In a model of closed head injury (CHI) in the rat we have shown the activation of phospholipase A2 and the production of eicosanoids after injury: at <em>15</em> min, mainly 5-hydroxyeicosatetraenoic acid (5-HETE), and at 24 h, mainly prostaglandin E2. The present study was designed to test whether CHI can also trigger the production of cytokines in the brain. CHI was induced in ether-anesthesized rats by a weight-drop device falling over the exposed skull covering the left hemisphere, 1-2 mm lateral to the midline in the midcoronal plane. In the posttraumatic period (1-24 h), the rats were decapitated, cortical tissue from the injured zone of the contused and contralateral hemispheres was removed and sonicated, and cytokine activity was assessed. Whereas no tumor necrosis factor alpha (TNF alpha) activity was found in normal brain tissue, it was detectable in the contused hemisphere (approximately of 72 +/- 50 pg/mg protein) as early as 1 h post-CHI. TNF alpha levels increased at 2 h, peaked at 4 h, (approximately of 609 +/- 540 pg/mg protein), and declined thereafter. At parallel intervals, only low levels of TNF alpha were detected in the contralateral hemisphere. In normal brain, <em>interleukin</em>-6 (IL-6) was nondetectable. Following CHI, high levels of IL-6 were present, although their accumulation lagged behind that of TNF alpha by 2-4 h, peaking at 8 h (62 +/- 31 ng/mg protein). We suggest that the rapid production of TNF alpha and IL-6 following CHI is a local inflammatory response of brain tissue to primary insult.

OBJECTIVE

To investigate the phenotype and function of CD4+ T cells in synovial fluid (SF) from the affected joints of children with oligoarticular-onset juvenile idiopathic arthritis (JIA), and to establish a possible link with disease activity.

METHODS

CD4+ T cells were obtained from the peripheral blood (PB) and SF of 23 children with oligoarticular-onset JIA, as well as from the PB of <em>15</em> healthy children. The cells were analyzed for the expression of CXCR3, CCR6, and CD161 and for the production of interferon-γ and <em>interleukin</em>-17A (IL-17A). Spectratyping and clonotype analyses were performed to assess different T cell subsets.

RESULTS

The numbers of CD4+CD161+ cells showing either the Th1 or the Th17/Th1 phenotype were higher in the SF than in the PB of children with JIA. The few Th17 cells from JIA SF underwent a spontaneous shift to the Th1 phenotype in vitro, whereas Th17 cells from the PB of healthy children shifted only in the presence of JIA SF; this effect was neutralized by antibody blockade of IL-12 activity. Spectratyping and clonotype analyses showed a similar skewing of the T cell receptor V(β) repertoire in both CD161+ Th17 cells and CD161+ Th1 cells derived from the SF of the same JIA patient. The frequencies of CD4+CD161+ cells, particularly the Th17/Th1 cells, in the JIA SF positively correlated with the erythrocyte sedimentation rate and levels of C-reactive protein.

CONCLUSIONS

These findings suggest that a shifting of CD4+CD161+ T cells from Th17 to the Th17/Th1 or Th1 phenotype can occur in the SF of children with oligoarticular-onset JIA, and indicate that the accumulation of these cells is correlated with parameters of inflammation. Thus, the results support the hypothesis that these cells may play a role in JIA disease activity.

The cytokine <em>interleukin</em>-<em>15</em> (IL-<em>15</em>) has been demonstrated to have anabolic effects in cell culture systems. We tested the hypothesis that IL-<em>15</em> is predominantly expressed by type 2 skeletal muscle fibres, and that resistance exercise regulates IL-<em>15</em> expression in muscle. Triceps brachii, vastus lateralis quadriceps and soleus muscle biopsies were obtained from normally physically active, healthy, young male volunteers (n = 14), because these muscles are characterized by having different fibre-type compositions. In addition, healthy, normally physically active male subjects (n = 8) not involved in any kind of resistance exercise underwent a heavy resistance exercise protocol that stimulated the vastus lateralis muscle and biopsies were obtained from this muscle pre-exercise as well as 6, 24 and 48 h post-exercise. IL-<em>15</em> mRNA levels were twofold higher in the triceps (type 2 fibre dominance) compared with the soleus muscle (type 1 fibre dominance), but Western blotting and immunohistochemistry revealed that muscle IL-<em>15</em> protein content did not differ between triceps brachii, quadriceps and soleus muscles. Following resistance exercise, IL-<em>15</em> mRNA levels were up-regulated twofold at 24 h of recovery without any changes in muscle IL-<em>15</em> protein content or plasma IL-<em>15</em> at any of the investigated time points. In conclusion, IL-<em>15</em> mRNA level is enhanced in skeletal muscles dominated by type 2 fibres and resistance exercise induces increased muscular IL-<em>15</em> mRNA levels. IL-<em>15</em> mRNA levels in skeletal muscle were not paralleled by similar changes in muscular IL-<em>15</em> protein expression suggesting that muscle IL-<em>15</em> may exist in a translationally inactive pool.

