Stress Conditions Affect the Immunomodulatory Potential of Candida albicans Extracellular Vesicles and Their Impact on Cytokine Release by THP-1 Human Macrophages.

Human immune cells possess the ability to react complexly and effectively after contact with microbial virulence factors, including those transported in cell-derived structures of nanometer sizes termed extracellular vesicles (EVs). EVs are produced by organisms of all kingdoms, including fungi pathogenic to humans. In this work, the immunomodulatory properties of EVs produced under oxidative stress conditions or at host concentrations of CO2 by the fungal pathogen Candida albicans were investigated. The interaction of EVs with human pro-monocytes of the U-937 cell line was established, and the most notable effect was attributed to oxidative stress-related EVs. The immunomodulatory potential of tested EVs against human THP-1 macrophages was verified using cytotoxicity assay, ROS-production assay, and the measurement of cytokine production. All fungal EVs tested did not show a significant cytotoxic effect on THP-1 cells, although a slight pro-oxidative impact was indicated for EVs released by C. albicans cells grown under oxidative stress. Furthermore, for all tested types of EVs, the pro-inflammatory properties related to increased IL-8 and TNF-α production and decreased IL-10 secretion were demonstrated, with the most significant effect observed for EVs released under oxidative stress conditions.

A review: zinc oxide nanoparticles - friends or enemies?

Modern nanotechnology allows obtaining zinc oxide nanomaterials with unique properties that let its use in a wide range of commercial applications. Direct contact with these particles as well as their release into the environment is almost inevitable. This review aims to consider whether the toxicity of zinc oxide nanoparticles found in numerous test models is a real threat to humans and plants. Emerging reports indicated both the risks and benefits associated with the use of zinc oxide nanoparticles in a manner dependent on the concentration and a method of synthesis, as well as the tested object. The amounts needed to achieve the antibacterial activity of ZnO-NPs, and the reported amounts of these nanoparticles in consumer products are sufficient to have a negative impact on living organisms. The most sensitive to their action are human cells, and the mechanism of cytotoxicity is mainly associated with the formation of oxidative stress caused by the action of zinc ions. ZnO-NPs in small concentration can have positive affect to plants, but it poses a threat to more sensitive ones.

Design cytotoxicity: The effect of silver nanoparticles stabilized by selected antioxidants on melanoma cells.

Silver nanoparticles (AgNPs) prepared and stabilized by diverse biologically active substances seem to be especially useful in diverse biological and medical applications. The combination of AgNPs with bioactive substances, such as antioxidants, can lead to the development of new systems of desired anticancer properties. In this research, AgNPs were prepared with the use of diverse antioxidant combinations including gallic acid (GA), (-)-epicatechin-3-gallate (EGCG), and caffeine (CAF). The insightful physicochemical characteristic revealed that each type of AgNPs exhibited spherical shape, comparable size distribution and negative surface charge. Surface-enhanced Raman spectroscopy (SERS) delivered the information about the chemistry of AgNP stabilizing layers, which turned out to be a crucial factor tuning toxicity of AgNPs toward murine B16 melanoma cells (B16-F0) and human skin melanoma (COLO 679) cells. EGCGAgNPs were the most cytotoxic among all the investigated AgNPs. They strongly reduced the activity of mitochondria, damaged cell membrane integrity, and penetrated inside the cells causing DNA damage. In turn, the toxicity of GAAgNPs strongly manifested via the induction of oxidative stress in the cells. It was found that CAFGAAgNPs exhibited the lowest toxicity toward the melanoma cells, which proved that a proper combination of antioxidants enable to prepare AgNPs of differentiated toxicity. It was established that human skin melanoma cells were significantly more sensitive to AgNPs than the murine melanoma cells.

The cell membrane as the barrier in the defense against nanoxenobiotics: Zinc oxide nanoparticles interactions with native and model membrane of melanoma cells.

