Molecular cloning of a human monocyte-derived neutrophil chemotactic factor (MDNCF) and the induction of MDNCF mRNA by interleukin 1 and tumor necrosis factor

Size dependent induction of proinflammatory cytokines and cytotoxicity of particulate beta-tricalciumphosphate in vitro

Cellular responses to particulate calcium phosphate ceramics can lead to inflammatory reactions under certain conditions that depend on particle composition, size and morphology. In this context, the potential influence of varying sizes of particulate beta-tricalciumphosphate (beta-TCP) on the induction of inflammation and cytotoxicity remains to be determined. The present work investigates the effects of beta-TCP particles of five different sizes (1, 3, 13, 32 and 40 μm) on human peripheral blood mononuclear cells (PBMC) in vitro concerning the release of TNF-alpha, IL-1beta and IL-8 after six and 18 h of incubation (ELISA) as well as intracellular TNF-alpha, IFN-gamma, IL-1alpha, IL-1beta and IL-8 levels within distinct PBMC subpopulations after 12 h (FACS). Potential cytotoxic effects were determined by assaying lactate dehydrogenase (LDH) and morphological analyses (electron microscopy). Beta-TCP 1 μm did not induce any cytokine after 6 h but slightly increases TNF-alpha, IL-1beta and IL-8 release after 18 h. Larger particles (32 and 40 μm) consistently caused higher levels of cytokine release by increasing the fraction of cytokine producing monocytes. They also caused higher levels of LDH release as did smaller, phagocytosable particles. These data suggest a less inflammatory and cytotoxic profile of beta-TCP devices with a smaller primary particle size when compared to larger particles.

Effect of subcutaneous glucose sensor implantation on skin mRNA expression in pigs

BACKGROUND

Tight glycemic control has the potential to reduce long- and short-term effects of diabetes mellitus. New and improved glucose sensors for short-term implantation in the subcutis offer an alternative to the classical self-monitored blood glucose concentration in the management of diabetes. The use of glucose sensors has an advantage over the latter due to its capacity to obtain continuous glucose measurements. However, instability of in vivo glucose sensor measurements has been reported, and this bioinstability is likely to be influenced by the inflammatory reaction to the implanted sensor. Gene expression analysis is now performed in an existing porcine model of subcutaneous glucose sensor implantation to investigate the time course of inflammation from a new perspective.

METHODS

Tissue surrounding glucose sensors was sampled to different time points (2 h, 24 h, 3 days, and 7 days) after implantation in the subcutis of pigs. From the tissue RNA was extracted, cDNA was synthesized, and real-time reverse transcription-polymerase chain reaction (RT-PCR) was performed for the quantification of immunoregulatory genes.

RESULTS

Genes coding for adhesion molecules, chemokines, cytokines, CD markers, and antigen presentation molecules were differentially expressed over time. Most of the investigated genes were significantly up-regulated 24 h and 7 days after implantation.

CONCLUSIONS

The present study demonstrated that the technology for targeted multiple-gene expression by real-time RT-PCR is useful in the evaluation of the immune response to subcutaneously implanted glucose sensors and that the expression levels also seemed to correspond to the histomorphological observations over time.

IL-8 decreases HIV-1 transcription in peripheral blood lymphocytes and ectocervical tissue explants

