innate immune activation, in zebrafish (Danio rerio) in response to different F. psychrophilum bath vaccines, which is the first step in evaluating vaccine effectiveness and efficiency in fish. Results indicated that bacterins of the LM-02-Fp isolate were more immunogenic than those from the LM-13-Fp isolate. However, no differences were observed between the same bacteria inactivated by either formaldehyde or heat. Importantly, the same vaccine formulation without an adjuvant only triggered a mild neutrophil migration compared to the complete vaccine. Observations also found that, after a year of storage at 4°C, the activation of the innate immune system by the different vaccines was considerably decreased. Finally, new vaccine formulations prepared with heat and formaldehyde inactivated LM-02-Fp were significantly more efficient than the available commercial vaccine in regard to stimulating the innate immune system.

Cannabidiol improves lung function and inflammation in mice submitted to LPS-induced acute lung injury.

We have previously shown that the prophylactic treatment with cannabidiol (CBD) reduces inflammation in a model of acute lung injury (ALI). In this work we analyzed the effects of the therapeutic treatment with CBD in mice subjected to the model of lipopolysaccharide (LPS)-induced ALI on pulmonary mechanics and inflammation. CBD (20 and 80 mg/kg) was administered (i.p.) to mice 6 h after LPS-induced lung inflammation. One day (24 h) after the induction of inflammation the assessment of pulmonary mechanics and inflammation were analyzed. The results show that CBD decreased total lung resistance and elastance, leukocyte migration into the lungs, myeloperoxidase activity in the lung tissue, protein concentration and production of pro-inflammatory cytokines (TNF and IL-6) and chemokines (MCP-1 and MIP-2) in the bronchoalveolar lavage supernatant. Thus, we conclude that CBD administered therapeutically, i.e. during an ongoing inflammatory process, has a potent anti-inflammatory effect and also improves the lung function in mice submitted to LPS-induced ALI. Therefore the present and previous data suggest that in the future cannabidiol might become a useful therapeutic tool for the attenuation and treatment of inflammatory lung diseases.

Restoring host-microbe homeostasis via selective chemoattraction of Tregs.

The disruption of host-microbe homeostasis at the site of periodontal disease is considered a key factor for disease initiation and progress. While the downstream mechanisms responsible for the tissue damage per se are relatively well-known (involving various patterns of immune response operating toward periodontal tissue destruction), we are only beginning to understand the complexity of host-microbe interactions in the periodontal environment. Unfortunately, most of the research has been focused on the disruption of host-microbe homeostasis instead of focusing on the factors responsible for maintaining homeostasis. In this context, regulatory T-cells (Tregs) comprise a CD4+FOXp3 +T-cell subset with a unique ability to regulate other leukocyte functions to avoid excessive immune activation and its pathological consequences. Tregs act as critical determinants of host-microbe homeostasis, as well as determinants of a balanced host response after the disruption of host-microbe homeostasis by pathogens. In periodontitis, Tregs play a protective role, with their natural recruitment being responsible for conversion of active into inactive lesions. With controlled-release technology, it is now possible to achieve a selective chemoattraction of Tregs to periodontal tissues, attenuating experimental periodontitis evolution due to the local control of inflammatory immune response and the generation of a pro-reparative environment.

Warifteine, an alkaloid purified from Cissampelos sympodialis, inhibits neutrophil migration in vitro and in vivo.

Cissampelos sympodialis Eichl is a plant from the Northeast and Southeast of Brazil. Its root infusion is popularly used for treatment of inflammatory and allergic diseases. We investigated whether warifteine, its main alkaloid, would have anti-inflammatory effect due to a blockage of neutrophil function. In vivo warifteine treatment inhibited casein-induced neutrophil migration to the peritoneal cavity but did not inhibit neutrophil mobilization from the bone marrow. Analysis of the direct effect of warifteine upon neutrophil adherence and migration in vitro demonstrated that the alkaloid decreased cell adhesion to P and E-selectin-transfected cells. In addition, fLMP-induced neutrophil migration in a transwell system was blocked by warifteine; this effect was mimicked by cAMP mimetic/inducing substances, and warifteine increased intracellular cAMP levels in neutrophils. The production of DNA extracellular traps (NETs) was also blocked by warifteine but there was no alteration on PMA-induced oxidative burst or LPS-stimulated TNF α secretion. Taken together, our data indicate that the alkaloid warifteine is a potent anti-inflammatory substance and that it has an effect on neutrophil migration through a decrease in both cell adhesion and migration.

Hydroxycarbamide reduces eosinophil adhesion and degranulation in sickle cell anaemia patients.

Inflammation, leucocyte and red cell adhesion to the endothelium contribute to the pathogenesis of sickle cell anaemia. Neutrophils appear to be important for vaso-occlusion, however, eosinophils may also participate in this phenomenon. The role of eosinophils in the pathophysiology of sickle cell anaemia (SCA) and the effect of hydroxycarbamide (HC) therapy on the functional properties of these cells are not understood. Patients with SCA and those on HC therapy (SCAHC) were included in the study. SCAHC individuals presented significantly lower absolute numbers of eosinophils than SCA. Furthermore, SCAHC eosinophils demonstrated significantly lower adhesive properties, compared to SCA eosinophils. SCA and SCAHC eosinophils presented greater spontaneous migration when compared with control eosinophils. Baseline eosinophil peroxidase and reactive oxygen species release was higher for SCA individuals than for control individuals, as were plasma levels of eosinophil derived neurotoxin. SCAHC eosinophil degranulation was lower than that of SCA eosinophil degranulation. Eotaxin-1 and RANTES levels were higher in the plasma of SCA and SCAHC individuals, when compared with controls. These data suggest that eosinophils exist in an activated state in SCA and indicate that these cells play a role in the vaso-occlusive process. The exact mechanism by which HC may alter SCA eosinophil properties is not clear.

