Serum Levels Of IFN-gamma Research Articles

Myeloid dendritic cells display downregulation of C-type lectin receptors and aberrant lectin uptake in systemic lupus erythematosus

IntroductionThere is a growing body of evidence implicating aberrant dendritic cell function as a crucial component in the immunopathogenesis of systemic lupus erythematosus. The purpose of the present study was to characterize the phagocytic capacity and expression of receptors involved in pathogen recognition and self-nonself discrimination on myeloid dendritic cells from patients with lupus.MethodsUnstimulated or stimulated monocyte-derived dendritic cells were obtained from lupus patients and healthy control individuals, and expression of C-type lectin receptors (mannose receptor and dendritic cell-specific intercellular adhesion molecule-grabbing nonintegrin), complement-receptor 3 and Fcγ receptors was determined by flow cytometry. Dextran uptake by lupus and control dendritic cells was also assessed by flow cytometry. Serum IFNγ was quantified by ELISA, and uptake of microbial products was measured using fluorescently labeled zymosan.ResultsWhen compared with dendritic cells from healthy control individuals, unstimulated and stimulated lupus dendritic cells displayed significantly decreased dextran uptake and mannose receptor and dendritic cell-specific intercellular adhesion molecule-grabbing nonintegrin expression. Decreased expression of the mannose receptor was associated with high serum IFNγ levels, but not with maturation status or medications. Diminished dextran uptake and mannose receptor expression correlated with lupus disease activity. There were no differences between control and lupus dendritic cells in the expression of other pattern recognition receptors or in the capacity to uptake zymosan particlesConclusionsLupus dendritic cells have diminished endocytic capacity, which correlates with decreased mannose receptor expression. While this phenomenon appears primarily intrinsic to dendritic cells, modulation by serum factors such as IFNγ could play a role. These abnormalities may be relevant to the aberrant immune homeostasis and the increased susceptibility to infections described in lupus.

IFN-γ Mediates the Rejection of Haematopoietic Stem Cells in IFN-γR1-Deficient Hosts

BackgroundInterferon-γ receptor 1 (IFN-γR1) deficiency is a life-threatening inherited disorder, conferring predisposition to mycobacterial diseases. Haematopoietic stem cell transplantation (HSCT) is the only curative treatment available, but is hampered by a very high rate of graft rejection, even with intra-familial HLA-identical transplants. This high rejection rate is not seen in any other congenital disorders and remains unexplained. We studied the underlying mechanism in a mouse model of HSCT for IFN-γR1 deficiency.Methods and FindingsWe demonstrated that HSCT with cells from a syngenic C57BL/6 Ifngr1 +/+ donor engrafted well and restored anti-mycobacterial immunity in naive, non-infected C57BL/6 Ifngr1 −/− recipients. However, Ifngr1 −/− mice previously infected with Mycobacterium bovis bacillus Calmette-Guérin (BCG) rejected HSCT. Like infected IFN-γR1-deficient humans, infected Ifngr1 −/− mice displayed very high serum IFN-γ levels before HSCT. The administration of a recombinant IFN-γ-expressing AAV vector to Ifngr1 −/− naive recipients also resulted in HSCT graft rejection. Transplantation was successful in Ifngr1 −/− × Ifng −/− double-mutant mice, even after BCG infection. Finally, efficient antibody-mediated IFN-γ depletion in infected Ifngr1 −/− mice in vivo allowed subsequent engraftment.ConclusionsHigh serum IFN-γ concentration is both necessary and sufficient for graft rejection in IFN-γR1-deficient mice, inhibiting the development of heterologous, IFN-γR1-expressing, haematopoietic cell lineages. These results confirm that IFN-γ is an anti-haematopoietic cytokine in vivo. They also pave the way for HSCT management in IFN-γR1-deficient patients through IFN-γ depletion from the blood. They further raise the possibility that depleting IFN-γ may improve engraftment in other settings, such as HSCT from a haplo-identical or unrelated donor.

