OBJECTIVE

Recently, the Th1/Th2 paradigm has been expanded by the discovery of Th17 cells, a subset of CD4+ memory T cells characterized by their unique ability to secrete interleukin-17 (IL-17) family cytokines. Importantly, Th17 cells appear to be intimately involved in autoimmunity. We undertook the present study to investigate whether the Th17/IL-23 system is up-regulated in Sjögren's syndrome (SS).

METHODS

Sera, saliva, and salivary glands from C57BL/6.NOD-Aec1Aec2 mice (a model for primary SS), as well as sera, saliva, and salivary gland biopsy specimens obtained from patients with primary SS, were evaluated for IL-17 and IL-23 expression by immunohistochemistry, real-time polymerase chain reaction, and the Luminex system.

RESULTS

Immunohistochemical stainings of submandibular glands from C57BL/6.NOD-Aec1Aec2 mice and of salivary gland biopsy specimens from SS patients revealed strong positive staining for both IL-17 and IL-23 within lymphocytic foci and diffuse staining on epithelial tissues. Temporal expression of IL-17 and IL-23 in submandibular glands of C57BL/6.NOD-Aec1Aec2 mice correlated with expression of retinoic acid-related orphan receptor gammat, the Th17 cell master control gene. While IL-17 could not be detected in saliva from 4-20-week-old C57BL/6.NOD-Aec1Aec2 mice, this cytokine was present in the blood of mice up to age 16 weeks. This contrasted with sera and saliva from SS patients, in which IL-17 and IL-6 were present at varying levels.

CONCLUSIONS

These results suggest that the Th17/IL-23 system is up-regulated in C57BL/6.NOD-Aec1Aec2 mice and SS patients at the time of disease. A correlation between up-regulated IL-17/IL-23 expression and specific clinical manifestations of SS has yet to be identified.

OBJECTIVE

Interleukin (IL)-10 is a cytokine with potent anti-inflammatory properties. We investigated the safety and efficacy of different doses of human recombinant (rhu)IL-10 in patients with Crohn's disease (CD).

METHODS

A prospective, multicenter, double-blind, placebo-controlled study was conducted in 329 therapy-refractory patients with CD. Clinical improvement was defined by a reduction of the Crohn's Disease Activity Index (CDAI) by 100 points or more and clinical remission by a decrease of the CDAI to <150 points. At selected centers, patients underwent ileocolonoscopies and activation of the nuclear factor-kappa B (NF-kappa B) system was assessed in biopsy specimens.

RESULTS

Subcutaneous treatment with rhuIL-10 over 28 days induced a fully reversible, dose-dependent decrease in hemoglobin and thrombocyte counts but no clinically significant side effects. No differences in the induction of remission were observed between rhuIL-10 groups (1 microg, 18% [9.6-29.2]; 4 microg, 20% [11.3-32.2]; 8 microg, 20% [11.1-31.8]; 20 microg, 28% [18-40.7]; and placebo, 18% [9.6-29.6]). Clinical improvement was observed in 46% (33.7-59) in the 8-microg/kg rhuIL-10 group in comparison with 27% (17-39.6) in patients taking placebo. Responders to rhuIL-10 showed inhibition of NF-kappaB p65 activation in contrast to nonresponders.

CONCLUSIONS

Up to 8 microg/kg of rhuIL-10 was well tolerated. A tendency toward clinical improvement but not remission was observed in the 8-microg/kg dose group. Further studies should delineate which subgroups of patients with CD benefit from rhuIL-10 therapy.

Transgenic (TG) mice expressing a high copy number of interleukin (<em>IL</em>)-7 cDNA under the control of the major histocomaptability complex (MHC) class II promoter display a 10-<em>20</em>-fold increase in total T cell numbers. Here, we show that the increase in T cell numbers in <em>IL</em>-7 TG mice is most apparent at the level of memory phenotype CD44hi CD122hi CD8+ cells. Based on studies with T cell receptor (TCR) TG mice crossed to <em>IL</em>-7 TG mice, increased levels of <em>IL</em>-7 may provide costimulation for TCR recognition of self-MHC ligands and thus cause naive CD8+ cells to proliferate and differentiate into memory phenotype cells. In addition, a marked increase in CD44hi CD122hi CD8+ cells was found in <em>IL</em>-7 TG <em>IL</em>-15(-) mice. Since these cell are rare in normal <em>IL</em>-15(-) mice, the dependency of memory phenotype CD8+ cells on <em>IL</em>-15 can be overcome by overexpression of <em>IL</em>-7.

