MyD88-BLT2-dependent cascade contributes to LPS-induced interleukin-6 production in mouse macrophage

Endotoxic responses to bacterial lipopolysaccharide (LPS) are triggered by Toll-like receptor 4 (TLR4) and involve the production of inflammatory mediators, including interleukin-6 (IL-6), by macrophages. The detailed mechanism of IL-6 production by macrophages in response to LPS has remained unclear, however. We now show that LPS induces IL-6 synthesis in mouse peritoneal macrophages via the leukotriene B4 receptor BLT2. Our results suggest that TLR4-MyD88 signaling functions upstream of BLT2 and that the generation of reactive oxygen species (ROS) by NADPH oxidase 1 (Nox1) and consequent activation of the transcription factor nuclear factor (NF)-kappaB function downstream of BLT2 in this response. These results suggest that a TLR4-MyD88-BLT2-Nox1-ROS-NF-kappaB pathway contributes to the synthesis of IL-6 in LPS-stimulated mouse macrophages.

Wound healing potential of flowers extracts of Woodfordia fruticosa Kurz.

Wound healing or repair is the body’s natural process of regenerating dermal and epidermal tissue. Woodfordia fruticosa Kurz (Family: Lythraceae) is used traditionally in wound healing by the tribals of Chhattisgarh district. However, there is a paucity of scientific data in support. In this study, we evaluated antimicrobial activity of petroleum ether, chloroform, ethanolic and aqueous extracts against a diverse range of gram +ve and gram -ve bacteria along with pathogenic fungi. The wound healing activity of ethanolic extract was also evaluated at dose levels of 250 and 500 mg/kg body wt in rats by excision, incision and dead space wound healing models along with histopathology of wound area of skin. The ethanolic extract showed potent wound healing activity, as evident from the increase in the wound contraction and breaking strength in dose-dependent manner. Treatment with ethanolic extract (250 and 500 mg/kg body wt) showed significant dose-dependently decrease in epithelization period and scar area. Hydroxyproline, hexuronic acid and hexosamine contents, the important constituents of extracellular matrix of healing were also correlated with the observed healing pattern. During early wound healing phase, pro-inflammatory cytokines TNF-α, IL-6 and anti-inflammatory cytokine IL-10 levels were found to be upregulated by the ethanolic extract treatment. The ethanolic extract exhibited a strong and broad spectrum antimicrobial activity, as compared to other extracts. It showed very low Minimum inhibitory concentration (MIC) values and inhibited the growth of E. coli, Staphylococcus aureus and Candida albicans in concentration of 2.5 µg/disc. Thus, the results of the present study demonstrated the strong wound healing potential and antimicrobial activities of W. fruticosa, flowers, supporting the folklore use of the plant by the tribal people of Chhattisgarh district.

Reactive oxygen species regulate context-dependent inhibition of NFAT5 target genes

The activation of nuclear factor of activated T cells 5 (NFAT5), a well-known osmoprotective factor, can be induced by isotonic stimuli, such as activated Toll-like receptors (TLRs). It is unclear, however, how NFAT5 discriminates between isotonic and hypertonic stimuli. In this study we identified a novel context-dependent suppression of NFAT5 target gene expression in RAW 264.7 macrophages stimulated with lipopolysaccharide (LPS) or a high salt (NaCl) concentration. Although LPS and NaCl both used NFAT5 as a core transcription factor, these stimuli mutually inhibited distinct sets of NFAT5 targets within the cells. Although reactive oxygen species (ROS) are essential for this inhibition, the source of ROS differed depending on the context: mitochondria for high salt and xanthine oxidase for TLRs. Specifically, the high salt-induced suppression of interleukin-6 (IL-6) production was mediated through the ROS-induced inhibition of NFAT5 binding to the IL-6 promoter. The context-dependent inhibition of NFAT5 target gene expression was also confirmed in mouse spleen and kidney tissues that were cotreated with LPS and high salt. Taken together, our data suggest that ROS function as molecular sensors to discriminate between TLR ligation and osmotic stimuli in RAW 264.7 macrophages, directing NFAT5 activity toward proinflammatory or hypertonic responses in a context-dependent manner.