CD30 supports lung inflammation

The physiological functions of CD30 have not been fully elucidated. Here we show that in CD30-deficient mice (CD30(-/-)), lung inflammation is significantly diminished in the ovalbumin (OVA) model of airway hyperreactivity. In CD30(-/-) mice, the recruitment of eosinophils into the airways after OVA-aerosol challenge of OVA-primed mice was significantly diminished when compared with wild-type (w.t.) mice. IL-13 levels were also significantly reduced in CD30(-/-) mice while levels of IFN-gamma, IL-4, IL-5 and IgE in bronchoalveolar lavage fluid, lung tissue and serum were comparable to w.t. mice. Peribronchial lymph node cells from CD30(-/-) mice, re-stimulated in vitro with OVA, secreted significantly lower levels of IL-13 than those from w.t. mice, but showed normal proliferative response and other cytokine production. Exogenous IL-13 reconstituted airway recruitment of leukocytes in OVA-challenged CD3O(-/-) mice. Adoptive transfer to naive w.t. mice of in vitro OVA-re-stimulated spleen cells from CD30(-/-) mice failed to induce eosinophilic pulmonary inflammation in contrast to transfer of primed cells from w.t. mice. These results indicate that CD30 is a regulator of T(h)2 responses in the effector-memory phase and a regulator of IL-13 production in memory cells in the lung.

Presence of otitis media with effusion and its risk factors affect serum cytokine profile in children

Otitis media with effusion (OME) is a condition that has significant impact on the quality of life of children. Although the etiology is multi-factorial, certain risk factors such as an allergic predisposition, daycare, and cigarette smoke exposure contribute to its pathogenesis. (1) To determine whether there is a tendency for children with chronic or recurrent OME (cases) to have higher serum levels of the T-helper 2 cell (Th-2) allergenic-type cytokines, interleukin-4 (IL-4), and IL-5, or the T-helper 1(Th-1) infectious-type cytokines, interferon-gamma (IFN-gamma), and tumor necrosis factor-alpha (TNF-alpha), compared to children without a history of recurrent OME (controls) and (2) to determine any possible correlations between the cytokine levels and risk factors associated with OME. We analyzed serum levels of these four cytokines by enzyme-linked immunosorbent assays of 19 cases and 17 controls. Cases, independent of age, had increased levels of serum IL-5 compared to controls (p=0.014). While a significant difference in serum IL-4 levels did not exist between cases and controls, children exposed to cigarette smoke had significantly higher levels of serum IL-4 (p=0.003). While serum levels of IFN-gamma were statistically significantly higher in cases than controls with univariate analysis (p=0.011), when controlling for age and smoke exposure with multivariate analyses, the difference did not reach significance (p=0.086). These results suggest that patients with chronic or recurrent OME and those exposed to cigarette smoke mount a Th-2 allergic-like response, as demonstrated by their serum cytokines.

Serum cytokines profiles in Iranian patients with preeclampsia.

Preeclampsia is a major cause of mortality and morbidity and is also a leading cause of preterm birth and intrauterine growth retardation. Several studies have reported abnormal levels of cytokines in women with preeclampsia. To detect serum levels of various cytokines in pregnant women with and without preeclampsia in the third trimester of pregnancy. Thirty patients with preeclampsia and thirty normal pregnant women were enrolled in the study. Blood samples were taken and serum levels of IFN gamma, IL-12p70, IL-18, IL-15, IL-4 and IL-10 were measured by enzyme-linked immunosorbent assay (ELISA). Preeclamptic women had significantly increased levels of circulating IL-12p70 (p < 0.05), IL-18 (p < 0.001), IL-4 (p < 0.001), IL-15 (p < 0.05) and IFN gamma (p < 0.001). By contrast, circulating levels of IL-10 were not significantly different between the two groups. The present study supports the hypothesis of altered immune response in preeclampsia and suggests that dysregulation of cytokine expression occurs in preeclampsia with increased levels of IFN gamma, IL-12p70, IL-15, IL-18 and IL-4.

Cytokine Patterns and Lymphocyte Subsets in Patients with Chronic GVHD after Allogeneic Stem Cell Transplantation with Reduced Intensity Conditioning.

