Role of Toll interleukin-1 receptor (IL-1R) 8, a negative regulator of IL-1R/Toll-like receptor signaling, in resistance to acute Pseudomonas aeruginosa lung infection

Toll interleukin-1 receptor (IL-1R) 8 (TIR8), also known as single Ig IL-1 receptor (IL-R)-related molecule, or SIGIRR, is a member of the IL-1R-like family, primarily expressed by epithelial cells. Current evidence suggests that TIR8 plays a nonredundant role as a negative regulator in vivo under different inflammatory conditions that are dependent on IL-R and Toll-like receptor (TLR) activation. In the present study, we examined the role of TIR8 in innate resistance to acute lung infections caused by Pseudomonas aeruginosa, a Gram-negative pathogen responsible for life-threatening infections in immunocompromised individuals and cystic fibrosis patients. We show that Tir8 deficiency in mice was associated with increased susceptibility to acute P. aeruginosa infection, in terms of mortality and bacterial load, and to exacerbated local and systemic production of proinflammatory cytokines (gamma interferon [IFN-γ], tumor necrosis factor alpha [TNF-α], IL-1β, and IL-6) and chemokines (CXCL1, CXCL2, and CCL2). It has been reported that host defense against P. aeruginosa acute lung infection can be improved by blocking IL-1 since exaggerated IL-1β production may be harmful for the host in this infection. In agreement with these data, IL-1RI deficiency rescues the phenotype observed in Tir8-deficient mice: in Tir8-/- IL-1RI-/- double knockout mice we observed higher survival rates, enhanced bacterial clearance, and reduced levels of local and systemic cytokine and chemokine levels than in Tir8-deficient mice. These results suggest that TIR8 has a nonredundant effect in modulating the inflammation caused by P. aeruginosa, in particular, by negatively regulating IL-1RI signaling, which plays a major role in the pathogenesis of this infectious disease.

The interleukin 4 receptor gene and its role in recurrent airway obstruction in Swiss Warmblood horses

Recurrent airway obstruction (RAO) in horses is the result of an interaction of genetic and environmental factors and shares many characteristics with human asthma. Many studies have suggested that the interleukin-4 receptor gene (IL4R) is associated with this disease, and a QTL region on chromosome 13 containing IL4R was previously detected in one of the two Swiss Warmblood families. We sequenced the entire IL4R gene in this family and detected 93 variants including five non-synonymous protein-coding variants. The allele distribution at these SNPs supported the previously detected QTL signal. Subsequently, we investigated IL4R mRNA expression in bronchoalveolar lavage fluid cells. During exacerbation, IL4R expression was increased in RAO-affected offspring in the implicated family, but not in the other family. These findings support that IL4R plays a role in some cases of RAO.

Immunohistochemical demonstration of interleukin-1 beta induced changes in acute-phase proteins and albumin in rat liver

Interleukin-1 beta is a potent mediator of the acute-phase response. However, the effects of interleukin-1 beta administration on the topic in vivo production of acute-phase proteins and albumin are so far not well understood. Overnight fasted rats were subcutaneously injected with 0.2 mL 0.9% NaCl (control group) or 6.25 micrograms recombinant human interleukin-1 beta, and rectal temperature was measured at intervals up to 48 h. Livers were perfused-fixed in vivo prior to injection (base-line), and at 9, 24, and 48 h following the interleukin-1 beta injection. Fibrinogen, orosomucoid (alpha 1-acid glycoprotein) and albumin were immunostained using a streptavidin-biotin-immunoperoxidase technique. Rectal temperature peaked 5 h after the single interleukin-1 beta injection, and fell gradually to base-line values by 24 h. Prior to injection only a few hepatocytes, randomly scattered throughout the liver lobule, stained positive for fibrinogen and orosomucoid. In contrast, all hepatocytes stained uniformly positive for fibrinogen and orosomucoid 9 h after interleukin-1 beta injection, whereas at 24 h a predominant centrilobular staining pattern occurred. Due to fasting, albumin positive hepatocytes were already reduced at base-line in both groups. Interleukin-1 beta induced a further significant loss of albumin positive cells in the periportal zone (35 +/- 21%) at 9 h when compared with controls (58 +/- 11%, p = 0.037). In conclusion, subcutaneous interleukin-1 beta (probably by stimulation of interleukin-6) strongly induces fibrinogen and orosomucoid expression in rat liver, and suppresses immunohistochemically stainable albumin in a heterogenous way, mainly in the periportal zone.