Currently, we are dealing with ever-increasing pollution of the environment with metal and metal oxide nanoparticles. One type of these, zinc oxide nanoparticles (ZnO-NPs), are increasingly used in areas such as cosmetology, electrical engineering, medicine, and even in the food and textile industries. As a consequence, ZnO-NPs may enter the human body in many ways. Their influence on the body is still not clear. Here, we define the mechanism of the initial toxicity of ZnO-NPs to cells based on interaction with the lipid part of the native and model cell membrane. The selected cell lines react differently to contact with nanoparticles. We found a disruption of the native membranes of B16-F0 cells and to a lesser extent of COLO 679. In turn, the membrane of COLO 679 cells was more peroxidated, and cell viability was much lower. A model of the lipid part of the membrane was created for B16-F0 cells and compared with previously published studies on immune cells. On the basis of physicochemical parameters obtained for individual lipids and a mix representing the native membrane of the tested cells, we concluded that exposure to nanoparticles resulted in a change within the model membranes (specifically with the polar parts of lipids). The greatest interaction has been noticed between ZnO-NPs and zwitterionic phospholipids (PC and PE), cholesterol, and negatively charged phosphatidylglycerol. Assessing the interactions between the membrane and nanoparticles will help to better understand the first steps of its toxicity mechanism.

Advantageous/Unfavorable Effect of Quercetin on the Membranes of SK-N-SH Neuroblastoma Cells.

Quercetin is a polyphenolic compound, the effects of which raise scientists' doubts. The results of many experiments show that it has anticancer, antiinflammatory, and antioxidant properties, while other studies indicate its pro-oxidative and cytotoxic action. This compound can react with reactive oxygen species, and due to its chemical properties, it can be found in the hydrophobic-hydrophilic area of cells. These features of quercetin indicate that its action in cells will be associated with the modification of membranes and its participation in maintaining the redox balance. Therefore, this study distinguishes these two mechanisms and determines whether they are important for cell function. We check: (1) Whether the selected concentrations of quercetin are cytotoxic and destructive for SK-N-SH cell membranes (MTT, LDH, MDA tests) in situations with and without the applied oxidative stress; (2) what is the level of changes in the structural/mechanical properties of the lipid part of the membranes of these cells due to the presence of polyphenol molecules; and (3) whether the antioxidative action of quercetin protects the membrane against its modification. Our results show that changes in the stiffness/elasticity of the lipid part of the membrane constitute the decisive mechanism of action of quercetin, potentially influencing cellular processes whose initial stages are associated with membranes (e.g., reception of signals from the environment, transport).

Effects of 3FTx Protein Fraction from Naja ashei Venom on the Model and Native Membranes: Recognition and Implications for the Mechanisms of Toxicity.

Three-finger toxins are naturally occurring proteins in Elapidae snake venoms. Nowadays, they are gaining popularity because of their therapeutic potential. On the other hand, these proteins may cause undesirable reactions inside the body's cells. A full assessment of the safety of Naja ashei venom components for human cell application is still unknown. The aim of the study was to determine the effect of the exogenous application of three-finger toxins on the cells of monocytes (U-937) and promyelocytes (HL-60), with particular emphasis on the modification of their membranes under the influence of various doses of 3FTx protein fraction (0-120 ng/mL). The fraction exhibiting the highest proportion of 3FTx proteins after size exclusion chromatography (SEC) separation was used in the experiments. The structural response of cell membranes was described on the basis of single-component and multi-component Langmuir monolayers that mimicked the native membranes. The results show that the mechanism of protein-lipid interactions depends on both the presence of lipid polar parts (especially zwitterionic type of lipids) and the degree of membrane saturation (the greatest-for unsaturated lipids). The biochemical indicators reflecting the tested cells (MDA, LDH, cell survival, induction of inflammation, LD50) proved the results that were obtained for the model.

Antioxidant-modulated cytotoxicity of silver nanoparticles.

The properties of silver nanoparticles (AgNPs) synthesized using compounds exhibiting biological activity seem to constitute an interesting issue worthy of examination. In these studies, two types of AgNPs were synthesized by a chemical reduction method using well-known antioxidants: gallic acid (GA) and ascorbic acid (AA). Transmission electron microscopy (TEM) and atomic force microscopy (AFM) revealed that the AgNPs were spherical. The average size was equal to 26 ± 6 nm and 20 ± 7 nm in the case of ascorbic acid-silver nanoparticles (AAgNPs) and gallic acid-silver nanoparticles (GAAgNPs), respectively. Surface-enhanced Raman spectroscopy (SERS) confirmed that the AgNPs were not stabilized by pure forms of applied antioxidants. Changes in mitochondrial activity and secretion of inflammatory and apoptosis mediators after the exposure of human promyelocytic (HL-60) and histiocytic lymphoma (U-937) cells to the AgNPs were studied to determine the impact of stabilizing layers on nanoparticle toxicity. The GAAgNPs were found to be more toxic for the cells than the AAgNPs. Their toxicity was manifested by a strong reduction in mitochondrial activity and induction of the secretion of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and caspase-9. The addition of pure antioxidants to the AgNP suspensions was found to influence their toxicity. There was a significant positive effect in the case of the mixture of AA with AAgNPs and GA with GAAgNPs. The results obtained suggest that the presence of stabilizing agents adsorbed on the surface of AgNPs is the main factor in shaping their toxicity. Nevertheless, the toxic effect can be also tuned by the introduction of free antioxidant molecules to the AgNP suspensions.