The local immune response to influenza virus infection was characterized by determining cytokine and chemokine levels in serial nasal lavage fluid samples from <em>15</em> volunteers experimentally infected with influenza A/Texas/36/91 (H1N1). The study was part of a randomized double-blind placebo-controlled trial to determine the prophylactic effect of intravenous zanamivir (600 mg 2x/day for 5 days), a highly selective inhibitor of influenza A and B virus neuraminidases, on the clinical symptoms of influenza infection. Nasal lavage fluid levels of <em>interleukin</em> (IL)-6, tumor necrosis factor-alpha, interferon-gamma, IL-10, monocyte chemotactic protein-1, and macrophage inflammatory protein-1alpha and -1beta increased in response to influenza virus infection and correlated statistically with the magnitude and time course of the symptoms. Treatment with zanamivir prevented the infection and abrogated the local cytokine and chemokine responses. These results reveal a complex interplay of cytokines and chemokines in the development of symptoms and resolution of influenza.

Large granular lymphocyte (LGL) leukemia is characterized by a clonal expansion of either CD3(+) cytotoxic T or CD3(-) NK cells. Prominent clinical features of T-LGL leukemia include neutropenia, anemia and rheumatoid arthritis (RA). The terminal effector memory phenotype (CD3(+)/CD45RA(+)/CD62L(-)CD57(+)) of T-LGL suggests a pivotal chronic antigen-driven immune response. LGL survival is then promoted by platelet-derived growth factor and <em>interleukin</em>-<em>15</em>, resulting in global dysregulation of apoptosis and resistance to normal pathways of activation-induced cell death. These pathogenic features explain why treatment of T-LGL leukemia is based on immunosuppressive therapy. The majority of these patients eventually need treatment because of severe or symptomatic neutropenia, anemia, or RA. No standard therapy has been established because of the absence of large prospective trials. The authors use low-dose methotrexate initially for T-LGL leukemia patients with neutropenia and/or RA. We recommend either methotrexate or oral cyclophosphamide as initial therapy for anemia. If treatment is not successful, patients are switched to either the other agent or cyclosporine. The majority of patients experience an indolent clinical course. Deaths infrequently occur because of infections related to severe neutropenia. As there are no curative therapeutic modalities for T-LGL leukemia, new treatment options are needed.

METHODS

The mRNA expressions of cytokines and chemokines were assessed in herniated lumbar disc specimens.

OBJECTIVE

To investigate whether the mRNAs of interleukin (IL)-1alpha, tumor necrosis factor (TNF)-alpha, RANTES, IL-8, IL-10, and transforming growth factor (TGF)-beta are expressed in surgically obtained herniated disc specimens; and to discover which of them are the predominant cytokines associated with the clinical symptoms and signs, and whether any differences in the mRNA expression exist depending on the different types of disc herniations.

BACKGROUND

It has been postulated that cytokines are involved in causing radicular leg pain in lumbar disc herniations. Although a few studies have been done on lumbar disc herniations concerning IL-1alpha and TNF-alpha, almost none has been carried out in the cases of the other of cytokines and chemokines.

METHODS

Using a reverse transcription-polymerase chain reaction, mRNA expressions of cytokines and chemokines were investigated in herniated disc specimens. The straight leg raising test, development of radicular pain by back extension, symptom duration, pain intensity using a visual analogue scale, and herniation types were described.

RESULTS

The mRNAs of IL-8, TNF-alpha, IL-1alpha, RANTES, and IL-10 were expressed in 16 (70%), 15 (65%), 9 (39%), 4 (17%), and 2 (9%) of the 23 herniated disc specimens, respectively. The mRNA of TGF-beta was expressed in 5 of 10 specimens (50%). IL-8 mRNA expression was associated with the development of radicular pain by back extension and short symptom duration (average 3.8 weeks). The mRNAs of IL-1alpha were expressed more frequently in transligamentous extensions than in subligamentous extensions, but the expression was weak.

CONCLUSIONS

Interleukin-8 appears to be associated with development of radicular pain by back extension and to be activated on acute or subacute disc herniations. IL-8 seems to participate in the pathomechanism of nerve root inflammation in lumbar disc herniations, which implies that it may be considered a target for therapeutic intervention.

Lymphoid organs contain a B220(+)CD11c(+)NK1.1(+) cell population that was recently characterized as a novel dendritic cell (DC) subset that functionally overlaps with natural killer (NK) cells and plasmacytoid DCs (PDCs). Using Siglec-H and NK1.1 markers, we unambiguously dissected B220(+)CD11c(+) cells and found that PDCs are the only professional interferon (IFN)-alpha-producing cells within this heterogeneous population. In contrast, B220(+)CD11c(+)NK1.1(+) cells are a discrete NK cell subset capable of producing higher levels of IFN-gamma than conventional NK cells. Unlike DCs, only a minute fraction of B220(+)CD11c(+)NK1.1(+) cells in the spleen expressed major histocompatibility complex class II ex vivo or after stimulation with CpG. Consistent with being a NK cell subset, B220(+)CD11c(+)NK1.1(+) cells depended primarily on <em>interleukin</em> <em>15</em> and common cytokine receptor gamma chain signaling for their development. In terms of function, expression of distinctive cell surface receptors, and location in lymphoid organs, NK1.1(+)B220(+)CD11c(+) appear to be the murine equivalent of human CD56(bright) NK cells.