Long-term systemic administration of human recombinant interleukin-1beta induces a dose-dependent fall in circulating parathyroid hormone in rats

The synergism/antagonism between interleukin (IL)-1beta and parathyroid hormone (PTH) has been the subject of in vitro and in vivo work, but a possible direct action of the cytokine on PTH release has not been reported. We have investigated the effect of a continuous infusion of human recombinant IL-1beta (rIL-1beta) on circulating PTH during a 14-day period in 7-week-old female rats. This time interval was chosen in order to exclude initial hypercalcemia and to enable data collection under steady-state conditions. Five groups of 20 animals each had miniosmotic pumps (Alzet 2002, 200 microl) implanted subcutaneously and primed to release either distilled water (controls) or 100, 500, 1,000 and 2, 000 ng/24 h of rIL-1beta. Blood was drawn on days 1 and 14 for PTH, corticosterone and Ca2+ determinations. Adequate biological activity of the infused rIL-1beta was supported by elevated rectal temperature records and significant elevations of plasma corticosterone on day 14. The 100-ng dose had no effect but 500-2, 000 ng rIL-1beta/24 h significantly reduced plasma PTH in a dose-dependent manner down to 54% of basal value (20.4 +/- 1.1 vs. 15.3 +/- 1.4 pg/ml for 500 ng, p < 0.005; 20.5 +/- 1.3 vs 12.3 +/- 1.1 for 1,000 ng, p < 0.001, and 19.5 +/- 2.0 vs. 10.6 +/- 1.1 pg/ml for 2,000 ng, p < 0.0008). Despite these findings, no differences in blood Ca2+ could be detected between treated animals and controls. The following conclusions can be inferred from the foregoing: Systemic administration of rIL-1beta to rats induced a dose-dependent fall in circulating PTH without altering calcemia, calling into question the biological relevance of the former finding. Although the recorded PTH depression may indeed not have been severe enough to cause hypocalcemia, it can be hypothesized that osteoclast activation by rIL-1beta would enhance bone mineral release into the pool compensating for depressed PTH activity.

Development of an Interleukin-1β Vaccine in Patients with Type 2 Diabetes

Interleukin-1β (IL-1β) is a key cytokine involved in inflammatory illnesses including rare hereditary diseases and common chronic inflammatory conditions as gout, rheumatoid arthritis, and type 2 diabetes mellitus, suggesting reduction of IL-1β activity as new treatment strategy. The objective of our study was to assess safety, antibody response, and preliminary efficacy of a novel vaccine against IL-1β. The vaccine hIL1bQb consisting of full-length, recombinant IL-1β coupled to virus-like particles was tested in a preclinical and clinical, randomized, placebo-controlled, double-blind study in patients with type 2 diabetes. The preclinical simian study showed prompt induction of IL-1β-specific antibodies upon vaccination, while neutralizing antibodies appeared with delay. In the clinical study with 48 type 2 diabetic patients, neutralizing IL-1β-specific antibody responses were detectable after six injections with doses of 900 µg. The development of neutralizing antibodies was associated with higher number of study drug injections, lower baseline body mass index, improvement of glycemia, and C-reactive protein (CRP). The vaccine hIL1bQb was safe and well-tolerated with no differences regarding adverse events between patients receiving hIL1bQb compared to placebo. This is the first description of a vaccine against IL-1β and represents a new treatment option for IL-1β-dependent diseases such as type 2 diabetes mellitus (ClinicalTrials.gov NCT00924105).Molecular Therapy (2016); doi:10.1038/mt.2015.227.

Melanoma Cell-Intrinsic PD-1 Receptor Functions Promote Tumor Growth.

Therapeutic antibodies targeting programmed cell death 1 (PD-1) activate tumor-specific immunity and have shown remarkable efficacy in the treatment of melanoma. Yet, little is known about tumor cell-intrinsic PD-1 pathway effects. Here, we show that murine and human melanomas contain PD-1-expressing cancer subpopulations and demonstrate that melanoma cell-intrinsic PD-1 promotes tumorigenesis, even in mice lacking adaptive immunity. PD-1 inhibition on melanoma cells by RNAi, blocking antibodies, or mutagenesis of melanoma-PD-1 signaling motifs suppresses tumor growth in immunocompetent, immunocompromised, and PD-1-deficient tumor graft recipient mice. Conversely, melanoma-specific PD-1 overexpression enhances tumorigenicity, as does engagement of melanoma-PD-1 by its ligand, PD-L1, whereas melanoma-PD-L1 inhibition or knockout of host-PD-L1 attenuate growth of PD-1-positive melanomas. Mechanistically, the melanoma-PD-1 receptor modulates downstream effectors of mTOR signaling. Our results identify melanoma cell-intrinsic functions of the PD-1:PD-L1 axis in tumor growth and suggest that blocking melanoma-PD-1 might contribute to the striking clinical efficacy of anti-PD-1 therapy.

