The effect of IκK-16 on lipopolysaccharide-induced impaired monocytes

This study focuses on impaired monocyte function, which occurs in some patients after trauma, major elective surgery, or sepsis. This monocyte impairment increases the risk of secondary infection and death. We aimed to determine the influence IκK-16 had on monocytes using an ex-vivo model of human monocyte impairment. We included the effects of the well-studied comparators interferon-gamma (IFN-γ) and granulocyte-macrophage colony-stimulating factor (GM-CSF) on impaired monocytes. Primary human monocytes were stimulated with 10 ng/mL of lipopolysaccharide (LPS) for 16 h and then challenged with 100 ng/mL LPS to assess the monocyte inflammatory response. Treatment regimens, consisting of either IκK-16, IFN-γ, or GM-CSF, were administered to impaired monocytes near the time of initial LPS stimulation. Stimulation with 10 ng/mL LPS initially promoted a pro-inflammatory response but subsequently impaired production of both tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10) and decreased HLA-DR expression. IκK-16 treatment attenuated TNF-α production and programmed death-ligand 1 (PD-L1) expression and increased IL-10 and CD14 expression. IFN-γ treatment increased TNF-α production as well as PD-L1 and HLA-DR expression. In conclusion, limiting early inflammation with IκK-16 suppresses TNF-α production and PD-L1 expression but enhances IL-10 production and preserves CD14 expression for potential future exposure to infective stimuli.     

High levels of plasma interferon gamma and +874T/A gene polymorphism is associated with HIV-TB co-infection

ObjectiveTuberculosis (TB) is one of the most frequent opportunistic infections in HIV patients leading to increased morbidity and death rate. This study was carried out to investigate the role of the cytokines IFN-γ and TNF-α level and their single nucleotide polymorphisms (SNPs) in HIV-TB co-infection.Methods247 HIV-TB (124 HIV-pulmonary TB, 123 HIV-extra pulmonary TB), 126 HIV positive individuals without tuberculosis and 129 healthy subjects (HS) were included to measure plasma levels of IFN-γ and TNF-α by sandwich ELISA and One way ANOVA statistical analysis was carried out among the groups. The SNPs of TNF-α-308 G/A, -238 G/A and IFN-γ + 874 T/A were also investigated using amplification refractory mutation system polymerase chain reaction (ARMS-PCR). The frequencies between the groups were compared by Pearson’s chi square statistical analysis.ResultsPlasma IFN-γ and TNF-α were significantly elevated in HIV-TB and TB (p < 0.05) as compared to those in HS group. There was significant association between IFN-γ + 874 ‘A’ allele and AA genotype in HIV-TB groups compared to HS and HIV (p < 0.05) and no such association was found for TNF-α-308 and -238. The plasma cytokine levels of TNF-α and IFN-γ reveals no significant association with levels of IFN-γ + 874 T/A, TNF-α -308 G/Aand-238 G/A genotypes in any of the study groups.ConclusionIn conclusion, the present study revealed elevated plasma IFN-γ and its +874 ‘A’ allele are associated with HIV-TB co-infection indicating 1.6 times increased risk for TB susceptibility. Elevated TNF-α levels in TB and HIV-TB suggest its involvement in TB pathogenesis.     

Maturation of human iDCs by IL-18 plus PGE2, but not by each stimulus alone,induced migration toward CCL21 and the secretion of IL-12 and IFN-γ

Dendritic cells (DCs) are potent antigen-presenting cells that initiate the primary immune response and whose functional properties in vivo depend on the maturation stimulus. We describe the functional properties of human monocyte-derived DCs after the maturation of immature DCs (iDCs) for 2 days with LPS (100 ng/ml), PGE2 (1 μg/ml), CD40L (1 μg/ml) or IL-18 (200 ng/ml) and with CD40L + PGE2 and IL-18 + PGE2 mixtures at the same concentrations as above. Neither IL-18 nor PGE2 alone stimulated IL-12 or IFN-γ secretion. When administered simultaneously to 1 × 10⁶ iDCs/ml, IL-18 + PGE2 induced the secretion of 131.4 ± 6.7 pg IL-12/ml and 355 ± 87 pg IFN-γ/ml but there was no detectable IL-10 secretion. However, PGE2 alone stimulated the secretion of 208 ± 89 pg IL-10/ml whereas IL-18 alone did not stimulate the secretion of IL-10, IL-12, TNF-α or INF-γ. When the mixture of CD40L + PGE2 was used, only migration toward CCL19 and CCL21 was induced. CD40L did not stimulate the secretion of IL-10, IL-12, TNF-α or IFN-γ and did not stimulate migration toward CCL19 or CCL21. The extent of stimulation of T cell proliferation was essentially the same for all stimuli at the concentrations given above. New properties such as IL-12 and INF-γ secretion and migration toward CCL21 emerged when a mixture of IL-18 + PGE2 was employed. These data show that when the pairs of stimuli reported here were used simultaneously their effect was not additive. This system can be used to prepare mDCs with properties useful for cell therapy and also as a model to investigate the mechanisms of cytokine secretion and cell migration.     