Background .Chronic GVHD (cGVHD) is the most common and severe late complication after allogeneic stem cell transplantation (SCT), because of increasing use of matched unrelated donors, peripheral blood stem cells and reduced intensity conditioning (RIC). Impaired immune reconstitution and unbalanced Th1-type or Th2-type immune response with cytokines dysregulation seem to play a key role in the pathogenesis of chronic GVHD (cGVHD).Aims. In order to study the immunologic mechanisms involved in cGVHD, we prospectively evaluated the Th1 (TNF-alpha, IFN-gamma) and Th2 (IL-4, IL-6, IL-10) cytokine patterns and lymphocyte subsets in the setting of allogeneic SCT-RIC.Patients and methods. We assessed by ELISA the serum levels of TNF-alpha, IFN-gamma, IL-4, IL-6, IL-10 and soluble tumor necrosis factor receptors I and II (sTNF-R) in 8 healthy donors and in 19 patients undergoing allogeneic SCT-RIC (13 patients with related and 6 patients with unrelated donor). Serum levels were assessed before transplantation and monthly from second to twelfth month after SCT. Total lymphocytes and their subsets with different co-stimulatory molecules (CD4, CD8, CD19, CD28/3,CD25/4, CD134/4, CD152/3, CD16/56, CD4/45ro, CD4/45ra, CD8/45ro, CD8/45ra) were evaluated by flow cytometry in peripheral blood (PB) monthly after SCT. Cyclosporine A was used as GVHD prophylaxis in all patients from third month until its tapering or until the beginning of the therapy against extensive cGVHD. Wilcoxon test was used for statistical analysis of the data.Results. Twelve out of 19 patients developed cGVHD at a median time of 7 months (range, 6–10); cGVHD was extensive in 8 patients at a median time of 8 months (range, 6–12). The levels of cytokines did not differ significantly in patients pre-SCT and healthy donors. Patients with cGVHD differed from those without cGVHD because of:1.significantly higher levels of TNF-alpha from third to sixth month after SCT (3rd, p=0.003; 4th p=0.001; 5th, p=0.0005; 6th, p=0.01);2.significantly higher levels of sTNF-R II at 6th (p=0.01);3.significantly higher levels of IL-10 (p= 0.004) at 4th month;4.significantly lower number of NK cells in PB from third to sixth month after SCT (3rd, p=0.004; 4th p=0.009; 5th, p=0.0007; 6th, p=0.0003);5.significantly lower number of CD 152/3 cells in PB from third to sixth month after SCT (3rd, p=0.009; 4th p=0.0004; 5th, p=0.0004; 6th, p=0.007);6.significantly lower number of CD 4/25 cells in PB at 4th (p=0.0004) and 5th (p=0.01)Discussion. Our sequential study showed:1.increased levels of Th1 (TNF-alpha) and Th2 (IL-10) cytokines with different kinetics after SCT and before the onset of cGVHD;2.a decrease of NK and T cells with regulatory molecules such as CD152 after SCT and before the onset of cGVHD.These results suggest an overall prevalence of a TNF-alpha oriented response in patients with cGVHD. Defects of immunoregulatory cells could be related to these fluctuating and unbalanced cytokine patterns. However, further studies with more patients are required to support these preliminary results.

ANALYSIS OF SELECTED CYTOKINES GENES POLYMORPHISMS IN PANCREATIC CANCER AND CHRONIC PANCREATITIS

Background: Several cytokines, such as tumor necrosis factor alpha (TNF alpha) and interferon gamma (IFN gamma), may be involved in pancreatic carcinogenesis, especially tumor dissemination and cachexia, related with extremely poor PA prognosis. The aim of the study was to asses the clinical significance of G-307A TNF alpha and A+874T INF gamma genes polymorphisms in PA and chronic pancreatitis (CP). Methods: The study included 120 patients: 31 with pancreatic adenocarcinoma, 51 with CP and 38 healthy controls. TNF alpha and INF gamma genes have been studied in DNA isolated from blood samples. The serum concentrations of TNF alpha and INF gamma have been measured with an enzyme-linked immunoassay (R&D Systems, USA). The associations of the analysed genotypes and clinical data at diagnosis have been evaluated. Results: The incidence of TNF alpha and INF gamma polymorphisms were similar in patients with PA, CP and control group (P > 0,5). Plasma levels of TNF alpha were significantly higher in PA patients (mean cytokine level:58,7 pg/ml) compared with CP patients (23,2 pg/ml) and control group (< 15,6 pg/ml; p < 0,01). In contrast, plasma levels of INF gamma in PA patients did not differ from those in the CP and control groups. In our study, there was no association between TNF alpha and IFN gamma serum levels as well as genes polymorphisms. Analysed polymorphisms were also unrelated to the tumor size, histological grade, regional or distant metastases or patients sex and age. Conclusion: These preliminary results indicate that analysed G-307A TNF alpha and A+874T INF gamma genes polymorphisms probably do not play the significant role in pancreatic carcinogenesis. Work supported by Medical University of Lodz, grant 502-11-537