Cytotoxicity studies of protein-stabilized fluorescent gold nanoclusters on human lymphocytes.

In this work, we clearly focus on the comparative cytotoxicity investigations of several protein-stabilized gold nanoclusters (Au NCs) towards lymphocytes B (COLO-720 L) and lymphocytes T (HUT-78) cells. For synthesis, the one-pot template-assisted method was carried out using lysozyme (LYZ), human (HSA) and bovine (BSA) serum albumins, and gamma globulin (γG) as stabilizing agents. Regardless of the type of proteins, all synthesized Au NCs possess intense red emission (λem ∼ 650 nm) and have similar size of a metal core (ca. 1.4 nm) with negative surface charge at pH = 7.4. During the treatment of cells with clusters, changes in mitochondrial activity, membrane integrity, secretion of inflammatory and apoptosis mediators of the lymphocytes were studied to determine the potential effect of protein layers on the toxicity of clusters. It was found that γG-Au NCs induced the highest disorders in mitochondrial activity, but the influence of other NCs on the cell viability was minor. Besides, all Au NCs caused oxidative stress by peroxidation of membrane lipids. The secretion of malonic dialdehyde (MDA) was enhanced by LYZ- and γG-Au NCs. Apart from LYZ-Au NCs, the clusters did not exhibit strong proinflammatory and apoptotic properties. The enhanced secretion of tumor necrosis factor (TNF-α) by lymphocytes B, in comparison to control, was independent of the clusters type. Despite the lack of significant influence of the Au NCs on the viability of the lymphocytes, they can stimulate undesirable cellular processes, which clearly depends on the stabilizing proteins.

Cytotoxicity of zinc oxide nanoparticles to innate and adaptive human immune cells.

Zinc oxide nanoparticles (ZnO-NPs) are widely used in almost every area of life. Therefore, exposure to them is unavoidable, which makes it necessary to assess their safety for humans. This paper aims to determine toxicity of ZnO-NPs of two diameters toward human immune cells responsible for: innate response (U-937 and HL-60) and acquired response (COLO-720L and HUT-78). Mitochondrial activity, membrane integrity, degree of cellular lipid oxidation, induction of inflammation, and activation of the apoptosis pathway were evaluated to determine differences in cellular response to the tested nanoparticles. ZnO-NPs with a diameter of 100 and 130 nm cause significant cell mortality at 25 and 12 mg/L, respectively. Mitochondrial damage leads to the activation of the caspase cascade and, consequently, to cell apoptosis. ZnO-NPs also cause peroxidation of membrane lipids. Due to the photocatalytic properties of ZnO-NPs, the effect of ultraviolet (UV) irradiation on the degree of their toxicity was also investigated. However, UV irradiation enhances the toxic effect of nanoparticles mainly by weakening the cell's defense capabilities. ZnO-NPs are cytotoxic to human immune system, and they may cause both long-term and short-term negative effects.

Structural and biochemical modifications of model and native membranes of human immune cells in response to the action of zinc oxide nanoparticles.