MicroRNAs may mediate the down-regulation of neurokinin-1 receptor in chronic bladder pain syndrome

Bladder pain syndrome (BPS) is a clinical syndrome of pelvic pain and urinary urgency-frequency in the absence of a specific cause. Investigating the expression levels of genes involved in the regulation of epithelial permeability, bladder contractility, and inflammation, we show that neurokinin (NK)1 and NK2 tachykinin receptors were significantly down-regulated in BPS patients. Tight junction proteins zona occludens-1, junctional adherins molecule -1, and occludin were similarly down-regulated, implicating increased urothelial permeability, whereas bradykinin B(1) receptor, cannabinoid receptor CB1 and muscarinic receptors M3-M5 were up-regulated. Using cell-based models, we show that prolonged exposure of NK1R to substance P caused a decrease of NK1R mRNA levels and a concomitant increase of regulatory micro(mi)RNAs miR-449b and miR-500. In the biopsies of BPS patients, the same miRNAs were significantly increased, suggesting that BPS promotes an attenuation of NK1R synthesis via activation of specific miRNAs. We confirm this hypothesis by identifying 31 differentially expressed miRNAs in BPS patients and demonstrate a direct correlation between miR-449b, miR-500, miR-328, and miR-320 and a down-regulation of NK1R mRNA and/or protein levels. Our findings further the knowledge of the molecular mechanisms of BPS, and have relevance for other clinical conditions involving the NK1 receptor.

Glucagonlike peptide-1 receptor: an example of translational research in insulinomas: a review

Glucagonlike peptide-1 receptors (GLP-1R) play an increasingly important role in endocrine gastrointestinal tumor management. In particular, virtually all benign insulinomas express GLP-1R in high density. Exendin-4 is a GLP-1 analog that has a longer half-life than GLP-1. Targeting GLP-1R by (111)In-DOTA-exendin-4 or (111)In-DPTA-exendin-4 offers a new approach that permits the successful localization of small benign insulinomas. It is likely that this new noninvasive technique has the potential to replace the invasive localization by selective arterial stimulation and venous sampling.

Value of the radiolabelled GLP-1 receptor antagonist exendin(9-39) for targeting of GLP-1 receptor-expressing pancreatic tissues in mice and humans

Radiolabelled glucagon-like peptide 1 (GLP-1) receptor agonists have recently been shown to successfully image benign insulinomas in patients. Moreover, it was recently reported that antagonist tracers were superior to agonist tracers for somatostatin and gastrin-releasing peptide receptor targeting of tumours. The present preclinical study determines therefore the value of an established GLP-1 receptor antagonist for the in vitro visualization of GLP-1 receptor-expressing tissues in mice and humans.

Glucagon-like peptide-1 receptor overexpression in cancer and its impact on clinical applications

Peptide hormones of the glucagon-like peptide (GLP) family play an increasing clinical role, such as GLP-1 in diabetes therapy. Moreover, GLP receptors are overexpressed in various human tumor types and therefore represent molecular targets for important clinical applications. In particular, virtually all benign insulinomas highly overexpress GLP-1 receptors (GLP-1R). Targeting GLP-1R with the stable GLP-1 analogs (111)In-DOTA/DPTA-exendin-4 offers a new approach to successfully localize these small tumors. This non-invasive technique has the potential to replace the invasive localization of insulinomas by selective arterial stimulation and venous sampling. Malignant insulinomas, in contrast to their benign counterparts, express GLP-1R in only one-third of the cases, while they more often express the somatostatin type 2 receptors. Importantly, one of the two receptors appears to be always expressed in malignant insulinomas. The GLP-1R overexpression in selected cancers is worth to be kept in mind with regard to the increasing use of GLP-1 analogs for diabetes therapy. While the functional role of GLP-1R in neoplasia is not known yet, it may be safe to monitor patients undergoing GLP-1 therapy carefully.