Stimulation of a normal type I mouse T helper cell clone (TH1) with concanavalin A in the absence of antigen presenting cells (APC) in vitro results in the induction of a hyporesponsive state known as T cell clonal anergy. This state is characterized by a decrease in proliferation following stimulation with antigen and APC resulting from a decrease in the production of <em>IL</em>-2. Production of the lymphokines <em>IL</em>-3/granulocyte macrophage colony stimulating factor and IFN-gamma is also reduced, although to a lesser degree. Stimulation of such anergic cells with <em>IL</em>-2 results in proliferation and a complete reversal of the state. We demonstrate that this reversal is not due to the outgrowth of a subpopulation of cells that had escaped anergy induction, but rather occurs in all the cells. Anergy also dissipated spontaneously, although much more slowly, in the absence of T cell antigen receptor occupancy. Finally, we show that a similar state can be produced by normal activation with antigen and APC if <em>IL</em>-2 and other factors are removed at 16-<em>20</em> h. These results indicate that the anergic state is not a permanent change in the TH1 cell. Anergy induction appears to be a consequence of the inability of the cell to divide extensively following stimulation through the antigen-specific receptor. We propose a model to explain these results in terms of a relatively stable negative regulatory factor.

Acute and chronic hyperglycemia are proinflammatory states, but the status of proinflammatory cytokines and markers of oxidative stress and cardiovascular risks is not known in hyperglycemic crises of diabetic ketoacidosis (DKA) and nonketotic hyperglycemia (NKH). We studied <em>20</em> lean and 28 obese patients with DKA, 10 patients with NKH, and 12 lean and 12 obese nondiabetic control subjects. We measured 1) proinflammatory cytokines (tumor necrosis factor-alpha, interleukin [<em>IL</em>]-6, <em>IL</em>1-beta, and <em>IL</em>-8), 2) markers of cardiovascular risk (C-reactive protein [CRP], homocysteine, and plasminogen activator inhibitor-1 [PAI-1]), 3) products of reactive oxygen species (ROS; thiobarbituric acid [TBA]-reacting material, and dichlorofluorescein [DCF]), and 4) cortisol, growth hormone (GH), and free fatty acids (FFAs) on admission (before insulin therapy) and after insulin therapy and resolution of hyperglycemia and/or ketoacidosis. Results were compared with lean and obese control subjects. Circulating levels of cytokines, TBA, DCF, PAI-1, FFAs, cortisol, and GH on admission were significantly increased two- to fourfold in patients with hyperglycemic crises compared with control subjects, and they returned to normal levels after insulin treatment and resolution of hyperglycemic crises. Changes in CRP and homocysteine in response to insulin therapy did not reach control levels after resolution of hyperglycemia. We conclude that DKA and NKH are associated with elevation of proinflammatory cytokines, ROS, and cardiovascular risk factors in the absence of obvious infection or cardiovascular pathology. Return of these values to normal levels with insulin therapy demonstrates a robust anti-inflammatory effect of insulin.

Angiopoietins 1 and 2 bind to Tie-2 expressed on endothelial cells and regulate vessel stabilization and angiogenesis. Tie-2(+) monocytes have been shown to be recruited to experimental tumors where they promote tumor angiogenesis. In this study, we show that <em>20</em>% of CD14(+) human blood monocytes express Tie-2, and that these cells coexpress CD16 (FcgammaRIII) and are predominantly CD34 negative. Ang-2 is up-regulated by endothelial cells in malignant tumors and inflamed tissues, so our finding that Ang-2 is a chemoattractant for human Tie-2(+) monocytes and macrophages, suggests that it may help to recruit and regulate their distribution in such tissues. Ang-2 was also found to markedly inhibit release of the important proinflammatory cytokine, TNF-alpha, by monocytes in vitro. Following extravasation of monocytes, and their differentiation into macrophages, many accumulate in the hypoxic areas of inflamed and malignant tissues. Ang-2 is known to be up-regulated by hypoxia and we show that monocytes and macrophages up-regulate Tie-2 when exposed to hypoxia. Furthermore, hypoxia augmented the inhibitory effect of Ang-2 on the release of the anti-angiogenic cytokine, <em>IL</em>-12 by monocytes. In sum, our data indicate that Ang-2 may recruit Tie-2(+) monocytes to tumors and sites of inflammation, modulate their release of important cytokines and stimulate them to express a proangiogenic phenotype.

BACKGROUND

The treatment of metastatic renal cell carcinoma (RCC) with high-dose interleukin-2 (HD <em>IL</em>-2) has resulted in durable tumor regression in a minority of patients. The current study presents the authors' <em>20</em>-year experience administering this immunotherapeutic agent.