Acetyl salicylic acid inhibits Th17 airway inflammation via blockade of IL-6 and IL-17 positive feedback

T-helper (Th)17 cell responses are important for the development of neutrophilic inflammatory disease. Recently, we found that acetyl salicylic acid (ASA) inhibited Th17 airway inflammation in an asthma mouse model induced by sensitization with lipopolysaccharide (LPS)-containing allergens. To investigate the mechanism(s) of the inhibitory effect of ASA on the development of Th17 airway inflammation, a neutrophilic asthma mouse model was generated by intranasal sensitization with LPS plus ovalbumin (OVA) and then challenged with OVA alone. Immunologic parameters and airway inflammation were evaluated 6 and 48 h after the last OVA challenge. ASA inhibited the production of interleukin (IL)-17 from lung T cells as well as in vitro Th17 polarization induced by IL-6. Additionally, ASA, but not salicylic acid, suppressed Th17 airway inflammation, which was associated with decreased expression of acetyl-STAT3 (downstream signaling of IL-6) in the lung. Moreover, the production of IL-6 from inflammatory cells, induced by IL-17, was abolished by treatment with ASA, whereas that induced by LPS was not. Altogether, ASA, likely via its acetyl moiety, inhibits Th17 airway inflammation by blockade of IL-6 and IL-17 positive feedback.

MRP8 promotes Th17 differentiation via upregulation of IL-6 production by fibroblast-like synoviocytes in rheumatoid arthritis

Myeloid-related protein (MRP)8/MRP14 is an endogenous Toll-like receptor 4 (TLR4) ligand and is abundant in synovial fluid (SF) of rheumatoid arthritis (RA) patients. Belonging to damage-associated molecular patterns, it amplifies proinflammatory mediators and facilitates a wide range of inflammatory and autoimmune diseases. Interleukin (IL)-17-producing T-helper (Th)17 cells have a crucial role in RA pathogenesis, and IL-6 is the key factor promoting Th17 differentiation. We investigated whether the level of MRP8/MRP14 is positively associated with IL-6 and IL-17 levels in RA SF and found that MRP8/MRP14 level had a significant correlation with IL-6 and IL-17 levels in RA SF. We also observed that MRP8-induced IL-17 production by peripheral blood mononuclear cells but MRP14 did not. Upon stimulation with MRP8, IL-6 production was enhanced by RA fibroblast-like synoviocytes (FLS) and was further elevated by coculturing RA FLS with activated CD4+ T cells. Moreover, we demonstrated that MRP8-activated IL-6 production by RA FLS promoted differentiation of Th17 cells using the coculture system consisting of CD4+ T cells and RA FLS. In addition, IL-6 blockade attenuated Th17 polarization of CD4+ T cells in the cocultures. Inhibitor studies revealed that MRP8 increased IL-6 production in RA FLS via TLR4/phosphoinositide 3-kinase/nuclear factor-kappaB and mitogen-activated protein kinase signaling pathways. Our results show that MRP8 has a crucial role in stimulating IL-6 expression by RA FLS, and subsequently promotes Th17 differentiation in RA, suggesting that neutralizing MRP8 level in RA synovium may be an effective therapeutic strategy in RA treatment.

12(S)-Hydroxyheptadeca-5Z,8E,10E-trienoic acid suppresses UV-induced IL-6 synthesis in keratinocytes, exerting an anti-inflammatory activity