BACKGROUND

The commensal intestinal microbiota drive the inflammation associated with Crohn's disease. However, bacteria such as bifidobacteria and Faecalibacterium prausnitzii appear to be immunoregulatory. In healthy subjects the intestinal microbiota are influenced by prebiotic carbohydrates such as fructo-oligosaccharides (FOS). Preliminary data suggest that FOS increase faecal bifidobacteria, induce immunoregulatory dendritic cell (DC) responses and reduce disease activity in patients with Crohn's disease.

OBJECTIVE

To assess the impact of FOS in patients with active Crohn's disease using an adequately powered randomised double-blind placebo-controlled trial with predefined clinical, microbiological and immunological end points. Patients with active Crohn's disease were randomised to <em>15</em> g/day FOS or non-prebiotic placebo for 4 weeks. The primary end point was clinical response at week 4 (fall in Crohn's Disease Activity Index of ≥ 70 points) in the intention-to-treat (ITT) population.

RESULTS

103 patients were randomised to receive FOS (n = 54) or placebo (n = 49). More patients receiving FOS (14 (26%) vs 4 (8%); p = 0.018) withdrew before the 4-week end point. There was no significant difference in the number of patients achieving a clinical response between the FOS and placebo groups in the ITT analysis (12 (22%) vs 19 (39%), p = 0.067). Patients receiving FOS had reduced proportions of interleukin (IL)-6-positive lamina propria DC and increased DC staining of IL-10 (p < 0.05) but no change in IL-12p40 production. There were no significant differences in the faecal concentration of bifidobacteria and F prausnitzii between the groups at baseline or after the 4-week intervention.

CONCLUSIONS

An adequately powered placebo-controlled trial of FOS showed no clinical benefit in patients with active Crohn's disease, despite impacting on DC function. ISRCTN50422530.

We have described a method for the generation, from fresh human renal cell cancers, of lymphoid cells that are capable of exhibiting significant antitumor reactivity when tested in short term 51Cr release assays. Tumor cell suspensions obtained from 37 consecutive fresh human renal cell cancer specimens (35 patients) could be separated by using enzymatic techniques and culturing in medium containing recombinant <em>interleukin</em> 2 (IL-2). The total cell recovery was 1.5 X 10(9) +/- 2.2 (SE) per tumor with a range of 1 X 10(8) to 5 X 10(9) cells. The percentage of tumor cells in the suspension ranged from 6 to 75% with a mean of 39.1 +/- 3.3%. The remaining cells were predominantly lymphocytes. Viability of mononuclear cells was greater than 90%. Activated tumor-infiltrating lymphocytes (TIL) within these tumors expand and by 10 to 14 days after initiation of culture a 5- to <em>15</em>-fold increase in the number of lymphocytes could be achieved with elimination of all autologous tumor cells. Lymphocytes were recultured in fresh medium containing IL-2 and continued to expand between 2- and 10-fold every 4 to 6 days for an average of 33.7 +/- 4.5 days, resulting in greater than 50,000-fold increase in the total number of lymphocytes. The average number of splits was 4.9 +/- 0.8, with a range of 0 to 21. In 11 of 11 cases tested, TIL exhibited a far better expansion capability in vitro compared to that of peripheral blood lymphocytes obtained from the same patient and grown under identical conditions. The majority of TIL were T cytotoxic/suppressor cells (Leu 2+ Leu 4+). With continued in vitro expansion (up to 50 days) there was a concomitant increase in the helper T (Leu 3+) and pan T populations (Leu 4+) and decrease in Leu 2+ and HLA-DR+ cells. Compared with expanded peripheral blood lymphocytes, these cells demonstrated higher levels of IL-2+ receptors and HLA-DR+ antigens. Renal TIL effectors expanded in IL-2 could lyse almost all autologous tumor targets in 4-h chromium release assays. Allogeneic renal as well as nonrenal targets were equally lysed. TIL lysis of cultured tumor targets K562 and Daudi was significantly better than lysis of autologous, allogeneic-renal, and nonrenal targets. No statistically significant difference in the cytotoxic activity of renal TIL or peripheral blood lymphocyte effectors in killing autologous or allogeneic targets could be demonstrated.(ABSTRACT TRUNCATED AT 400 WORDS)

Virus-specific CD8+ T cells emerge after infection with herpesviruses and maintain latency to these persistent pathogens. It has been demonstrated that murine memory CD8+ T-cell precursors specific for acute lymphocytic choriomeningitis virus express <em>interleukin</em>-7 receptor alpha (IL-7Ralpha), and IL-7 is involved in maintaining memory populations after the clearance of antigen. To investigate whether human CD8+ T cells reactive toward persistent viruses are maintained similarly, we analyzed IL-7Ralpha expression and function on these virus-specific cells. During primary infection, all cytomegalovirus (CMV)-specific CD8+ T cells and most Epstein-Barr virus (EBV)-specific CD8+ T cells lacked IL-7Ralpha expression. Only some virus-specific T cells expressed IL-7Ralpha late after viral replication became undetectable. CD8+ T cells specific for cleared viruses, influenza (FLU), and respiratory syncytial virus (RSV) all expressed IL-7Ralpha. Remarkably, the percentage of IL-7Ralpha- CMV-specific T cells correlated with the height of viral replication in the acute phase. Virus-specific IL-7Ralpha+ cells proliferated vigorously in response to IL-7, IL-<em>15</em>, or peptide, whereas IL-7Ralpha- cells required both peptide and helper-cell activation or IL-2 or IL-<em>15</em> for optimal expansion. Our data suggest that although IL-7 is essential for the maintenance of memory cells in the absence of antigen, CD8+ T cells specific for latent viruses need T-cell receptor activation plus helper factors to persist.