IL-8 is enhanced in the peripheral blood and lymphoid tissue of HIV-infected individuals, suggesting that IL-8 is important in the pathogenesis of HIV-1 infection and progression to AIDS. Characterizing the mechanisms of IL-8 regulation of HIV-1 replication may be relevant in addressing the role of IL-8 as a therapeutic target in HIV-1 infection. We evaluated replication of primary R5-tropic HIV-1 in peripheral blood lymphocytes and ectocervical tissue explants infected in vitro in the presence of physiological concentrations of IL-8 found in the serum and genital tract secretions of HIV-infected individuals. To identify the specific stages of the viral life cycle targeted by IL-8, we performed real-time polymerase chain reaction to detect HIV-1 reverse transcription, integration, and transcription. Early during the infection, IL-8 decreased HIV-1 reverse transcription and viral integration. This effect was transient, as on day 4 after infection, we detected no differences on HIV-1 DNA or proviral DNA in peripheral blood lymphocyte. IL-8 decreased HIV-1 transcription in both lymphocytes and ectocervical tissue explants. The decrease in viral RNA expression was associated with reduced HIV-1 replication, as measured by viral p24 release in the culture supernatants. This is the first report to suggest that IL-8 decreases replication of primary R5-tropic HIV-1 by transcriptional mechanisms.

The role of serum interleukin-8 in hepatic resections

PURPOSE

Interleukin-8 (IL-8) is a neutrophil chemotactic factor, which is associated with some inflammatory diseases and various types of surgical stress. The aim of this study was to investigate whether the early postoperative serum IL-8 level may potentially be a new indicator of a surgical stress in patients undergoing a hepatic resection.

METHODS

The serum IL-8 levels were measured in 37 patients who underwent a hepatectomy. The serum IL-8 levels were serially measured using an enzyme-linked immunosorbent assay both before and after a hepatic resection. In addition, the correlation between the postoperative IL-8 value and several clinical variables were examined.

RESULTS

The mean level of IL-8 significantly increased immediately after the operation (P < 0.01 vs before the operation) and decreased on the first postoperative day (POD 1, P < 0.05 vs after the operation). The early postoperative IL-8 levels positively correlated with the length of the procedure (r = 0.383; P < 0.05), the estimated blood loss (r = 0.483; P < 0.01) and the serum bilirubin level on POD 1 (r = 0.390; P < 0.05), and inversely correlated with the white blood cell counts (r = -0.388; P < 0.05) and lymphocyte counts on POD 1 (r = -0.424; P < 0.05). In a comparison of the postoperative IL-8 levels with the surgical factors, there was a significant difference in the extension of the resection (P < 0.05) and in blood transfusion. The patients with a fever of more than 38 degrees C showed higher levels of IL-8 immediately after the operation than those without fever (P < 0.01).

CONCLUSIONS

The early postoperative serum IL-8 level was found to correlate with the degree of the severity of surgery in patients undergoing a hepatic resection, and it is also considered to be a new indicator of surgical stress and liver injury.

Effect of ulinastatin on cytokine reaction during gastrectomy

Background

Inflammation plays an important role in the postoperative morbidity of organs, which is related to the activation of pro-inflammatory and anti-inflammatory cytokines. Ulinastatin (Urinary trypsin inhibitor, UTI) is a serine protease inhibitor found in human urine or serum that inhibits the activation of human leukocyte elastase. This study examined the effect of UTI on the inflammation response in patients undergoing a gastrectomy.

Methods

Thirty patients scheduled to undergo a gastrectomy were divided into two groups as follows: Control group (untreated, n = 15) and UTI group (100,000 units of UTI were continuously injected intravenously for 2 hours, n = 15). Arterial blood was sampled before surgery (T0), 10 minutes after its onset (T1), at its end (T2), and 1 hour after surgery (T3) to measure the level of cytokines.

Results

Both the control and treatment groups had higher interleukin (IL)-6 levels at T2 and T3 than T0, and the level increased with time. However, the increase was smaller in the treatment group. The IL-8 levels were not activated significantly in any of the groups.

Conclusions

UTI inhibits the secretion of IL-6, which is an inflammatory cytokine produced after a gastrectomy. This shows that UTI can decrease the inflammation reaction caused by surgical stress.

