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IL-4 and IL-13 elicit several important responses in airway epithelium including chemokine secretion and mucous secretion that may contribute to airway inflammation, cell migration, and differentiation. These cytokines have overlapping but not identical effector profiles likely due to shared subunits in their receptor complexes. These receptors are variably described in epithelial cells, and the relative expression, localization, and function of these receptors in differentiated and repairing epithelial cells are not clear. We examined IL-4/IL-13 receptor expression and localization in primary airway epithelial cells collected from normal human lungs and grown under conditions yielding both undifferentiated and differentiated cells inclusive of basal, goblet, and ciliated cell phenotypes. Gene expression of the IL-4R[alpha], IL-2R[gamma]c, IL-13R[alpha]1, and IL-13R[alpha]2 receptor subunits increased with differentiation, but different patterns of localization and protein abundance were seen for each subunit based on both differentiation and the cell subtypes present. Increased expression of receptor subunits observed in more differentiated cells was associated with more substantial functional responses to IL-4 stimulation including increased eotaxin-3 expression and accelerated migration after injury. We demonstrate substantial differences in IL-4/IL-13 receptor subunit expression and responsiveness to IL-4 based on the extent of airway epithelial cell differentiation and suggest that these differences may have functional consequences in airway inflammation. interleukin-4; interleukin-13; eotaxin-3; migration doi: 10.1152/ajplung.00422.2009.

TNF-[alpha] is a proinflammatory cytokine and is an important mediator of maternal endothelial dysfunction leading to preeclampsia. In this study, we tested whether IL-10 protects against TNF-[alpha]-induced endothelial dysfunction in murine aorta. In in vitro experiments, aortic rings of C57BL/6 female mice were incubated in Dulbecco's modified Eagle's medium in the presence of either vehicle (distilled [H.sub.2]O), TNF-[alpha] (4 nmol/1), or recombinant mouse IL-10 (300 ng/ml) or in the presence of both TNF-[alpha] and IL-10 for 22 h at 37[degrees]C. In in vivo experiments C57BL6/IL-10 knockout female mice were treated with saline or TNF-[alpha] (220 ng x [kg.sup.-1] x [day.sup.-1]) for 14 days. Aortic rings were isolated from in vitro and in vivo experiments and mounted in a wire myograph (Danish Myotech) and stretched to a tension of 5 mN. Endothelium-dependent relaxation was assessed by constructing cumulative concentration-response curves to acetylcholine (ACh, 0.001-10 [micro]mol/l) during phenylephrine (10 [micro]mol/l)-induced contraction. As a result, overnight exposure of aortic rings to TNF-[alpha] resulted in significant blunted maximal relaxing responses ([E.sub.max]) to ACh compared with untreated rings (22 [+ or -] 4 vs. 82 [+ or -] 3%, respectively). IL-10 knockout mice treated with TNF-[alpha] showed significant impairment in ACh responses ([E.sub.max]) compared with C57BL/6 mice treated with TNF-[alpha] (51 [+ or -] 3 vs. 72 [+ or -] 3%, respectively). Western blot analysis showed that endothelial nitric oxide synthase (eNOS) expression was reduced by TNF-[alpha] in in vitro and in vivo experiments, whereas IL-10 restored the eNOS expression. In conclusion, the anti-inflammatory cytokine IL-10 prevents impairment in endothelium-dependent vasorelaxation caused by TNF-[alpha] by protecting eNOS expression. tumor necrosis factor-[alpha]; nuclear factor-[kappa]B doi: 10.1152/ajpheart.00763.2009.

Activated pancreatic stellate cells (PSCs) play a pivotal role in pancreatic fibrosis in chronic pancreatitis and pancreatic cancer. Recent studies have suggested a role of IL-33, a newly identified IL-1 family member, in fibrosis. We here examined the expression of IL-33 and the IL-33-mediated regulation of cell functions in PSCs. PSCs were isolated from human and rat pancreas tissues. The expression of IL-33 was examined by Western blotting, PCR, ELISA, and immunostaining. The roles of IL-33 in the regulation of PSC functions were examined by using recombinant IL-33 and small interfering RNA. Activated PSCs expressed IL-33 in the nucleus, and the expression was increased by IL-l[beta], TNF-[alpha] PDGF-BB, and IFN-[gamma], but not TGF-[beta]1. Nuclear IL-33 expression was also observed in the pancreatic acinar and ductal cells. IL-l[beta] induced IL-33 expression mainly through the activation of NF-[kappa]B and ERK pathways and partially through that of p38 MAP kinase, whereas PDGF-BB induced IL-33 expression mainly through the activation of ERK pathway. PSCs expressed soluble ST2, ST2L, and IL-1RAcP, but the expression level of ST2L was relatively low. Recombinant IL-33 did not stimulate key cell functions of PSCs. Decreased IL-33 expression by small interfering RNA resulted in decreased proliferation in response to PDGF-BB. In conclusion, activated PSCs expressed IL-33 in the nucleus. IL-33 might regulate the PDGF-induced proliferation in PSCs. pancreatic cancer; pancreatitis; fibrosis; signal transduction; inflammation doi: 10.1152/ajpgi.00178.2010.

