Synergistic effects of IL-4 and IL-18 on IL-12-dependent IFN-gamma production by dendritic cells

Preparation and immunological activity evaluation of an intranasal protein subunit vaccine against ancestral and mutant SARS-CoV-2 with curdlan sulfate/O-linked quaternized chitosan nanoparticles as carrier and adjuvant

Chitosan and its derivatives are ideal nasal vaccine adjuvant to deliver antigens to immune cells. Previously, we successfully used a chitosan derivative, O-(2-Hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (O-HTCC), and a β-glucan derivative, curdlan sulfate (CS), to prepare a nanoparticle adjuvant CS/O-HTCC which could deliver ovalbumin to antigen presenting cells (APCs) through nasal inhalation. In this article, we used SARS-CoV-2 spike receptor binding domain (S-RBD) as the antigen and CS/O-HTCC nanoparticles as the adjuvant to develop a nasal mucosal protein subunit vaccine, CS/S-RBD/O-HTCC. The humoral immunity, cell-mediated immunity and mucosal immunity induced by vaccines were evaluated. The results showed that CS/S-RBD/O-HTCC could induce desirable immunization with single or bivalent antigen through nasal inoculation, giving one booster vaccination with mutated S-RBD (beta) could bring about a broad cross reaction with ancestral and different mutated S-RBD, and vaccination of the BALB/c mice with CS/S-RBD/O-HTCC containing S-RBD mix antigens (ancestral and omicron) could induce the production of binding and neutralizing antibodies against both of the two antigens. Our results indicate that CS/O-HTCC is a promising nasal mucosal adjuvant to prepare protein subunit vaccine for both primary and booster immunization, and the adjuvant is suitable for loading more than one antigen for preparing multivalent vaccines.

Association of HBV serological markers with host antiviral immune response relevant hepatic inflammatory damage in chronic HBV infection

The natural progression of chronic hepatitis B virus (HBV) infection is dynamic, but the longitudinal landscape of HBV serological markers with host antiviral immune response relevant hepatic inflammatory damage remains undetermined. To this issue, we studied the association of HBV serological markers with the severity of hepatic inflammatory damage and enumerated HBV-specific T cells using the cultured enzyme-linked immune absorbent spot (ELISpot). Five hundred and twenty-four treatment-naïve chronic HBV infection patients were enrolled. The Spearman correlation analysis revealed that in hepatitis B e antigen (HBeAg)-positive patients, all HBV virologic indicators negatively correlated with liver inflammatory damage and fibrosis (p < 0.01). Stronger correlations were accessed in the subgroup of HBeAg-positive patients with HBV DNA > 2 × 106 IU/mL (p < 0.01), whereas negative correlations disappeared in patients with HBV DNA ≤ 2 × 106 IU/mL. Surprisingly, in HBeAg-negative patients, the HBV DNA level was positively correlated with the hepatic inflammatory damage (p < 0.01). The relationship between type Ⅱ interferon genes expression and HBV DNA levels also revealed a direct shift from the initial negative to positive in HBeAg-positive patients with HBV DNA declined below 2 × 106 IU/mL. The number of HBV-specific T cells were identified by interferon γ ELISpot assays and showed a significant increase from HBeAg-positive to HBeAg-negative group. The host's anti-HBV immunity remains effective in HBeAg-positive patients with HBV DNA levels exceeding 2 × 106 IU/mL, as it efficiently eliminates infected hepatocytes and inhibits HBV replication. However, albeit the increasing number of HBV-specific T cells, the host antiviral immune response shifts towards dysfunctional when the HBV DNA load drops below this threshold, which causes more pathological damage and disease progression.

Epigenetics in T-cell driven inflammation and cancer

For decades, scientists have been investigating how processes such as gene expression, stem cell plasticity, and cell differentiation can be modulated. The discovery of epigenetics helped unravel these processes and enabled the identification of major underlying mechanisms that, for example, are central for T cell maturation. T cells go through various stages in their development evolving from progenitor cells into double positive CD4/CD8 T cells that finally leave the thymus as naïve T cells. One major mechanism driving T cell maturation is the modulation of gene activity by temporally sequenced transcription of spatially exposed gene loci. DNA methylation, demethylation, and acetylation are key processes that enable a sequenced gene expression required for T cell differentiation. In vivo, differentiated T cells are subjected to enormous pressures originating from the microenvironment. Signals from this environment, particularly from an inflammatory or a tumor microenvironment, can push T cells to differentiate into specific effector and memory T cells, and even prompt T cells to adopt a state of dysfunctional exhaustion, en route of an epigenetically controlled mechanism. Fundamentals of these processes will be discussed in this review highlighting potential therapeutic interventions, in particular those beneficial to revive exhausted T cells.

Recent Emerging Immunological Treatments for Primary Brain Tumors: Focus on Chemokine-Targeting Immunotherapies

Primary brain tumors are a leading cause of death worldwide and are characterized by extraordinary heterogeneity and high invasiveness. Current drug and radiotherapy therapies combined with surgical approaches tend to increase the five-year survival of affected patients, however, the overall mortality rate remains high, thus constituting a clinical challenge for which the discovery of new therapeutic strategies is needed. In this field, novel immunotherapy approaches, aimed at overcoming the complex immunosuppressive microenvironment, could represent a new method of treatment for central nervous system (CNS) tumors. Chemokines especially are a well-defined group of proteins that were so named due to their chemotactic properties of binding their receptors. Chemokines regulate the recruitment and/or tissue retention of immune cells as well as the mobilization of tumor cells that have undergone epithelial–mesenchymal transition, promoting tumor growth. On this basis, this review focuses on the function and involvement of chemokines and their receptors in primary brain tumors, specifically examining chemokine-targeting immunotherapies as one of the most promising strategies in neuro-oncology.

IFN-γ Contributes to the Immune Mechanisms of Hypertension

Hypertension is the leading cause of cardiovascular disease and the primary risk factor for mortality worldwide. For more than half a century, researchers have demonstrated that immunity plays an important role in the development of hypertension; however, the precise mechanisms are still under investigation. The current body of knowledge indicates that proinflammatory cytokines may play an important role in contributing to immune-related pathogenesis of hypertension. Interferon gamma (IFN-γ), in particular, as an important cytokine that modulates immune responses, has been recently identified as a critical regulator of blood pressure by several groups, including us. In this review, we focus on exploring the role of IFN-γ in contributing to the pathogenesis of hypertension, outlining the various immune producers of this cytokine and described signaling mechanisms involved. We demonstrate a key role for IFN-γ in hypertension through global knockout studies and related downstream signaling pathways that IFN-γ production from CD8+ T cell (CD8T) in the kidney promoting CD8T-stimulated salt retention via renal tubule cells, thereby exacerbating hypertension. We discuss potential activators of these T cells described by the current literature and relay a novel hypothesis for activation.

Evaluation of the Immunogenicity in Mice Orally Immunized with Recombinant Lactobacillus casei Expressing Porcine Epidemic Diarrhea Virus S1 Protein

Porcine epidemic diarrhea (PED), characterized by diarrhea, vomiting, and dehydration, is an acute enteric infectious disease of pigs. The disease is caused by porcine epidemic diarrhea virus (PEDV), which infects the intestinal mucosal surface. Therefore, mucosal immunization through the oral route is an effective method of immunization. Lactic acid bacteria, which are acid resistant and bile-salt resistant and improve mucosal immunity, are ideal carriers for oral vaccines. The S1 glycoprotein of PEDV mediates binding of the virus with cell receptors and induces neutralizing antibodies against the virus. Therefore, we reversely screened the recombinant strain pPG-SD-S1/Δupp ATCC 393 expressing PEDV S1 glycoprotein by Lactobacillus casei deficient in upp genotype (Δupp ATCC 393). Mice were orally immunized three times with the recombinant bacteria that had been identified for expression, and the changes of anti-PEDV IgG and secreted immunoglobulin A levels were observed over 70 days. The results indicated that the antibody levels notably increased after oral administration of recombinant bacteria. The detection of extracellular cytokines on the 42nd day after immunization indicated high levels of humoral and cellular immune responses in mice. The above results demonstrate that pPG-SD-S1/Δupp ATCC 393 has great potential as an oral vaccine against PEDV.