Dendritic cells pulsed with glioma RNA induce immunity against intracranial gliomas

To investigate the anti-tumor effect of dendritic cells (DC) pulsed with G422 glioblastomas RNA in mice bearing intracranially G422 glioblastomas. DCs were pulsed in vitro with glioblastomas G422 cell RNA. The tumor-bearing mice were injected intratumorally or subcutaneously with pulsed DCs, PBS, non-pulsed DCs. The survival duration of mice was recorded. Serum levels of cytokine IFN-gamma, IL-2, IL-10, IL-4 were detected. Pathological examination was performed. The survival duration of mice with DC-based vaccine increased significantly(P<0.01). The serum IFN-gamma level was increased (P<0.01) and IL-10 level was decreased (P<0.05) after treatment. Pathological examination showed necrotic tumor in the treatment mice. DC vaccination can significantly increase survival duration of mice with intratumoral or subcutaneous administration of vaccines.

Splenectomy does not interfere with immune response to Leishmania major infection in mice

Spleen is one of the largest lymphoid organs in the body; it harbors immune cells including antigen presenting cells, B and T lymphocytes. It has an important role in humoral and cellular immune responses. Herein we investigated the role of spleen in the immune response to experimental Leishmania major infection. It is known that C57BL/6 mice are resistant to L. major infection whereas BALB/c mice are susceptible. Although splenectomy was associated with reduced serum levels of IFN-gamma, absence of the spleen did not change the profile of L. major infection in the resistant C57BL/6 and BALB/c susceptible mice. Both strains of mice maintained the same profile of cytokine production in regional lymph nodes after splenectomy and responded in the same way against the infection. Only splenectomized BALB/c mice had a reduction in IL-4 and IL-10 production by lymph node cells early in infection. Our data suggest that, in localized infections, regional lymph nodes may replace efficiently the immunological role of spleen in the cellular and humoral immune responses.

Involvement of immune response in anti-tumor effects of Staphylococcus Aureus Filtrate Preparation

Staphylococcus Aureus Filtrate Preparation (SAFP) is a preparation of low-virulence strain of Staphylococcus aureus. In our study, we aimed to determine the anti-tumor activity of SAFP in vivo and explore the potential mechanism. Our study evaluated the anti-tumor activity of SAFP in four cancer cell models in vivo and determined its up-regulatory effects on mice immune system in vivo. It showed that 7.2 ng/10 g SAFP could inhibit the progression of murine hepatoma H22 and sarcoma S180, and the tumor inhibition rates achieved 48.1 and 35.7%, respectively. In human non-small cell lung cancer A549 and hepatoma BEL7402 xenograft athymic mice models, T/C of 7.2 ng/10 g SAFP group reached 41.0% in A549 model and 21.0% in BEL7402 model. Meanwhile, SAFP also significantly increased the proliferation of cultured mice splenocytes to 162.1%, and 7.2 ng/kg SAFP significantly (P < 0.001) raised the activity of NK cells, elevated the serum level of IL-2, TNF-alpha and IFN-gamma in mice. SAFP exhibited high efficiency in inhibiting the growth of cancer cells in a dose-dependent manner, which possibly attributed to its regulatory effects of immune system.

Role for nerve growth factor in the in vivo regulation of glutathione in response to LPS in mice.