METHODS

Patients with metastatic RCC (n = 259) were treated with HD <em>IL</em>-2 alone from January 13, 1986 through December 31, <em>20</em>06 at the Surgery Branch of the National Cancer Institute. Potential predictive factors for response and survival, both pretreatment and treatment-related, were first subjected to univariate analysis and then to multivariate logistic regression or a Cox proportional hazards model. Finally, the authors investigated Memorial Sloan-Kettering Cancer Center (MSKCC) prognostic factors for survival to assess their predictive value in the patient population in the current study.

RESULTS

A total of 23 patients experienced a complete response and 30 patients achieved a partial response, for an overall objective response rate of <em>20</em>%. All partial responders had developed disease recurrence at the time of last follow-up, but only 4 complete responders had experienced disease recurrence by that time. Despite toxicities, only 2 patients developed treatment-related mortalities over this same time period. A higher baseline weight (P = .05) and MSKCC prognostic factors (P = .02) were found to be the variables most associated with response. For survival >4 years and overall survival, several pretreatment and treatment-related factors maintained significance, but none more so than response (P < .0001).

CONCLUSIONS

HD IL-2 can induce complete tumor regression in a small number of patients, and many patients have experienced extended disease-free intervals. Given its relative safety, HD IL-2 should still be considered a first-line therapy in patients with metastatic RCC who have an overall good performance status.

Four rat mAb directed against mouse <em>IL</em>-5 have been characterized by their ability to remove and neutralize mouse <em>IL</em>-5 activity in various bioassays. All four mAb absorbed <em>IL</em>-5 activity from solution. Although all were able to neutralize mouse <em>IL</em>-5 bioactivity, two were significantly more effective. These two were also able to neutralize the activity of mouse <em>IL</em>-5 delivered to B cells during a cognate-linked interaction with a Th cell clone. A two-site sandwich ELISA specific for mouse <em>IL</em>-5 was developed by using pairs of mAb. The mouse <em>IL</em>-5 ELISA is capable of detecting natural or mouse r<em>IL</em>-5 in supernatants, crude bacterial lysates, and high concentrations of mouse serum, and has a detection limit of less than <em>20</em> pg. Two of these antibodies cross-reacted with and neutralized human r<em>IL</em>-5, and one of these was used for development of an ELISA for human <em>IL</em>-5.

The new interleukin (<em>IL</em>)-1 family cytokine <em>IL</em>-33 is synthesized as a 30-kDa precursor. Like pro-<em>IL</em>-1beta, human pro-<em>IL</em>-33 was reported to be cleaved by caspase-1 to generate an 18-kDa fragment, which is sufficient to activate signaling by the <em>IL</em>-33 receptor T1/ST2. However, the proposed caspase-1 cleavage site is poorly conserved between species. In addition, it is not clear whether caspase-1 cleavage of pro-<em>IL</em>-33 occurs in vivo and whether, as for <em>IL</em>-1beta, this cleavage is a prerequisite for <em>IL</em>-33 secretion and bioactivity. In this study, we further investigated caspase-1 cleavage of mouse and human pro-<em>IL</em>-33 and assessed the potential bioactivity of the <em>IL</em>-33 precursor. We observed the generation of a <em>20</em>-kDa <em>IL</em>-33 fragment in cell lysates, which was enhanced by incubation with caspase-1. However, in vitro assays of mouse and human pro-<em>IL</em>-33 indicated that <em>IL</em>-33 is not a direct substrate for this enzyme. Consistently, caspase-1 activation in THP-1 cells induced cleavage of pro-<em>IL</em>-1beta but not of pro-<em>IL</em>-33, and activated THP-1 cells released full-length pro-<em>IL</em>-33 into culture supernatants. Finally, addition of full-length pro-<em>IL</em>-33 induced T1/ST2-dependent <em>IL</em>-6 secretion in mast cells. However, we observed in situ processing of pro-<em>IL</em>-33 in mast cell cultures, and it remains to be determined whether full-length pro-<em>IL</em>-33 itself indeed represents the bioactive species. In conclusion, our data indicate that pro-<em>IL</em>-33 is not a direct substrate for caspase-1. In addition, our results clearly show that caspase-1 cleavage is not required for pro-<em>IL</em>-33 secretion and bioactivity, highlighting major differences between <em>IL</em>-1beta and <em>IL</em>-33.