Polymorphisms of IFN-γ (+874A/T) and IL-12 (+1188A/C) in tuberculosis patients and their household contacts in Hyderabad,India

Several cytokine gene variants have shown to be associated with host susceptibility to infectious diseases including tuberculosis (TB). High rates of transmission were identified within household members of TB patients. In this study, we examined whether single nucleotide polymorphisms of IFN-γ +874A/T and IL-12 +1188A/C affect susceptibility to TB. Genomic DNA from patients with active disease, their household contacts HHC and healthy controls HC was genotyped for IFN-γ +874A/T and IL-12 +1188A/C SNPs by amplification refractory mutation system-polymerase chain reaction (ARMS-PCR). IFN-γ +874 AA and AT genotypes were significantly with different frequencies in patients and total HHC as compared to HC (p < 0.0001). In patients IL-12 +1188 AC and CC genotypes were associated with TB (p < 0.003, p < 0.008). In total HHC AC, CC genotypes and both alleles (A&C) were significantly different as compared to HC (p < 0.004, p < 0.001, p < 0.034) and the same result was obtained when HHC were stratified into related (p < 0.02, p < 0.001) and unrelated (p < 0.009, p < 0.017) individuals. Allelic frequencies, however, were significant only in related contacts (p < 0.021). Generalized multifactor dimensionality reduction method (GMDR) testing revealed high risk combinations of several genotypes in IFN-γ & IL-12 genes. Our findings suggest an important role of genetic variations of IFN-γ and IL-12 for susceptibility to TB.     

Detection of Fcγ receptors on human endothelial cells stimulated with cytokines tumour necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ)

This investigation was conducted to detect Fcγ receptors (FcγR) on cytokine-stimulated human endothelial cells (EC) by measuring anti-FcγR MoAb binding with an ELISA. TNF-α and IFN-γ significantly increased the expression of FcγR type II (FcγRII) and type III (FcγRIII) on aortic EC. Simultaneous treatment with both cytokines had a synergistic effect and pretreatment of EC with IFN-γ augmented the effect of TNF-α. The greatest effect was the increase (up to four-to-six-fold) in expression of FcγRII found by the simultaneous treatment of aortic EC with both cytokines. The receptors were expressed on the cell surface and showed receptor capping after incubation at 37°C. This study showed that the inflammatory cytokines TNF-α and IFN-γ enhanced low-affinity FcγR expression on human EC in vitro. The expression of FcγR may contribute to the specific localization of circulating immune complexes on blood vessels in areas of vasculitis.     

IL-36α induces maturation of Th1-inducing human MDDC and synergises with IFN-γ to induce high surface expression of CD14 and CD11c

We show that IL-36α induced maturation of human MDDCs and stimulated differentiation of IFN-γ producing (Type 1) CD3+ lymphocytes but was not as effective as IL-36β in doing so. For the first time, we also show that IL-36α induced expression of CD14 by MDDCs and this was highly potentiated by co-cultured with IFN-γ. In contrast, lipopolysaccharide (LPS) did not increase CD14 expression by MDDCs, suggesting that if MDDCs represent a physiologically relevant population in vivo, they need to be stimulated by relevant inflammatory cytokines prior to CD14 expression and detection of LPS, expressed by Gram negative bacteria. IFN-γ synergised with IL-36α to restore the high levels of CD11c expression by MDDCs, which was reduced by culture with these cytokines in isolation. IL-36α/IFN-γ synergy also correlated with increased binding of the opsonic complement protein (iC3b) to MDDCs. However although IL-36α increased the phagocytic capacity of MDDCs for Salmonella Typhimurium 4/74 this was not synergistically increased by IFN-γ (P > 0.05).In conclusion we report the hitherto unknown effects of IL-36α on the innate cell function of human MDDCs.     