BACKGROUND

The metabolic syndrome is associated with increased angiotensin II activity, induction of a proinflammatory and oxidative state, and endothelial dysfunction. We evaluated the ability of irbesartan, an angiotensin receptor blocker, and lipoic acid, an antioxidant, to affect endothelial function and inflammation in patients with the metabolic syndrome.

RESULTS

We randomized 58 subjects with the metabolic syndrome in a double-blinded manner to irbesartan <em>15</em>0 mg/d (n=14), lipoic acid 300 mg/d (n=<em>15</em>), both irbesartan and lipoic acid (n=<em>15</em>), or matching placebo (n=14) for 4 weeks. Endothelium-dependent and -independent flow-mediated vasodilation was determined under standard conditions. Plasma levels of <em>interleukin</em>-6, plasminogen activator-1, and 8-isoprostane were measured. After 4 weeks of therapy, endothelium-dependent flow-mediated vasodilation of the brachial artery was increased by 67%, 44%, and 75% in the irbesartan, lipoic acid, and irbesartan plus lipoic acid groups, respectively, compared with the placebo group. Treatment with irbesartan and/or lipoic acid was associated with statistically significant reductions in plasma levels of <em>interleukin</em>-6 and plasminogen activator-1. In addition, treatment with irbesartan or irbesartan plus lipoic acid decreased 8-isoprostane levels. No significant changes in blood pressure were noted in any of the study groups.

CONCLUSIONS

Administration of irbesartan and/or lipoic acid to patients with the metabolic syndrome improves endothelial function and reduces proinflammatory markers, factors that are implicated in the pathogenesis of atherosclerosis.

Following traumatic brain injury (TBI), cascades of inflammatory processes occur. Laboratory studies implicate the cytokines <em>interleukin</em>-1alpha (IL-1alpha) and IL-1beta in the pathophysiology of TBI and cerebral ischemia, whilst exogenous and endogenous <em>interleukin</em>-1 receptor antagonist (IL-1ra) is neuroprotective. We analyzed IL-1alpha, IL-1beta, and IL-1ra in brain microdialysates (100-kDa membrane) in <em>15</em> TBI patients. We also analyzed energy-related molecules (glucose, lactate, pyruvate, glutamate, and the lactate/pyruvate ratio) in these brain microdialysates. Mean of mean (+/-SD) in vitro microdialysis percentage recoveries (extraction efficiencies) were IL-1alpha 19.7+/-7.6%, IL-1beta 23.9+/-10.5%, and IL-1ra 20.9+/-6.3%. In the patients' brain microdialysates, mean of mean cytokine concentrations (not corrected for percentage recovery) were IL-1alpha 5.6+/-14.8 pg/mL, IL-1beta 10.4+/-14.7 pg/mL, and IL-1ra 2796+/-2918 pg/mL. IL-1ra was consistently much higher than IL-1alpha and IL-1beta. There were no significant relationships between IL-1 family cytokines and energy-related molecules. There was a significant correlation between increasing IL-1beta and increasing IL-1ra (Spearman r=0.59, p=0.028). There was also a significant relationship between increasing IL-1ra and decreasing intracranial pressure (Spearman r=-0.57, p=0.041). High concentrations of IL-1ra, and also high IL-1ra/IL-1beta ratio, were associated with better outcome (Mann Whitney, p=0.018 and p=0.0201, respectively), within these <em>15</em> patients. It is unclear whether these IL-1ra concentrations are sufficient to antagonize the effects of IL-1beta in vivo. This study demonstrates feasibility of our microdialysis methodology in recovering IL-1 family cytokines for assessing their inter-relationships in the injured human brain, and suggests a neuroprotective role for IL-1ra. It remains to be seen whether exogenous IL-1ra or other agents can be used to manipulate cytokine levels in the brain, for potential therapeutic effect.