12(S)-Hydroxyheptadeca-5Z,8E,10E-trienoic acid (12-HHT) is an enzymatic product of prostaglandin H2 (PGH2) derived from cyclooxygenase (COX)-mediated arachidonic acid metabolism. Despite the high level of 12-HHT present in tissues and bodily fluids, its precise function remains largely unknown. In this study, we found that 12-HHT treatment in HaCaT cells remarkably down-regulated the ultraviolet B (UVB) irradiation-induced synthesis of interleukin-6 (IL-6), a pro-inflammatory cytokine associated with cutaneous inflammation. In an approach to identify the down-stream signaling mechanism by which 12-HHT down-regulates UVB-induced IL-6 synthesis in keratinocytes, we observed that 12-HHT inhibits the UVB-stimulated activation of p38 mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-kappaB). In addition, we found that 12-HHT markedly up-regulates MAPK phosphatase-1 (MKP-1), a critical negative regulator of p38 MAPK. When MKP-1 was suppressed by siRNA knock-down, the 12-HHT-mediated inhibitory effects on the UVB-stimulated activation of p38 MAPK and NF-kappaB, as well as the production of IL-6, were attenuated in HaCaT cells. Taken together, our results suggest that 12-HHT exerts anti-inflammatory effect via up-regulation of MKP-1, which negatively regulates p38 MAPK and NF-kappaB, thus attenuating IL-6 production in UVB-irradiated HaCaT cells. Considering the critical role of IL-6 in cutaneous inflammation, our findings provide the basis for the application of 12-HHT as a potential anti-inflammatory therapeutic agent in UV-induced skin diseases.

Legionella lipoprotein activates toll-like receptor 2 and induces cytokine production and expression of costimulatory molecules in peritoneal macrophages

Legionella bacterium, an intracellular pathogen of mononuclear phagocytes, causes acute fatal pneumonia, especially in patients with impaired cellular immune responses. Until recently, however, the toll-like receptor (TLR) engagement of bacterial proteins derived from Legionella is uncertain. We previously showed that a 19-kDa highly conserved peptidoglycan-associated lipoprotein (PAL) of Legionella pneumophila induced the PAL-specific B cell and T cell responses in mice. In this study, we observed that the rPAL antigen of L. pneumophila, as an effector molecule, activated murine macrophages via TLR2 and produced proinflammatory cytokines such as IL-6 and TNF-alpha. In both BALB/c and TLR4-deficient C3H/HeJ mice, pretreatment of macrophages with anti-TLR2 mAb showed severely impaired cytokine production in response to the rPAL. In addition, in vitro the rPAL treatment increased the cell surface expression of CD40, CD80, CD86 and MHC I/II molecules. We further showed that the synthetic CpG-oligodeoxynucleotides (CpG ODN) coadministered with the rPAL enhanced IL-12 and IL-6 production and expression of CD40, CD80 and MHC II compared to the rPAL treatment alone. In conclusions, these results indicate that Legionella PAL might activate macrophages via a TLR2-dependent mechanism which thus induce cytokine production and expression of costimulatory and MHC molecules.

Triptolide downregulates Rac1 and the JAK/STAT3 pathway and inhibits colitis-related colon cancer progression

Triptolide, a diterpenoid triepoxide from the traditional Chinese medicinal herb Tripterygium wilfordii Hook. f., is a potential treatment for autoimmune diseases as well a possible anti-tumor agent. It inhibits proliferation of coloretal cancer cells in vitro and in vivo. In this study, its ability to block progress of colitis to colon cancer, and its molecular mechanism of action are investigated. A mouse model for colitis-induced colorectal cancer was used to test the effect of triptolide on cancer progression. Treatment of mice with triptolide decreased the incidence of colon cancer formation, and increased survival rate. Moreover, triptolide decreased the incidence of tumors in nude mice inoculated with cultured colon cancer cells dose-dependently. In vitro, triptolide inhibited the proliferation, migration and colony formation of colon cancer cells. Secretion of IL6 and levels of JAK1, IL6R and phosphorylated STAT3 were all reduced by triptolide treatment. Triptolide prohibited Rac1 activity and blocked cyclin D1 and CDK4 expression, leading to G1 arrest. Triptolide interrupted the IL6R-JAK/STAT pathway that is crucial for cell proliferation, survival, and inflammation. This suggests that triptolide might be a candidate for prevention of colitis induced colon cancer because it reduces inflammation and prevents tumor formation and development.