Am J Physiol Regul Integr Comp Physiol 298: R198-R210, 2010. First published November 11, 2009; doi: 10.1152/ajpregu.00325.2009.--Expression of the cytokine interleukin-6 (IL-6) by skeletal muscle is hugely increased in response to a single bout of endurance exercise, and this appears to be mediated by increases in intracellular calcium. We examined the effects of endurance exercise on IL-6 mRNA levels and promoter activity in skeletal muscle in vivo, and the role of the calcium-activated calcineurin signaling pathway on muscle IL-6 expression in vivo and in vitro. IL-6 mRNA levels in the mouse tibialis anterior (TA) were increased 2-10-fold by a single bout of treadmill exercise or by 3 days of voluntary wheel running. Moreover, an IL-6 promoter-driven luciferase transgene was activated in TA by both treadmill and wheel-running exercise and by injection with a calcineurin plasmid. Exercise also increased muscle mRNA expression of the calcineurin regulatory gene MCIP1, as did treatment of [C.sub.2][C.sub.12] myotubes with the calcium ionophore A23187. Cotransfection of [C.sub.2][C.sub.12] myotubes with a constitutively active calcineurin construct significantly increased while cotransfection with the calcineurin inhibitor CAIN inhibited activity of a mouse IL-6 promoter-reporter construct. Cotransfection with a myocyte enhancer-factor-2 (MEF-2) expression construct increased basal IL-6 promoter activity and augmented the effects of calcineurin cotransfection, while cotransfection with the MEF-2 antagonist MITR repressed calcineurin-activated IL-6 promoter activity in vitro. Surprisingly, cotransfection with a dominant-negative form of another calcineurin-activated transcription factor, nuclear factor activator of T cells (NFAT), greatly potentiated both basal and calcineurin-stimulated IL-6 promoter activity in [C.sub.2][C.sub.12] myotubes. Mutation of the MEF-2 DNA binding sites attenuated, while mutation of the NFAT DNA binding sites potentiated basal and calcineurin-activated 1L-6 promoter activity. Finally, CREB and C/EBP were necessary for basal IL-6 promoter activity and sufficient to increase IL-6 promoter activity but had minimal roles in calcineurin-activated IL-6 promoter activity. Together, these results suggest that IL-6 transcription in skeletal muscle cells can be activated by a calcineurin-MEF-2 axis which is antagonized by NFAT. transcription; cytokine

The expression of Ig-like transcript (ILT) inhibitory receptors is a characteristic of tolerogenic dendritic cells (DCs). However, the mechanisms of modulation of DCs via ILT receptors remain poorly defined. HLA-G is a preferential ligand for several ILTs. Recently, we demonstrated that triggering of ILT4 by HLA-G1 inhibits maturation of human monocyte-derived conventional DCs and murine DCs from ILT4 transgenic mice, resulting in diminished expression of MHC class II molecules, CD80 and CD86 costimulatory molecules, and prolongation of skin allograft survival. Different isoforms of HLA-G have diverse effects on the efficiency to induce ILT-mediated signaling. In this work, we show that HLA-G1 tetrameric complex and HLA-G5 dimer, but not HLA-G5 monomer, induce strong ILT-mediated signaling. We determined that the arrest of maturation of ILT4-positive DCs by HLA-G ligands involves the IL-6 signaling pathway and STAT3 activation. Ligation of ILT4 with HLA-G on DCs results in recruitment of SHP-1 and SHP-2 protein tyrosine phosphatases. We propose a model where SHP-2 and the IL-6-STAT3 signaling pathway play critical roles in the modulation of DC differentiation by ILT4 and HLA-G. immunomodulation | inhibitory receptor

