Chemical characterization and biological effect of exopolysaccharides synthesized by Antarctic yeasts Cystobasidium ongulense AL101 and Leucosporidium yakuticum AL102 on murine innate immune cells

The current study aimed to investigate exopolysaccharides (EPSs) produced by two Antarctic yeasts isolated from soil and penguin feathers samples collected on Livingston Island (Antarctica). The strains were identified as belonging to the species Leucosporidium yakuticum (LY) and Cystobasidium ongulense (CO) based on molecular genetic analysis. The EPS production was investigated using submerged cultivation. Different chemical, chromatographic, and spectral analyses were employed to characterize EPSs. LY accumulated 5.5 g/L biomass and 4.0 g/L EPS after 120 h of cultivation, while CO synthesized 2.1 g/L EPS at the end of cultivation, and the biomass amount reached 5.5 g/L. LY-EPS was characterized by a higher total carbohydrate content (80%) and a lower protein content (18%) by comparison with CO-EPS (62%, 30%). The LY-EPS mainly consisted of mannose (90 mol%), whereas CO-EPS had also glucose, galactose, and small amounts of uronic acids (8-5 mol%). Spectral analyses (FT-IR and 1D, 2D NMR) revealed that LY-EPS comprised a typical β-(1 → 4)-mannan. Branched (hetero)mannan, together with β/α-glucans constituted the majority of CO-EPS. Unlike LY-EPS, which had a high percentage of high molecular weight populations, CO-EPS displayed a large quantity of lower molecular weight fractions and a higher degree of heterogeneity. LY-EPS (100 ng/mL) elevated significantly interferon gamma (IFN-γ) production in splenic murine macrophages and natural killer (NK) cells. The results indicated that newly identified EPSs might affect IFN-γ signaling and in turn, might enhance anti-infectious responses. The data obtained also revealed the potential of EPSs and yeasts for practical application in biochemical engineering and biotechnology.

Human decidual gamma/delta T cells possess unique effector and TCR repertoire profiles during pregnancy

Human γδ T cells are enriched at the maternal-fetal interface (MFI, decidua basalis) showing a highly differentiated phenotype. However, their functional potential is not well-known and it is not clear whether this decidua-enrichment is associated with specific γδ T cell receptors (TCR) as is observed in mice. Here we addressed these open questions by investigating decidual γδ T cells during early and late gestation, in comparison with paired blood samples, with flow cytometry (cytotoxic mediators, cytokines) and TCR high-throughput sequencing. While decidual γδ T cells expressed less perforin than their counterparts in the blood, they expressed significant more granulysin during early pregnancy. Strikingly, this high granulysin expression was limited to early pregnancy, as it was reduced at term pregnancy. In contrast to this granulysin expression pattern, decidual γδ T cells produced reduced levels of IFNγ and TNFα (compared to paired blood) in early pregnancy that then increased by term pregnancy. TCR repertoire analysis indicated that human decidual γδ T cells are not generated early in life as in the mouse. Despite this, a specific enrichment of the Vγ2 chain in the decidua in early pregnancy was observed that disappeared later onwards, reflecting dynamic changes in the decidual γδ TCR repertoire during human gestation. In conclusion, our data indicate that decidual γδ T cells express a specific and dynamic pattern of cytotoxic mediators, Th1 cytokines and TCR repertoire suggesting an important role for these unconventional T cells in assuring a healthy pregnancy in human.

Induced Polyspecificity of Human Secretory Immunoglobulin A Antibodies: Is It Possible to Improve Their Ability to Bind Pathogens?

INTRODUCTION

As has been shown previously, various protein-modifying agents can change the antigen-binding properties of immunoglobulins. However, induced polyspecificity of human secretory immunoglobulin A (sIgA) has not been previously characterized in detail.

METHODS

In the present study, human secretory immunoglobulin A (IgA) was exposed to buffers with acidic pH, to free heme, or to pro-oxidative ferrous ions, and the antigen-binding behavior of the native and modified IgA to viral and bacterial antigens was compared using Western blotting and enzyme-linked immunosorbent assay. The ability of these agents to modulate the antigen-binding properties of human sIgA toward a wide range of pathogen peptides was investigated using an epitope microarray.

RESULTS

We have shown that acidic pH, heme, and pro-oxidative ferrous ions influenced the binding of secretory IgA in opposite directions (either increasing or decreasing); however, the strongest effect was observed when using buffers with low pH. This fraction had the highest number of affected reactivities; most of them were increased and most of the new ones were toward common pathogens.

CONCLUSIONS

Thus, it was shown that all investigated treatments can alter to some degree the antigen-binding of secretory IgA, but acidic pH has the most potentially beneficial effect by increasing binding to a largest number of common pathogens' antigens.

Plant-derived verbascoside and isoverbascoside regulate Toll-like receptor 2 and 4-driven neutrophils priming and activation

BACKGROUND

Neutrophils have a short live in circulation and accelerate greatly local immune responses via increased granulopoiesis and migration at high numbers to infected or inflamed tissue.

HYPOTHESIS

Since neutrophils produce a variety of factors with destructive and pro-inflammatory potential the regulation of their homeostasis and functions might be eventually beneficial in inflammation-related pathological conditions. Herein we investigated the effect of natural-derived verbascoside (Verb) and its positional isomer isoverbascoside (IsoVerb) on neutrophil functions.