Polymorphisms in the immunoregulatory genes are associated with hematopoietic recovery and increased susceptibility to bacterial infections in patients with thalassaemia major undergoing matched related hematopoietic stem cell transplantation

In this study, the impact of polymorphisms in the genes of proinflammatory (IL-β, TNF-α, IL-6, IFN-γ), anti-inflammatory (transforming growth factor [TGF]-β, IL-10, IL-Ra), and other immunoregulatory factors (FcγRIIa, NOS3) along with the conventional risk factors on the rate of hematopoietic recovery and first episodes of bacterial, viral, or invasive fungal infections in 102 patients with β-thalassaemia major who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) with relatively uniform protocols at our center from June 1995 to June 2004 with a minimum follow-up of at least 2 years were studied retrospectively for 180 days after hematopoietic stem cell transplantation (HSCT). Our data show that (1) donor IL-1RN?2/2 (hazard ratio [HR], 2.4; 95% confidence interval [CI], 1.17-5.09; P = .018) and FCγRIIA +4481G/G genotypes (HR, 3.1; 95% CI, 1.56-6.31; P = .001) increased the incidence of bacterial infection; (2) fungal infection was increased in recipients with whose donors had IFN-γ +874T/T genotype (HR, 3.8; 95% CI, 1.08-13.62; P = .037); (3) time to neutrophil recovery was shorter in splenectomized patients (HR, 3.1; 95% CI, 1.70-5.64; P < .001), donors without IL-10 -1082A, -819T, and -592A haplotype (HR, 1.6; 95% CI, 1.02-2.39; P = .039), and recipients with IFN-γ +874A/A genotype (HR, 1.6; 95% CI, 1.05-2.56; P?= .029); and (4) time to platelet recovery was shorter in patients with IL-10 -1082A/A genotype (HR, 1.8; 95% CI, 1.14-2.68; P = .010) and with donors having TNF-α -308G/G genotypes (HR, 1.8; 95% CI, 1.06-2.93; P = .028). These data suggest that outcome after allogeneic stem cell transplantation could be affected by many factors. The mechanisms by which they bring about such impact needs further evaluation.     

流式微球阵列法检测肺结核患者血清部分细胞因子的临床意义

目的:探讨流式微球阵列法(CBA)检测不同类型肺结核患者血清中细胞因子IL-2、IL-4、IL-6、IL-10、TNF-α和IFN-γ水平的临床意义。方法:采用BD CBA Flex Set检测试剂盒和流式微球阵列法(CBA)检测84例肺结核患者(46例活动性肺结核患者及38例非活动性肺结核患者)和30例正常人的6种细胞因子(IL-2、IL-4、IL-6、IL-10、TNF-α、IFN-γ)的水平。结果:肺结核患者血清IL-2、IL-6、IL-10和IFN-γ的水平显著高于正常对照组(P<0.01或P<0.05),且活动性结核组高于非活动性结核组(P<0.01或P<0.05)。血清IL-4与TNF-α水平肺结核患者与正常对照组无显著性差异。结论:CBA法能快速、灵敏、多参数批量同步定量检测血清中6种细胞因子;这些细胞因子在肺结核的免疫发病中具有重要的意义。     

Association of Interleukin-10 promoter polymorphisms with neurosyphilis

Interleukin 10 (IL-10) is a potent anti-inflammatory cytokine. Increased production of IL-10 has been found in late syphilis, presumably creating favorable conditions for bacteria persistence. Single-nucleotide polymorphisms (SNPs) within the promoter of IL-10 gene have been found to influence IL-10 production. We investigated whether SNPs in the IL-10 gene promoter are associated with cerebrospinal fluid (CSF) levels of IL-10 and neurosyphilis.Polymorphisms in the gene for IL-10 (G → A mutation at the position −1084 and C → A mutation at the position −592) were sought in 35 patients with syphilis and 24 healthy volunteers. CSF examination (i.e. routine laboratory tests and IL-10 levels) was performed in all syphilis patients. Neurosyphilis was defined as reactive CSF VDRL test or CSF white blood cells ⩾ 5/μL and CSF protein concentration ⩾ 45 mg/dL.Overall, 31% of patients with syphilis had neurosyphilis. CSF IL-10 levels were significantly higher in patients with neurosyphilis when compared to those with syphilis but not neurosyphilis. −1082 GG and −592 CC genotypes were significantly associated with higher CSF IL-10 levels. Moreover, these genotypes were found to be more frequent in individuals with neurosyphilis in comparison to those without neurosyphilis.Anti-inflammatory immune response seems to be important in pathogenesis of neurosyphilis. Our data suggest that host-related factors, such as SNPs of immune regulatory genes may influence the susceptibility to neurosyphilis.     