MoPn-specific T-cell clones were isolated from a T-cell line that was capable of curing chlamydial genital infection by the Chlamydia trachomatis agent of mouse pneumonitis (MoPn) after adoptive transfer. Two clones (designated as 2.14-0 and 2.14-3) were characterized by flow cytometry techniques to be homogenous for L3T4, CD3, and alpha/beta T cell receptor (TcR) T-helper cell markers. The two clones were biovar specific, because they reacted to MoPn but not the Chlamydia psittaci agent of guinea pig inclusion conjunctivitis (GPIC) or C. trachomatis, serovar type E. Cytokine profile analysis, by a combination of bioassays, ELISA, and slot/Northern blotting for specific cytokine messenger RNAs, further revealed that cultures of antigen-stimulated clone 2.14-0 contained interleukin-2 (<em>IL</em>-2), tumor necrosis factor-alpha, and gamma interferon (a T helper 1 cell [Th1] profile). Clone 2.14-3 was also positive for gamma interferon, a level much lower than that of clone 2.14-0, and negative for <em>IL</em>-4 secretion, suggesting a Th1 profile as well. The ability of these clones to bring about the resolution of the chronic genital chlamydial infection of nude mice was tested by the adoptive transfer of 10(7) cells of each clone into the mice. By 4 weeks after cell transfer of clone 2.14-0, 81% of recipient nude mice (30 of 37) resolved the disease. In contrast, clone 2.14-3 or a control T-cell clone specific for a heterologous antigen were unable to resolve the infection in <em>20</em> recipients in each case, even after 100 days.(ABSTRACT TRUNCATED AT 250 WORDS)

Mechanical ventilation can injure the lung, causing edema and alveolar inflammation. Interleukin-8 (<em>IL</em>-8) plays an important role in this inflammatory response. We postulated that cyclic cell stretch upregulates the production and release of <em>IL</em>-8 by human alveolar epithelium in the absence of structural cell damage or paracrine stimulation. To test this hypothesis, alveolar epithelial cells (A549 cells) were cultured on a deformable silicoelastic membrane. When stretched by 30% for up to 48 h, the cells released 49 +/- 34% more <em>IL</em>-8 (P < 0.001) than static controls. Smaller deformations (<em>20</em>% stretch) produced no consistent increase in <em>IL</em>-8. Stretch of 4 h duration increased <em>IL</em>-8 gene transcription fourfold above baseline. Stretch had no effect on cell proliferation, cell viability as assessed by (51)Cr release assay, or the release of granulocyte-macrophage colony-stimulating factor and tumor necrosis factor-alpha. We conclude that deformation per se can trigger inflammatory signaling and that alveolar epithelial cells may be active participants in the alveolitis associated with ventilator-induced lung injury.

Using animal models or healthy volunteers, injection of lipopolysaccharide (LPS) or bacteria causes activation of macrophages with excessive synthesis and secretion of proinflammatory cytokines. Although these models mimic the effects of LPS in the host, they may represent more of an experimental expression of endotoxemia than natural infection itself. Therefore, as an ex vivo model of sepsis, whole blood from 15 patients with severe sepsis and <em>20</em> control patients without infection was stimulated with LPS to study the kinetics of mRNA expression and release of proinflammatory cytokines, tumor necrosis factor (TNF)-alpha, interleukin (<em>IL</em>)-1 beta, and <em>IL</em>-6. Stimulation of whole blood with 1 microgram/mL LPS resulted in a maximum increase of cytokine secretion in the control group, while a marked (P < .01) depression of TNF-alpha, <em>IL</em>-1 beta, and <em>IL</em>-6 release was observed in the septic group, which persisted up to 10 days after study enrollment. While <em>IL</em>-1 beta mRNA expression was similar in peripheral blood mononuclear cells (PBMCs) harvested from LPS-stimulated whole blood in septic and control patients, the half-life and consequently the expression of TNF-alpha and <em>IL</em>-6 mRNA were strongly reduced in the septic group. These data indicate a downregulatory mechanism of cytokine release in whole blood from patients with severe sepsis that occurs on different levels. Although excessive secretion of proinflammatory cytokines has been considered deleterious for the host, the reduced capacity of PBMCs in whole blood from septic patients to synthesize and secrete proinflammatory cytokines to an inflammatory stimulus may result in immunodeficiency, because these cytokines in low concentrations are involved in the upregulation of essential cellular and humoral immune functions.