Characterization of agapornis fischeri interferon gamma and its activity against beak and feather disease virus

This study sought to clone and sequence the interferon-γ (IFN-γ) gene of the Fischer's lovebird parrot (Agapornis fischeri). Raw264.7 cells treated with the expressed IFN-γ protein exhibited an upregulation in inducible nitric oxide synthase protein expression and nitric oxide (NO) production coupled with increases in phagocytosis and pinocytosis, as well as an induction of interferon-stimulated genes through the activation of the NF-κB factor, all of which are indicators of the innate immune responses of the activated macrophages. Similar to the IFN-γ protein of other species, the NO production activity of the parrot IFN-γ protein decreased by 80% after exposure at 60 °C for 4 min. Additionally, only half of the NO production activity of the parrot IFN-γ protein remained upon exposure to HCl for 30 min. These findings suggested that the parrot IFN-γ protein was heat-labile and sensitive to acidic conditions. Therefore, all of these effects contributed to the blockage of the uptake of BFDV virus-like particles (VLPs) by cells, the nuclear entry of the Cap protein of BFDV VLPs, and the clearance of the virus from BFDV-infected parrots by the IFN-γ protein of Agapornis fischeri. This study is the first to describe the cloning of the IFN-γ gene of Agapornis fischeri and characterize the anti-beak and feather disease virus activity of the IFN-γ protein of Agapornis fischeri.

Association of interleukin-18 genotypes (-607C > A) and (-137 G > C) with the hepatitis B virus disease progression to hepatocellular carcinoma

Chronic infection with HBV has been reported to be associated with the development of HCC. The inflammation mounted by cytokine-mediated immune system plays an important role in the pathogenesis of HBV-associated HCC. IL-18 is a pro-inflammatory cytokine whose role in the development of HBV-associated chronic to malignant disease state has not been much studied. The present study was conceived to determine the role of genetic polymorphisms in IL-18, serum levels of IL-18, and expression level of its signal transducers in the HBV disease progression. A total of 403 subjects were enrolled for this study including 102 healthy subjects and 301 patients with HBV infection in different diseased categories. Polymorphism was determined using PCR-RFLP. Genotypic distributions between the groups were compared using odd's ratio and 95% CI were calculated to express the relative risk. Circulating IL-18 levels were determined by ELISA. Expression levels of pSTAT-1 and pNFƙB was determined by western blotting. In case of IL-18(- 607C > A), the heterozygous genotype (CA) was found to be a protective factor while in case of IL-18(- 137G > C) the heterozygous genotype (GC) acted as a risk factor for disease progression from HBV to HCC. Moreover, serum IL-18 levels were significantly increased during HBV disease progression to HCC as compared to controls. Also the levels of activated signal transducers (pSTAT-1 and pNF-κB) of IL-18 in stimulated PBMCs were significantly increased during HBV to HCC disease progression. These findings suggest that IL-18 has the potential to act as a biomarker of HBV-related disease progression to HCC.

Effect of O-linked glycosylation on the antigenicity, cellular uptake and trafficking in dendritic cells of recombinant Ber e 1

Ber e 1, a major Brazil nut allergen, has been successfully produced in the yeast Pichia pastoris expression system as homogenous recombinant Ber e 1 (rBer e 1) with similar physicochemical properties and identical immunoreactivity to its native counterpart, nBer e 1. However, O-linked glycans was detected on the P.pastoris-derived rBer e 1, which is not naturally present in nBer e 1, and may contribute to the allergic sensitisation. In this study, we addressed the glycosylation differences between P. pastoris-derived recombinant Ber e 1 and its native counterparts. We also determined whether this fungal glycosylation could affect the antigenicity and immunogenicity of the rBer e 1 by using dendritic cells (DC) as an immune cell model due to their role in modulating the immune response. We identified that the glycosylation occurs at Ser96, Ser101 and Ser110 on the large chain and Ser19 on the small polypeptide chain of rBer e 1 only. The glycosylation on rBer e 1 was shown to elicit varying degree of antigenicity by binding to different combination of human leukocyte antigens (HLA) at different frequencies compared to nBer e 1 when tested using human DC-T cell assay. However, both forms of Ber e 1 are weak immunogens based from their low response indexes (RI). Glycans present on rBer e 1 were shown to increase the efficiency of the protein recognition and internalization by murine bone marrow-derived dendritic cells (bmDC) via C-type lectin receptors, particularly the mannose receptor (MR), compared to the non-glycosylated nBer e 1 and SFA8, a weak allergenic 2S albumin protein from sunflower seed. Binding of glycosylated rBer e 1 to MR alone was found to not induce the production of IL-10 that modulates bmDC to polarise Th2 cell response by suppressing IL-12 production and DC maturation. Our findings suggest that the O-linked glycosylation by P. pastoris has a small but measurable effect on the in vitro antigenicity of the rBer e 1 compared to its non-glycosylated counterpart, nBer e 1, and thus may influence its applications in diagnostics and immunotherapy.

White Tip Silver Needle (Slightly Fermented White Tea) Flavonoids Help Prevent Aging via Antioxidative and Anti-Inflammatory Effects

AIM

White tip silver needle, a slightly fermented white tea, is abundant in flavonoids, and it has great significance in terms of D-galactose/lipopolysaccharide-induced aging in mice.

METHODS

We analyzed the antioxidant capacity of white tip silver needle flavonoids (WTSNF) in vitro, assessed the effects of WTSNF on organ indexes, pathological changes, liver function indexes, biochemical indicators, molecular biological indicators, and genes related to oxidation and inflammation.

RESULTS

Ultra-high performance liquid chromatography-tandem mass spectrometry results showed that WTSNF contained baicalin, kaempferol, kaempferide, quercetin, isorhamnetin, lespenephryl, and rutin. WTSNF showed strong scavenging ability for both 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) free radicals. Pathological analysis results showed that WTSNF reduced liver, kidney, and lung damage in mice with induced aging. In the serum and liver tissue, WTSNF effectively increased the antioxidant-related levels of superoxide dismutase, catalase, glutathione peroxidase, glutathione, and total antioxidant capacity and reduced the levels of aspartate aminotransferase, alanine aminotransferase, malondialdehyde and nitric oxide. WTSNF also reduced the inflammation-related levels of interleukin-6, interleukin-1 beta, tumor necrosis factor alpha (TNFα), and interferon gamma (IFN-γ) and increased the levels of interleukin-10 and interleukin-12. Furthermore, WTSNF upregulated the mRNA expression levels of cupro-zinc superoxide dismutase, manganese superoxide dismutase, catalase, glutathione peroxidase, interleukin-10, neuronal nitric oxide synthase, endothelial nitric oxide synthase, nuclear factor erythroid 2-related factor, heme oxygenase 1, NAD(P)H dehydrogenase [quinone] 1, nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IκB-α), and thioredoxin, while it downregulated the mRNA expression levels of interleukin-6, interleukin-18, interleukin-1 beta, TNFα, IFN-γ, inducible nitric oxide synthase, cyclooxygenase-2, and nuclear factor kappa-light chain-enhancer of activated B cells (NF-κB).

CONCLUSION

WTSNF is a high-quality natural product with antioxidative and anti-inflammatory properties that can inhibits D-galactose/lipopolysaccharide-induced aging in mice.

Interferons at the crossroad of cell death pathways during gastrointestinal inflammation and infection

Interferons (IFNs) are pleiotropic immune-modulatory cytokines that are well known for their essential role in host defense against viruses, bacteria, and other pathogenic microorganisms. They can exert both, protective or destructive functions depending on the microorganism, the targeted tissue and the cellular context. Interferon signaling results in the induction of IFN-stimulated genes (ISGs) influencing different cellular pathways including direct anti-viral/anti-bacterial response, immune-modulation or cell death. Multiple pathways leading to host cell death have been described, and it is becoming clear that depending on the cellular context, IFN-induced cell death can be beneficial for both: host and pathogen. Accordingly, activation or repression of corresponding signaling mechanisms occurs during various types of infection but is also an important pathway for gastrointestinal inflammation and tissue damage. In this review, we summarize the role of interferons at the crossroad of various cell death pathways in the gut during inflammation and infection.