Since the redox state regulator glutathione (GSH), which influences lipopolysaccharide (LPS) anorexia, may be controlled by cytokines, we studied the roles of tumour necrosis factor-alpha (TNFalpha) and nerve growth factor (NGF) in the GSH response to intraperitoneal (ip) LPS injection in mice. Basal NGF and total reduced GSH (trGSH) levels were up-regulated in brain and liver of TNFalpha-knock-out (KO) mice, and this was associated with attenuated LPS anorexia. The increases in NGF and trGSH presumably contributed to the attenuated anorexia in response to LPS because transgenic mice over-expressing NGF (NGF-tg mice) also had increased trGSH levels and displayed attenuated anorexia compared to the corresponding wild type (WT) mice. Attenuated LPS anorexia in NGF-tg mice was accompanied by reduced serum TNFalpha and IFNgamma levels compared to WT mice. In response to a second injection of LPS, NGF and trGSH levels, but not TNFalpha levels changed. This suggests that in vivo tissue trGSH changes following LPS in LPS-naïve or LPS-pretreated mice are regulated by NGF rather than TNFalpha. The finding that genetic TNFalpha deficiency did not inhibit the acute trGSH response to LPS supports this interpretation. In sum, the results indicate i) that a decrease or increase in NGF is accompanied by a decrease or increase in trGSH levels and ii) that elevated NGF and/or trGSH levels attenuate some of the responses to LPS such as anorexia and cytokine production.

Enhancement of IFN-γ production for Th1-cell therapy using negatively charged liposomes containing phosphatidylserine

We have developed an efficient method of interferon-gamma (IFN-gamma) induction for Th1-cell therapy. OVA (ovalbumin)-specific Th1 clone 42-6A cells cocultured with antigen presenting cells (APCs) from spleen resulted in high levels of OVA-specific IFN-gamma production by the treatment of phosphatidylserine (PS), but not phosphatidic acid (PA), liposomes-encapsulated OVA (OVA-liposomes). The IFN-gamma production was increased in a manner dependent on the PS content of the liposomes and inhibited by the addition of annexin V, a PS binding protein. Furthermore, coadministration of Th1 cells plus OVA-liposomes in mice strikingly enhanced IFN-gamma levels in serum and in spleen cells compared with that of Th1 cells plus OVA. In addition, serum levels of IL-12 p70 increased and ongoing OVA-specific IgE immune response was dramatically attenuated. These results first suggest that antigen delivery using negatively charged liposomes containing PS is very useful for the enhancement of IFN-gamma production in Th1-cell therapy.

The Mechanism of How Anti-IL-18 Prevents Concanavalin-A-Induced Hepatic Fibrosis on a Mouse Model

The administration of concanavalin A (ConA) induces severe hepatic fibrosis in mice. Tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma) and interleukin 4 (IL-4) were the key cytokines involved in the process. The aim of this research was to explore the effects and the mechanisms of IL-18 and anti-IL-18 on hepatic fibrosis in a ConA induced hepatic fibrosis model in BABL-C mice. One hundred eighty BABL-C mice were randomly divided into five groups (Group a, b, c, d, e). The mice were administered saline, immunoglobulin G, ConA, IL-18 + ConA, Anti-IL-18 + ConA, respectively. At 1, 7, 14, 21 wk, the levels of serum alanine aminotransferase, TNF-alpha, IFN-gamma, IL-4, matrix metalloproteinase (MMP)-2-RNA, and tissue inhibitor of metalloproteinase-1-mRNA were measured. The levels of serum TNF-alpha and IFN-gamma detected in the IL-18 + ConA group was higher than in the anti-IL-18 + ConA group (P < 0.05). Similarly, the levels of MMP-2-RNA and tissue inhibitor of metalloproteinase-1-mRNA expressed in IL-18 + ConA group was higher than in the anti-IL-18 + ConA group (P < 0.05). A majority of these cytokines was secreted by CD4(+)T cells. The immunological response to hepatic fibrosis by repeated injection of ConA in the mouse model was aggravated by IL-18 and blocked by anti-IL-18.

Lambda interferon (IFN-lambda) in serum is decreased in hantavirus-infected patients, and in vitro-established infection is insensitive to treatment with all IFNs and inhibits IFN-gamma-induced nitric oxide production.