Therapies to limit the life-threatening vascular leak observed in patients with acute lung injury (ALI) are currently lacking. We explored the effect of simvastatin, a 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase inhibitor that mediates endothelial cell barrier protection in vitro, in a murine inflammatory model of ALI. C57BL/6J mice were treated with simvastatin (5 or <em>20</em> mg/kg body wt via intraperitoneal injection) 24 h before and again concomitantly with intratracheally administered LPS (2 microg/g body wt). Inflammatory indexes [bronchoalveolar lavage (BAL) myeloperoxidase activity and total neutrophil counts assessed at 24 h with histological confirmation] were markedly increased after LPS alone but significantly reduced in mice that also received simvastatin (<em>20</em> mg/kg; approximately 35-60% reduction). Simvastatin also decreased BAL albumin (approximately 50% reduction) and Evans blue albumin dye extravasation into lung tissue (100%) consistent with barrier protection. Finally, the sustained nature of simvastatin-mediated lung protection was assessed by analysis of simvastatin-induced gene expression (Affymetrix platform). LPS-mediated lung gene expression was significantly modulated by simvastatin within a number of gene ontologies (e.g., inflammation and immune response, NF-kappaB regulation) and with respect to individual genes implicated in the development or severity of ALI (e.g., <em>IL</em>-6, Toll-like receptor 4). Together, these findings confirm significant protection by simvastatin on LPS-induced lung vascular leak and inflammation and implicate a potential role for statins in the management of ALI.

Already <em>20</em> years have passed since the cloning of the granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor alpha-chain, the first member of the GM-CSF/interleukin (<em>IL</em>)-3/<em>IL</em>-5 family of hemopoietic cytokine receptors to be molecularly characterized. The intervening 2 decades have uncovered a plethora of biologic functions transduced by the GM-CSF receptor (pleiotropy) and revealed distinct signaling networks that couple the receptor to biologic outcomes. Unlike other hemopoietin receptors, the GM-CSF receptor has a significant nonredundant role in myeloid hematologic malignancies, macrophage-mediated acute and chronic inflammation, pulmonary homeostasis, and allergic disease. The molecular mechanisms underlying GM-CSF receptor activation have recently been revealed by the crystal structure of the GM-CSF receptor complexed to GM-CSF, which shows an unexpected higher order assembly. Emerging evidence also suggests the existence of intracellular signosomes that are recruited in a concentration-dependent fashion to selectively control cell survival, proliferation, and differentiation by GM-CSF. These findings begin to unravel the mystery of cytokine receptor pleiotropy and are likely to also apply to the related <em>IL</em>-3 and <em>IL</em>-5 receptors as well as other heterodimeric cytokine receptors. The new insights in GM-CSF receptor activation have clinical significance as the structural and signaling nuances can be harnessed for the development of new treatments for malignant and inflammatory diseases.

BACKGROUND

A large transmural myocardial infarction may initiate structural and geometric changes in the left ventricle that are commonly referred to as remodeling. Progressive, adverse remodeling of the myocardium may lead to ventricular dilatation and congestive heart failure. Recent studies have highlighted the effects of some cytokines on immune-mediated myocyte injury, postischemic myocardial inflammation, and cardiac function. However, studies of the involvement of cytokines in remodeling of the heart are few.

RESULTS

In a rat model of myocardial infarction, progressive dilatation of the left ventricular cavity and lack of appropriate hypertrophy of the surviving myocardium were confirmed by transthoracic echocardiography. The relative expression of mRNA for tumor necrosis factor (TNF)-alpha, interleukin (<em>IL</em>)-1beta, and <em>IL</em>-6 in the infarcted and noninfarcted myocardium of these rats, as well as in a group of sham-operated animals, was assessed by the technique of quantitative polymerase chain reaction amplification. In the infarcted region, TNF-alpha, <em>IL</em>-1beta, and <em>IL</em>-6 gene expression peaked at 1 week after infarction and decreased rapidly thereafter. In contrast, at <em>20</em> weeks after infarction, the gene expression levels of these cytokines remained significantly higher in the noninfarcted than in the infarcted zone or in the myocardium of sham-operated animals. Furthermore, the levels of these cytokines in the noninfarcted region correlated with the left ventricular end-diastolic diameter measured at 8 and <em>20</em> weeks after infarction. Among these cytokines, <em>IL</em>-1beta expression was highest, and its level correlated well with collagen deposition in the noninfarcted myocardium at 8 and <em>20</em> weeks after surgery. At <em>20</em> weeks after infarction, immunohistochemical analysis revealed the presence of <em>IL</em>-1beta in macrophages, endothelial cells, and vascular smooth muscle cells in the noninfarcted region, whereas no such immunoreactivity was found in the myocardium of sham-operated animals.

CONCLUSIONS

These findings suggest the possible involvement of cytokines during the remodeling process of the noninfarcted left ventricular myocardium.