Immune disruption occurs through altered gut microbiome and NOD2 in arsenic induced mice: Correlation with colon cancer markers

The gut microbial compositions are easily affected by the environmental chemicals like arsenic (As) leading to dysbiosis. The dysbiosis of gut microbiome has associated with numerous diseases; among which cancer is one of the major diseases. The meticulous mechanism underlying As- altered gut microbiome, Nucleotide domine containing protein 2 (NOD2) and how altered gut microbiome disturbs the intestinal homeostasis to regulate colon cancer markers remains unclear. For this, one hundred twenty 8-week old age male mice were divided into two exposure periods (3 and 6 months), and each exposure group animals were further divided into four groups as control (received only distilled H₂O), low (0.15 mg As₂O₃/L), medium (1.5 mg As₂O₃/L) and high (15 mg As₂O₃/L) dose (each group containing 15 mice) administrated for 3 and 6 months. The results showed that As exposure highly altered gut microbiome with a significant depletion in NOD2 in contrast to control groups. Moreover, the dendritic cells (CD11a, CD103, CX3CR1) and macrophages (F4/80) were significantly increased by As exposure. Interestingly, increased trend of inflammatory cytokines (TNF-α, IFN-γ, IL-17) and depleted anti-inflammatory cytokines (IL-10) was observed in As exposed mice. Furthermore, the colon cancer markers β-catenin has increased while APC was arrested by As both in 3 and 6 months treated animals. Many studies reported that As altered gut microbial compositions, in this study, our results suggested that altered gut microbiome indirectly regulates colon cancer marker through immune system destruction mediated by inflammatory cytokines.

Genetic association of interleukin 18 (-607C/A, rs1946518) single nucleotide polymorphism with asthmatic children, disease severity and total IgE serum level

Introduction

Bronchial asthma is a chronic inflammatory disease. Interleukin 18 (IL-18) single nucleotide polymorphisms (SNPs) can influence IL-18 production and activity. IL-18-607C/A and -137 C/G are two of the commonly studied SNPs of IL-18 due to their role in the etiopathogenesis of allergic diseases.

Aim of the study

The case control study was conducted to investigate the genetic association between IL-18-607C/A polymorphism and pediatric asthma. Also attempts were made to evaluate the prognostic effect of -607C/A SNP with disease severity and total serum IgE.

Material and methods

The case control study was conducted on 60 asthmatic children and 40 healthy subjects; aged 2 to 12 years. PCR-RFLP was used to detect IL-18-607C/A SNP and total serum IgE level was detected using ELISA technique.

Results

Regarding IL-18-607C/A SNP, the frequency of the A allele and CA genotype was significantly higher in asthmatic children compared to healthy control subjects (p < 0.001). Further on, asthmatic children carrying the AA/AC genotype of -607C/A SNP were associated with an increased risk of occurrence of asthma (OR = 6.417; CI = 2.432-17.289). IgE was higher in asthmatic patients carrying the heterozygous CA genotype compared to patients carrying the AA and CC genotypes (p = 0.054).

Conclusion

The frequency of the heterozygous CA genotype and A allele in IL-18-607C/A SNP was higher in asthmatic children. There is no association between the severity of asthma and -607C/A SNP. Total IgE was higher in patients carrying the CA genotypes compared to patients carrying the AA and CC genotypes, respectively.

Sostdc1 Regulates NK Cell Maturation and Cytotoxicity

NK cells are innate-like lymphocytes that eliminate virally infected and cancerous cells, but the mechanisms that control NK cell development and cytotoxicity are incompletely understood. We identified roles for sclerostin domain-containing-1 (Sostdc1) in NK cell development and function. Sostdc1-knockout (Sostdc1 ^-/-) mice display a progressive accumulation of transitional NK cells (tNKs) (CD27⁺CD11b⁺) with age, indicating a partial developmental block. The NK cell Ly49 repertoire in Sostdc1 ^-/- mice is also changed. Lower frequencies of Sostdc1 ^-/- splenic tNKs express inhibitory Ly49G2 receptors, but higher frequencies express activating Ly49H and Ly49D receptors. However, the frequencies of Ly49I⁺, G2⁺, H⁺, and D⁺ populations were universally decreased at the most mature (CD27^-CD11b⁺) stage. We hypothesized that the Ly49 repertoire in Sostdc1 ^-/- mice would correlate with NK killing ability and observed that Sostdc1^-/- NK cells are hyporesponsive against MHC class I-deficient cell targets in vitro and in vivo, despite higher CD107a surface levels and similar IFN-γ expression to controls. Consistent with Sostdc1's known role in Wnt signaling regulation, Tcf7 and Lef1 levels were higher in Sostdc1 ^-/- NK cells. Expression of the NK development gene Id2 was decreased in Sostdc1^-/- immature NK and tNK cells, but Eomes and Tbx21 expression was unaffected. Reciprocal bone marrow transplant experiments showed that Sostdc1 regulates NK cell maturation and expression of Ly49 receptors in a cell-extrinsic fashion from both nonhematopoietic and hematopoietic sources. Taken together, these data support a role for Sostdc1 in the regulation of NK cell maturation and cytotoxicity, and identify potential NK cell niches.

Enhancement of natural killer activity and IFN-γ production in an IL-12-dependent manner by a Brassica rapa L

Certain food components possess immunomodulatory effects. The aim of this study was to elucidate the mechanism of the immunostimulatory activity of Brassica rapa L. We demonstrated an enhancement of natural killer (NK) activity and interferon (IFN)-γ production in mice that were orally administered an insoluble fraction of B. rapa L. The insoluble fraction of B. rapa L. significantly induced IFN-γ production in mouse spleen cells in an interleukin (IL)-12-dependent manner, and NK1.1+ cells were the main cells responsible for producing IFN-γ. Additionally, the results suggested that the active compounds in the insoluble fraction were recognized by Toll-like receptor (TLR) 2, TLR4, and C-type lectin receptors on dendritic cells, and they activated signaling cascades such as MAPK, NF-κB, and Syk. These findings suggest that B. rapa L. is a potentially promising immuno-improving material, and it might be useful for preventing immunological disorders such as infections and cancers by activating innate immunity.

Human dendritic cell immunodeficiencies

The critical functions of dendritic cells (DCs) in immunity and tolerance have been demonstrated in many animal models but their non-redundant roles in humans are more difficult to probe. Human primary immunodeficiency (PID), resulting from single gene mutations, may result in DC deficiency or dysfunction. This relatively recent recognition illuminates the in vivo role of human DCs and the pathophysiology of the associated clinical syndromes. In this review, the development and function of DCs as established in murine models and human in vitro systems, discussed. This forms the basis of predicting the effects of DC deficiency in vivo and understanding the consequences of specific mutations on DC development and function. DC deficiency syndromes are associated with heterozygous GATA2 mutation, bi-allelic and heterozygous IRF8 mutation and heterozygous IKZF1 mutation. The intricate involvement of DCs in the balance between immunity and tolerance is leading to increased recognition of their involvement in a number of other immunodeficiencies and autoimmune conditions. Owing to the precise control of transcription factor gene expression by super-enhancer elements, phenotypic anomalies are relatively commonly caused by heterozygous mutations.

Serum Cytokine Profiling in Cats with Acute Idiopathic Cystitis

BACKGROUND

Feline idiopathic cystitis (FIC) is a common lower urinary tract disorder of domestic cats that resembles interstitial cystitis/painful bladder syndrome (IC/PBS) in humans. Diagnosis of FIC is based on clinical signs and exclusion of other disorders because of a lack of specific pathologic findings or other objective biomarkers. Cytokines are potential noninvasive biomarkers to define the presence, severity, and progression of disease, and response to treatment.

OBJECTIVES

The objective of this pilot study was to determine concentrations of selected cytokines in serum from healthy cats and cats with acute FIC.

ANIMALS

Serum samples from 13 healthy cats and from 12 cats with nonobstructive acute FIC were utilized.

METHODS

Multiplex analysis of 19 cytokines (CCL2, CCL5, CXCL1, CXCL12, CXCL8, Flt3L, GM-CSF, IFN-γ, IL-12 (p40), IL-13, IL-18, IL-1β, IL-2, IL-4, IL-6, PDGF-BB, SCF, sFas, and TNF-α) was performed with a commercially available feline-specific multiplex bead-based assay.