The decoy Fcγ receptor encoded by the cytomegalovirus UL119-UL118 gene has differential affinity to IgG proteins expressing different GM allotypes

Human cytomegalovirus (HCMV) is a ubiquitous herpesvirus that has been implicated in many diseases. However, there is significant divergence between HCMV seroprevalence and the prevalence of HCMV-associated diseases, implying the presence of host genetic factors that might modulate immunity to this virus. HCMV deploys many sophisticated strategies to evade host immunosurveillance. One strategy involves encoding for proteins that have functional properties of the Fcγ receptor (FcγR). The aim of the present investigation was to determine whether the UL119-UL118-encoded recombinant FcγR ectodomain binds differentially to genetically disparate IgG1 proteins. Results show that mean absorbance values for binding of HCMV UL119-UL118-encoded Fcγ receptor to the immunoglobulin GM (γ marker) 1,17-expressing IgG1 were significantly higher than to the IgG1 expressing the allelic GM 3 allotype (0.225 vs. 0.151; p = 0.039). These findings suggest possible mechanisms underlying the maintenance of immunoglobulin GM gene polymorphism and its putative role in the etiology of HCMV-associated diseases.     

Divergent effects of FcγRIIIA ligands on the functional activities of human natural killer cells in vitro

The Fcγ receptor (R)IIIA (CD16) plays an important role in regulating the cytotoxic and non-cytotoxic functions of human natural killer (NK) cells. Some anti-CD 16 monoclonal antibodies (mAb) have been shown to stimulate NK activity, while human monomeric (m) IgG induces dose-dependent inhibition of NK activity. To explore further these interactions mediated via FcγRIIIA, purified NK cells were cultured for 2–3 days in the presence of mIgG, 3G8 mAb, interleukin-2 (IL-2) or a combination of mIgG or 3G8 with IL-2. Binding of mIgG or 3G8 to FcγRIIIA induced divergent effects of functions of cultured NK cells: 3G8 mAb + IL-2 induced dose-dependent inhibition of proliferation attributable to apoptosis; in contrast, mIgG + IL-2 significantly increased NK cell proliferation. Incubation of NK cells in the presence of mIgG up-regulated expression of surface activation markers (CD69, IL-2Rα, ICAM-1), cytotoxicity, cytokine production (IL-1β, IFN-γ and TNF-α) and release of soluble IL-2R. Thus, mIgG binding to FcγRIIIA induced stimulatory signals in human NK cells, leading to up-regulation of IL-2Rα expression, cell proliferation and cytokine release.     

Il-10 deficient mice express IFN-γ mRNA and clear Leptospira interrogans from their kidneys more rapidly than normal C57BL/6 mice

Leptospira interrogans (L. interrogans), the causative agent of leptospirosis, is a widespread zoonotic spirochete that lives a dual lifestyle. L. interrogans infects mice, rats, and wildlife in a persistent and asymptomatic fashion, while also causing productive and acute infections in other mammals such as humans and hamsters. Infections in humans can be fatal, accompanied by a cytokine storm and shock-like symptoms. Production of IL-10 has been noted in both rodent and human infections which has led a number of investigators to hypothesize that IL-10 plays a role in the pathogenesis of this disease. To test this hypothesis we have compared bacteremia and the cytokine response of normal and IL-10 deficient C57Bl/6 mice following ip infection with L. interrogans. In normal mice bacterial 16 s mRNA was detected in both lung and kidney tissues within a day after infection. Levels of 16 s mRNA then dropped in both organs with complete elimination from the lung by day 3 but persistence in the kidney for 7 days after infection. In contrast, in IL-10 deficient mice, the organism was eliminated more rapidly from the kidney. We found that infection of both control and IL-10 deficient mice produced similar levels of a number of pro-inflammatory cytokine mRNAs. On the other hand, IFN-γ mRNA was only induced in IL-10 deficient mice. These results support the hypothesis that L. interrogans ability to induce IL-10, which in turn prevents production of IFN-γ and inhibits T cell immunity, may contribute to the persistent growth of this microorganism in the murine kidney.     