METHODS

We used purified murine bone marrow (BM) neutrophils to study cell responsiveness to priming or activation via Toll-like receptors (TLRs) 2 and 4. The expression of CD11b, chemokine (CXC motif) receptor 2 (CXCR2), the intracellular level of phosphorylated p38 mitogen-activated protein kinase (MAPK) and tumor necrosis factor (TNF)-α in neutrophils were determined by flow cytometry while the release of macrophage inflammatory protein (MIP)-2 in culture supernatant was determined by enzyme-linked immunosorbent assay (ELISA).

RESULTS

We found that Verb appeared less powerful inhibitor of TLR2 and TLR4-mediated apoptosis than IsoVerb. However at concentrations below 16 µM and in LPS priming conditions Verb was more selective inhibitor of CD11b and CXCR2 expression than IsoVerb. Both compounds showed similar activity on integrin/chemokine receptor expression when neutrophils were stimulated with ZY or were activated with LPS. Verb sustained CXCR2 expression and turnover via regulation of the cell responsiveness to its ligand KC (CXCL1) and via the release of MIP-2 (CXCL2). Both Verb and IsoVerb increased TNF-α production and inhibited p38 phosphorylation in TNF-α⁺ cells. We fail to discriminate sharply between Verb's and IsoVerb's efficacy when studying p38 phosphorylation in LPS stimulated neutrophils. The multi-parametric analysis provides critical insight on the range of on-target effects of Verb and IsoVerb.

CONCLUSION

The strength and selectivity of Verb and IsoVerb depended on the degree of activation and functional state of neutrophils, and both compounds are with potential to affect neutrophil-related pathologies/conditions in heterogenic populations.

Early Pregnancy Human Decidua is Enriched with Activated, Fully Differentiated and Pro-Inflammatory Gamma/Delta T Cells with Diverse TCR Repertoires

Pregnancy is a state where high and stage-dependent plasticity of the maternal immune system is necessary in order to equilibrate between immunosuppression of harmful responses towards the fetus and ability to fight infections. TCR γδ cells have been implicated in the responses in infectious diseases, in the regulation of immune responses, and in tissue homeostasis and repair. The variety of functions makes γδ T cells a particularly interesting population during pregnancy. In this study, we investigated the proportion, phenotype and TCR γ and δ repertoires of γδ T cells at the maternal–fetal interface and in the blood of pregnant women using FACS, immunohistochemistry and spectratyping. We found an enrichment of activated and terminally differentiated pro-inflammatory γδ T-cell effectors with specific location in the human decidua during early pregnancy, while no significant changes in their counterparts in the blood of pregnant women were observed. Our spectratyping data revealed polyclonal CDR3 repertoires of the δ1, δ2 and δ3 chains and γ2, γ3, γ4 and γ5 chains and oligoclonal and highly restricted CDR3γ9 repertoire of γδ T cells in the decidua and blood of pregnant women. Early pregnancy induces recruitment of differentiated pro-inflammatory γδ T-cell effectors with diverse TCR repertoires at the maternal–fetal interface.

Clinopodium vulgare L. (wild basil) extract and its active constituents modulate cyclooxygenase-2 expression in neutrophils

Clinopodium vulgare L. (wild basil) has a wide range of ethnopharmacological applications and accumulates a broad spectrum of phenolic compounds, recognized for their anti-inflammatory and anticancer properties. The triggered cyclooxygenase-2 (COX-2) expression is creating an immunosuppressive microenvironment in the inflamed tissue and considered to be the main cause of failure of even new anticancer-/immune-therapies. Nowadays, selective and novel plant-derived COX-2 inhibitors with safe profile are subject of profound research interest. This study aimed to analyze the metabolic profile of C. vulgare and search for phenolic molecules with potential biological properties. By application of ¹H and 2D-NMR (Nuclear Magnetic Resonance) profiling, caffeic, chlorogenic acids and catechin were identified along with a bunch of primary and secondary metabolites. Further, the biological effect of C. vulgare extract (CVE) and its constituents on zymosan-induced COX-2 expression and apoptosis of murine neutrophils have been studied. The CVE, caffeic and chlorogenic acids inhibited zymosan-induced COX-2 expression in bone marrow neutrophils, in vitro and in vivo activated. The obtained data indicate that CVE may have a good potential to manipulate neutrophil functions, however, its action may depend on the cellular state, the inflammatory milieu and the relative content of caffeic and chlorogenic acid in the extract.

ANTIOXIDANT ACTIVITY AND MINERAL CONTENT OF ROCKET (ERUCA SATIVA) PLANT FROM ITALIAN AND BULGARIAN ORIGINS

Rocket plant (Eruca sativa) is a green leafy vegetable with significant levels of bioactive active components. Although, this plant is known in Bulgaria, scanty data concerning chemical composition of representatives with Bulgarian origin is available. The aim of this study was to evaluate and to compare the biological potential of Italian and Bulgarian rockets in terms of their antioxidant activity, total phenolic content and total hydroxycinnamic acid derivatives. The micro- and macro elements were evaluated as well. The highest content of total phenolic content was detected in Bulgarian rocket – 4.45 mg gallic acid equivalent per g dry weight, while in Italian samples dominated the total hydroxycinnamic acid derivatives – 1.52 mg chlorogenic acid equivalent per g dry weight. The antioxidant activity was not significantly different in both samples. The presence Co and Al was reported for the first time, as in our study their values were higher in a rocket from Italian origin (75.6 and 595 mg/kg). Italian rocket contained arsenic (0.07 mg/g) in comparison with Bulgarian samples where it was not found. The results revealed the sample with Italian origin as a significant better source of antioxidants with potential beneficial effects. Bulgarian rocket was evaluated with smaller amount of some metals as nickel, arsenic, chromium, manganese, aluminum and sodium, but the concentrations of Pb (0.58 mg/kg) and Cd (0.27 mg/kg) were higher than accepted levels by EU.