Progressive hepatic fibrosis and cirrhosis develops in <em>20</em>% to 30% of patients with chronic hepatitis C virus (HCV). We propose that host genetic factors influencing fibrogenesis may account for some of the variability in progression of this disease. In progressive fibrosis of other organs, particularly heart and kidney, production of the profibrogenic cytokine, transforming growth factor beta1 (TGF-beta1), may be enhanced by angiotensin II, the principal effector molecule of the renin-angiotensin system. The inheritance of polymorphisms in TGF-beta1, interleukin 10 (<em>IL</em>-10), tumor necrosis factor alpha (TNF-alpha), and genes of the renin-angiotensin system was examined in 128 patients with chronic HCV. The influence of genotypes on the stage of hepatic fibrosis was tested after adjustment for potential confounders (age, gender, alcohol consumption, portal inflammation, and steatosis), which may have independent effects on histological severity. The stage of fibrosis was 0 in 30 (23.4%), 1 in 44 (34.4%), 2 in 27 (21.1%), and 3 or 4 in 27 (21.1%). A statistically significant relationship was seen between inheritance of high TGF-beta1- and angiotensinogen (AT)-producing genotypes and the development of progressive hepatic fibrosis. This association persisted after correcting for potential confounders. Patients who inherited neither of the profibrogenic genotypes had no or only minimal fibrosis. Knowledge of these polymorphisms may have prognostic significance in patients with chronic HCV and may direct more aggressive therapy towards those patients with an increased risk of disease progression. The documentation of a significant relationship between AT genotype and fibrosis raises the novel suggestion that angiotensin II may be another mediator of extracellular matrix production in the liver.

BACKGROUND

Previous studies of bioactive molecules in platelet-rich plasma (PRP) have documented growth factor concentrations that promote tissue healing. However, the effects of leukocytes and inflammatory molecules in PRP have not been defined.

OBJECTIVE

The hypothesis for this study was that the concentration of growth factors and catabolic cytokines would be dependent on the cellular composition of PRP.

METHODS

Controlled laboratory study.

METHODS

Platelet-rich plasma was made from 11 human volunteers using 2 commercial systems: Arthrex ACP (Autologous Conditioned Plasma) Double Syringe System (PRP-1), which concentrates platelets and minimizes leukocytes, and Biomet GPS III Mini Platelet Concentrate System (PRP-2), which concentrates both platelets and leukocytes. Transforming growth factor-β1 (TGF-β1), platelet-derived growth factor-AB (PDGF-AB), matrix metalloproteinase-9 (MMP-9), and interleukin-1β (IL-1β) were measured with enzyme-linked immunosorbent assay (ELISA).

RESULTS

The PRP-1 system consisted of concentrated platelets (1.99×) and diminished leukocytes (0.13×) compared with blood, while PRP-2 contained concentrated platelets (4.69×) and leukocytes (4.26×) compared with blood. Growth factors were significantly increased in PRP-2 compared with PRP-1 (TGF-β1: PRP-2 = 89 ng/mL, PRP-1 = 20 ng/mL, P < .05; PDGF-AB: PRP-2 = 22 ng/mL, PRP-1 = 6.4 ng/mL, P < .05). The PRP-1 system did not have a higher concentration of PDGF-AB compared with whole blood. Catabolic cytokines were significantly increased in PRP-2 compared with PRP-1 (MMP-9: PRP-2 = 222 ng/mL, PRP-1 = 40 ng/mL, P < .05; IL-1β: PRP-2 = 3.67 pg/mL, PRP-1 = 0.31 pg/mL, P < .05). Significant, positive correlations were found between TGF-β1 and platelets (r(2) = .75, P < .001), PDGF-AB and platelets (r(2) = .60, P < .001), MMP-9 and neutrophils (r(2) = .37, P < .001), IL-1β and neutrophils (r(2) = .73, P < .001), and IL-1β and monocytes (r(2) = .75, P < .001).

CONCLUSIONS

Growth factor and catabolic cytokine concentrations were influenced by the cellular composition of PRP. Platelets increased anabolic signaling and, in contrast, leukocytes increased catabolic signaling molecules. Platelet-rich plasma products should be analyzed for content of platelets and leukocytes as both can influence the biologic effects of PRP.

CONCLUSIONS

Depending on the clinical application, preparations of PRP should be considered based on their ability to concentrate platelets and leukocytes with sensitivity to pathologic conditions that will benefit most from increased platelet or reduced leukocyte concentration.

OBJECTIVE

The role of interleukin (IL)-5 in the pathogenesis of eosinophilic esophagitis (EoE) has been established in animal models; anti-IL-5 therapy has been reported to be effective in adults. We investigated whether IL-5 has a role in accumulation of esophageal eosinophils in children with EoE and whether therapy with mepolizumab, an antibody against IL-5, reduces the number of esophageal intraepithelial eosinophils in children with EoE.