The development of nanotechnology has led to the increased production of zinc oxide nanoparticles (ZnO-NPs) and their application in a wide variety of everyday products. It creates the need for a full assessment of their safety for humans. The aim of the study was to assess the toxic effects of ZnO-NPs on model human cells of the immune system: U-937, HL-60, HUT-78, and COLO-720L. Particular attention was paid to the direct interaction of the nanoparticles with membrane lipids and the role of zinc ions in the mechanism of their toxicity. Cell viability, lipid peroxidation, cell membrane integrity, and the amount of zinc ions released from nanoparticles were tested. Disruption in cell metabolism was noted for ZnO-NPs concentrations from 6.25 mg/L. Contact with ZnO-NPs caused lipid peroxidation of all cells and correlated with membrane disruption of HL-60, HUT-78, and COLO-720L cells. Model monolayers (Langmuir technique) were used to assess the interaction of the nanoparticles with the studied lipids. Physicochemical parameters, such as the area per molecule at maximal layer compression, the pressure at which the monolayer collapses, and the static compression modulus, were calculated. The models of the HL-60 and U-937 cell membranes under ZnO-NPs treatment reacted in a different way. It has also been shown that Zn2+ are not the main causative factor of ZnO-NPs toxicity. Investigating the early stages of mechanism of nanoparticles toxicity will allow for a more complete risk assessment and development of methods for a safer synthesis of engineering nanomaterials.

Toxicity of pesticides toward human immune cells U-937 and HL-60.

The industrialization of the agricultural sector has significantly increased the use of chemicals such as pesticides. Therefore, exposure to them is unavoidable, which makes it necessary to assess their safety for humans at actual exposure doses. This paper aims to determine toxicity of three types of pesticides toward human immune cells (HL-60 and U-937): glyphosate (GLY), deltamethrin (DEL), and chlorothalonil (CHL). Cell viability, membrane integrity, inflammation induction, and antioxidant activity were evaluated to determine differences in cellular response to the tested plant protection agents. In experimental models, all tested substances caused increased mortality of cells after only 24 h. Cell membrane damage was recorded under DEL and CHL influences. The largest disintegration of the cell membrane was due to the action of 100 µg/mL DEL for U-937 and CHL at 1 µg/mL for HL-60. GLY at a concentration of 3,600 µg/mL caused significant peroxidation of U-937 cells' lipids. CHL-induced inflammation in both types of cells tested. DEL and GLY also induced antioxidant activity in cells. These results lead to the conclusion that the tested pesticides act cytotoxically to the cells of the human immune system in doses to which both farmers and consumers are exposed.

Effect of ZnO, TiO2, Al2O3 and ZrO2 nanoparticles on wheat callus cells.

Effect of metal oxide nanoparticles on calli of two wheat varieties: Parabola (stress tolerant) and Raweta (sensitive) was studied. ZnO induced 10% larger membrane damage in Raweta calli. TiO2, Al2O3, and ZrO2 caused nearly 30% greater lactate dehydrogenase leakage for Raweta compared to Parabola. UV-irradiation of samples containing ZnO particles intensified this effect. Membrane lipid peroxidation in ZnO treated Raweta calli was twice as high as in Parabola and further increased after UV-irradiation. TiO2, Al2O3, and ZrO2 nanoparticles caused a 4-fold increase in malondialdehyde concentration in Raweta calli in comparison to Parabola calli. The nanoparticles studied damaged the cellular defense system by inactivating the antioxidative enzymes.

Highly efficient microwave synthesis of rhodanine and 2-thiohydantoin derivatives and determination of relationships between their chemical structures and antibacterial activity.

Here we report studies on the synthesis of 12 new heterocyclic derivatives that differ in three structural motifs and the simultaneous evaluation of the impact of these three variables on the biological properties. The examined compounds are based on rhodanine and 2-thiohydantoin cores equipped with hydrogen or carboxymethyl substituents at the N-3 position and linked to a triphenylamine moiety through 1,4-phenylene, 1,4-naphthalenylene and 1,9-anthracenylene spacers at the C-5 position of the heterocycles. All the compounds were synthesized very quickly, selectively and in high yields according to the developed microwave-assisted Knoevenagel condensation protocol, and they were characterized thoroughly with NMR, FT-IR and ESI-HRMS techniques. The derivatives were tested for their activity against selected strains of Gram-positive and Gram-negative bacteria and yeast. Two compounds showed good activity against Gram-positive bacteria, and all of them showed low cytotoxicity against three cell lines of the human immune system. Based on membrane permeability assays it was demonstrated that the active compounds do not penetrate the cell membrane, and thus they must act on the bacterial cell surface. Finally, we proved that the evaluated structure modifications had a synergistic effect and the simultaneous presence of a 1,4-phenylene spacer and carboxymethyl group at N-3 caused the highest boost in antimicrobial activity.