COX-2 and prostaglandin EP3/EP4 signaling regulate the tumor stromal proangiogenic microenvironment via CXCL12-CXCR4 chemokine systems

Bone marrow (BM)-derived hematopoietic cells, which are major components of tumor stroma, determine the tumor microenvironment and regulate tumor phenotypes. Cyclooxygenase (COX)-2 and endogenous prostaglandins are important determinants for tumor growth and tumor-associated angiogenesis; however, their contributions to stromal formation and angiogenesis remain unclear. In this study, we observed that Lewis lung carcinoma cells implanted in wild-type mice formed a tumor mass with extensive stromal formation that was markedly suppressed by COX-2 inhibition, which reduced the recruitment of BM cells. Notably, COX-2 inhibition attenuated CXCL12/CXCR4 expression as well as expression of several other chemokines. Indeed, in a Matrigel model, prostaglandin (PG) E2 enhanced stromal formation and CXCL12/CXCR4 expression. In addition, a COX-2 inhibitor suppressed stromal formation and reduced expression of CXCL12/CXCR4 and a fibroblast marker (S100A4) in a micropore chamber model. Moreover, stromal formation after tumor implantation was suppressed in EP3-/- mice and EP4-/- mice, in which stromal expression of CXCL12/CXCR4 and S100A4 was reduced. The EP3 or EP4 knockout suppressed S100A4+ fibroblasts, CXCL12+, and/or CXCR4+ stromal cells as well. Immunofluorescent analyses revealed that CXCL12+CXCR4+S100A4+ fibroblasts mainly comprised stromal cells and most of these were recruited from the BM. Additionally, either EP3- or EP4-specific agonists stimulated CXCL12 expression by fibroblasts in vitro. The present results address the novel activities of COX-2/PGE2-EP3/EP4 signaling that modulate tumor biology and show that CXCL12/CXCR4 axis may play a crucial role in tumor stromal formation and angiogenesis under the control of prostaglandins.

Selective upregulation of interleukin-8 by human rhabdomyosarcomas in response to hypoxia: therapeutic implications

Rhabdomyosarcoma (RMS) is the most common soft-tissue sarcoma of adolescence and childhood. Because RMS tumors are highly vascularized, we sought to determine which factors secreted by RMS cells are crucial in stimulating angiogenesis in response to hypoxia. To address this issue, we evaluated expression of several proangiogenic factors [interleukin (IL)-8, vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF)-2, stromal-derived factor (SDF)-1, hepatocyte growth factor (HGF) and leukemia inhibitory factor (LIF)] in 8 human RMS cell lines in both normal steady-state and hypoxic conditions. We found by real-time quantitative polymerase chain reaction (RQ-PCR) and confirmed by enzyme-linked immunosorbent assay (ELISA) that from all the factors evaluated, IL-8, whose expression is very low in normoxia, had been very highly expressed and secreted by RMS cells lines during hypoxic conditions ( approximately 40-170 times). Interestingly, this upregulation was not affected by knocking down hypoxia-inducible factor (HIF)-1alpha, but was inhibited by mitogen-activated protein kinase (MAPK)p42/44 and phosphatidylinositaol 3-kinase (PI3K)/AKT pathway inhibitors. This suggests that IL-8 expression is regulated in an activating protein (AP)-1- and nuclear factor (NF)-kappaB-dependent manner. Furthermore, we found that conditioned media (CM) harvested from RMS cells exposed to hypoxia activated and stimulated chemotactic responses in human umbilical vein endothelial cells (HUVECs) and that IL-8 was responsible for hypoxia-related effects. Finally, by employing shRNA, the expression of IL-8 in human RH-30 cells was downregulated. We noticed that such RMS cells, if injected into skeletal muscles of immunodeficient mice, have a reduced ability for tumor formation. We conclude that IL-8 is a pivotal proangiogenic factor released by human RMS cells in hypoxic conditions and that the targeting of IL-8 may prove to be a novel and efficient strategy for inhibiting RMS growth.