New iridoids from Verbascum nobile and their effect on lectin-induced T cell activation and proliferation

The Verbascum species are widely used traditional herb remedies against respiratory, inflammatory conditions and disorders. In the present study methanol extract of the aerial parts of the endemic Verbascum nobile Velen, was investigated and two novel iridoid glycosides 1 and 2, together with nine known constituents: iridoids, phenylethanoids, and saponins characteristic of Verbascum genus were identified. Further, the biological activity of the extract and selected isolated compounds on concanavalin (Con A)-induced T cell proliferation and activation of human Jurkat T cell line and splenic murine CD3 T cells was evaluated. T cell growth was studied by colorimetric-based WST proliferation assay while DNA content, cell cycling, dynamic of cell proliferation, expression of activation markers, intracellular expression of cytokine IFN-γ, and phosphorylation of ERK were analyzed by flow cytometry. Caspase-mediated apoptosis resulting in a poly (ADP-ribose) polymerase (PARP) cleavage was assessed by colorimetric in-cell kit. It was found that the extract, and all tested compounds (1, 2, 3 and 9) inhibited lectin-induced cell growth of Jurkat T cell line. The novel compounds decreased the frequencies of cells in S phase without causing a significant cell cycle arrest at G1 phase, caspases-mediated apoptosis and/or a profound change in the dynamic of splenic murine CD3⁺ T cell proliferation. Both compounds showed stronger inhibitory effect on Con A-induced ERK phosphorylation than the known bioactive compounds 3 and 9, and suppressed the expression of early activation marker CD69, the intracellular level of IFN-γ, and the generation of CD3⁺IFN-γ⁺ effectors. Our data suggest that the novel iridoid glycosides might have a potential to modulate T cell-related pathologies.

Altered expression of TRAIL on mouse T cells via ERK phosphorylation by Rhodiola rosea L. and its marker compounds

Rhodiola rosea L. extracts have shown neuroprotective, anti-fatigue, anti-inflammatory and anti-tumor properties. However, the studies on their effect on T cell function are rather scarce. We examined the potential of R. rosea extract and its major constituents - salidroside, rosarin, rosavin and rosin to alter cell growth of human Jurkat T cells, apoptosis of splenic mouse CD3 T cells and expression of the surface markers and phosphorylation of extracellular signal-regulated kinase (ERK). The initial screening for cell viability in Jurkat T cells and for apoptosis of mouse T cells showed the strongest activity for rosavin and rosarin. Rosarin and rosavin did not alter significantly the dynamic of CD69 expression upon stimulation, but altered TNF-related apoptosis-inducing ligand (TRAIL) expression. Rosavin inhibited TRAIL up-regulation, while rosarin showed an opposite effect. Indeed, rosarin increased the frequencies of CD3⁺TRAIL⁺ T cells and the fold inhibition of ERK phosphorylation. Our data showed that different effects of rosarin and rosavin on TRAIL expression can involve distinct action on ERK signaling and hence highlighted their potential to manipulate TRAIL as a tool to rescue the resistance to apoptosis in autoimmune diseases and cancer.

CXCR3/CXCL10 Axis Regulates Neutrophil-NK Cell Cross-Talk Determining the Severity of Experimental Osteoarthritis

Several immune cell populations are involved in cartilage damage, bone erosion, and resorption processes during osteoarthritis. The purpose of this study was to investigate the role of NK cells in the pathogenesis of experimental osteoarthritis and whether and how neutrophils can regulate their synovial localization in the disease. Experimental osteoarthritis was elicited by intra-articular injection of collagenase in wild type and Cxcr3^-/- 8-wk old mice. To follow osteoarthritis progression, cartilage damage, synovial thickening, and osteophyte formation were measured histologically. To characterize the inflammatory cells involved in osteoarthritis, synovial fluid was collected early after disease induction, and the cellular and cytokine content were quantified by flow cytometry and ELISA, respectively. We found that NK cells and neutrophils are among the first cells that accumulate in the synovium during osteoarthritis, both exerting a pathogenic role. Moreover, we uncovered a crucial role of the CXCL10/CXCR3 axis, with CXCL10 increasing in synovial fluids after injury and Cxcr3^-/- mice being protected from disease development. Finally, in vivo depletion experiments showed that neutrophils are involved in an NK cell increase in the synovium, possibly by expressing CXCL10 in inflamed joints. Thus, neutrophils and NK cells act as important disease-promoting immune cells in experimental osteoarthritis and their functional interaction is promoted by the CXCL10/CXCR3 axis.

Intravenous Immunoglobulin with Enhanced Polyspecificity Improves Survival in Experimental Sepsis and Aseptic Systemic Inflammatory Response Syndromes

Sepsis is a major cause for death worldwide. Numerous interventional trials with agents neutralizing single proinflammatory mediators have failed to improve survival in sepsis and aseptic systemic inflammatory response syndromes. This failure could be explained by the widespread gene expression dysregulation known as "genomic storm" in these patients. A multifunctional polyspecific therapeutic agent might be needed to thwart the effects of this storm. Licensed pooled intravenous immunoglobulin preparations seemed to be a promising candidate, but they have also failed in their present form to prevent sepsis-related death. We report here the protective effect of a single dose of intravenous immunoglobulin preparations with additionally enhanced polyspecificity in three models of sepsis and aseptic systemic inflammation. The modification of the pooled immunoglobulin G molecules by exposure to ferrous ions resulted in their newly acquired ability to bind some proinflammatory molecules, complement components and endogenous "danger" signals. The improved survival in endotoxemia was associated with serum levels of proinflammatory cytokines, diminished complement consumption and normalization of the coagulation time. We suggest that intravenous immunoglobulin preparations with additionally enhanced polyspecificity have a clinical potential in sepsis and related systemic inflammatory syndromes.