We aimed to investigate whether increased consumption of fructose is linked to the increased prevalence of fatty liver. The prevalence of nonalcoholic steatohepatitis (NASH) is 3% and 20% in nonobese and obese subjects, respectively. Obesity is a low-grade chronic inflammatory condition and obesity-related cytokines such as <em>interleukin</em>-6, adiponectin, leptin, and tumor necrosis factor-α may play important roles in the development of nonalcoholic fatty liver disease (NAFLD). Additionally, the prevalence of NASH associated with both cirrhosis and hepatocellular carcinoma was reported to be high among patients with type 2 diabetes with or without obesity. Our research group previously showed that consumption of fructose is associated with adverse alterations of plasma lipid profiles and metabolic changes in mice, the American Lifestyle-Induced Obesity Syndrome model, which included consumption of a high-fructose corn syrup in amounts relevant to that consumed by some Americans. The observation reinforces the concerns about the role of fructose in the obesity epidemic. Increased availability of fructose (e.g., high-fructose corn syrup) increases not only abnormal glucose flux but also fructose metabolism in the hepatocyte. Thus, the anatomic position of the liver places it in a strategic buffering position for absorbed carbohydrates and amino acids. Fructose was previously accepted as a beneficial dietary component because it does not stimulate insulin secretion. However, since insulin signaling plays an important role in central mechanisms of NAFLD, this property of fructose may be undesirable. Fructose has a selective hepatic metabolism, and provokes a hepatic stress response involving activation of c-Jun N-terminal kinases and subsequent reduced hepatic insulin signaling. As high fat diet alone produces obesity, insulin resistance, and some degree of fatty liver with minimal inflammation and no fibrosis, the fast food diet which includes fructose and fats produces a gene expression signature of increased hepatic fibrosis, inflammation, endoplasmic reticulum stress and lipoapoptosis. Hepatic de novo lipogenesis (fatty acid and triglyceride synthesis) is increased in patients with NAFLD. Stable-isotope studies showed that increased de novo lipogenesis (DNL) in patients with NAFLD contributed to fat accumulation in the liver and the development of NAFLD. Specifically, DNL was responsible for 26% of accumulated hepatic triglycerides and <em>15</em>%-23% of secreted very low-density lipoprotein triglycerides in patients with NAFLD compared to an estimated less than 5% DNL in healthy subjects and 10% DNL in obese people with hyperinsulinemia. In conclusion, understanding the underlying causes of NAFLD forms the basis for rational preventive and treatment strategies of this major form of chronic liver disease.

BACKGROUND

The objective of this prospective controlled trial was to investigate the ability of a group of serum and peritoneal fluid (PF) markers to predict, non-surgically, endometriosis.

RESULTS

Serum and PF samples were obtained from 130 women while undergoing laparoscopy for pain, infertility, tubal ligation or sterilization reversal. Concentrations of six cytokines [<em>interleukin</em> (IL)-1beta, IL-6, IL-8, IL-12, IL-13 and tumour necrosis factor (TNF)-alpha] were measured in serum and PF, and reactive oxygen species (ROS) in PF, and levels were compared among women who were allocated to groups according to their post-surgical diagnosis. Fifty-six patients were diagnosed with endometriosis, eight with idiopathic infertility, 27 underwent tubal ligation or reanastomosis (control group) and 39 were excluded due to bloody PF. Only serum IL-6 and PF TNF-alpha could be used to discriminate between patients with and without endometriosis with a high degree of sensitivity and specificity (P < 0.001). A threshold of <em>15</em> pg/ml PF TNF-alpha provided 100% sensitivity and 89% specificity (positive likelihood ratio of 9.1 and negative likelihood ratio of 0). A threshold of 2 pg/ml for serum IL-6 provided a sensitivity of 90% and specificity of 67% (positive likelihood ratio of 2.7 and negative likelihood ratio of 0.14).

CONCLUSIONS

By measuring serum IL-6 and PF TNF-alpha, it was possible to discriminate between patients with endometriosis and those without. Before these markers can be used as a non-surgical diagnostic tool, these data should be verified in a larger study.

<em>Interleukin</em> <em>15</em> (IL-<em>15</em>) is a critical factor for the proliferation and activation of natural killer (NK) and CD8 T cells. Recently, we demonstrated that IL-<em>15</em>Ralpha expressed on monocytes/dendritic cells captures and presents IL-<em>15</em> to neighboring cells in trans (trans-presentation of IL-<em>15</em>) through cell-cell contact. In the current study, we provide evidence that the IL-<em>15</em> presented in trans, but not soluble IL-<em>15</em> at physiologic concentrations, augments the killing activity mediated by NK cells in vitro. In addition, transfection of IL-<em>15</em>Ralpha into a colon carcinoma cell line (MC38) enabled these cells to present IL-<em>15</em> in trans to NK cells and augmented their killing activity, resulting in the efficient lysis of MC38 cells by NK cells in vitro. Furthermore, these transfected MC38 cells no longer form fatal pulmonary metastases in mice. It was also shown that NK cells play an important role in the rejection of MC38 cells under these circumstances. These results collectively suggest that the IL-<em>15</em> trans-presentation mechanism operates in vivo to augment the tumor immune surveillance mechanism. Furthermore, our observation provides the scientific basis for a novel strategy to prevent cancer development/metastasis.