A novel beta-glucan produced by Paenibacillus polymyxa JB115 induces nitric oxide production in RAW264.7 macrophages

The effect of extracellular beta-(1-->3), (1-->6)-glucan, produced by Paenibacillus polymyxa JB115, on nitric oxide (NO) production in RAW264.7 macrophages was investigated. beta-glucan induced the production of NO by RAW264.7 macrophages in a concentration- and time-dependent manner. Moreover, beta-glucan stimulation increased the mRNA expression of iNOS, COX-2 and IL-6 in RAW264.7 macrophages in a concentration-dependent manner.

Differential response of cytokines induced by Leptospira interrogans, serogroup Pomona, serovar Pomona, in mouse and human cell lines.

Leptospira interrogans, the causative agent of leptospirosis, is an important zoonotic bacterium. The mechanisms and roles of cytokine induction in both humans and animals remain unclear. Therefore, the IFN-gamma, IL-6, IL-10 and IL-12 levels were measured by enzyme-linked immunosorbent assay (ELISA) in human THP-1 and mouse RAW 264.7 monocyte cell lines following stimulation with heat-killed Leptospira interrogans serogroup Pomona serovar Pomona, L. biflexa, E. coli or Salmonella group B. The production of IL-6 and IL-12 were higher and rose more rapidly in the RAW 264.7 cells with all bacteria. The IL-10 was not detected in the RAW 264.7 cells when induced by leptospires. The IFN-gamma level in human peripheral blood mononuclear cells (PBMCs) induced by leptospires was also significantly lower than with other bacteria. When IL-10 and IL-12 mRNA expressions were detected in hamster's spleen, their patterns were similar to what was observed in THP-1 in that IL-12 was only slightly increased while IL-10 expression was high. Moreover, the IFN-gamma expression could not be detected in hamsters. The more potent cytokine responses in the RAW 264.7 cells may indirectly reflect the disease outcome in mice which render them to be a good reservoir of leptospirosis. Whether these cytokines have contributed to immunoprotection during the L. interrogans infection remains to be further investigated.

Hemophagoctic lymphohistiocytosis--recent concept.

Hemophagocytic lymphohistiocytosis is a rare condition characterized by highly stimulated but inactive immune response. The disease may be inherited or acquired due to infections, collagen vascular diseases and malignancies. The pathological hallmark of the syndrome is aggressive proliferation of macrophages and histiocytes. Decreased NK cell activity results in increased T cell activation resulting production of large quantities of interferon gamma (IFN gamma), tumor necrosis factor alpha (TNF alpha) and granulocyte macrophage colony stimulating factor (GM-CSF). This causes sustained macrophage activation and tissue infiltration as well as production of interleukin 1 (IL1) and interleukin 6 (IL6).The resulting inflammatory reaction causes extensive damage and associated symptoms. Patients with HLH commonly present with high fever, anemia and splenomegaly. Minimal diagnostic parameters are a complete hemogram, liver function test, serum triglycerides and ferritin, coagulation profile including fibrinogen and bone marrow aspiration. Two highly sensitive diagnostic marker are an increased plasma concentration of the alpha chain of soluble IL2 receptor (CD25) and impaired NK cell activity. Hyperinflammation can be treated with steroid, Cyclosporine prevents T lymphocytes and immunoglobulin infusion helps to control the infection. Etoposide may be life saving specially in case of HLH with Ebstein Barr Viruses infection. The Histiocyte Society in 1994 developed a common treatment protocol (HLH-94). In January 2004 a revised HLH treatment protocol was opened entitled HLH-2004, which is based on HLH-94 with minor modifications. There is a high remission rate on the HLH-94 and HLH-2004 treatment protocols.

Brain edema after intracerebral hemorrhage in rats: the role of inflammation.