Psoriasis is a chronic skin disease resulting from the dysregulated interplay between keratinocytes and infiltrating immune cells. We report on a psoriasis-like disease model, which is induced by the transfer of [CD4.sup.+][CD45RB.sup.hi][CD25.sup.-] cells to pathogen-free scid/scid mice. Psoriasis-like lesions had elevated levels of antimicrobial peptide and proinflammatory cytokine mRNA. Also, similar to psoriasis, disease progression in this model was dependent on the p40 common to IL-12 and IL-23. To investigate the role of IL-22, a Th17 cytokine, in disease progression, mice were treated with IL-22-neutralizing antibodies. Neutralization of IL-22 prevented the development of disease, reducing acanthosis (thickening of the skin), inflammatory infiltrates, and expression of Th17 cytokines. Direct administration of IL-22 into the skin of normal mice induced both antimicrobial peptide and proinflammatory cytokine gene expression. Our data suggest that IL-22, which acts on keratinocytes and other nonhematopoietic cells, is required for development of the autoreactive Th17 cell--dependent disease in this model of skin inflammation. We propose that IL-22 antagonism might be a promising therapy for the treatment of human psoriasis., Introduction Psoriasis is a common, chronic autoimmune disease of the skin, which affects approximately 2% of the general population. The lesions are characterized by red, scaly, raised plaques at different [...]

Expression of IL-22 is induced in several human inflammatory conditions, including inflammatory bowel disease (IBD). Expression of the IL-22 receptor is restricted to innate immune cells; however, the role of IL-22 in colitis has not yet been defined. We developed what we believe to be a novel microinjection-based local gene-delivery system that is capable of targeting the inflamed intestine. Using this approach, we demonstrated a therapeutic potency for IL-22-mediated activation of the innate immune pathway in a mouse model of Th2-mediated colitis that induces disease with characteristics similar to that of IBD ulcerative colitis (UC). IL-22 gene delivery enhanced STAT3 activation specifically within colonic epithelial cells and induced both STAT3-dependent expression of mucus-associated molecules and restitution of mucus-producing goblet cells. Importantly, IL-22 gene delivery led to rapid amelioration of local intestinal inflammation. The amelioration of disease by IL-22 was mediated by enhanced mucus production. In addition, local gene delivery was used to inhibit IL-22 activity through overexpression of IL-22-binding protein. Treatment with IL-22-binding protein suppressed goblet cell restitution during the recovery phase of a dextran sulfate sodium--induced model of acute colitis. These data demonstrate what we believe to be a novel function for IL-22 in the intestine and suggest the potency of a local IL-22 gene--delivery system for treating UC., Introduction IL-22 belongs to the IL-10 family of cytokines (1-3) and has recently been shown to be preferentially expressed by the Th17 subset (4), (5). IL-22 targets innate immune pathways [...]

Insights into genes that regulate eosinophilic inflammation are discussed with information about the acquisition of those insights from model systems. The role of interleukin (IL)-5 in eosinophil differentiation, the regulation of adhesive interactions in circulating neutrophils and eosinophils, and roles of chemokines in eosinophil chemotaxis into tissues are all of importance.

Interleukin 16 (IL-16) has been shown to function as chemoattractant factor, as a modulator of T-cell activation, and as an inhibitor of immunodeficiency virus replication. The recent identification of inconsistencies in published IL-16 cDNA nucleotide sequences led to the proposal that IL-16 is synthesized in the form of a large precursor protein (pro-IL-16). To identify the true transcriptional start of the IL-16 mRNA rapid amplification of cDNA ends methods were applied. The complete pro-IL-16 cDNA was subsequently molecularly cloned, sequenced, and expressed in COS-7 cells. We report here that pro-IL-16 is most likely synthesized as a 67-kDa protein and is encoded from a major 2.6-kb transcript. Recombinant pro-IL-16 polypeptides are specifically cleaved in lysates of CD8(+) cells, suggesting that the naturally secreted bioactive form of IL-16 is smaller than the originally published 130 amino acids fragment. Moreover, in contrast to other interleukins such as IL-15, IL-16 mRNA expression is almost exclusively limited to lymphatic tissues underlining the potential of IL-16 as an immune regulatory molecule.