Hantaviruses, causing hemorrhagic fever with renal syndrome (HFRS) and hantavirus cardiopulmonary syndrome (HCPS), are known to be sensitive to nitric oxide (NO) and to pretreatment with type I and II interferons (alpha interferon [IFN-alpha]/IFN-beta and IFN-gamma, respectively). Elevated serum levels of NO and IFN-gamma have been observed in HFRS patients, but little is known regarding the systemic levels of other IFNs and the possible effects of hantaviruses on innate antiviral immune responses. In Puumala virus-infected HFRS patients (n = 18), we report that the levels of IFN-alpha and IFN-beta are similar, whereas the level of IFN-lambda (type III IFN) is significantly decreased, during acute (day of hospitalization) compared to the convalescent phase. The possible antiviral effects of IFN-lambda on the prototypic hantavirus Hantaan virus (HTNV) replication was then investigated. Pretreatment of A549 cells with IFN-lambda alone inhibited HTNV replication, and IFN-lambda combined with IFN-gamma induced additive antiviral effects. We then studied the effect of postinfection treatment with IFNs. Interestingly, an already-established HTNV infection was insensitive to subsequent IFN-alpha, -beta, -gamma, and -lambda stimulation, and HTNV-infected cells produced less NO compared to noninfected cells when stimulated with IFN-gamma and IL-1beta. Furthermore, less phosphorylated STAT1 after IFN treatment was observed in the nuclei of infected cells than in those of noninfected cells. The results suggest that hantavirus can interfere with the activation of antiviral innate immune responses in patients and inhibit the antiviral effects of all IFNs. We believe that future studies addressing the mechanisms by which hantaviruses interfere with the activation and shaping of immune responses may bring more knowledge regarding HFRS and HCPS pathogenesis.

Th cell differentiation in chronic stage of viral myocarditis in mice and interference of Qingxin-Ⅱ Recipe

To investigate part mechanisms of Th cell differentiation, and to observe the interference effect of Qingxin-II Recipe in the chronic stage of viral myocarditis (VMC), so as to provide some experimental evidences for illuminating the pathogenesis of VMC and treatment mechanisms of Qingxin-II Recipe. According to 20%-40% death rate of experiment in advance, 100 BALB/c male mice (4 weeks old and weighing 12-15 g) were used. Twenty mice were randomly assigned to normal control group, and the other 80 mice were intraperitoneally injected with 0.1 ml normal saline containing coxsackie virus B3 at the 1st, 4th and 28th day (the virus densities were 1:2000, 1:1000 and 1:500 respectively) to induce chronic VMC. At the 42nd day, the surviving mice were randomly divided into untreated group and treatment group, with 20 mice in each group. Mice in the treatment group were orally administered with 0.2 ml Qingxin-II Recipe every day, while mice in the normal control group and the untreated group were administered with 0.2 ml normal saline. All the mice were sacrificed after 45 days, and the sera, heart and spleen cells were collected. Then the myocardial pathological changes were observed by using a light microscope, and the levels of IL-4, IL-10 and IFN-gamma in serum were detected by enzyme linked immunosorbent assay (ELISA). And the Th cell differentiation was observed by flow cytometry. No obvious myocardial pathological changes were observed in mice of the normal control group. Myocardial pathological changes in the treatment group were slighter than those in the untreated group. The difference of serum IL-10 level between the normal control group and the untreated group showed no significance (P>0.05), and the levels of IFN-gamma and IL-4 of the untreated group were higher than those of the normal control group (P<0.05 or P<0.01). There was no statistical difference in IL-10 level between the treatment group and the untreated group (P>0.05), while the serum levels of IL-4 and IFN-gamma of the treatment group were lower than those of the untreated group (P<0.05 or P<0.01). There was no significant difference of the Th1 cell responder between the treatment group and the untreated group (P>0.05), while the Th2 cell responder was inhibited significantly in the treatment group (P<0.05). Qingxin-II Recipe can restore the balance of Thl and Th2 cells through inhibiting the reaction of Th2.

TGF-beta insensitive dendritic cells: an efficient vaccine for murine prostate cancer.