RESULTS

Mean serum concentrations of IL-12 (p40; P < 0.0001), CXCL12 (P = 0.002), IL-18 (P = 0.032), and Flt3L (P = 0.0024) were significantly increased in FIC cats compared to healthy cats. GM-CSF, IL-1b, IL-2, and PDGF-BB were undetectable or detected in an insufficient number of cats to allow meaningful comparisons.

CONCLUSIONS AND CLINICAL IMPORTANCE

We have identified increased serum concentrations of pro-inflammatory cytokines and chemokines CXCL12, IL-12, IL-18, and Flt3L in FIC-affected cats. These findings suggest potential candidates for noninvasive biomarkers for diagnosis, staging, and therapeutic outcome monitoring of affected cats and provide additional insight into the etiopathogenesis of FIC.

Regulatory B cells induced by pancreatic cancer cell-derived interleukin-18 promote immune tolerance via the PD-1/PD-L1 pathway

Dysregulation of regulatory B cells (Bregs), a type of immunosuppressive lymphocyte, are associated with development of autoimmune diseases and cancers. Bregs produce immune tolerance-inducing cell surface molecules and tolerogenic cytokines (interleukin [IL]-10 and transforming growth factor-beta). We previously showed that levels of the inflammatory cytokine IL-18 were increased in patients with pancreatic cancer. In the present study study, we found that pancreatic cancer cell-derived IL-18 increases Breg-induced immunosuppression. IL-18 also promoted B-cell proliferation and IL-10 expression in vivo and in vitro. In addition, IL-18 upregulated membrane PD-1 in B cells and inhibited the antibody-dependent cellular cytotoxicity of Tc cells and natural killer cells. Finally, the combination of a natural IL-18 inhibitor (IL-18BP) and a PD-1/PD-L1 inhibitor suppressed tumor growth and metastasis in a murine pancreatic cancer model. Our results show that IL-18 and PD-1/PD-L1 could be therapeutic targets in pancreatic cancer.

The immune mechanism of Mycoplasma hyopneumoniae 168 vaccine strain through dendritic cells

Background

Mycoplasma hyopneumoniae (Mhp) causes porcine enzootic pneumonia, a disease that cause major economic losses in the pig industry. Dendritic cells (DCs), the most effective antigen-presenting cells, are widely distributed beneath respiratory epithelium, DCs uptake and present antigens to T cells, to initiate protective immune responses in different infections. In this study, we investigated the role of porcine DCs in vaccine Mhp-168 exposure.

Results

The antigen presenting ability of DCs were improved by vaccine Mhp-168 exposure. DCs could activate T-cell proliferation by up-regulating the antigen presenting molecule MHCII expression and co-stimulatory molecule CD80/86. However, the up-regulation of IL-10 and accompany with down-regulation of IFN-γ gene level may account for the limitation of attenuated Mhp-168 strain use as vaccine alone.

Conclusion

These findings are benefit for exploring the protection mechanisms and the possible limitations of this attenuated Mhp-168 vaccine.

EFFECTS OF COMBRETUM HEREROENSE AND CANTHIUMMUNDIANUM water EXTRACTS ON PRODUCTION AND EXPRESSION OF INTERLEUKIN-4

BACKGROUND

Combretum hereroense and Canthium mundianum are two plants commonly used by traditional healers in the Northern region of Limpopo, South Africa for the treatment of diarrhea and inflammation. In the present study, the effects of their water extracts on the production and expression of interleukin-4 by peripheral blood mononuclear cells (PBMC'S) from HIV positive and negative individuals was evaluated.

MATERIALS AND METHODS

Blood samples were collected from both HIV positive and HIV negative volunteers and were used for the purification of Peripheral blood mononuclear cells (PBMC). The PBMCs were cultured together with the water extracts after activation with phytohemagglutinin (PHA) for three days. Solid-phase sandwich ELISA (MABTECH) kit was used to detect IL-4 on un-stimulated and stimulated PBMC'S with phytohemaglutinin (PHA) and plant extracts, followed by the isolation of RNA using RNAesy Qiagen mini kit from the cells. Reverse transcriptase real time PCR was used to evaluate IL-4 gene expression by the cells.

RESULTS

Combretum hereroense showed higher production of IL-4 at three different concentrations and a significant expression of mRNA with 4-fold amplification increase at 300μg/ml and 2-fold amplification increase at 20μg/ml. Canthium mundianum also showed increased production of IL-4 at 300μg/ml, but inhibited its production at 20μg/ml. Both extracts showed no expression at 50μg/ml. The response of the PBMCs from HIV negative individuals was more pronounced than that of HIV positive individuals who mostly increased production of IL4 at smaller concentrations unlike their HIV negative counterparts. Although in vitro studies do not necessarily predict in vivo outcomes, the plant extracts modulated the immune system by enhancing the production and expression of IL-4 in both HIV- and HIV+ individuals at different concentrations.

CONCLUSIONS

For the first time we have shown that the immunomodulatory effect of medicinal plants may depend on the clinical status of the individual. The present study revealed that the effect of the water extracts from the two plants on IL-4 expression and production is dependent on the microbiological state of the individual and is dose dependent. Further studies are needed to identify the active components in the extracts and also characterize the patients further for a better understanding of the mechanisms of action of these extracts.

Inflammatory Cytokine Gene Expression in Different Types of Granulomatous Lesions during Asymptomatic Stages of Bovine Paratuberculosis

The granulomatous lesions in bovine paratuberculosis have been classified into two types, i.e., the lepromatous type and the tuberculoid type. To clarify the immunopathologic mechanisms at the site of infection, we compared inflammatory cytokine gene expression between the two types of lesions. Samples were obtained from noninfected control cows ( n =5) and naturally infected cows ( n =7) that were diagnosed by enzyme-linked immunosorbent assay (ELISA) and fecal culture test. Although none of the infected cows showed clinical signs, tuberculoid lesions were observed in five cows (tuberculoid group) and lepromatous lesions in two cows (lepromatous group). Among the cytokines examined by reverse transcription-polymerase chain reaction (RT-PCR), Th2-type cytokines interleukin-4 (IL-4) and IL-10, and Th1-type cytokine IL-2 were expressed more significantly in the lepromatous group than in the tuberculoid ( P < 0.01) and noninfected groups ( P < 0.05). No statistical differences were observed in the expression of interferon-gamma, IL-1 beta, TNF-alpha, and GM-CSF among lepromatous, tuberculoid, and noninfected groups. Expression of proinflammatory cytokine IL-12 mRNA, however, did not differ among the three groups; IL-18 was expressed at lower levels in the lepromatous group than in the tuberculoid group and the noninfected group ( P < 0.0001). Moreover, the number of cells in which IL-18 mRNAs were detected by in situ hybridization was markedly decreased in the lepromatous group. These results indicate that the formation of lepromatous-type lesions or tuberculoid-type lesions may be influenced by alterations in Th1/Th2-type cytokine production and that IL-18 may play an important role in a Th1-to-Th2 switch in paratuberculosis.

Potential therapeutic targets from genetic and epigenetic approaches for asthma

Asthma is a complex disorder characterised by inflammation of airway and symptoms of wheeze and shortness of breath. Allergic asthma, atopic dermatitis and allergic rhinitis are immunoglobulin E (IgE) related diseases. Current therapies targeting asthma rely on non-specific medication to control airway inflammation and prevent symptoms. Severe asthma remains difficult to treat. Genetic and genomic approaches of asthma and IgE identified many novel loci underling the disease pathophysiology. Recent epigenetic approaches also revealed the insights of DNA methylation and chromatin modification on histones in asthma and IgE. More than 30 microRNAs have been identified to have regulating roles in asthma. Understanding the pathways of the novel genetic loci and epigenetic elements in asthma and IgE will provide new therapeutic means for clinical management of the disease in future.