BACKGROUND: Intracerebral hemorrhage (ICH) results in secondary brain edema and injury that may lead to death and disability. ICH also causes inflammation. It is unclear whether inflammation contributes to brain edema and neuron injury or functions in repairing the brain tissue. AIMS: To understand the effect of inflammation in ICH, we have carried out an investigation on the various aspects and the dynamic changes of inflammation. SETTINGS AND DESIGN: An ICH model was generated by injecting 50 microl autologous tail artery blood stereotactically into the right caudate nucleus of 30 rats, which were randomly divided into five ICH groups. Similarly, five Sham control groups were generated by inserting the needle to the right caudate nucleus of rats. MATERIALS AND METHODS: Rat behavior was evaluated over the time course (6 h, 24 h, 48 h, 72 h and 7 d) in each group. The rats were then killed by administering an overdose of pentobarbital. Following the euthanasia, the brain water content, neuronal loss, glia proliferation, inflammatory infiltration and brain morphology of the rats were measured. Additionally, the expression of TNF-alpha, IL-6, ICAM-1, VEGF, NF-kappaB, C3 and CR2 was analyzed by immunohistochemistry. STATISTICAL ANALYSIS: The data were analyzed by student's t test. RESULTS: Rat brain water content increased progressively over the time course and reached its peak at 48 h followed ICH. The maximum of inflammatory infiltrate (especially neutrophils) and immunopositive cells of TNF-alpha, IL-6 and NF-kappaB, were at 48 h. The expression of C3 and CR2 reached their peaks at 48-72 h, while the expression ICAM-1 and VEGF were at maximum at 72 h followed ICH. CONCLUSIONS: The results suggested that the inflammatory cytokines, complement system and VEGF may have a function in the development of the brain edema and neuron injury followed ICH.

Cytokine generation in stored platelet concentrate: comparison of two methods of preparation.

BACKGROUND & OBJECTIVES: Contaminating white blood cells (WBCs) in stored platelet concentrates (PC) are the main source of pro-inflammatory cytokines including interleukin-6 (IL-6), interleukin- 8 (IL-8) and tumour necrosis factor-alpha (TNF-alpha) that are implicated in transfusion reactions. We compared the levels of these cytokines in stored platelet preparations prepared by two methods. Effect of pre-storage leucofiltration on these cytokine levels was also studied. METHODS: Twelve units of pooled PCs were prepared by platelet rich plasma (PRP) method and buffy-coat (BC) method each and stored for 5 days. IL-6, IL-8 and TNF-alpha levels were measured in platelet supernatants on day 0, 1, 3 and 5 of the storage using commercially available immunoassays. Pre-storage leucofiltration was done in 4-pooled units of PRP-PC and cytokine levels compared with unfiltered PCs. RESULTS: Median IL-6 levels increased from day 0 to day 5 in both PRP-PC and BC-PC. In PRP-PC, IL-8 increased from <3 pg/ml on day 0 to 817 pg/ml on day 5, while in BC-PC the corresponding levels were 10 and 346.5 pg/ml, respectively. No significant increase in levels of TNF-alpha was observed in BC-PC during storage period, while levels increased significantly in PRP-PC on day 1 only. There was no significant change in the levels of all three cytokines in leucofiltered PCs over 5 days of storage. INTERPRETATION & CONCLUSION: Findings of our study showed that method of preparation and WBC content are the critical factors in determining the cytokine levels in stored PCs.

Cytokine Production by Whole Blood Cells: Relationship to Interleukin Gene Polymorphism and Bone Mass

The aims of this study were to investigate the relationships between the production of interleukin-1 (IL-1), and IL-6 system by whole blood cells, and bone mineral density (BMD), and polymorphisms in IL-1 system and IL-6 gene in postmenopausal Korean women. The production of IL-1alpha, IL-1beta, IL-1 receptor antagonist (IL-1ra), IL-6, and soluble IL-6 receptor (sIL-6r) by lipopolysaccharide-stimulated whole blood cells was measured by ELISA in 110 subjects. Serum osteocalcin, C-telopeptide of type I collagen, and BMD at lumbar spine and proximal femur were measured. IL-1alphaC(-889)T polymorphism, IL-1beta C(-511)T polymorphism, 86-base pair variable number tandem repeat polymorphism in the IL-1ra gene, and IL-6 C(-634)G polymorphism were analyzed. The production of IL-1beta correlated positively with BMD at femoral neck, whereas the production of other ILs did not correlate with BMD at the skeletal sites examined. No significant differences in the production of ILs were observed among normal, osteopenic and osteoporotic postmenopausal women, and among the different IL system polymorphisms groups studied. No correlation between bone turnover markers and the production of ILs was noted. In conclusion IL-1beta may regulate bone metabolism at femoral neck, and the IL system polymorphism do not affect the production of ILs by whole blood cells.