Interferon (IFN)-[Alpha]/[Beta]-mediated negative regulation of interleukin 12 (IL-12) and IFN-[Gamma] proteins is reported here. Both IFN-[Alpha] and IFN-[Beta] inhibited fixed Staphylococcus aureus Cowan strain induction of IL-12 and IFN-[Gamma] production by mouse splenic leukocytes in culture. Extended studies with IFN-[Alpha] demonstrated that inhibition was at the level of biologically active IL-12 p70. Effects were selective, as induction of tumor necrosis factor was unaffected and induction of IL-6 was enhanced. Neutralization of IFN-[Alpha]/[Beta] expressed endogenously during infections with murine cytomegalovirus (MCMV) enhanced early IL-12 and IFN-[Gamma] protein production. Furthermore, during infections of mice with lymphocytic choriomeningitis virus (LCMV), this treatment revealed a previously undetected early IL-12 and IFN-[Gamma] protein expression, and mice deficient in IFN-[Alpha]/[Beta] receptor function, but not control mice, also expressed endogenous LCMV-induced IL-12. The effects of IFN-[Alpha]/[Beta] neutralization on production of IL-12 and IFN-[Gamma] during the viral infections were detected in both serum samples and medium conditioned with splenic leukocytes isolated from infected animals. In vitro studies demonstrated that splenic leukocytes isolated from LCMV-infected mice were primed to produce IL-12 in response to stimulation with Staphylococcus aureus Cowan strain, but that this responsiveness was sensitive to added IFN-[Alpha]. Moreover, endogenous IFN-[Alpha]/[Beta] induced by LCMV inhibited in vivo lipopolysaccharide stimulation of IL-12 production. These results demonstrate a new pathway for regulating cytokine responses, and suggest a mechanism for inhibition of IL-12-dependent immune responses during viral infections.

The mechanism of interleukin (IL)-8 gene expression before viral replication was analyzed in A549 cells infected with respiratory syncytial virus (RSV). Induction of IL-8 gene expression by intracellular RSV in A549 cells was mediated by activation of nuclear factor (NF)-IL-6 and NF-kappaB expression. Furthermore, the transcriptional activation of IL-8 is characterized by increased NF-kappaB levels for cooperative binding in RSV-infected cells.

We have identified a cDNA from a human phytohemagglutinin-activated lymphoblast library encoding a protein that binds 125I-labeled human interleukin 12 (125I-huIL-12) with a [K.sub.d] of about 5 nM when expressed in COS-7 cells. When coexpressed in COS-7 cells with the previously identified IL-12 [Beta] receptor (IL-12R[Beta]) protein, two classes of 125I-huIL-12 binding sites were measured with [K.sub.d]s of about 55 pM and 8 nM, corresponding to the high- and low-affinity binding sites seen on phytohemagglutinin-activated lymphoblasts. This newly identified huIL-12R subunit is a member of the cytokine receptor superfamily, with closest resemblance to the [Beta]-type cytokine receptor gp130 and the receptors for leukemia inhibitory factor and granulocyte colony-stimulating factor. Consequently, we have reclassified the previously identified IL-12R[Beta] subunit as huIL-12R[Beta]1 and designated the newly identified subunit as huIL-12R[Beta]2. huIL-12R[[Beta].sup.2] is an 862-amino acid type I transmembrane protein with a 595-amino-acid-long extracellular domain and a cytoplasmic tail of 216 amino acids that contains three tyrosine residues. A cDNA encoding the mouse homolog of the huIL12R[Beta]2 protein has also been isolated. Human and mouse IL-12R[Beta]2 proteins show a 68% amino acid sequence identity. When expressed in COS-7 cells, huIL-12R[Beta]2 exists as a disulfide-linked oligomer with an apparent monomeric molecular weight of 130 kDa. Coexpression of the two identified IL-12R subunits in Ba/F3 cells conferred IL-12 responsiveness, and clones of these cotransfected Ba/F3 cells that grew continuously in the presence of IL-12 were isolated and designated LJM-1 cells. LJM-1 cells exhibited dose-dependent proliferation in response to huIL-12, with an [ED.sub.50] of about 1 pM huIL-12. Interestingly, Ba/F3 cells transfected with IL-12R[Beta]2 alone proliferated in response to huIL-12 with an [ED.sub.50] of about 50 pM, although a role for endogenous mouse IL-12R[Beta]1 in IL-12 signal transduction in these transfectants cannot be ruled out. These results demonstrate that the functional high-affinity IL-12R is composed of at least two [Beta]-type cytokine receptor subunits, each independently exhibiting a low affinity for IL-12.