Enhancement of the Th1-phenotype immune system by the intake of Oyster mushroom (Tamogitake) extract in a double-blind, placebo-controlled study

Pleurotus cornucopiae (Oyster mushroom, Tamogitake) has long been eaten as a functional food for enhancement of the immune system, but its effectiveness has not been well confirmed in humans. To this end, we set up a double-blind placebo-controlled human clinical trial to investigate the potential of Oyster mushrooms with respect to the up-regulation of the immune system. The subjects ingested Oyster mushroom extract for 8 weeks. We measured the serum cytokine levels involved in regulation of the immune system, including interferon (IFN)-γ, interleukin (IL)-4, IL-5, IL-10, IL-12, IL-13, and tumor-necrosis factor (TNF)-α. We found that intake of Oyster mushroom extract elevated IFN-γ (P = 0.013) and IL-12, whereas serum levels of IL-10 and IL-13 and other cytokines were minimally changed. We also measured natural killer (NK) cell activity, the levels of which tended to increase, but not significantly. Taken together, these facts suggest that Oyster mushrooms have the potential to enhance the immune system, through Th1 phenotype potentiation as the macrophage-IL-12 - IFN-γ pathway. This results in activation of the cell-mediated immune system as exemplified by up-regulation of NK cell activity. Oyster mushroom extract may be beneficial for the prevention of various diseases, including infectious diseases and cancer, due to its stimulation of the immune system.

Inflammation induced loss of skeletal muscle

Inflammation is an important contributor to the pathology of diseases implicated in skeletal muscle dysfunction. A number of diseases and disorders including inflammatory myopathies and Chronic Obstructive Pulmonary Disorder (COPD) are characterized by chronic inflammation or elevation of the inflammatory mediators. While these disease states exhibit different pathologies, all have in common the loss of skeletal muscle mass and a deregulated skeletal muscle physiology. Pro-inflammatory cytokines are key contributors to chronic inflammation found in many of these diseases. This section of the review focuses on some of the known inflammatory disorders like COPD, Rheumatoid Arthritis (RA) and inflammatory myopathies that display skeletal muscle atrophy and also provides the reader an overview of the mediators of inflammation, their signaling pathways, and mechanisms of action. This article is part of a Special Issue entitled "Muscle Bone Interactions".

An interferon-γ-delivery system based on chitosan/poly(γ-glutamic acid) polyelectrolyte complexes modulates macrophage-derived stimulation of cancer cell invasion in vitro

Macrophages represent a large component of the tumour microenvironment and are described to establish interactions with cancer cells, playing crucial roles in several stages of cancer progression. The functional plasticity of macrophages upon stimulation from the environment makes them susceptible to the influence of cancer cells and also renders them as promising therapeutic targets. In this work, we describe a drug delivery system to modulate the phenotype of macrophages, converting them from the pro-tumour M2 phenotype to the anti-tumour M1 phenotype, based on the incorporation of a pro-inflammatory cytokine (interferon-γ) in chitosan (Ch)/poly(γ-glutamic acid) (γ-PGA) complexes. Ch is a biocompatible cationic polysaccharide extensively studied and γ-PGA is a biodegradable, hydrophilic and negatively charged poly-amino acid. These components interact electrostatically, due to opposite charges, resulting in self-assembled structures that can be designed to deliver active molecules such as drugs and proteins. Ch and γ-PGA were self-assembled into polyelectrolyte multilayer films (PEMs) of 371nm thickness, using the layer-by-layer method. Interferon-γ (IFN-γ) was incorporated within the Ch layers at 100 and 500ng/mL. Ch/γ-PGA PEMs with IFN-γ were able to modulate the phenotype of IL-10-treated macrophages at the cell cytoskeleton and cytokine profile levels, inducing an increase of IL-6 and a decrease of IL-10 production. More interestingly, the pro-invasive role of IL-10-treated macrophages was hindered, as their stimulation of gastric cancer cell invasion in vitro decreased from 4 to 2-fold, upon modulation by Ch/γ-PGA PEMs with IFN-γ. This is the first report proposing Ch/γ-PGA PEMs as a suitable strategy to incorporate and release bioactive IFN-γ with the aim of modulating macrophage phenotype, counteracting their stimulating role on gastric cancer cell invasion.

Sphingosine 1-Phosphate Receptor 3-Deficient Dendritic Cells Modulate Splenic Responses to Ischemia-Reperfusion Injury

The plasticity of dendritic cells (DCs) permits phenotypic modulation ex vivo by gene expression or pharmacologic agents, and these modified DCs can exert therapeutic immunosuppressive effects in vivo through direct interactions with T cells, either inducing T regulatory cells (T(REG)s) or causing anergy. Sphingosine 1-phosphate (S1P) is a sphingolipid and the natural ligand for five G protein-coupled receptors (S1P1, S1P2, S1P3, S1P4, and S1P5), and S1PR agonists reduce kidney ischemia-reperfusion injury (IRI) in mice. S1pr3(-/-)mice are protected from kidney IRI, because DCs do not mature. We tested the therapeutic advantage of S1pr3(-/-) bone marrow-derived dendritic cell (BMDC) transfers in kidney IRI. IRI produced a rise in plasma creatinine (PCr) levels in mice receiving no cells (NCs) and mice pretreated with wild-type (WT) BMDCs. However, S1pr3(-/-) BMDC-pretreated mice were protected from kidney IRI. S1pr3(-/-) BMDC-pretreated mice had significantly higher numbers of splenic T(REG)s compared with NC and WT BMDC-pretreated mice. S1pr3(-/-) BMDCs did not attenuate IRI in splenectomized, Rag-1(-/-), or CD11c(+) DC-depleted mice. Additionally, S1pr3(-/-) BMDC-dependent protection required CD169(+)marginal zone macrophages and the macrophage-derived chemokine CCL22 to increase splenic CD4(+)Foxp3(+) T(REG)s. Pretreatment with S1pr3(-/-) BMDCs also induced T(REG)-dependent protection against IRI in an allogeneic mouse model. In summary, adoptively transferred S1pr3(-/-) BMDCs prevent kidney IRI through interactions within the spleen and expansion of splenic CD4(+)Foxp3(+) T(REG)s. We conclude that genetically induced deficiency of S1pr3 in allogenic BMDCs could serve as a therapeutic approach to prevent IRI-induced AKI.

Mechanisms of interferon-γ production by neutrophils and its function during Streptococcus pneumoniae pneumonia

Bacterial pneumonia is a common public health problem associated with significant mortality, morbidity, and cost. Neutrophils are usually the earliest leukocytes to respond to bacteria in the lungs. Neutrophils rapidly sequester in the pulmonary microvasculature and migrate into the lung parenchyma and alveolar spaces, where they perform numerous effector functions for host defense. Previous studies showed that migrated neutrophils produce IFN-γ early during pneumonia induced by Streptococcus pneumoniae and that early production of IFN-γ regulates bacterial clearance. IFN-γ production by neutrophils requires Rac2, Hck/Lyn/Fgr Src family tyrosine kinases, and NADPH oxidase. Our current studies examined the mechanisms that regulate IFN-γ production by lung neutrophils during acute S. pneumoniae pneumonia in mice and its function. We demonstrate that IFN-γ production by neutrophils is a tightly regulated process that does not require IL-12. The adaptor molecule MyD88 is critical for IFN-γ production by neutrophils. The guanine nucleotide exchange factor CalDAG-GEFI modulates IFN-γ production. The CD11/CD18 complex, CD44, Toll-like receptors 2 and 4, TRIF, and Nrf2 are not required for IFN-γ production by neutrophils. The recently described neutrophil-dendritic cell hybrid cell, identified by its expression of Ly6G and CD11c, is present at low numbers in pneumonic lungs and is not a source of IFN-γ. IFN-γ produced by neutrophils early during acute S. pneumoniae pneumonia induces transcription of target genes in the lungs, which are critical for host defense. These studies underline the complexity of the neutrophil responses during pneumonia in the acute inflammatory response and in subsequent resolution or initiation of immune responses.

Genkwadaphnin induces IFN-γ via PKD1/NF-κB/STAT1 dependent pathway in NK-92 cells

The flower buds of Daphne genkwa Sieb. et Zucc. have been used as a traditional Chinese medicine although their functional mechanisms have not been discovered yet. We have studied the potential effects of the plant extracts on natural killer (NK) cell activation, and isolated an active fraction. Genkwadaphnin (GD-1) displayed a potent efficacy to induce IFN-γ transcription in NK cells with concentration- and time-dependent manners. GD-1 treatment triggered the phosphorylation of PKD1, a member of PKC family, MEK and ERK, resulting in IKK activation to induce IκB degradation, and the nuclear localization of p65, an NF-κB subunit, which regulates IFN-γ transcription. GD-1 effect on IFN-γ production was blocked by the addition of Rottlerin, a PKC inhibitor, CID 755673, a PKD inhibitor, or Bay11-7082, an IKKα inhibitor. The nuclear localization of p65 was also inhibited by the kinase inhibitors. Secreted IFN-γ activates STAT1 phosphorylation as autocrine-loops to sustain its secretion. GD-1 induced the phosphorylation of STAT1 probably through the increase of IFN-γ. STAT1 inhibitor also abrogated the sustained IFN-γ secretion. These results suggest that GD-1 is involved in the activation of PKD1 and/or ERK pathway, which activate NK-κB triggering IFN-γ production. As positive feedback loops, secreted IFN-γ activates STAT1 and elongates its production in NK-92 cells.