The skin has long been recognized as a major producer of cytokines, but the keratinocyte as principal epidermal cell has received less attention as potential source and target of cytokines. Nevertheless, keratinocytes produce a plethora of cytokines including <em>interleukin</em> (IL)-1, -6, -7, -8, -10, -12, -<em>15</em>, -18, and -20, and tumor necrosis factor alpha (TNF). The production by keratinocytes of pro-inflammatory (IL)-1, -6, -8, and TNF was recognized early and is well studied. Keratinocyte-derived IL-7 and -<em>15</em> are considered to be significant in T-cell trafficking, possibly even in the pathogenesis of cutaneous T-cell lymphoma. Immunomodulatory IL-10 and -12 originating from keratinocytes are considered to be responsible for systemic effects, and IL-18 perhaps has a similar action. Keratinocytes were fairly recently recognized as being source or target of other IL-10 family members like IL-20 and IL-24 and the role of these cytokines in specific diseases is under investigation. In addition, a variety of cytokine receptors are present on keratinocytes like those for IL-4, -13, and -17 and to lesser degree IL-2. The ability to study the expression of cytokines by keratinocytes in vivo and in vitro using primary cells, immortalized cells or even organotypic culture systems offers many possibilities to further investigate the role of cytokine production in keratinocyte biology and disease.

<em>Interleukin</em>-33 (IL-33) is a tissue-derived nuclear cytokine from the IL-1 family abundantly expressed in endothelial cells, epithelial cells and fibroblast-like cells, both during homeostasis and inflammation. It functions as an alarm signal (alarmin) released upon cell injury or tissue damage to alert immune cells expressing the ST2 receptor (IL-1RL1). The major targets of IL-33 in vivo are tissue-resident immune cells such as mast cells, group 2 innate lymphoid cells (ILC2s) and regulatory T cells (Tregs). Other cellular targets include T helper 2 (Th2) cells, eosinophils, basophils, dendritic cells, Th1 cells, CD8+ T cells, NK cells, iNKT cells, B cells, neutrophils and macrophages. IL-33 is thus emerging as a crucial immune modulator with pleiotropic activities in type-2, type-1 and regulatory immune responses, and important roles in allergic, fibrotic, infectious, and chronic inflammatory diseases. The critical function of IL-33/ST2 signaling in allergic inflammation is illustrated by the fact that IL33 and IL1RL1 are among the most highly replicated susceptibility loci for asthma. In this review, we highlight <em>15</em> years of discoveries on IL-33 protein, including its molecular characteristics, nuclear localization, bioactive forms, cellular sources, mechanisms of release and regulation by proteases. Importantly, we emphasize data that have been validated using IL-33-deficient cells.

METHODS

This study was designed to examine the behaviorial immunohistochemical changes of spinal glial cells and spinal Interleukin (IL)-1beta expression after various nerve root injuries used as models of lumbar radiculopathy.

OBJECTIVE

In order to better understand the role of central inflammation in the pathophysiologic mechanisms that give rise to pain associated with lumbar radiculopathy, this research studied the relationship between pain-related behavior associated with spinal glial activation and IL-1beta expression generated by three types of nerve root injury: loose ligation with chromic gut, loose ligation with silk, and tight ligation with silk.

BACKGROUND

An animal model of lumbar radiculopathy originally described by Kawakami and Weinstein involved loose ligation of unilateral L4-L6 nerve roots with chromic gut. Characterization and establishment of such an animal model of low back pain enables further investigation of the nature of the pathophysiologic mechanisms associated with lumbar radiculopathy in humans.

METHODS

Seventy-three rats were divided into four treatment groups. Chromic group (n = 25): The L5 nerve roots (dorsal and ventral) were exposed by hemilaminectomy and loosely ligated with chromic gut. Tight silk group (n = 18): The exposed L5 nerve roots were tightly ligated extradurally with 5-0 silk suture. Loose silk group (n = 15): two loose ligatures of 5-0 silk were placed around the exposed L5 nerve roots. Sham group (n = 15): the rats were subjected to laminectomy alone for exposing nerve roots. Following surgery, thermal hyperalgesia and mechanical allodynia was assessed time-dependently up to 42 days post operatively. At 1, 3, 7, 14, and 42 days postoperatively, the rats in each group were perfused with fixative. The L5 spinal cord segments was harvested and cryosectioned for glial and cytokine immunohistochemistry.

RESULTS

In the chromic and the tight silk group, an immediate and sustained mechanical allodynia was observed in the ipsilateral hind paw up to 35 days postoperatively. The loose silk group also showed an immediate mechanical allodynia that subsided by 14 days postoperatively. Sham-treated animals exhibited mild mechanicalallodynia for the initial 7 days after the surgery. Thermalhyperalgesia was evident in the three primary treatment groups, but not in the sham-treated rats. OX-42 expression was elevated in the gray matter of the L5 spinal section by 3 days in the chromic, the tight silk, and the loose silk groups as compared to the sham group. Astrocytic activation increased over time in all groups except the sham group. There was no direct correlation between degree of microglial response and severity of pain behaviors. In contrast, astrocytic activation demonstrated a direct relationship with the elevation of mechanical allodynia for the first 7 days. In addition, spinal IL-1beta protein expression was increased bilaterally in the superficial layer of the dorsal horn and cell nuclei of the ventral horns in the ligature treated groups as compared with the sham group.