Induction of interleukin-6 by coal containing bioavailable iron is through both hydroxyl radical and ferryl species.

Coal mining causes health problems, such as pneumoconiosis. We have previously shown that prevalence of pneumoconiosis in workers from various coalmine regions positively correlates with levels of bioavailable iron (BAI) in the coals from that region. In the present study, the nature of reactive oxygen species formed by BAI in the coals and its mechanisms of the induction of biological responses were investigated. Human lung epithelial cell line, A549 cells, were used to examine the induction of interleukin-6 (IL-6), a pro-inflammatory cytokine, which is known to play a crucial role in the development of pneumoconiosis. We found that levels of IL-6 protein as well as its mRNA were significantly increased in the cells treated for 24 h with 20 microg/cm2 of the BAI-containing Pennsylvania (PA) coal; for example we observed 6.7-fold increase in IL-6 protein. Levels of IL-6 protein in cells treated with the Utah (UT) coal containing low-BAI were only 1.9-fold of the control levels. The enhancing effect on the IL-6 by the PA coal was similar to that caused by hydrogen peroxide. Superoxide dismutase (SOD), catalase (CAT), and N-acetyl-L-cysteine (NAC) all had inhibitory effects on the PA coal-induced IL-6 formation. However, CAT had the least protective effect as compared to SOD and NAC. Our results indicate that BAI in the PA coal may induce IL-6 through both ferryl species (via iron autoxidation) and hydroxyl radicals (via the Fenton/Haber Weiss reactions).

Citoquinas inducidas por la inmunización experimental antitetánica. Efecto de la formulación vacunal / [Cytokines induced by experimental anti-tetanus immunization. Vaccine formulation effect]

Several factors are involved in the selective activation of T helper 1 or T helper 2 cells, such as the type of antigen-presenting cells involved in the immune response and the different physical characteristics of antigens. The aim of this work was to evaluate if adding other antigens to tetanus toxoid modifies the original immune response. BALB/c mice were immunized with tetanus and diphtheria toxoids associated with whole-cell Bordetella pertussis (DTPw vaccine), B. pertussis soluble antigens (DTPa vaccine) or Salmonella typhi plus DTPa (DTPaSt vaccine). DTPw and DTPaSt immunization induced a T helper 1/T helper 2 (Th1/Th2) anti-tetanus response with gamma interferon and interleukin 5 production. DTPa immunization induced a Th2 response with production of interleukin 5 and interleukin 6. Only DTPw vaccine induced higher levels of IL-12 in non-immunized mice. Our findings indicate that the co-injection of whole-cell antigens such as B. pertussis or S. typhi, modifies the anti-tetanus response shifting it from Th2 to Th1 type. However, the original Th2 immune response is not modified when the vaccine consists only of soluble antigens.

Effects of High Glucose on Interleukin-6 Production in Human Mesangial Cells

Interleukin (IL)-6 is an autocrine growth factor for mesangial cells. It is not known whether high glucose influences IL-6 production in mesangial cells. Angiotensin II (AGII) is involved in the progression of renal diseases including diabetic nephropathy. Therefore, we evaluated the effects of high glucose in concert with AGII on IL-6 production in human mesangial cells and the modulation by blocking AGII. After 48 hr of culture, IL-6 mRNA expression was analyzed by reverse transcription and polymerase chain reaction (PCR). Quantitative determination of IL-6 concentrations in the culture supernatants of mesangial cells was performed using a sandwich enzyme immunoassay kit. Incubation of mesangial cells with high glucose (450 mg/dL) reduced the ratio of PCR products for IL-6 to beta-actin on densitometric results, while AGII (10(-7)M) increased it. The IL-6 secretion in the supernatant was also increased by AGII and decreased by high glucose. The IL-6 mRNA expression and IL-6 secretion in combination of high glucose and AGII were higher than those in high glucose and similar with those in control media. The addition of losartan (10(-6)M) or captopril (10(-6)M) to high glucose had no additional effects on IL-6 production. These results suggest that whereas AGII increases IL-6 production, high glucose decreases it. The IL-6 production of mesangial cells in diabetic milieu may be complicated and depend on the local effects of high glucose and/or AGII.