A eukaryotic expression plasmid carrying chicken interleukin-18 enhances the response to newcastle disease virus vaccine

Interleukin-18 (IL-18) is an important cytokine involved in innate and acquired immunity. In this study, we cloned the full-length chicken IL-18 (ChIL-18) gene from specific-pathogen-free (SPF) chicken embryo spleen cells and provided evidence that the ChIL-18 gene in a recombinant plasmid was successfully expressed in chicken DT40 cells. ChIL-18 significantly enhanced gamma interferon (IFN-γ) mRNA expression in chicken splenocytes, which increased IFN-γ-induced nitric oxide (NO) synthesis by macrophages. The potential genetic adjuvant activity of the ChIL-18 plasmid was examined in chickens by coinjecting ChIL-18 plasmid and inactivated Newcastle disease virus (NDV) vaccine. ChIL-18 markedly elevated serum hemagglutination inhibition (HI) titers and anti-hemagglutinin-neuraminidase (anti-HN)-specific antibody levels, induced the secretion of both Th1- (IFN-γ) and Th2- (interleukin-4) type cytokines, promoted the proliferation of T and B lymphocytes, and increased the populations of CD3(+) T cells and their subsets, CD3(+) CD4(+) and CD3(+) CD8(+) T cells. Furthermore, a virus challenge revealed that ChIL-18 contributed to protection against Newcastle disease virus challenge. Taken together, our data indicate that the coadministration of ChIL-18 plasmid and NDV vaccine induces a strong immune response at both the humoral and cellular levels and that ChIL-18 is a novel immunoadjuvant suitable for NDV vaccination.

The interaction between mother and fetus and the development of allergic asthma

The rising prevalence of asthma and atopic disease in industrialized countries in the last 50 years has raised important questions about how and why the disease develops in susceptible populations. Most asthma begins in childhood in association with allergic sensitization and the development of a TH2 phenotype. It is recognized that asthma arises in the context of a complex interaction between genetic factors and the evolving immune system of the infant and the environment to which it is exposed, which now includes its in utero exposure. Early life exposures that lead to allergen sensitization and airway damage, especially in the form of viral respiratory tract infections, may lead to disease induction that commence the process that leads in some to asthma. Asthma models and early life observations suggest that repeated exposure to allergens and viral infection perpetuate a state of chronic airway inflammation leading to a maladaptive innate immune response that fails to resolve, characterized by chronic airway inflammation, airway remodeling and airway hyperresponsiveness. This article will concentrate on the development of asthma in the context of early life and maternal influences, including the effect of asthma on both the fetus and the mother.

The relationship between interleukin-18 polymorphisms and allergic disease: a meta-analysis

Recent studies have suggested that IL-18 −607C/A and −137G/C polymorphisms may be associated with the risk of allergic disease; however, individually published results are inconclusive. Therefore, we performed a meta-analysis to clarify whether IL-18 −607C/A and −137G/C polymorphisms were associated with the risk of allergic disease. A total of 21 studies including 5,331 cases and 9,658 controls were involved in this meta-analysis. In the overall analysis and the subgroup analysis according to ethnicity, we did not find significant association between IL-18 −607C/A or −137G/C polymorphism and the risk of allergic disease (all P > 0.05). However, in a stratified analysis by type of allergic disease, our results indicated that IL-18 −607C/A polymorphism was associated with a significantly decreased risk of allergic asthma in heterozygous comparison and IL-18 −137G/C was associated with a significantly decreased risk of allergic dermatitis in recessive model and homozygous comparison. In the stratified analysis by source of control, IL-18−607C/A showed significantly reduced risk in population-based subgroup, and for IL-18 −137G/C only significantly decreased risk was found in the hospital-based subgroup. Our meta-analysis suggests that IL-18 −607C/A and −137G/C polymorphisms may be protective factors for the risk of allergic asthma and allergic dermatitis, respectively.

Interferon-γ resets muscle cell fate by stimulating the sequential recruitment of JARID2 and PRC2 to promoters to repress myogenesis

The inflammatory cytokine interferon-γ (IFN-γ) orchestrates a diverse array of fundamental physiological processes. IFN-γ and the class II transactivator (CIITA) play essential roles in inhibiting muscle development during the inflammatory response. We describe the mechanism through which IFN-γ and CIITA inhibit myogenesis by repressing gene expression in muscle cells subjected to inflammation. In mice, the presence of increased amounts of circulating IFN-γ resulted in the increased abundance of Polycomb repressive complex 2 (PRC2) in muscle fibers, a tissue in which PRC2 is not normally present in the adult. We showed that CIITA first interacted with the Jumonji family protein JARID2, a noncatalytic subunit of PRC2, which caused an RNA polymerase II (RNAPII), phosphorylated at serine-5, to pause at target promoters. Additional subunits of the PRC2 complex, including the catalytic subunit EZH2, were then recruited in a JARID2-dependent manner that was concurrent with the loss of RNAPII and the methylation of Lys(27) of histone H3 (H3K27), which is associated with gene repression. IFN-γ and CIITA act to both promote the abundance of PRC2 subunits, which are not normally present during muscle differentation, and recruit the PRC2 complex to block myogenesis. Together, these data indicate that increased amounts of IFN-γ reset myogenic cell fate through a multistep mechanism that culminates in the recruitment of PRC2 to silence muscle-specific genes.

Development of a manual self-assembled colloidal gold nanoparticle-immunochromatographic strip for rapid determination of human interferon-γ

Interferons (IFNs) play a role in inhibition of tumor growth and participate in immunoreactions. Among IFNs, interferon-γ (IFNγ) is one of the most important therapeutic proteins and its immunodulation ability is better than that of other types. The objective of this study is to develop a manual self-assembled colloidal gold nanoparticle-immunochromatographic strip for human IFNγ using anti-human IFNγ polyclonal and monoclonal antibodies. Colloidal gold with a 25 nm diameter was made from chloroauric acid (HAuCl4), and labeled on anti-IFNγ mAbs as a chrominance reagent. A good linear relationship existed between the pixel intensity and the human IFNγ concentrations from 10-1000 ng mL(-1) in mouse serum and buffer, respectively, the regression equation was Y = 0.159logX + 0.0648, R(2) = 0.992 in mouse serum; Y = 0.294logX + 0.091, R(2) = 0.9969 in phosphate buffer by this proposed strip. Moreover, in the determination for mouse serum samples no cross-reaction occurred and the detection time was approximately 10 minutes. The shelf life of the strip was above 28 days at room temperature. The major advantages of the manual operation model were no expensive instruments and less reagents required. This proposed strip was highly specific, economic, convenient, and no machine was needed in clinical diagnosis.

Passive carriage of rabies virus by dendritic cells

The rabies virus (RABV) is highly neurotropic and it uses evasive strategies to successfully evade the host immune system. Because rabies is often fatal, understanding the basic processes of the virus-host interactions, particularly in the initial events of infection, is critical for the design of new therapeutic approaches to target RABV. Here, we examined the possible role of dendritic cells (DCs) in the transmission of RABV to neural cells at peripheral site of exposure. Viral replication only occurred at a low level in the DC cell line, JAWS II, after its infection with either pathogenic RABV (CVS strain) or low-pathogenic RABV (ERA strain), and no progeny viruses were produced in the culture supernatants. However, both viral genomic RNAs were retained in the long term after infection and maintained their infectivity. The biggest difference between CVS and ERA was in their ability to induce type I interferons. Although the ERA-infected JAWS II cells exhibited cytopathic effect and were apparently killed by normal spleen cells in vitro, the CVS-infected JAWS II cells showed milder cytopathic effect and less lysis when cocultured with spleen cells. Strongly increased expression of major histocompatibility complex classes I, costimulatory molecules (CD80 and CD86), type I interferons and Toll- like receptor 3, and was observed only in the ERA-inoculated JAWS II cells and not in those inoculated with CVS. During the silencing of the cellular immune response in the DCs, the pathogenic CVS strain cryptically maintained an infectious viral genome and was capable of transmitting infectious RABV to permissive neural cells. These findings demonstrate that DCs may play a role in the passive carriage of RABV during natural rabies infections.