[Breast metastasis of a squamous cell carcinoma of the uterine cervix. A case report]

The breast is an extremely rare target organ for metastasis of extramammary neoplasms. The occurence varies between 1.7% to 6.6% in autopsies; between 1.2% and 2% in clinical cases; and around 2.7% in sputum series. In accordance with the primary tumor localization, it is more common to find metastases of lymphoma, melanoma, rhabdomyosarcoma, tumors of the lung and ovarian tumors. Breast metastasis of the uterine cervix is a very seldomly found. According to the published literature so far there have been around 30 documented cases with such pathology. This study presents the case of a 48-year-old female with a squamous cell carcinoma of the uterine cervix, which was histologically verified in 2010. Three years after the initial tumor diagnosis, radiotherapy and chemotherapy, the patient was found to have a cystic tumor formation in one of her breasts. The formation was painful to pressure. Quadrantectomy with an open bisopsy was performed to the patient. Histological and immunohistochemical diagnosis rejected primary squamous cell carcinoma of the breast. The differential diagnosis of metastatic lesions in the breast is problematic and requires careful clinical history, immunohistochemical study and multidisciplinary approach in the management. Mammary metastases are a bad predictor and they serve as an indicator of generalized dissemination of the primary tumor process.

The effect of interleukin 17 and Toll-like receptor 2 on CD11b expression and apoptosis of neutrophils in zymosaninduced arthritis and paw oedema

We investigated the effect of interleukin (IL)-17 on Ly6G(+) cell apoptosis in zymosan-induced arthritis (ZIA) and oedema (ZIO). Zymosan injection at the ankle joint caused swelling and coincided with histological joint alterations and IL-17A expression in areas with cell infiltrates. Flow cytometry of blood demonstrated increased frequencies of Ly6G(+)CD11b(+) cells and their decreased apoptosis in ZIA. Annexin V(+) neutrophils had lower CD11b expression, unlike Annexin V(-) cells. Cell survival for 12 hours was affected neither by IL-17 nor by zymosan alone, while both stimuli diminished Annexin V(+) cell frequencies and up-regulated CD11b on Annexin V(-) cells. Interleukin 17 antagonised to the effects of zymosan in 24-hour cultures. The administration of IL-17 in ZIO increased paw thickness, enlarged the blood Ly6G(+) pool, elevated CD11b expression and decreased apoptosis. We suggest that altered neutrophil apoptosis in arthritis can be overcome by anti-IL-17 therapy combined with an inhibition of Toll-like receptor (TLR) 2 and CD11b signalling.

Tyrosine Kinase Inhibitor Tyrphostin AG490 Inhibits Osteoclast Differentiation in Collagenase-Induced Osteoarthritis

The janus kinase (JAK)-signal transducer and activator of transcription (STAT) cascade plays a principal role in the signaling of a vast array of cytokines and growth factors which stimulates diverse cellular functions and immune responses. Osteoarthritis (OA) is the most common joint disease in the adult population. The present study was designed to evaluate the effects of tyrosine kinase inhibitor, tyrphostin AG490 in a mouse model of collagenase-induced osteoarthritis (CIOA). CIOA was provoked by two intraarticular (i.a.) injections of collagenase in mice and intraperitoneally (i.p.) treated with AG490 at a dose of 5 mg/kg at days 0, 5 and 10 and at a dose of 8 mg/kg at day 18. The administration of AG490 in CIOA mice inhibited osteoclast generation in bone and the loss of glycosaminoglycans and proteoglycans in cartilage. Tyrphostin decreased the levels of IFN-γ, IL1, IL-6 and IL-17 in the synovial fluid (SF) dependant on the time post AG490 administration. Limited numbers of CD11b positive Ly6G neutrophils in blood and SF along with a decrease of F4/80 positive cells in synovial fluid (SF) were observed in tyrphostin AG490-treated arthritic mice. AG490 inhibited M-CSF+RANKL-induced cytokine production by bone marrow (BM) cells and the differentiation of BM cells in vitro. Because of the findings presented, we argue that tyrphostin AG490 may hold promising therapeutic potential against important clinical conditions such as osteoarthritis (OA).

Septicaemia models using Streptococcus pneumoniae and Listeria monocytogenes: understanding the role of complement properdin

Streptococcus pneumoniae and Listeria monocytogenes, pathogens which can cause severe infectious disease in human, were used to infect properdin-deficient and wildtype mice. The aim was to deduce a role for properdin, positive regulator of the alternative pathway of complement activation, by comparing and contrasting the immune response of the two genotypes in vivo. We show that properdin-deficient and wildtype mice mounted antipneumococcal serotype-specific IgM antibodies, which were protective. Properdin-deficient mice, however, had increased survival in the model of streptococcal pneumonia and sepsis. Low activity of the classical pathway of complement and modulation of FcγR2b expression appear to be pathogenically involved. In listeriosis, however, properdin-deficient mice had reduced survival and a dendritic cell population that was impaired in maturation and activity. In vitro analyses of splenocytes and bone marrow-derived myeloid cells support the view that the opposing outcomes of properdin-deficient and wildtype mice in these two infection models is likely to be due to a skewing of macrophage activity to an M2 phenotype in the properdin-deficient mice. The phenotypes observed thus appear to reflect the extent to which M2- or M1-polarised macrophages are involved in the immune responses to S. pneumoniae and L. monocytogenes. We conclude that properdin controls the strength of immune responses by affecting humoral as well as cellular phenotypes during acute bacterial infection and ensuing inflammation.