Induction of the Neurokinin 1 Receptor by TNFα in Endometriotic Tissue Provides the Potential for Neurogenic Control Over Endometriotic Lesion Growth

Context: Endometriosis is characterized by the growth of ectopic endometrial tissue. Nerve fibers are frequently associated with ectopic lesions, and neurogenic inflammation may play a role in endometriosis. Objective: The purpose of this study was to determine the presence of tachykinin receptors in endometriotic lesions and the role of TNFα on their expression. Design: This study was an assessment of matching eutopic and ectopic endometrial tissue and peritoneal fluid from patients with endometriosis and an in vitro analysis of primary endometrial cells. Setting: The setting was a university hospital. Patients: Participants were premenopausal women undergoing laparoscopy. Interventions: Endometriotic lesions were removed surgically. Main Outcome Measures: Tachykinin mRNA (TACR1/2) and protein (neurokinin 1 receptor [NK1R]) expression in both eutopic and ectopic endometrial tissue from patients with endometriosis and the correlation to peritoneal fluid TNFα were measured. Primary endometrial epithelial and stromal cells were assessed in vitro to determine the induction of TACR1/2 and NK1R expression after TNFα treatment. Cell viability of endometrial stromal cells after substance P exposure was also assessed. Results: Expression of both TACR1 and TACR2 mRNA was significantly higher in the ectopic than in the eutopic tissue. Both TACR1 mRNA and NK1R protein expression was significantly correlated with peritoneal fluid TNFα, and in vitro studies confirmed that TNFα treatment induced both TACR1 mRNA and NK1R protein expression in endometrial stromal cells. In endometrial stromal cells, substance P treatment enhanced cell viability, which was inhibited by a specific NK1R antagonist. Conclusions: NK1R expression is induced in ectopic endometrial tissue by peritoneal TNFα. Induction of NK1R expression may permit endometriotic lesion maintenance via exposure to substance P.

Targeting the insulin-like growth factor-1 receptor in human cancer

The insulin-like growth factor (IGF) signaling system plays a crucial role in human cancer and the IGF-1 receptor (IGF-1R) is an attractive drug target against which a variety of novel anti-tumor agents are being developed. Deregulation of the IGF signaling pathway frequently occurs in human cancer and involves the establishment of autocrine loops comprising IGF-1 or IGF-2 and/or IGF-1R over-expression. Epidemiologic studies have documented a link between elevated IGF levels and the development of solid tumors, such as breast, colon, and prostate cancer. Anti-cancer strategies targeting the IGF signaling system involve two main approaches, namely neutralizing antibodies and small molecule inhibitors of the IGF-1R kinase activity. There are numerous reports describing anti-tumor activity of these agents in pre-clinical models of major human cancers. In addition, multiple clinical trials have started to evaluate the safety and efficacy of selected IGF-1R inhibitors, in combination with standard chemotherapeutic regimens or other targeted agents in cancer patients. In this mini review, I will discuss the role of the IGF signaling system in human cancer and the main strategies which have been so far evaluated to target the IGF-1R.

[Lys40(Ahx-DTPA-111In)NH2]exendin-4, a very promising ligand for glucagon-like peptide-1 (GLP-1) receptor targeting

High levels of glucagon-like peptide-1 (GLP-1) receptor expression in human insulinomas and gastrinomas provide an attractive target for imaging, therapy, and intraoperative tumor localization, using receptor-avid radioligands. The goal of this study was to establish a tumor model for GLP-1 receptor targeting and to use a newly designed exendin-4-DTPA (DTPA is diethylenetriaminepentaacetic acid) conjugate for GLP-1 receptor targeting. METHODS: Exendin-4 was modified C-terminally with Lys(40)-NH(2), whereby the lysine side chain was conjugated with Ahx-DTPA (Ahx is aminohexanoic acid). The GLP-1 receptor affinity (50% inhibitory concentration [IC(50)] value) of [Lys(40)(Ahx-DTPA)NH(2)]exendin-4 as well as the GLP-1 receptor density in tumors and different organs of Rip1Tag2 mice were determined. Rip1Tag2 mice are transgenic mice that develop insulinomas in a well-defined multistage tumorigenesis pathway. This animal model was used for biodistribution studies, pinhole SPECT/MRI, and SPECT/CT. Peptide stability, internalization, and efflux studies were performed in cultured beta-tumor cells established from tumors of Rip1Tag2 mice. RESULTS: The GLP-1 receptor affinity of [Lys(40)(Ahx-DTPA)NH(2)]exendin-4 was found to be 2.1 +/- 1.1 nmol/L (mean +/- SEM). Because the GLP-1 receptor density in tumors of Rip1Tag2 mice was very high, a remarkably high tumor uptake of 287 +/- 62 %IA/g (% injected activity per gram tissue) was found 4 h after injection. This resulted in excellent tumor visualization by pinhole SPECT/MRI and SPECT/CT. In accordance with in vitro data, [Lys(40)(Ahx-DTPA-(111)In)NH(2)]exendin-4 uptake in Rip1Tag2 mice was also found in nonneoplastic tissues such as pancreas and lung. However, lung and pancreas uptake was distinctly lower compared with that of tumors, resulting in a tumor-to-pancreas ratio of 13.6 and in a tumor-to-lung ratio of 4.4 at 4 h after injection. Furthermore, in vitro studies in cultured beta-tumor cells demonstrated a specific internalization of [Lys(40)(Ahx-DTPA-(111)In)NH(2)]exendin-4, whereas peptide stability studies indicated a high metabolic stability of the radiopeptide in beta-tumor cells and human blood serum. CONCLUSION: The high density of GLP-1 receptors in insulinomas as well as the high specific uptake of [Lys(40)(Ahx-DTPA-(111)In)NH(2)]exendin-4 in the tumor of Rip1Tag2 mice indicate that targeting of GLP-1 receptors in insulinomas may become a useful imaging method to localize insulinomas in patients, either preoperatively or intraoperatively. In addition, Rip1Tag2 transgenic mice represent a suitable animal tumor model for GLP-1 receptor targeting.