Production of pro-inflammatory cytokines [gm-csf, il-8 and il-6] by monocytes from fasciolosis patients

The production of proinflammatory cytokines by monocytes in vitro has been measured in eight patients with acute fascioliasis and 15 patients in the chronic stage of the disease before and after stimulation by excretory/secretory Fasciola antigen. The results were compared with those of a control group of 12 individuals. The monocytes from patients with acute fascioliasis produced significantly higher levels of GM-CSF, IL-8 and IL-6 as compared to controls. With chronicity, the production of these cytokines was decreased as compared to the acute stage probably due to decreased antigen level in blood. Stimulation of monocytes of healthy control with E/S Fasciola antigen was accompanied with a markedly increased production of proinflammatory cytokines, while monocytes from patients with acute or chronic fascioliasis revealed minimal increase in production. This denoted the importance of E/S Fasciola antigen as an activator of monocytes. A second exposure to the same antigen was accompanied with a limited response

Interleukin-1 beta, -6 and interferon-gamma productions in patients undergoing continuous ambulatory peritoneal dialysis

In order to investigate cytokine productions in patients undergoing continuous ambulatory peritoneal dialysis (CAPD), we studied the production of interleukin (IL)-1 beta, -6 and interferon (IFN)-gamma by cultured peripheral blood mononuclear cells (PBMC) in peritonitis-free CAPD patients. The correlation of cytokine production with plasma parathyroid hormone (PTH) and albumin levels was also evaluated. While the release of IL-1 beta was not markedly different from controls release of IL-6 from 24-hour cultured PBMCs was significantly greater than that of controls, (Mean +/- S.D., IL-6: 2186.8 +/- 1217.9 pg/ml, vs 1516.3 +/- 767.9, P 0.05). No difference of baseline IFN-gamma was detected between CAPD patients controls, but phytohemagglutinin (PHA, 10 micrograms/ml)-stimulated IFN-gamma release was significantly higher in CAPD patients than controls (2425.9 +/- 1565.0 pg/ml vs 1364.0 +/- 755.1, P <0.05). There was no significant correlation between PTH and, IL-1 beta, serum albumin level and LPS-stimulated IL-6 production (r = 0.54, P <0.05). In conclusion, CAPD seems to partly induce activation of PBMCs with an enhanced release of IL-6 and IFN-gamma, and CAPD patients with higher serum albumin levels tend to show higher IL-6 production in immune response.

level of Interleukin 6 in septic and aseptic meningitis

In this study the level of interleukin-6 [IL[6]] was evaluated in cerebrospinal fluid [CSF] and serum of septic [n=14] and aseptic meningitis [n=16] patients, in addition to its evaluation in 10 controls. CSF IL6 was elevated in 85.7% of patients with septic meningitis [SM] [mean 1471. 4 pg/ml] and in 43.7% of aseptic meningitis [AM] patients [mean 192.8 pg/ml], the difference in between was significant [P< 0. 0001]. Elevation of serum IL[6] was found in 28. 6% of the SM group [means 192.8 pg/ml] and none of the AM group [mean 122.5]. CRP was elevated in CSF and serum of SM and Am groups. Positive correlation was found between IL[6] and CRP in CSF and serum but not with other inflammatory parameters. It is concluded that marked elevation of IL[6] in patients with meningitis suggest a septic aetiology. It is also claimed that IL[6] plays a role in aseptic meningitis which is believed to be dependant on the causative agent