New fluorogenic dyes for analysis of cellular processes by flow cytometry and confocal microscopy

Fluorescent microscopy and fluorescent imaging by flow cytometry are two of the fastest growing areas in the medical and biological research. Innovations in fluorescent chemistry and synthesis of new dye probes are closely related to the development of service equipment such as light sources, and detection techniques. Among compounds known as fluorescent labels, the cyanine-based dyes have become widely used since they have high excitation coefficients, narrow emission bands and high fluorescence upon binding to nucleic acids. The key methods for evaluation of apoptosis and cell cycle allow measuring DNA content by several flow cytometric techniques. We have synthesized new monomethine cyanine dyes and have characterized their applicability for staining of live and/or apoptotic cells. Imaging experiments by flow cytometry and confocal laser scanning microscopy (CLSM) have been also performed. Two of the dyes have shown high-affinity binding to the nuclei at high dilutions, up to 10(-9)M. Flow cytometry and CLSM have confirmed that these dyes labeled selectively non-living, e.g. ethanol-fixed cells that makes them appropriate for estimations of cell viability and apoptosis. The novel structures proved to be appropriate also for analysis of the cell cycle.

Harpagoside: from Kalahari Desert to pharmacy shelf

Harpagoside is an iridoid glycoside that was first isolated from Harpagophytum procumbens (devil's claw, Pedaliaceae), a medicinal plant in which it is the major constituent of the iridoid pool. Both the pure compound and devil's claw extracts have potent anti-rheumatic, anti-inflammatory and analgesic effects. According to the European Pharmacopoeia commercial devil's claw products should contain at least 1.2% harpagoside. However, the compound has also been isolated from several other plant species and in vitro plant culture systems. Recent advances in knowledge of harpagoside distribution, biosynthesis/accumulation and pharmacology are summarized in this review. We also discuss the possible synergism and/or antagonism between major constituents in harpagoside-containing phytopharmaceutical products. Finally, future perspectives for its potential application are highlighted.

Abrogated RANKL expression in properdin-deficient mice is associated with better outcome from collagen-antibody-induced arthritis

Introduction

Properdin amplifies the alternative pathway of complement activation. In the present study, we evaluated its role in the development of collagen antibody-induced arthritis (CAIA).

Methods

Arthritis was induced by intraperitoneal injection of a collagen antibody cocktail into properdin-deficient (KO) and wild-type (WT) C57BL/6 mice. Symptoms of disease were evaluated daily. The degree of joint damage was assessed histologically and with immunostaining for bone-resorption markers. Phenotypes of cell populations, their receptor expression, and intracellular cytokine production were determined with flow cytometry. Osteoclast differentiation of bone marrow (BM) precursors was evaluated by staining for tartrate-resistant acid phosphatase (TRAP).

Results

Properdin-deficient mice developed less severe CAIA than did WT mice. They showed significantly improved clinical scores and downregulated expression of bone-resorption markers in the joints at day 10 of disease. The frequencies of Ly6G⁺CD11b⁺ cells were fewer in BM, blood, and synovial fluid (SF) of KO than of WT CAIA mice. The receptor activator of nuclear factor κB ligand (RANKL) was downregulated on arthritic KO neutrophils from BM and the periphery. Decreased C5a amounts in KO SF contributed to lower frequencies of CD5aR⁺-bearing neutrophils. In blood, surface C5aR was detected on KO Ly6G⁺ cells as a result of low receptor engagement. Circulating CD4⁺ T cells had an altered ability to produce interleukin (IL)-17 and interferon (IFN)-γ and to express RANKL. In KO CAIA mice, decreased frequencies of CD4⁺ T cells in the spleen were related to low CD86 expression on Ly6G^highCD11b⁺ cells. Arthritic KO T cells spontaneously secreted IFN-γ but not IL-17 and IL-6, and responded to restimulation with less-vigorous cytokine production in comparison to WT cells. Fewer TRAP-positive mature osteoclasts were found in KO BM cell cultures.

Conclusions

Our data show that the active involvement of properdin in arthritis is related to an increased proinflammatory cytokine production and RANKL expression on immune cells and to a stimulation of the RANKL-dependent osteoclast differentiation.

Pro-inflammatory action of Candida albicans DNA in zymosan-induced arthritis

OBJECTIVE

This study was designed to examine the potential ability of Candida albicans DNA to influence joint inflammation in a mouse model of zymosan-induced arthritis (ZIA) relating to Toll-like receptor-9 (TLR9) expression and cytokine production in different compartments.

METHODS

To induce ZIA, mice were injected in the ankle joint with 180 μg zymosan. TLR9 expression in synovial extracts, peritoneal macrophages, splenocytes and popliteal lymph node cells was analyzed by flow cytometry. The levels of interferon (IFN)-γ, interleukin (IL)-6 and IL-10 in synovial fluid and sera were measured by ELISA. The expression of TLR9 in the joints was determined by immunohistochemistry.

RESULTS

A single intraperitoneal injection of C. albicans DNA did not elevate TLR9 expression and cytokine levels in the joints. It increased TLR9 expression by peritoneal macrophages isolated from healthy and arthritic mice and elevated the IFN-γ level in circulation. In-vitro stimulation with DNA enhanced IL-6, IFN-γ and IL-10 production by different cells isolated from mice with ZIA.

CONCLUSION

These results suggest that small quantities of C. albicans DNA can provoke a pro-inflammatory systemic response rather than locally in the joint.