Microbiological composition associated with interleukin-1 gene polymorphism in subjects undergoing supportive periodontal therapy

BACKGROUND: Interleukin-1 gene polymorphism (IL-1 gene) has been associated with periodontitis. The present study examined the subgingival microbiota by IL-1 gene status in subjects undergoing supportive periodontal therapy (SPT). METHODS: A total of 151 subjects with known IL-1 gene status (IL-1A +4845/IL-1B -3954) (IL-1 gene) were included in this study. Clinical data and subgingival plaque samples (40 taxa) were collected. These taxa were determined by the checkerboard DNA-DNA hybridization method. RESULTS: Gender, smoking habits (n-par tests), age, and clinical periodontal conditions did not differ by IL-1 gene status. IL-1 gene-negative subjects had a higher total bacterial load (mean difference, 480.4 x 10(5); 95% confidence interval [CI], 77 to 884 x 10(5); P <0.02). The levels of Actinobacillus actinomycetemcomitans (mean difference, 30.7 x 10(5); 95% CI, 2.2 to 59.5 x 10(5); P <0.05), Eubacterium nodatum (mean difference, 4.2 x 10(5); 95% CI, 0.6 to 7.8 x 10(5); P <0.02), Porphyromonas gingivalis (mean difference, 17.9 x 10(5); 95% CI, 1.2 to 34.5 x 10(5); P <0.05), and Streptococcus anginosus (mean difference, 4.0 x 10(5); 95% CI, 0.2 to 7.2 x 10(5); P <0.05) were higher in IL-1 gene-negative subjects, an observation specifically found at sites with probing depths <5.0 mm. CONCLUSIONS: Bleeding on probing did not differ by IL gene status, reflecting clinical SPT efficacy. IL-1 gene-negative subjects had higher levels of periodontal pathogens. This may suggest that among subjects undergoing SPT, a lower bacterial load is required in IL-1 gene-positive subjects to develop the same level of periodontitis as in IL-1 gene-negative subjects.

Insulin-like growth factor type-1 receptor down-regulation associated with dwarfism in Holstein calves

Perturbations in endocrine functions can impact normal growth. Endocrine traits were studied in three dwarf calves exhibiting retarded but proportionate growth and four phenotypically normal half-siblings, sired by the same bull, and four unrelated control calves. Plasma 3,5,3'-triiodothyronine and thyroxine concentrations in dwarfs and half-siblings were in the physiological range and responded normally to injected thyroid-releasing hormone. Plasma glucagon concentrations were different (dwarfs, controls>half-siblings; P<0.05). Plasma growth hormone (GH), insulin-like growth factor-1 (IGF-1) and insulin concentrations in the three groups during an 8-h period were similar, but integrated GH concentrations (areas under concentration curves) were different (dwarfs>controls, P<0.02; half-siblings>controls, P=0.08). Responses of GH to xylazine and to a GH-releasing-factor analogue were similar in dwarfs and half-siblings. Relative gene expression of IGF-1, IGF-2, GH receptor (GHR), insulin receptor, IGF-1 type-1 and -2 receptors (IGF-1R, IGF-2R), and IGF binding proteins were measured in liver and anconeus muscle. GHR mRNA levels were different in liver (dwarfs1R mRNA abundance in liver in half-siblings and controls was 2.4- and 2.5-fold higher (P=0.003 and P=0.001, respectively) and in muscle tissue was 2.3- and 1.8-fold higher (P=0.01 and P=0.08, respectively) than in dwarfs. Hepatic IGF-1R protein levels (Western blots) in muscle were 2.5-fold higher (P<0.05) and in liver and muscle (quantitative immunohistochemistry) were higher (P<0.02 and P<0.07, respectively) in half-siblings than in dwarfs. The reduced presence of IGF-1R may have been the underlying cause of dwarfism in studied calves.