CONCLUSIONS

Direct mechanical and/or chemical injury to lumbar roots in the rat gives rise to pain behavior suggestive of lumbar radiculopathy. The finding that glial activation and enhanced IL-1beta expression are observed in the spinal cord after root injury supports a central, neuroimmune component in the generation of lumbar radiculopathy. A further understanding of the immunologic consequences of root injury may lead to further development and the novel use of selective cytokine-inflammatory inhibitors for the treatment of low back pain associated with radiculopathy.

In order to identify residues required for the binding of <em>interleukin</em>-8 (IL-8) to its receptor, mutants were constructed in which clusters of charged amino acids were systematically replaced with alanine along the entire IL-8 sequence. The mutants were tested for their ability to induce a receptor-mediated rise in cytosolic free Ca2+, a property of wild-type IL-8 which can readily be detected by flow cytometry using neutrophils loaded with the calcium probe Indo-1. Eleven of the 12 mutants caused neutrophil calcium mobilization at 5 nM; the exception being a triple alanine mutant at positions K3, E4, and R6, which was inactive at all concentrations tested (<em>15</em>0 nM maximum). A second set of mutants was generated in which residues 1-<em>15</em> were individually mutated to alanine. Mutants E4A, L5A, or R6A were all inactive in the Ca2+ assay at 5 nM and competed poorly with 125I-IL-8 for neutrophil receptor binding; I10A, E4A, L5A, and R6A had approximately 30-, 100-, 100-, and 1000-fold reduced affinity, as compared with control IL-8, respectively. The nuclear magnetic resonance structure of IL-8 indicates that, in solution, the side chains of E4, L5, R6, and I10 point away from the core of the protein and do not participate in any intramolecular hydrogen bonds or salt bridges (Clore, G. M., and Gronenborn, A. M. (1991) J. Mol. Biol. 217, 611-620).

The antigen responsible for autoimmunization in systemic lupus erythematosus is unknown. In spite of this obstacle, we show that T helper (Th) cell lines that are functionally relevant to this disease can be established in vitro. We derived a total of 396 <em>interleukin</em> 2-dependent T-cell lines from the in vivo activated T cells of five patients with lupus nephritis. Only 59 (approximately <em>15</em>%) of these lines had the ability to selectively augment the production of pathogenic anti-DNA autoantibodies that were IgG in class, cationic in charge, specific for native DNA, and clonally restricted in spectrotype. Forty-nine of these autoantibody-inducing Th lines were CD4+ and expressed the alpha beta T-cell receptor (TCR). The other 10 were CD4-8- (double negative), 3 expressing the alpha beta TCR and 7 expressing the gamma delta TCR. All of the autoantibody-inducing Th lines responded to some endogenous antigen presented by autologous B cells. The autoreactive responses of the CD4+ Th lines were restricted to HLA class II antigens, whereas those of the double-negative cells were not. Endogenous heat shock or stress proteins of the HSP60 family that were expressed by the lupus patients' B cells were involved in stimulating an autoreactive proliferation of the gamma delta Th cells. These studies demonstrate a novel helper activity of certain gamma delta T cells in a spontaneous autoimmune response.

OBJECTIVE

Colorectal cancer (CRC) harbours different types of DNA alterations, including microsatellite instability (MSI). Cancers with high levels of MSI (MSI-H) are considered to have a good prognosis, probably related to lymphocyte infiltration within tumours. The aim of the present study was to characterise the intratumoural expression of markers associated with the antitumour immune response in mismatch repair (MMR)-proficient (MSS) colon cancers.

METHODS

Ninety human colon cancers (T) and autologous normal colon mucosa (NT) were quantified for the expression of <em>15</em> markers of the immune response with quantitiative reverse transcription-PCR (qRT-PCR). mRNA expression levels were correlated with MMR status. Immunohistochemistry (IHC) was performed using both <em>interleukin</em> 17 (IL17) and CD3 antibodies.

RESULTS

Expression of cytotoxic markers (FasL, granzyme B and perforin), inflammatory cytokines (IL1beta, IL6, IL8, IL17 and transforming growth factor beta (TGFbeta)) and a marker of regulatory T cells (forkhead box P3 (Foxp3)) was significantly higher in tumours than in autologous normal tissues. Adjusting for MMR status, higher tumoural expression of both granzyme B and perforin was associated with the MSI-H phenotype, and the perforin T/NT ratio was higher in MSI-H tissues than in MSS tissues. Higher tumoural expression of Foxp3, IL17, IL1beta, IL6 and TGFbeta was associated with the MSS phenotype, and the IL17 T/NT ratio was higher in MSS tissues than in MSI-H tissues as assessed by both qRT-PCR and IHC.

CONCLUSIONS

Immune gene expression profiling in CRC displayed different patterns according to MMR status. Higher Foxp3, IL6, TGFbeta and IL17 expression is a particular determinant in MMR-proficient CRC. These may be potential biomarkers for a new prognostic "test set" in sporadic CRCs.