Bone resorption and remodeling in murine collagenase-induced osteoarthritis after administration of glucosamine

Introduction

Glucosamine is an amino-monosaccharide and precursor of glycosaminoglycans, major components of joint cartilage. Glucosamine has been clinically introduced for the treatment of osteoarthritis but the data about its protective role in disease are insufficient. The goal of this study was to investigate the effect of long term administration of glucosamine on bone resorption and remodeling.

Methods

The effect of glucosamine on bone resorption and remodeling was studied in a model of collagenase-induced osteoarthritis (CIOA). The levels of macrophage-inflammatory protein (MIP)-1α, protein regulated upon activation, normal T-cell expressed, and secreted (RANTES), soluble receptor activator of nuclear factor kappa-B ligand (RANKL), tumor necrosis factor (TNF)-α, and interleukin (IL)-6, 4 and 10 in synovial fluid were measured by enzyme-linked immunosorbent assay (ELISA). Cell populations in synovial extracts and the expression of RANKL, of receptors for TNF-α (TNF-αR) and interferon γ (IFN-γR) on clusters of differentiation (CD) three positive T cells were analyzed by flow cytometry. Transforming growth factor (TGF)-β3, bone morphogenetic protein (BMP)-2, phosphorylated protein mothers against decapentaplegic homolog 2 (pSMAD-2), RANKL and Dickkopf-1 protein (DKK-1) positive staining in CIOA joints were determined by immunohistochemistry.

Results

The administration of glucosamine hydrochloride in CIOA mice inhibited loss of glycosaminoglycans (GAGs) and proteoglycans (PGs) in cartilage, bone erosion and osteophyte formation. It decreased the levels of soluble RANKL and IL-6 and induced IL-10 increase in the CIOA joint fluids. Glucosamine limited the number of CD11b positive Ly6G neutrophils and RANKL positive CD3 T cells in the joint extracts. It suppressed bone resorption via down-regulation of RANKL expression and affected bone remodeling in CIOA by decreasing BMP-2, TGF-β3 and pSMAD-2 expression and up-regulating DKK-1 joint levels.

Conclusions

Our data suggest that glucosamine hydrochloride inhibits bone resorption through down-regulation of RANKL expression in the joints, via reduction of the number of RANKL positive CD3 T cells and the level of sRANKL in the joints extracts. These effects of glucosamine appear to be critical for the progression of CIOA and result in limited bone remodeling of the joints.

The role of properdin in murine zymosan-induced arthritis

Using properdin-deficient and wild-type mice, we have investigated the role of properdin in development and progression of zymosan-induced arthritis. At the initial phase of local, zymosan-induced inflammation, properdin-deficient and wild-type mice showed bone erosion, proteoglycan loss and cell infiltration. Compared to wild-type, properdin-deficient mice had reduced C5a and IL-6 but similar synovial TNF-alpha and sRANKL levels. Both groups showed a systemic immune response. Elevated IFN-gamma production and STAT1 signaling in splenocytes and a shift to Th1 response in popliteal lymph nodes were observed in properdin-deficient mice. Properdin-deficient mice had significantly less circulating zymosan-specific IgG antibodies than wild-type. In the chronic phase, the lack of properdin resulted in significant proteoglycan loss in the joints and lower cartilageneous STAT1 expression. The level of synovial C5a on day 30 was comparable in both groups, but C5aR staining was more apparent in the joints of properdin-deficient mice. Our data show that properdin is an important player in processes involved in inflammatory joint degradation.

Inhibition of zymosan-induced kidney dysfunction by tyrphostin AG-490

Background

Zymosan-induced shock has been associated with an increased production of pro-inflammatory cytokines and mediators, causing a generalized dysfunction of liver, lung and kidneys. Herein, we investigate the effects of tyrphostin AG-490 on the early inflammation and on the late renal injury provoked by zymosan injection.

Methods

Shock was induced by intraperitoneal injection of zymosan in a dose of 0.8–1.0 mg/g body weight in BALB/c mice and 0.8 mg/g body weight in SCID mice. Tyrphostin AG-490 was administered intraperitoneally in a dose of 5 mg/kg immediately after shock induction. Blood, peritoneal lavage and kidneys were collected at certain time points after zymosan injection. The levels of MIP-1α, RANTES, IL-6, IL-10, α1-antitrypsin and C5a in plasma were determined by ELISA. The number of IL-10-secreting cells in peritoneum was assayed by ELISPOT. Kidney function was monitored by measurement of urine/plasma creatinine levels and proteinuria. Histological assessment of renal injury was performed in a blinded fashion after hematoxylin/eosin staining. Immunohistochemistry analyses were used to evaluate the expression of C5aR, STAT1, STAT3 and the binding ability of IgGs in kidneys.

Results

Tyrphostin AG-490 attenuated the early phase of zymosan-induced shock via inhibition of MIP-1α, RANTES and C5a plasma levels and via elevation of IL-10 in plasma. The drug increased IL-10 production in peritoneum and the number of IL-10-secreting peritoneal cells. AG-490 was able to retain the time of coagulation and the level of α1-antitrypsin to normal values. At the late stage of shock, AG-490 decreased scores of tubular injury, cell infiltration and glomerular lesions in parallel with diminished creatinine plasma level and protein excretion. These beneficial effects of AG-490 were related to lowered levels of circulating IL-6, MIP-1α and C5a, and to inhibited expression of STAT1, STAT3 and C5aR in kidneys. The drug diminished the production of zymosan-specific IgG antibodies and hindered the glomeruli from IgGs recognition.