Hypertonic saline solution drives neutrophil from bystander organ to infectious site in polymicrobial sepsis: a cecal ligation and puncture model.

The effects of hypertonic saline solution (HSS) have been shown in several animal models of ischemia and shock. Literature has shown potential benefits of HSS modulating inflammatory response after sepsis in an animal model. We studied the HSS effects in sepsis through cecal ligation and puncture (CLP) in Balb-C mice. Groups studied: 1- CLP without treatment (CLP-C); 2- CLP treated with normal saline solution NaCl 0.9% - 34 ml/Kg (CLP-S); 3- CLP treated with HSS NaCl 7.5% - 4 ml/Kg (CLP-H); and 4- group (Basal) without no CLP or treatment. Volume infusion was always applied 30 min after CLP. Lung and peritoneal lavage were harvested after 6h and 24h of CLP to analyze cytokines amount, oxide nitric, lipid peroxidation and neutrophil infiltration. Neutrophil infiltration, ICAM-1, CXCR-2, and CXCL-1 in lung were reduced by HSS (CLP-H) compared to CLP-C or CLP-S. Neutrophil in peritoneal lavage was increased in 24h with HSS (CLP-H) compared to CLP and CLP-S. Peritoneal CXCR-2 was increased in CLP-C and CLP-S but presented a lower increase with HSS (CLP-H) after 6 hours. GRK-2 presented difference among the groups at 24 h, showing a profile similar to neutrophil infiltration. Pro-inflammatory cytokines (TNF-α and IL-6) were reduced by HSS treatment; CLP-S increased TNF-α. IL-10 was increased in lung tissue by the HSS treatment. The oxidative stress (TBARS and nitric oxide biochemistry markers) was reduced with HSS. Animal survival was 33.3% in CLP-C group, 46.6% in CLP-S group and 60% in the CLP-H group after the sixth day. The HSS protects the animal against sepsis. Our results suggest that the volume replacement modulate pro and anti-inflammatory mediators of an inflammatory response, but HSS presented a more effective and potent effect.

Effect of olmesartan on leukocyte recruitment in choroid-sclera complex in hypercholesterolemia model.

PURPOSE: Demonstrate that the blockade of angiotensin II AT-1 receptors, through the systemic administration of olmesartan, can reduce the MCP-1 expression and the resulting macrophage accumulation in the choroid and sclera of hypercholesterolemic rabbits. METHODS: Thirty-two New Zealand rabbits were divided into 3 groups: group I (GI) was fed a standard rabbit diet; group II (GII) was fed a hypercholesterolemic diet; and group III (GIII) was fed a hypercholesterolemic diet plus olmesartan. Serum levels of total cholesterol, triglyceride, HDL cholesterol, and blood glucose were determined in fasting rabbits at the beginning of the experiment and on the day of euthanasia. The choroid and sclera were submitted to morphometric analysis as well as immunohistochemical analysis with MCP-1 and RAM-11 (macrophage marker) antibodies. RESULTS: No abnormality was detected in GI. Group II and III had significant increases in choroid-sclera complex thicknesses when compared with group I (P<0.001). GII showed a significant increase in immunoreactivity for MCP-1 in relation to GI (P=0.001) and GIII (P=0.004). GII showed a significant increase in immunoreactivity for RAM-11 of the choroid-sclera complex in relation to GI (P<0.001) and GIII (P=0.034). A significant increase in immunoreactivity for RAM-11 was observed in GIII in relation to GI (P=0.008). CONCLUSION: Olmesartan reduced the MCP-1 expression and the resultant macrophage accumulation in the choroid-sclera complex of hypercholesterolemic rabbits.

Effects of MK-801 and amphetamine treatments on allergic lung inflammatory response in mice.

Glutamate acts as a neurotransmitter within the Central Nervous System (CNS) and modifies immune cell activity. In lymphocytes, NMDA glutamate receptors regulate intracellular calcium, the production of reactive oxygen species and cytokine synthesis. MK-801, a NMDA receptor open-channel blocker, inhibits calcium entry into mast cells, thereby preventing mast cell degranulation. Several lines of evidence have shown the involvement of NMDA glutamate receptors in amphetamine (AMPH)-induced effects. AMPH treatment has been reported to modify allergic lung inflammation. This study evaluated the effects of MK-801 (0.25mg/kg) and AMPH (2.0mg/kg), given alone or in combination, on allergic lung inflammation in mice and the possible involvement of NMDA receptors in this process. In OVA-sensitized and challenged mice, AMPH and MK-801 given alone decreased cellular migration into the lung, reduced IL-13 and IL10 levels in BAL supernatant, reduced ICAM-1 and L-selectin expression in granulocytes in the BAL and decreased mast cell degranulation. AMPH treatment also decreased IL-5 levels. When both drugs were administered, treatment with MK-801 reversed the decrease in the number of eosinophils and neutrophils induced by AMPH in the BAL of OVA-sensitized and challenged mice as well as the effects on the expression of L-selectin and ICAM-1 in granulocytes, the IL-10, IL-5 and IL-13 levels in BAL supernatants and increased mast cell degranulation. At the same time, treatment with MK-801, AMPH or with MK-801+AMPH increased corticosterone serum levels in allergic mice. These results are discussed in light of possible indirect effects of AMPH and MK-801 via endocrine outflow from the CNS (i.e., HPA-axis activity) to the periphery and/or as a consequence of the direct action of these drugs on immune cell activity, with emphasis given to mast cell participation in the allergic lung response of mice.