METHODS

We performed an international, multicenter, double-blind, randomized, prospective study of 59 children with EoE, defined as baseline peak count of esophageal intraepithelial eosinophils of ≥ 20 in at least 1 high-power field (hpf). Patients received an infusion every 4 weeks (a total of 3 infusions) of 0.55, 2.5, or 10 mg/kg mepolizumab. No placebo group was used.

RESULTS

Baseline peak and mean esophageal intraepithelial eosinophil counts were (mean ± SE) 122.5 ± 8.78 and 39.1 ± 3.63 per hpf, respectively. Four weeks after the third infusion, peak eosinophil counts were <5 per hpf in 5 of 57 children (8.8%); we did not observe differences among groups given different doses of mepolizumab. Reduced peak and mean eosinophil counts, to <20 per hpf, were observed in 18 of 57 (31.6%) and 51 of 57 (89.5%) children, respectively. Peak and mean esophageal intraepithelial eosinophil counts decreased significantly to 40.2 ± 5.17 and 9.3 ± 1.25 per hpf, respectively (P < .0001). An analysis to evaluate predictors of response associated a higher mean baseline esophageal intraepithelial eosinophil count with a greater reduction in mean count (P < .0001).

CONCLUSIONS

IL-5 is involved in the pathogenesis of EoE in children. Mepolizumab, an antibody against IL-5, reduces esophageal eosinophilic inflammation in these patients.

Selective skewing of autoreactive interferon-gamma (IFN-gamma)-producing T helper cells (Th1) toward an interleukin-4 (<em>IL</em>-4)-producing (Th2) phenotype can in experimental animals alleviate autoimmune disease without inducing general immunosuppression. In a prospective dose escalation study, we assessed treatment with human <em>IL</em>-4 (rhu<em>IL</em>-4) in <em>20</em> patients with severe psoriasis. The therapy was well tolerated, and within six weeks all patients showed decreased clinical scores and 15 improved more than 68%. Stable reduction of clinical scores was significantly better at 0.2-0.5 microg rhu<em>IL</em>-4 than at < or =0.1 microg rhu<em>IL</em>-4 (P = 0.009). In psoriatic lesions, treatment with 0.2-0.5 microg/kg rhu<em>IL</em>-4 reduced the concentrations of <em>IL</em>-8 and <em>IL</em>-19, two cytokines directly involved in psoriasis; the number of chemokine receptor CCR5+ Th1 cells; and the IFN-gamma/<em>IL</em>-4 ratio. In the circulation, 0.2-0.5 microg/kg rhu<em>IL</em>-4 increased the number of <em>IL</em>-4+CD4+ T cells two- to three-fold. Thus, <em>IL</em>-4 therapy can induce Th2 differentiation in human CD4+ T cells and has promise as a potential treatment for psoriasis, a prototypic Th1-associated autoimmune disease.

It has been estimated that>><em>20</em>% of all malignancies are initiated or exacerbated by inflammation. Until recently, the molecular basis of this process has not been clarified. However, recent studies have uncovered the molecular mechanism of intracellular signaling pathways of inflammatory cytokines such as tumor necrosis factor (TNF)-alpha, interferon (IFN)-gamma and interleukin (<em>IL</em>)-6. Three major transcription factors including NF-kappaB, STAT1 and STAT3 have been shown to play major roles in transmitting inflammatory cytokine signals to the nucleus. One function of NF-kappaB and STAT3 in tumor cells is the promotion of cell growth and cell survival through the induction of target genes, whose products promote cell division and inhibit apoptosis. In addition, NF-kappaB and STAT1 are important transcription factors that induce inflammatory mediators from inflammatory cells, especially macrophages, while STAT3 often antagonizes this process. STAT1 is generally believed to be an anti-oncogene because it promotes apoptosis through p53, but it could promote inflammation-mediated tumor development by enhancing tissue injury, remodeling, fibrosis and inflammation. Hence, the inhibition of NF-kappaB and STATs offers a strategy for treatment of a variety of malignancies and can convert inflammation-induced tumor growth into inflammation-induced tumor regression.

BACKGROUND

Pulmonary metastasis continues to be the most common cause of death in osteosarcoma. Indeed, the 5-year survival for newly diagnosed osteosarcoma patients has not significantly changed in over <em>20</em> years. Further understanding of the mechanisms of metastasis and resistance for this aggressive pediatric cancer is necessary. Pet dogs naturally develop osteosarcoma providing a novel opportunity to model metastasis development and progression. Given the accelerated biology of canine osteosarcoma, we hypothesized that a direct comparison of canine and pediatric osteosarcoma expression profiles may help identify novel metastasis-associated tumor targets that have been missed through the study of the human cancer alone.