Conclusion

Tyrphostin AG-490 reduced the magnitude of the initial inflammatory response in zymosan-induced shock and prevented the development of severe kidney dysfunction. Our data suggest that the drug might be used as a therapeutic approach in cases where shock is combined with acute renal injury.

Effect of Candida albicans dsDNA in gastrointestinal Candida infection

Neonates are highly sensitive to infections because they are biased to develop Th2 immune responses. When exposed to certain agents, such as DNA vaccines or CpG DNA motifs, neonates are capable to mount adult-like Th1 protective responses. This study investigates the capacity of Candida albicans (C. albicans) dsDNA to induce host resistance in newborn mice against gastrointestinal C. albicans infection. The protective properties of dsDNA are related to an increased number of spleen CD4+ T cells secreting IFN-gamma. In infected DNA-treated mice, an enhanced production of IFN-gamma by Peyer's patch cells was observed together with reduced colonization and histopathological changes in the stomach. Our results indicated that C. albicans dsDNA administration in neonates elicited the protective immune response against gastrointestinal Candida infection.

Inflammatory response in patients with active and inactive osteoarthritis

In the present study, we have investigated comparatively the inflammatory response of patients with active and inactive osteoarthritis. The sera from 31 healthy individuals, 37 patients with active OA, and 19 patients with inactive OA were assayed for TNF-alpha, IL-6, sRANKL, RANTES, and MRP8 using ELISA in order to evaluate their potential as markers of disease activity. Also, the spontaneous and LSP-induced release of TNF-alpha and IL-6 by peripheral blood neutrophils was determined. The activation of OA is associated with elevated TNF-alpha, IL-6, and RANTES serum levels while sRANKL and MRP8 appeared to be increased in both active and inactive OA. The neutrophil spontaneous and up-regulated by LPS cytokine release can contribute to the exacerbation of OA.

Inhibition of Candida albicans extracellular enzyme activity by selected natural substances and their application inCandidainfection

Extracellular enzymes secreted by Candida albicans are claimed to be virulence factors responsible for penetration of the yeast into host cells. Substances able to inhibit lipolytic and proteinase activities of the fungus might be of therapeutic use in some pathologic conditions caused by C. albicans. In the present work, we have tested the influence of the flavonoid compounds apigenin and kaempferol, the indole alkaloid ibogaine, and the protoberberine alkaloid berberine on the in vitro enzyme activity of C. albicans. The substances showed complex suppressive effects concerning the processes of adherence to epithelial cells, secreted aspartyl proteinase activity, and the rate of cell wall protein glycosylation. Apigenin and kaempferol were administered in systemic C. albicans infection, demonstrating an increased number of survivors by kaempferol. The application of apigenin, kaempferol, ibogaine, and berberine in cutaneous infection suppressed the symptoms and accelerated elimination of the yeast from the site of inoculation.

Decrease of dehydrogenase activity of cerebral glyceraldehyde-3-phosphate dehydrogenase in different animal models of Alzheimer's disease

Recently, a relationship between glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and the beta-amyloid precursor protein (betaAPP) in relationship with the pathogenesis of Alzheimer's disease (AD) has been suggested. Therefore, we studied the specific activity of GAPDH in the different animal models of AD: transgenic mice (Tg2576) and rats treated with beta-amyloid, or thiorphan, or lipopolysaccharides (LPS) and interferon gamma (INFgamma). We observed that GAPDH activity was significantly decreased in the brain samples from TG mice. The injection of beta-amyloid, or thiorphan, an inhibitor of neprilysin involved in beta-amyloid catabolism, in rat brains resulted in a pronounced reduction of the enzyme activity. The infusion of LPS and IFNgamma, which can influence the progression of the AD, significantly reduced the enzyme activity.

Influence of leflunomide on gastrointestinal Candida albicans infection induced in naive and arthritic newborn mice

Mucosal Candida albicans infection in immunocompromised individuals being treated with recently advanced drugs can progress to systemic disease. One such medication applied in patients with rheumatoid arthritis is leflunomide. The object of the present study was to investigate the effect of leflunomide on a model of gastrointestinal (g.i.) C. albicans infection induced in naïve or arthritic mice and on the host resistance to systemic re-infection. Newborn mice were orally inoculated with 1 x 10(5) colony forming units (CFU) of C. albicans and at age of 5 weeks they were treated with 5 mg/kg or 20 mg/kg of leflunomide for 10 consecutive days. Both doses elevated the yeast colonization of the stomach, without the dissemination into the internal organs. This was in parallel with the enhanced delayed type hypersensitivity (DTH) reaction to the yeast. Contrary to that, leflunomide caused a shift to Th2 reactivity by prevalence of IL-4 to IFN-gamma and a suppression of anti-Candida antibody synthesis by a higher dose. It might be supposed that infection increased autoimmune response in arthritic mice, according to stimulated DTH reaction to collagen. The administration of leflunomide during the simultaneous development of infection and arthritis diminished anti-Candida and anti-collagen antibody synthesis compared to untreated infected arthritic mice. The improved survival of arthritic infected animals against severe systemic re-infection was not changed after administration of leflunomide to re-infected arthritic mice. We can conclude that although leflunomide influenced cytokine secretion and suppressed anti-Candida antibody production it neither provokes a progression from gastrointestinal to systemic C. albicans infection nor increases the susceptibility to severe C. albicans re-infection of arthritic mice.