The formyl peptide N-formyl-methionyl-leucyl-phenylalanine downregulates the expression of FcgammaRs in interferon-gamma-activated monocytes/macrophages in vitro and in vivo

N-Formyl peptides are cleavage products of bacterial and mitochondrial proteins that have pro-inflammatory activities and play an important role in antibacterial host defence. FcγRI is a receptor for the Fc portion of immunoglobulin G expressed in monocytes that mediates cytotoxicity and is upregulated by interferon-γ (IFN-γ) and interleukin-10 (IL-10). In this report, we demonstrate that N-formyl-methionyl-leucyl-phenylalanine (FMLP) downregulates the expression of FcγRI in IFN-γ-treated monocytes, but not in IL-10-treated monocytes. We determine that supernatants obtained from monocytes treated with IFN-γ and then exposed to FMLP induce the downregulation of FcγRI in naïve monocytes. This effect is abrogated by the protease inhibitors phenylmethylsulphonyl fluoride and phosphoramidon, which inhibit serine and metalloproteases, respectively. Supernatants from FMLP-treated neutrophils also induce the downregulation of FcγRI, when added to naïve monocytes. Similar observations were obtained in vivo in a mouse model of chronic inflammation. In vivo, FMLP also downregulates the expression of FcγRs in IFN-γ-activated macrophages. Our results support the existence of a new mechanism through which FMLP could modulate the activity of monocytes/macrophages during bacterial infections.     

Association of a coding polymorphism in Fc gamma receptor 2A and graft survival in re-transplant candidates

The family of Fc gamma receptors (FcγRs) is involved in mediating immunological effector functions. FcγRs are differentially expressed on immune cells and can act either activating or inhibitory, with FcγR2A belonging to the first group. The polymorphism H131R (rs1801274) in FCGR2A has been associated with acute rejection and can shift the overall balance between activating and inhibitory FcγRs. Anti-HLA allo-antibodies in transplant recipients have been identified as risk factor for organ survival after transplantation. In this study we genotyped FCGR2A H131R in 200 patients who had undergone kidney transplantation and experienced loss of graft function. FCGR2A polymorphism was related to graft survival and anti-HLA antibodies. Graft survival was calculated as the time interval between transplantation and return to chronic dialysis after transplantation. The gene frequency of FCGR2A R/R131 was found significantly more often in patients with earlier (⩽60 months) compared to patients with later (>60 months) graft failure. Overall patients homozygous for R/R131 had a significantly shorter graft survival, compared to H/H131 or H/R131 which is even more pronounced, when anti-HLA antibodies were present. These data suggest, that FCGR2A polymorphisms constitute a risk factor for graft loss following kidney transplantation and that this effect is related to anti-HLA antibodies.     

活动性结核病患者外周血单个核细胞中结核分枝杆菌抗原特异性多能CD4+和CD8+T淋巴细胞的特征研究

目的 研究活动性结核病患者外周血单个核细胞中结核分枝杆菌抗原特异性多能T淋巴细胞细胞因子的分泌特征.方法 利用γ干扰素释放试验和多色流式细胞术分析了13例活动性结核病患者、11例肺部感染性/肿瘤疾病患者以及14例健康对照者外周血中结核分枝杆菌抗原特异性(ESAT-6和CFP-10)CD4+Th1和CD8+Tc淋巴细胞表达细胞因子IFN-γ、TNF-α和IL-2的情况.结果 与肺部感染性/肿瘤疾病组和健康对照组相比:(1)活动性结核病组具有较低比例的分泌TNF-α+的CD4+Th1细胞、较高比例的分泌IFN-γ+和IFN-γ+TNF-α+IL-2+的CD4+Th1细胞;(2)活动性结核病组具有较高比例的分泌IFN-γ+TNF-α+IL-2+的CD8+Tc细胞.结论 实验结果提示活动性结核病患者中表达IFN-γ+TNF-α+IL-2+的多能CD4+Th1及CD8+Tc细胞,可能在区别活动性结核病与肺部感染性/肿瘤疾病方面具有一定的临床参考价值.