Cytokine patterns in patients with cancer: a systematic review

Active, but dysfunctional, immune responses in patients with cancer have been studied in several tumour types, but owing to the heterogeneity of cancer theories of common reaction mechanisms seem to be obsolete. In this Review of published clinical studies of patients with cancer, expression and interplay of the following cytokines are examined: interleukin 2, interleukin 6, interleukin 8, interleukin 10, interleukin 12, interleukin 18, tumour necrosis factor α (TNFα), transforming growth factor β (TGFβ), interferon-γ, HLA-DR, macrophage migration inhibitory factor (MIF), and C-X-C motif chemokine receptor 4 (CXCR4). Clinical data were analysed in a non-quantitative descriptive manner and interpreted with regard to experimentally established physiological cytokine interactions. The clinical cytokine pattern that emerged suggests that simultaneous immunostimulation and immunosuppression occur in patients with cancer, with increased concentrations of the cytokines MIF, TNFα, interleukin 6, interleukin 8, interleukin 10, interleukin 18, and TGFβ. This specific cytokine pattern seems to have a prognostic effect, since high interleukin 6 or interleukin 10 serum concentrations are associated with negative prognoses in independent cancer types. Although immunostimulatory cytokines are involved in local cancer-associated inflammation, cancer cells seem to be protected from immunological eradication by cytokine-mediated local immunosuppression and a resulting defect of the interleukin 12-interferon-γ-HLA-DR axis. Cytokines produced by tumours might have a pivotal role in this defect. A working hypothesis is that the cancer-specific and histology-independent uniform cytokine cascade is one of the manifestations of the underlying paraneoplastic systemic disease, and this hypothesis links the stage of cancer with both the functional status of the immune system and the patient's prognosis. Neutralisation of this cytokine pattern could offer novel and so far unexploited treatment approaches for cancer.

Mechanisms of regulatory T cell counter-regulation by innate immunity

One of the most significant advances in the field of immunology in the last decade is delineation of the pivotal role of regulatory T cells (Tregs) in the maintenance of self-tolerance. While Tregs are just now being applied therapeutically in early phase clinical trials, data gleaned from basic and translational studies to-date suggest enormous potential to intervene in human disease. Data from our work and the work of others suggest that the innate immune system plays an important role in the differentiation and function of Tregs, largely through the production of cytokines but also through expression of cell surface ligands. These molecules are expressed differentially depending on whether the stimulus includes trauma, ischemia/necrosis, and microbial infection, and have opposing effects on Tregs, in contrast to those associated with dendritic cell maturation and somatic cell apoptosis, which promote Treg differentiation and function. We refer to the former process as Treg counter-regulation. Since the transplantation procedure involves surgical trauma, organ ischemia, and exposure to environmental microbes, Treg counter-regulation represents a key area of intervention to improve strategies for promoting allograft tolerance.

Genetic and genomic approaches to asthma: new insights for the origins

PURPOSE OF REVIEW

The aim is to update current understanding of the genes identified by the recent genome-wide association studies (GWASs) of asthma and its associated traits. The review also discusses how to dissect the functional roles of novel genes in future research.

RECENT FINDINGS

More than 10 GWAS aimed at identifying the genes underlying asthma and relevant traits have been published in the past 3 years. The largest of these was from the GABRIEL consortium, which discovered that the IL18R1, IL33, SMAD3, ORMDL3, HLA-DQ and IL2RB loci were all significantly associated with asthma. Many novel asthma genes, including those previously identified by positional cloning, are expressed within the respiratory epithelium, emphasizing the importance of epithelial barriers in causing asthma . The genes controlling IgE levels have surprisingly little overlap with the genes mediating asthma susceptibility, suggesting that atopy is secondary to asthma rather than a primary driver of the disease. The next challenge will be the systematic analysis of the precise functions of these genes in the pathogenesis of asthma.

SUMMARY

GWAS have uncovered many novel genes underlying asthma and detailed functional dissection of their roles in asthma will point the way to new therapies for the disease.

Synergy between TLR3 and IL-18 promotes IFN-γ dependent TRAIL expression in human liver NK cells

Natural killer (NK) cells are a component of innate immunity against viral infections through their rapid cytotoxic activity and cytokine production. However, intra-hepatic NK cells' ability to respond to virus is still mostly unknown. Our results show that the synthetic dsRNA polyinosinic-polycytidylic acid (poly I:C), a mimic of a common product of viral infections, activates NK cells directly in the context of cytokines found in the liver, i.e.: poly I:C plus inflammatory cytokines (IL-18, IL-12, and IL-2) induced NK cell IFN-γ production and TRAIL expression, and anti-inflammatory cytokines (TGF-β and IL-10) inhibit NK cell IFN-γ production. Neutralization of IFN-γ blocks poly I:C plus inflammatory cytokines-induced NK cell TRAIL expression, suggesting that IFN-γ is an autocrine differentiation factor for these cells. A better understanding of the intra-hepatic NK cell activation against viral infection may help in the design of therapies and vaccines for the control of viral hepatitis.

A large-scale, consortium-based genomewide association study of asthma

BACKGROUND

Susceptibility to asthma is influenced by genes and environment; implicated genes may indicate pathways for therapeutic intervention. Genetic risk factors may be useful in identifying subtypes of asthma and determining whether intermediate phenotypes, such as elevation of the total serum IgE level, are causally linked to disease.

METHODS

We carried out a genomewide association study by genotyping 10,365 persons with physician-diagnosed asthma and 16,110 unaffected persons, all of whom were matched for ancestry. We used random-effects pooled analysis to test for association in the overall study population and in subgroups of subjects with childhood-onset asthma (defined as asthma developing before 16 years of age), later-onset asthma, severe asthma, and occupational asthma.

RESULTS

We observed associations of genomewide significance between asthma and the following single-nucleotide polymorphisms: rs3771166 on chromosome 2, implicating IL1RL1/IL18R1 (P=3×10(−9)); rs9273349 on chromosome 6, implicating HLA-DQ (P=7×10(−14)); rs1342326 on chromosome 9, flanking IL33 (P=9×10(−10)); rs744910 on chromosome 15 in SMAD3 (P=4×10(−9)); and rs2284033 on chromosome 22 in IL2RB (P=1.1×10(−8)). Association with the ORMDL3/GSDMB locus on chromosome 17q21 was specific to childhood-onset disease (rs2305480, P=6×10(−23)). Only HLA-DR showed a significant genomewide association with the total serum IgE concentration, and loci strongly associated with IgE levels were not associated with asthma.

CONCLUSIONS

Asthma is genetically heterogeneous. A few common alleles are associated with disease risk at all ages. Implicated genes suggest a role for communication of epithelial damage to the adaptive immune system and activation of airway inflammation. Variants at the ORMDL3/GSDMB locus are associated only with childhood-onset disease. Elevation of total serum IgE levels has a minor role in the development of asthma. (Funded by the European Commission and others.)

DC subsets in positive and negative regulation of immunity

Since their discovery in 1973, dendritic cells (DCs) have gained strong interest from immunologists because of their unique capacity to sensitize naive T cells. There is now strong evidence that cells of the dendritic family not only control immunity but also regulate responses to self and non-self, thereby avoiding immunopathology. These two complementary functions are critical to ensure the integrity of the organism in an environment full of antigens. How DCs display these opposite functions is still intriguing. Here, we review the role of DC subsets in the regulation of T-helper responses in vivo.

Cloning and expression of pigeon IFN-γ gene

This is the first paper describing the cloning of pigeon IFN-γ gene (PiIFN-γ) and the analysis of the in vitro expressed recombinant protein. The PiIFN-γ gene was identified by RT-PCR as a 498bp, fragment coding for a precursor protein of 165 amino acids instead of 164 amino acids, as observed in the other avian species. The recombinant protein was expressed in vitro by an eukaryotic system and the biological properties of the cytokine were tested using a chicken macrophage cell line. The high degree of amino acid and nucleotide identity, shared with the ChIFN-γ, and the fact that the pigeon protein was functional on chicken cells, indicates a cross-reactivity between pigeon and chicken IFN-γ. The detection of the PiIFN-γ could represent an useful instrument in understanding the role played by this cytokine in immune response related to vaccinations and infectious diseases in the pigeon.