Host resistance to Candida albicans infection of mice with collagen-induced arthritis treated with leflunomide

The dehydro-orotate dehydrogenase inhibitor leflunomide is used for the treatment of rheumatoid arthritis. In the present study, its influence on host resistance to Candida albicans infection in mice with collagen-induced arthritis (CIA) was investigated. Leflunomide administered at a dose of 5 mg/kg for 5 consecutive days in mice with CIA inhibited collagen-specific cellular and humoral responses. The drug did not change the severity of primary C. albicans infection evaluated by kidney and liver colonization. At the early stage of infection leflunomide inhibited IFN-gamma production and enhanced IL-4 secretion. The effect of the drug on IL-4 production was less pronounced at the late phase of infection. Leflunomide enhanced anti-Candida IgM antibody production and diminished anti-Candida IgG antibody synthesis. This correlated with impaired resistance to reinfection. Results demonstrate that leflunomide administration to mice with collagen-induced arthritis might affect mechanisms of the late immune response to C. albicans infection.

Ibogaine reduces organ colonization in murine systemic and gastrointestinal Candida albicans infections

In the present study the effect of the indole alkaloid ibogaine on the in vitro lipolytic activity and adherence to epithelial cells of Candida albicans was investigated. The substance was administered intraperitoneally at a dose of 5 mg kg(-1) day(-1) in mice with disseminated and gastrointestinal C. albicans infections. Ibogaine significantly decreased the rate of mortality and the number of C. albicans c.f.u. recovered from the kidney, liver and spleen. Ibogaine interfered with the early stages of both disseminated and gastrointestinal C. albicans infections but did not reduce the number of C. albicans c.f.u. in the organs at the late phase of infections. The development of a specific immune response was not influenced by ibogaine, since the delayed-type hypersensitivity reaction to C. albicans and the production of interferon (IFN)-gamma were similar in control and ibogaine-treated mice. The combined use of amphotericin B plus ibogaine in the treatment of mice with gastrointestinal infection reduced organ colonization more strongly than each substance alone.

Candida albicans double-stranded DNA can participate in the host defense against disseminated candidiasis

In the present work, we studied the in vitro immunomodulatory properties of double-stranded Candida albicans DNA and its protective effect in murine disseminated candidiasis. DNA induced the production of TNF-alpha by peritoneal macrophages and splenocytes in vitro through a chloroquine-dependent mechanism. Yeast DNA acted synergistically with IFN-gamma in triggering the secretion of nitric oxide by macrophages and enabled them to stimulate the proliferation of T cells in response to soluble anti-CD3. The effect of DNA on splenocytes is associated with an enhanced synthesis of IFN-gamma, IL-2 and IL-10. In vivo, DNA decreased the mortality and lowered the kidney contamination in mice intraperitoneally inoculated with C. albicans simultaneously with an increase in the specific proliferative response and cytokine production. The present results indicate that C. albicans DNA can provide protection against disseminated infection.

Restriction of de novo pyrimidine biosynthesis inhibits Th1 cell activation and promotes Th2 cell differentiation

Leflunomide, an inhibitor of de novo pyrimidine biosynthesis, has recently been introduced as a treatment for rheumatoid arthritis in an attempt to ameliorate inflammation by inhibiting lymphocyte activation. Although the immunosuppressive ability of leflunomide has been well described in several experimental animal models, the precise effects of a limited pyrimidine supply on T cell differentiation and effector functions have not been elucidated. We investigated the impact of restricted pyrimidine biosynthesis on the activation and differentiation of CD4 T cells in vivo and in vitro. Decreased activation of memory CD4 T cells in the presence of leflunomide resulted in impaired generation and outgrowth of Th1 effectors without an alteration of Th2 cell activation. Moreover, priming of naive T cells in the presence of leflunomide promoted Th2 differentiation from uncommitted precursors in vitro and enhanced Th2 effector functions in vivo, as indicated by an increase in Ag-specific Th2 cells and in the Th2-dependent Ag-specific Ig responses (IgG1) in immunized mice. The effects of leflunomide on T cell proliferation and differentiation could be antagonized by exogenous UTP, suggesting that they were related to a profound inhibition of de novo pyrimidine biosynthesis. These results indicate that leflunomide might exert its anti-inflammatory activities in the treatment of autoimmune diseases by preventing the generation of proinflammatory Th1 effectors and promoting Th2 cell differentiation. Moreover, the results further suggest that differentiation of CD4 T cells can be regulated at the level of nucleotide biosynthesis.

Effect of Cu/Zn-superoxide dismutase from the fungal strain Humicola lutea 103 on antioxidant defense of Graffi tumor-bearing hamsters

A novel Cu/Zn-containing superoxide dismutase (SOD) was isolated from the fungal strain Humicola lutea 103. Previously, a protective effect of this enzyme (HLSOD) against tumor growth and also superoxide production in Graffi tumor-bearing hamsters (TBH) were established. The aim of the present study was to investigate the effect of HLSOD on the activity of endogenous SOD and catalase in the cells from TBH during tumor progression. Our results point out that transplantation of Graffi tumor causes a significant decrease in SOD activity in the cells from liver of the hosts (from 35 to 59% compared to the control). In the tumor cells relatively low levels of SOD (about 7 U mg protein(-1)) were found, and Cu/ZnSOD was the main isoenzyme in total SOD activity. Tumor growth resulted in a reduction of catalase activity, which correlated with the process of tumor progression. A single dose (65 U) treatment with HLSOD caused an increase in endogenous SOD and catalase activity in healthy animals and resulted in restoration of the antioxidant ability in liver cells of the hosts at the early stage of tumor progression. The results show the possible participation of HLSOD in the host oxidant-antioxidant balance, which is probably one of the factors of its immunoprotective action established earlier.