Dendritic cells (DCs) are highly potent initiators of the immune response, but DC effector functions are often inhibited by immunosuppressants such as transforming growth factor beta (TGF-beta). The present study was conducted to develop a treatment strategy for prostate cancer using a TGF-beta-insensitive DC vaccine. Tumor lysate-pulsed DCs were rendered TGF-beta insensitive by dominant-negative TGF-beta type II receptor (TbetaRIIDN), leading to the blockade of TGF-beta signals to members of the Smad family, which are the principal cytoplasmic intermediates involved in the transduction of signals from TGF-beta receptors to the nucleus. Expression of TbetaRIIDN did not affect the phenotype of transduced DCs. Phosphorylated Smad-2 was undetectable and expression of surface co-stimulatory molecules (CD80/CD86) were upregulated in TbetaRIIDN DCs after antigen and TGF-beta1 stimulation. Vaccination of C57BL/6 tumor-bearing mice with the TbetaRIIDN DC vaccine induced potent tumor-specific cytotoxic T lymphocyte responses against TRAMP-C2 tumors, increased serum IFN-gamma and IL-12 level, inhibited tumor growth and increased mouse survival. Furthermore, complete tumor regression occurred in two vaccinated mice. These results demonstrate that blocking TGF-beta signals in DC enhances the efficacy of DC-based vaccines.

Clinical Features, Serum Interleukin-6, and Interferon-γ Levels of 34 Turkish Patients With Hepatoportal Sclerosis

Hepatoportal sclerosis (HPS) is a clinical disorder of obscure pathogenesis with a variable clinical profile. The aim of the study was to summarize the clinical features of Turkish patients with HPS and to measure the serum levels of interleukin (IL)-6 and interferon (IFN)-gamma to determine the T helper cell profile in the pathogenesis. The study was conducted on 34 HPS patients (17 men, 17 women; mean age at diagnosis, 27+/-10 years) and 15 healthy controls. The clinical features of HPS patients including demographics, clinical history, laboratory, and ultrasonography findings were summarized. Serum IL-6 and IFN-gamma levels were measured by using commercially available enzyme-linked immunosorbent assay kits. Gastrointestinal bleeding was the most common dominant presenting symptom. Majority of the patients had preserved liver function tests. Serum triglyceride levels were decreased in 30%. Abdominal ultrasonography revealed well-demarcated bands of increased echogenicity surrounding the portal vein wall and sudden narrowing of the intrahepatic second-degree portal vein branches in all cases. Spontaneous shunts and/or collaterals were seen in 13 cases (37%). Extrahepatic portal vein thrombosis were seen in 7 (20%) patients after at least 5 years of disease duration. Serum levels of both IL-6 (median, 3.2 pg/mL) and IFN-gamma (median, 7.8 pg/mL) were significantly higher in HPS patients compared with the control group (median, 1 pg/mL). HPS has variable clinical profile in different geographic areas of the world. Both Th1 and 2 cells may have a role in the regulation of immune response and pathogenesis of the disease.

4-1BB engagement costimulates NKT cell activation and enhances airway hyperreactivity and airway inflammation mediated by NKT cells (88.19)

Abstract Multiple studies have demonstrated that 4-1BB (CD137), a member of the TNF receptor superfamily, is expressed in several immune cells, including activated T cells. However, the expression and the potential roles of 4-1BB on CD1d-restricted invariant NKT (iNKT) cell have not fully characterized. In this study, it was demonstrated that 4-1BB on iNKT cells was consititutively expressed, and the expressions was increased by TCR engagement. Also, 4-1BB signaling provided by 3H3, an anti-4-1BB agonistic mAb, promoted iNKT cells activation, resulting in enhanced proliferation and cytokine production of iNKT cells driven by alpha-galactosylcerimide (alpha-GalCer) or anti-CD3 mAb in vitro. Administration of 3H3 further increased IL-4 and IFN-gamma levels in serum induced by alpha-GalCer administration in vivo. When 3H3 and alpha-GalCer were intranasally co-administrated, airway hyperreacitivity and inflammatory cell accumulation were severely aggravated. In conclusion, 4-1BB on iNKT cell functions as a costimulatory molecule, and facilitates the induction of more severe airway hyperreacitivity and inflammatory cell accumulation in NKT cell-mediated airway inflammation.