Binding studies with fluorochrome-labeled interleukin 7 (IL-7) indicate the expression of IL-7 protein in chronic lymphocytic leukemia (CLL) cells' cytoplasm and the influence of contact between endothelial cells on this expression. This endothelial cell contact inhibits apoptosis by blocking the CLL neoplastic cells after activation, implying the role of integrins in CLL cell viability.

Randomly generated immune responses activated by enteric antigens result in bowel infection in mice mutants which lack Interleukin-10 (IL-10) activity. IL-10 affects immunoregulation in the intestinal tract, and influences the growth and cell differentiation of immune system cell populations. Chronic enterocolitis in IL-10 deficient mutants affects the duodenum, the adjacent jejunum and colon. IL-10 is thus experimentally demonstrated to regulate intestinal immuno-responses.

Researchers replaced a tight turn in the cytokine sequence with the large loop in soybean trypsin inhibitor that binds to the active region of trypsin, based on the finding that the polent inflammatory cytokine human interleukin 1 beta has the same overall structure as soybean trypsin inhibitor (STI). The results permit the receptor and intracellular transduction regions on the protein to be mapped in detail.

The effects of interferon-beta (IFN-beta) on the tumor necrosis factor (TFN)-induced interleukin-8 (IL-8) expression in human fibroblasts were investigated. The results showed that IFN-beta treatment leads to a decrease in levels of IL-8 transcripts. The presence of protein inhibitors did not diminish the transcriptional down-regulation of IL-8. These results indicate that the regulatory mechanism of IFN-beta on IL-8 expression involves a temporary alteration of a preexisting factor.

The constitutive expression of cytokine messenger RNA in biopsies from epithelial ovarian carcinomas were determined using PCR-assisted messenger RNA amplification assay. It was shown that a selective expression of interleukin-10, granulocyte-macrophage colony-stimulating factor and interferon gamma messenger RNA was present in ovarian tumor tissue. The study further correlated cytokine messenger RNA pattern of each tumor biopsy to the T-cell variable region beta chain gene repertoire.

The cDNA coding for the murine interleukin-9 (IL-9) receptor was expressed in COS cells and characterized. Analysis of the 52-kDa protein showed the presence of a typical membrane-spanning domain and a putative signal peptide. Sequence analysis showed that the IL-9 receptor is highly similar to the hematopoietin receptor superfamily. Furthermore, this receptor is expressed in both membrane-bound and soluble forms.

The mechanism of interleukin2 (IL-2) activation of the c-fos protooncogene was elucidated using a mouse proB-cell line. The c-fos gene contains an upstream serum-responsive element (SRE)which has been shown to be an inducibe enhancer element. The results show that SRE is the primary target of IL-2 as well as IL-3 and erythropoietin. Furthermore, the IL-2-induced activation of c-fos depends on the presence of two distinct cytoplasmic regions of the IL-2 beta receptor, the serine-rich andacidic regions.

Intraperitoneal administration of recombinant interleukin 12 (rIL-12) in BALB/c mice induces the non-T and non-B cells to secrete interferon gamma that releases nitric oxide to protect the mice from Plasmodium yoelii sporozoite-induced malaria. Introduction of a nitric oxide synthase inhibitor or an interferon gamma monoclonal antibody abolishes the effect of rIL-12. rIL-12 treatment protects the mice from the effects of cytotoxic anti-CD8 and -CD4 monoclonal antibodies and T- and B-cell immunodeficiency.

A reversibly switchable mouse transgenic model of Myc-dependent Beta-cell carcinogenesis is used to delineate the kinetics and causal sequence of angingenic processes following acute Myc activation. It is shown that the onset of endothelial cell proliferation is induced shortly after Myc-induced cell cycle entry of beta cells.

Research has been conducted on cytokine hormone interkleukin-2 containing adaptive region which binds druglike small molecules. The authors have explored the binding properties of this region, and have described the results.

Research has been conducted on skeletal muscle formation and growth which requires myoblast fusion to form myofibers or myotubes. Results demonstrate that after myotube formation they recruit myoblast fusion via IL-4 secretion, which leads to muscle growth.

The authors discuss the publication on the role of Interleukin-4 in myoblast fusion regulation. The topics of interest include the effect of Interleukin-4 expression and secretion on myoblast fusion with pre-existing myotubes.

Abstract Background--Interleukin 1β (IL-1β) is a potent inhibitor of gastric acid secretion. Regulatory actions at several levels have previously been demonstrated, including direct inhibition of parietal cell acid secretion. Although [...]