Exposure of human lymphoma cells (U-937) to the action of a single mycotoxin as well as in mixtures with the potential protectors 24-epibrassinolide and selenium ions.

The progressive contamination of food products by mycotoxins such as zearalenone (ZEN) has prompted the search for specific substances that can act as protectors against an accumulation of these toxins. This paper discusses the effect of selenium ions and 24-epibrassinolide (EBR) as non-organic and organic compounds that preserve human lymphoblastic cells U-937 under ZEN stressogenic conditions. Based on measurements of cell viability and a DAPI test, concentrations of ZEN at 30 µmol/l, Se at 2.5 µmol/l and EBR at 0.005 µmol/l were selected. The addition of both protectors resulted in an increase in the viability of ZEN-treated cells by about 16%. This effect was connected with a decrease in lipid peroxidation (a decrease in the malonyldialdehyde content) and the generation of reactive oxygen species, which were determined by a cellular ROS/superoxide detection assay and the SOD activity. The Se protection was observed as the blocking of the all excess ROS, while the EBR action was mainly concentrated on something other than the superoxide radical itself. The experiments on the model lipid membranes that mimic the environment of U-937 cells confirmed the affect of ZEN on the structure and physicochemical properties of human membranes. Although the presence of both Se and EBR reduced the effect of ZEN by blocking its interaction with a membrane, the action of Se was more evident.

Physicochemical properties and cytotoxicity of cysteine-functionalized silver nanoparticles.

The preparation of stable cysteine-capped silver nanoparticles (AgNPs), via the reduction of silver ions with sodium borohydride and modification of formed nanoparticles by l-cysteine, was developed. The micrographs from transmission electron microscopy (TEM) revealed that the spherical AgNPs exhibited an average size equal to 22±4nm. Surface enhanced Raman spectroscopy (SERS) and inductively coupled plasma optical emission spectrometry (ICP-OES) confirmed a chemisorption of cysteine molecules on the AgNPs. Additionally, dynamic light scattering (DLS) measurements showed that the AgNPs were stable for ionic strength lower than 5×10-3molL-1 and at 6.8

Toxicity of silver nanoparticles towards tumoral human cell lines U-937 and HL-60.

The toxicity of three types of silver nanoparticles towards histiocytic lymphoma (U-937) and human promyelocytic cells (HL-60) was studied. The nanoparticles were synthesized in a chemical reduction method using sodium borohydride. Trisodium citrate and cysteamine hydrochloride were used to generate a negative and positive nanoparticle surface charge. The evaluation of cell viability, membrane integrity, antioxidant activity and the induction of inflammation were used to evaluate the difference in cellular response to the nanoparticle treatment. The results revealed that the cysteamine-stabilized (positively charged) nanoparticles (SBATE) were the least toxic although they exhibited a similar ion release profile as the unmodified (negatively charged) nanoparticles obtained using sodium borohydride (SBNM). Citrate-stabilized nanoparticles (SBTC) induced superoxide dismutase (SOD) activity in the HL-60 cells and total antioxidant activity in the U-937 cells despite their resistance to oxidative dissolution. The toxicity of SBNM nanoparticles was manifested in the disruption of membrane integrity, decrease in the mitochondrial functions of cells and the induction of inflammation. These findings allowed to conclude that mechanism of silver nanoparticle cytotoxicity is the combination of effects coming from the surface charge of nanoparticles, released silver ions and biological activity of stabilizing agent molecules.

Toxicological effects of three types of silver nanoparticles and their salt precursors acting on human U-937 and HL-60 cells.

The growing popularity of nanomaterials requires a systematic study of their effects on the human body. Silver nanoparticles (AgNPs), due to their antiseptic properties, are used in almost every area of life. The purpose of the study was to examine whether the precursor used for the synthesis of nanoparticles affects their bio-influence and modifies their impact on cells of the human immune system. To compare the effects of precursor silver salts (AgNO3, CH3COOAg and AgClO4) and corresponding nanoparticles (TAN TAA and TAC) cytotoxicity study was conducted on two cell lines U-937 and HL-60. For both cell lines, silver salts are more toxic than the corresponding nanoparticles. Cell viability after treatment with the two forms of silver (salt/particle) is dependent on silver dose and degree of cells differentiation. Addition of the silver salt of doses greater than 5 mg/L results in decreased cell viability by over 60%, whereas nanoparticles' addition reduces cell viability on average by 30%. On the basis of the determined LD50 values it can be stated that for the tested cells the most toxic are AgClO4 and TAC. Production of nitric oxide, which is a mediator of inflammation, is the greatest after treatment of the cells by TAC. Different interactions of studied nanoparticles with albumin has been found and it was shown that addition of albumin to the cells treated by nanoparticles reduces their toxic effects. Obtained by us highly purified, mono-disperse AgNPs exhibit diverse effects relative to the biological systems, depending on the precursor salt used.