Dichotomous role of interferon-gamma in allogeneic bone marrow transplant

Interferon (IFN)-gamma is a pleiotropic cytokine with a central role in innate and adaptive immunity. As a potent pro-inflammatory and antitumor cytokine, IFN-gamma is conventionally thought to be responsible for driving cellular immune response. On the other hand, accumulating evidence suggests that IFN-gamma also has immunosuppressive activity. An important role for IFN-gamma in inhibiting graft-versus-host disease (GVHD) has been demonstrated in murine models, despite IFN-gamma being one of the key factors amplifying T cell activation during the process of acute GVHD (aGVHD), the major complication and cause of post-transplant mortality in allogeneic bone marrow transplantation (BMT). At the same time, IFN-gamma facilitates graft-versus-leukemia (GVL) activity. Dissociation of GVL effects from GVHD has been the ultimate goal of allogeneic BMT in the treatment of hematologic malignancies. This paradoxic role of IFN-gamma makes modulating its activity a promising strategy to maximize GVL while minimizing GVHD and improve clinical outcomes in BMT. In this review, the effects of IFN-gamma on GVHD and GVL are discussed with consideration of the mechanism of IFN-gamma action.

IL-12 inhibits TNF-alpha induced osteoclastogenesis via a T cell-independent mechanism in vivo

It has been reported that TNF-alpha plays an important role in bone resorption in pathological conditions. IL-12, which is a T cell mediator, is also an important inflammatory cytokine. We previously reported that IL-12 induces apoptosis in bone marrow cells treated with TNF-alpha in vitro via an interaction between TNF-alpha-induced Fas and IL-12-induced Fas ligand (FasL), and that, as a result, osteoclastogenesis is inhibited. The purpose of this study was to investigate the effects of IL-12 on TNF-alpha-mediated osteoclastogenesis in vivo. We administered TNF-alpha with and without IL-12 into the supracalvaria in mice. The numbers of osteoclasts in the sutures in the calvaria were higher in mice administered TNF-alpha than in control mice not administered TNF-alpha. The numbers of osteoclasts in mice administered both TNF-alpha and IL-12 were lower than those in mice administered only TNF-alpha. Next, we determined the levels of mRNAs for cathepsin K and tartrate-resistant acid phosphatase (TRAP). mRNA levels were increased in mice administered TNF-alpha compared with control mice, but not in mice administered both TNF-alpha and IL-12. We also evaluated the amounts of tartrate-resistant acid phosphatase 5b (TRACP 5b) in mouse sera. The levels of TRACP 5b in mice administered TNF-alpha were higher than those in control mice. On the other hand, in mice administered both TNF-alpha and IL-12, the levels were lower than those in mice administered TNF-alpha alone. Fas and FasL expression levels were analyzed by real-time RT-PCR. The levels of Fas mRNA were increased in the calvaria of mice administered TNF-alpha compared with control mice, while those of FasL mRNAs were increased in the calvaria of mice administered IL-12. In TdT-mediated dUTP-biotin nick end-labeling (TUNEL) assays, many apoptotic cells were found in the sutures in the calvaria of mice administered both TNF-alpha and IL-12. IL-12 also inhibited TNF-alpha-induced osteoclastogenesis in mice whose T cells were blocked by anti-CD4 and anti-CD8 antibodies. These results suggest that IL-12 inhibits TNF-alpha-mediated osteoclastogenesis and induces apoptotic changes through an interaction between TNF-alpha-induced Fas and IL-12-induced FasL, in vivo, via a T cell-independent mechanism.

In vitro cytokine responses of peripheral blood mononuclear cells from healthy dogs to distemper virus, Malassezia and Toxocara

Naïve CD4+ T cells may differentiate into a number of subsets including T helper 1 (Th1) Th2, Th3, Th17 and T regulatory (Treg) cells depending on the type of antigen they encounter. These CD4+ families have been defined based on the array of cytokines they produce and the effects they have on adaptive immune responses. CD4+ subsets are cross regulatory and at times cooperative. The study of these adaptive immune modulators has revealed the important role that cytokines play in mounting effective as well as detrimental immune responses to pathogens. Examining the cytokine responses of lymphocytes in culture can provide important understanding of how immune responses to pathogens are orchestrated. For this purpose the in vitro cytokine production of peripheral blood mononuclear cells (PBMC) from healthy dogs was examined in response to stimulation with antigens from a common canine virus (canine distemper virus, CDV), a commensal skin yeast of dogs (Malassezia pachydermatis) and a common canine helminth (Toxocara canis (T. canis)). Cell culture supernatants were removed from antigen stimulated and unstimulated control PBMC after 4, 24, 48 and 72 h and the concentration of Th1 type cytokines (IL-2, IFN-gamma, TNF-alpha) and Th2 type cytokines (IL-4, IL-5, IL-10) was determined using sandwich ELISA assays. CDV induced low levels of cytokine production initially with a predominance of IL-10 at 24h and a balanced response at 48 h of incubation. Malassezia antigen stimulated an early type 2 cytokine response with dramatic production of IL-4 at 24h of incubation compared to the other stimulants examined. By 48 h of incubation, however, the cytokine mix in response to Malassezia had also moved toward a Th1 type response. T. canis induced early production of Th2 type cytokines with IL-5 predominating; however, with longer incubation (48-72 h) there was a switch to a balanced Th1/Th2 response. In conclusion, the cytokines produced in vitro by canine PBMC in response to prototypical Th1 and Th2 type pathogens were not clearly polarized and shifted over time. While the in vitro study of PBMC cytokine responses cannot be directly extrapolated to in vivo responses to the same antigens, the results do highlight the dynamic and fluctuating nature of cytokine production.

A novel role for IkappaBzeta in the regulation of IFNgamma production

IkappaBzeta is a novel member of the IkappaB family of NFkappaB regulators, which modulates NFkappaB activity in the nucleus, rather than controlling its nuclear translocation. IkappaBzeta is specifically induced by IL-1beta and several TLR ligands and positively regulates NFkappaB-mediated transcription of genes such as IL-6 and NGAL as an NFkappaB binding co-factor. We recently reported that the IL-1 family cytokines, IL-1beta and IL-18, strongly synergize with TNFalpha for IFNgamma production in KG-1 cells, whereas the same cytokines alone have minimal effects on IFNgamma production. Given the striking similarities between the IL-1R and IL-18R signaling pathways we hypothesized that a common signaling event or gene product downstream of these receptors is responsible for the observed synergy. We investigated IkappaBzeta protein expression in KG-1 cells upon stimulation with IL-1beta, IL-18 and TNFalpha. Our results demonstrated that IL-18, as well as IL-1beta, induced moderate IkappaBzeta expression in KG-1 cells. However, TNFalpha synergized with IL-1beta and IL-18, whereas by itself it had a minimal effect on IkappaBzeta expression. NFkappaB inhibition resulted in decreased IL-1beta/IL-18/TNFalpha-stimulated IFNgamma release. Moreover, silencing of IkappaBzeta expression led to a specific decrease in IFNgamma production. Overall, our data suggests that IkappaBzeta positively regulates NFkappaB-mediated IFNgamma production in KG-1 cells.

How diverse--CD4 effector T cells and their functions

CD4 effector T cells, also called helper T (Th) cells, are the functional cells for executing immune functions. Balanced immune responses can only be achieved by proper regulation of the differentiation and function of Th cells. Dysregulated Th cell function often leads to inefficient clearance of pathogens and causes inflammatory diseases and autoimmunity. Since the establishment of the Th1-Th2 dogma in the 1980s, different lineages of effector T cells have been identified that not only promote but also suppress immune responses. Through years of collective efforts, much information was gained on the function and regulation of different subsets of Th cells. In this review, we attempt to sample the essence of what has been learnt in this field over the past two decades. We will discuss the classification and immunological functions of effector T cells, the determinants for effector T cell differentiation, as well as the relationship between different lineages of effector T cells.