RESULTS

Using parallel oligonucleotide array platforms, shared orthologues between species were identified and normalized. The osteosarcoma expression signatures could not distinguish the canine and human diseases by hierarchical clustering. Cross-species target mining identified two genes, interleukin-8 (IL-8) and solute carrier family 1 (glial high affinity glutamate transporter), member 3 (SLC1A3), which were uniformly expressed in dog but not in all pediatric osteosarcoma patient samples. Expression of these genes in an independent population of pediatric osteosarcoma patients was associated with poor outcome (p = 0.0<em>20</em> and p = 0.026, respectively). Validation of IL-8 and SLC1A3 protein expression in pediatric osteosarcoma tissues further supported the potential value of these novel targets. Ongoing evaluation will validate the biological significance of these targets and their associated pathways.

CONCLUSIONS

Collectively, these data support the strong similarities between human and canine osteosarcoma and underline the opportunities provided by a comparative oncology approach as a means to improve our understanding of cancer biology and therapies.

Cytokines are involved in virtually every aspect of immunity and inflammation. A cascade of responses evolves after cytokine activation, although optimal function might ultimately involve several complementary cytokines. Understanding the function of individual cytokines is complicated because their role can vary depending on the cellular source, target, and phase of the immune response. In fact, numerous cytokines have both proinflammatory and anti-inflammatory potential, with the contrasting outcome observed being determined by the immune cells present and their state of responsiveness to the cytokine. These issues make the study of cytokine biology daunting, particularly so for IL-10 and IL-10-related genes. The IL-10 superfamily is highly pleiotropic. These genes are linked together through genetic similarity and intron-exon gene structure. Significant commonality exists not only through shared receptors but also through conserved signaling cascades. However, its members mediate diverse activities, including immune suppression, enhanced antibacterial and antiviral immunity, antitumor activity, and promotion of self-tolerance in autoimmune diseases.

OBJECTIVE

Ulcerative colitis (UC) is a chronic relapsing inflammatory bowel disease. We aimed to assess whether clinical, biological, and histologic parameters in quiescent UC predict time to clinical relapse.

METHODS

Seventy-four patients with clinically and endoscopically determined inactive UC were followed up for 1 year or for a shorter period if they had a relapse. Serum erythrocyte sedimentation rate; C-reactive protein, interleukin (IL)-1beta, IL-6, and IL-15 values; anti-neutrophil cytoplasmic antibody titers; and rectal biopsy specimens were obtained at baseline, at 6 and 12 months, and/or at relapse. Multivariate survival analysis was performed to determine independent predictors of clinical relapse.

RESULTS

Twenty-seven patients relapsed (19/42 women; 8/32 men). Multivariate Cox regression analysis retained younger age (P = 0.003; hazard ratio, 0.4 per decade), greater number of prior relapses in women (P < 0.001; hazard ratio, 1.6 per prior relapse), and basal plasmacytosis (P = 0.003; hazard ratio, 4.5) on rectal biopsy specimens as predictors of shorter time to clinical relapse. Kaplan-Meier survival curves showed the 20-30-year-old age group and women with more than 5 prior relapses to be groups with shorter times to relapse.

CONCLUSIONS

Younger age, multiple previous relapses (for women), and basal plasmacytosis on rectal biopsy specimens were independent predictors of earlier relapse. These findings may help identify patients with inactive UC who will require optimal maintenance medical therapy.

MicroRNAs (miRNAs) are small noncoding RNAs that post-transcriptionally regulate gene expression by targeting specific mRNAs. Altered expression of circulating miRNAs have been associated with age-related diseases including cancer and cardiovascular disease. Although we and others have found an age-dependent decrease in miRNA expression in peripheral blood mononuclear cells (PBMCs), little is known about the role of circulating miRNAs in human aging. Here, we examined miRNA expression in human serum from young (mean age 30 years) and old (mean age 64 years) individuals using next generation sequencing technology and real-time quantitative PCR. Of the miRNAs that we found to be present in serum, three were significantly decreased in <em>20</em> older individuals compared to <em>20</em> younger individuals: miR-151a-5p, miR-181a-5p and miR-1248. Consistent with our data in humans, these miRNAs are also present at lower levels in the serum of elderly rhesus monkeys. In humans, miR-1248 was found to regulate the expression of mRNAs involved in inflammatory pathways and miR-181a was found to correlate negatively with the pro-inflammatory cytokines <em>IL</em>-6 and TNFα and to correlate positively with the anti-inflammatory cytokines TGFβ and <em>IL</em>-10. These results suggest that circulating miRNAs may be a biological marker of aging and could also be important for regulating longevity. Identification of stable miRNA biomarkers in serum could have great potential as a noninvasive diagnostic tool as well as enhance our understanding of physiological changes that occur with age.