Cytotoxic Activity of Highly Purified Silver Nanoparticles Sol Against Cells of Human Immune System.

The widespread use of silver nanoparticles (AgN) in the articles of common use justifies the need to investigate their effects on the human body. Nanosilver toxicity of highly purified, stable, and well-characterized Ag sol toward human immune cells at various differentiation stages has been studied. Human promyelocytic leukemia cells (HL-60) were differentiated to granulocytes using dimethyl sulfoxide and to macrophage-like cells by phorbol ester. Human monocytic cells (U-937) were differentiated to monocytes and macrophages by phorbol ester. In the presence of AgN, different changes of their survival time were observed depending on cell differentiation. Differentiated cells showed a significantly higher resistance than the non-differentiated cells, depending on the contact time and AgN concentration. In the presence of AgN at concentration of 25 mg/l, fraction of non-differentiated cells alive after 24 h was equal to 45 %; for granulocytes this number increased to 75 % and for macrophages to 65 %. The presence of AgN increases the levels of intracellular antioxidant -glutathione and of nitric oxide - one of inflammation mediators. By checking the effect caused by effluent obtained from AgN sol purification resulting at AgN sol purification, it was proved that cytotoxity should be attributed to the action of silver particles themselves.

Protective effect of ascorbic acid after single and repetitive administration of cadmium in Swiss mice.

The aim of the study was to delineate the protective effect of ascorbic acid with plausible mechanism after single and repetitive cadmium administration to Swiss mice. The effects of single high dose administration of CdCl(2) (6 mg/kg) or ascorbic acid (AsA) (50 mg/kg) and chronic (three times) administration of Cd at low dose (2 mg/kg) or AsA at same dose (50 mg/kg) were compared in Swiss albino mice. Changes of lipid peroxidation [determined by the malonyldialdehyde (MDA) concentration] were taken as a measure of the oxidative stress intensity. Lipid fatty acid's unsaturation related to the permeability of cell membranes was also examined. Mobilization of the immune system was determined by analyzing changes in antioxidant concentrations of AsA and glutathione (GSH), and by measuring the activation of antioxidant enzymes SOD, GPx and CAT. In addition, the level of free polyamines and variation in their proportions were examined. In conclusion, exposure to higher levels of cadmium will have more deleterious effects on the body rather than chronic exposure at lower levels with this toxic metal, while this study clearly demonstrated the protective effects of AsA in a mouse model.

Kinin generation from exogenous kininogens at the surface of retinoic acid-differentiated human neuroblastoma IMR-32 cells after stimulation with interferon-γ.

Bradykinin-related peptides, kinins, ubiquitously occur in the nervous system and together with other pro-inflammatory mediators contribute to pathological states of that tissue such as edema and chronic pain. In the current work we characterized the kinin-forming system of neuronal cells obtained by differentiation of human neuroblastoma cell line IMR-32 with retinoic acid. These cells were shown to concentrate exogenous kinin precursors, kininogens, on the surface, release kinins from kininogens and subsequently convert kinins to their des-Arg metabolites. Significantly higher amounts of kinins and des-Arg-kinins were produced after cell stimulation with interferon-γ, a potent pro-inflammatory mediator involved in many neurological disorders. The expression of the major tissue kininogenase (the human kallikrein 1) and the major cell membrane-bound kininase (the carboxypeptidase M) also increased after cell stimulation with interferon-γ, suggesting the involvement of these enzymes in the kinin production and degradation, respectively. Interferon-γ was also able to up-regulate the expression of two known subtypes of kinin receptors. On the protein level, the changes were only observed in the expression of the des-Arg-kinin-specific type 1 receptor which functions in the propagation of the inflammatory state. Taken together, these results suggest a novel way for local kinin and des-Arg-kinin generation in the nervous tissue during pathological states accompanied by interferon-γ release.