IL‐18 time‐dependently modulates Th1/Th2 cytokine production by ligand‐activated NKT cells

While IL-18 synergizes with IL-12 to induce a Th1 immune response, it also promotes a Th2 response. Here we investigate the modulatory role of IL-18 on the Th1/Th2 cytokine response. The injection of alpha-galactosylceramide (alpha-GalCer), a ligand for NKT cells, elevated mouse serum levels of both IFN-gamma and IL-4. When the mice were treated 2 h before alpha-GalCer challenge with IL-18, IFN-gamma production but not IL-4 production was remarkably up-regulated. In contrast, pretreatment with IL-18 6 h before the challenge enhanced IL-4 production. However, this IL-18-enhanced IL-4 production was not elicited in mice injected with anti-CD3 Ab. Liver mononuclear cells (MNC) produced a similar cytokine production pattern when MNC from mice treated with IL-18 either 2 h or 6 h before challenge were stimulated with alpha-GalCer in vitro. Expression of SOCS1 and SOCS3 was notably up-regulated in the liver MNC from mice pretreated 6 h before with IL-18; in particular, SOCS3 expression was confined to the liver NKT cells. Inhibition of SOCS3 by RNA interference up-regulated the phosphorylation of STAT3 and suppressed in vitro IL-4 production by IL-18-primed liver MNC stimulated with alpha-GalCer, but it did not affect IFN-gamma production. These results suggest that IL-18 time-dependently modulates Th1/Th2 cytokine production in ligand-activated NKT cells by regulating/inducing SOCS3 expression.

Synergistic Therapeutic Potential of Dexamethasone and l-arginine in Lipopolysaccharide-Induced Septic Shock

Dexamethasone (DEX) is demonstrated to have anti-inflammatory properties and known to induce hemodynamic improvement in sepsis and septic shock. L-arginine (L-arg), a semi-essential amino acid, depending on its metabolic pathway, becomes very essential in stress situations such as heatstroke, burns, sepsis, trauma, and wound healing. The aim of this study was to evaluate the synergistic therapeutic effect of DEX and L-arg in rescuing the mice from experimental septic shock induced by bacterial lipopolysaccharide (LPS). The experiments were designed to delineate the molecular mechanisms responsible for the increased therapeutic benefit of the combination therapy (CT) in LPS-induced septic shock. Acute endotoxemia was induced in Swiss male mice by i.p. injection of LPS (18 mg kg(-1)) at 0 h. LPS-treated mice were divided into four groups. The first group (DEX group) received DEX (2 mg kg(-1)) i.p. at +2 h of LPS. The second group (L-arg group) received L-arg i.p. at a dose of 120 mg/kg at +6 h of LPS injection. The third group (CT group) received DEX (2 mg kg(-1)) at +2 h LPS followed by L-arg at +6 h of LPS injection. The fourth group received saline in place of L-arg or DEX (LPS group). A sham group was also included, where normal mice received saline in place of LPS or L-arg or DEX. At +6 h, mice from sham group, LPS group, and DEX group were sacrificed at +24 h. Mice from sham group, DEX group, L-arg group, and CT group were sacrificed to examine various parameters associated with LPS endotoxemia. The CT with DEX followed by L-arg significantly increased the survival of mice injected with a lethal dose of LPS. Monotherapy with either DEX or L-arg given at the same dose and time did not increase the survival of the mice injected with LPS. DEX administration could significantly reduce the levels of serum TNF-alpha, IL-1beta, IFN-gamma, aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT), and nitrite. DEX also down-regulated the expression of liver-inducible nitric oxide synthase (iNOS), and up-regulated the levels of serum anti-inflammatory cytokines like TGF-beta1 and IL-4, hepatic and splenic arginase, in LPS-injected mice. The enhanced therapeutic effect of CT correlated with reduced pathological symptoms, decreased Th1 cytokines, increased TGF-beta1 and arginase levels compared to the mice administered with either of the monotherapies. The CT group had significantly increased expression of hepatic Hsp 70 and reduced septic shock associated histopathology, in lung and liver, compared to the mice treated with either DEX or L-arg. The therapeutic combination therapy with DEX and L-arg, at the appropriate dose, time, and sequence of administration, changed the cytokine profile, in favor of reducing the inflammatory response. The significantly enhanced survival observed in the CT group was accompanied by an increased hepatic Hsp 70, hepatic arginase, splenic arginase, and decreased organ injury. This novel concept of combined therapy could form the basis of an effective therapeutic approach in the treatment of sepsis and septic shock.