Diabetes confers an increased propensity to atherosclerosis. Inflammation is pivotal in atherogenesis, and diabetes is a proinflammatory state. <em>Interleukin</em> (IL)-6, in addition to inducing the acute-phase response, contributes to insulin resistance. Monocytes from type 2 diabetic patients secrete increased IL-6. The aim of this study was to examine molecular mechanisms for increased IL-6 release from monocytes under hyperglycemia. Monocytic cells (THP-1) were cultured in the presence of 5.5 mmol/l (normal) or <em>15</em> mmol/l (high) glucose and mannitol. Secreted IL-6, intracellular IL-6, and IL-6 mRNA were significantly increased with hyperglycemia (P < 0.001). Incubation of cells with inhibitors of reactive oxygen species failed to affect high-glucose-induced IL-6 release. Pan-protein kinase C (PKC) inhibitors significantly decreased high-glucose-induced IL-6 release. A specific inhibitor of p38 mitogen-activated protein kinase (MAPK; SB 202190), but not the extracellular signal-regulated kinase inhibitor PD98059, significantly decreased high-glucose-induced IL-6 release. Furthermore, the PKC-alpha/beta2 inhibitor decreased p38MAPK and the resulting high-glucose-induced IL-6 release. Both antisense oligos to PKC-beta and -alpha as well as small interfering RNA (siRNA) to PKC-alpha and -beta resulted in significantly decreased high-glucose-induced IL-6 release. Nuclear factor-kappaB (NF-kappaB) inhibitors significantly decreased IL-6 mRNA and protein. siRNA to PKC-beta and -alpha also significantly decreased NF-kappaB activity and IL-6 release. The combination was not additive to either siRNA alone, suggesting that they work through a common pathway. Thus, IL-6 release from monocytes under hyperglycemia appears to be mediated via upregulation of PKC, through p38MAPK and NF-kappaB, resulting in increased mRNA and protein for IL-6. Thus, inhibition of PKC-alpha and -beta can ameliorate the proinflammatory state of diabetes.

Tissue fibrosis results, in part, from an interaction between growth regulatory molecules released by mononuclear phagocytes and fibroblasts. In the chronic interstitial lung disorders, alveolar macrophages, the mononuclear phagocytes of the lung, are known to spontaneously release two growth factors for fibroblasts, fibronectin and alveolar macrophage-derived growth factor (AMDGF) that together stimulate nonreplicating lung fibroblasts to divide. In addition to these two primary growth promoting signals, alveolar macrophages are able to release other mediators that may have a potential role in modulating lung fibroblast replication in response to these primary signals, including interferon gamma (IFN gamma), prostaglandin E2 (PGE2), and <em>interleukin</em> 1 (IL-1). To evaluate this possibility, we examined the effect of each of these other mediators on lung fibroblast replication in response to fibronectin and AMDGF in serum-free, defined medium. IFN gamma had no effect on fibroblast replication. In contrast, PGE2 resulted in a dose-dependent inhibition of fibroblast replication in response to fibronectin and AMDGF with 50% of the maximum inhibition observed at a PGE2 concentration of less than 10 ng/ml. IL-1, while not active as a primary growth promoting signal, at concentrations of 4-10 U/ml, augmented fibroblast replication in response to fibronectin and AMDGF by 10 to <em>15</em>%. Temporally, the growth augmenting effect of IL-1 occurred early in the G1 phase of the cell cycle. These data indicate that lung fibroblast replication in response to two of the primary growth promoting signals spontaneously released by alveolar macrophages in the interstitial lung disorders, while uninfluenced by IFN gamma, can be inhibited by PGE2 and modestly augmented by IL-1. Understanding the relevant fibroblast growth modulatory signals within the alveolar microenvironment in the chronic interstitial disorders may lead to rational therapeutic strategies designed to interrupt the fibrotic process.

The stages of human natural killer (NK) cell differentiation are not well established. Culturing CD34(+) progenitors with <em>interleukin</em> 7 (IL-7), IL-<em>15</em>, stem cell factor (SCF), FLT-3L, and murine fetal liver cell line (EL08.1D2), we identified 2 nonoverlapping subsets of differentiating CD56(+) cells based on CD117 and CD94 (CD117(high)CD94(-) and CD117(low/-)CD94(+) cells). Both populations expressed CD161 and NKp44, but differed with respect to NKp30, NKp46, NKG2A, NKG2C, NKG2D, CD8, CD16, and KIR. Only the CD117(low/-) CD94(+) population displayed cytotoxicity and interferon-gamma production. Both populations arose from a single CD34(+)CD38(-) Lin(-) cell and their percentages changed over time in a reciprocal fashion, with CD117(high)CD94(-) cells predominating early and decreasing due to an increase of the CD117(low/-)CD94(+) population. These 2 subsets represent distinct stages of NKcell differentiation, since purified CD117(high) CD94(-) cells give rise to CD117(low/-)CD94(+) cells. The stromal cell line (EL08.1D2) facilitated the transition from CD117(high)CD94(-) to CD117(low/-)CD94(+) via an intermediate phenotype (CD117(low)CD94(low/-)). EL08.1D2 also maintained the mature phenotype, preventing the reversion of CD117(low/-)CD94(+) cells to the intermediate (CD117(low)CD94(low/-)) phenotype. An analogous population of CD56(+)CD117(high)CD94(-) cells was found in cord blood. The identified stages of NK-cell differentiation provide evidence for coordinated acquisition of HLA-specific inhibitory receptors (ie, CD94/NKG2A) and function in developing human NK cells.