Small interfering RNA-mediated CXCR1 or CXCR2 knock-down inhibits melanoma tumor growth and invasion

CXCR1 and CXCR2 are receptors for CXCL-8 and are differentially expressed on melanoma and endothelial cells. In this study, we determined the functional role of these receptors in melanoma progression. We stably knock-down the expression of CXCR1 and/or CXCR2 in A375-SM (SM; high metastatic) human melanoma cells by short-hairpin RNA transfection. Cell proliferation, migration, invasion, ERK phosphorlyation and cytoskeletal rearrangements were carried out in vitro. In vivo growth was evaluated using murine subcutaneous xenograft model. Our data demonstrate that knock-down of CXCR1 and/or CXCR2 expression, inhibited melanoma cell proliferation, survival, migration and invasive potential in vitro. Moreover, we also observed inhibition of ERK phosphorylation and cytoskeltal rearrangement in SM-shCXCR1, SM-shCXCR2 and SM-shCXCR1/2 cells. Furthermore, when SM-shCXCR1 or SM-shCXCR2 cells implanted in nude mice, tumor growth, proliferation and microvessel density was significantly inhibited as compared to SM-control cells. In addition, we observed a significant increase in melanoma cell apoptosis in SM-shCXCR1 and SM-shCXCR2 tumors compared to SM-control tumors. Together, these data demonstrate that CXCR1 and CXCR2 expression play a critical role in human melanoma tumor progression and, functional blockade of CXCR1 and CXCR2 could be potentially used for future therapeutic intervention in malignant melanoma.

Association of interleukin-8 with cachexia from patients with low-third gastric cancer

Background. Interleukin (IL)-8 has been implicated in the development of cancer cachexia. The polymorphism of IL-8 gene, which may affect the production level of IL-8, may be associated with cancer cachexia. Methods. The serum IL-8 level in our study was examined by radioimmunoassay. We also analyzed single nucleotide polymorphisms (SNPs) −251 A/T and +781 C/T of IL-8 gene, using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Results. The serum levels of IL-8 were significantly elevated in patients with low-third gastric cancer compared with controls, and were further up-regulated in patients with cachexia than those without (Z = −3.134, P = .002). A significantly increased frequency of +781 T allele was noted in patients with cachexia (OR = 2.247, 95% CI: 1.351–3.737, P = .002). The +781 TT genotype was observed to be associated with a significantly increased risk of cachexia (OR = 3.167, 95% CI: 1.265–7.929, P = .011), and with odds ratio of 3.033 (95% CI: 1.065–8.639, P = .038) for cachexia after adjusting for potential confounding factors. Meanwhile, haplotype analysis indicated a borderline positive association between T²⁵¹T⁷⁸¹ haplotype and cachexia as compared with the T²⁵¹C⁷⁸¹ haplotype (OR = 4.92, 95% CI: 1.00–24.28;, P = .053). Conclusions. IL-8 appears to be associated with cachexia from patients with low-third gastric cancer.

Sequential cancer immunotherapy: targeted activity of dimeric TNF and IL-8

Polymorphonuclear neutrophils (PMNs) are potent effectors of inflammation and their attempts to respond to cancer are suggested by their systemic, regional and intratumoral activation. We previously reported on the recruitment of CD11b+ leukocytes due to tumor site-specific enrichment of TNF activity after intravenous administration of a dimeric TNF immunokine with specificity for fibroblast activation protein (FAP). However, TNF-induced chemo-attraction and extravasation of PMNs from blood into the tumor is a multistep process essentially mediated by interleukin 8. With the aim to amplify the TNF-induced and IL-8-mediated chemotactic response, we generated immunocytokines by N-terminal fusion of a human anti-FAP scFv fragment with human IL-8 (IL-8(72)) and its N-terminally truncated form IL-8(3-72). Due to the dramatic difference in chemotaxis induction in vitro, we favored the mature chemokine fused to the anti-FAP scFv for further investigation in vivo. BALB/c nu/nu mice were simultaneously xenografted with FAP-positive or -negative tumors and extended chemo-attraction of PMNs was only detectable in FAP-expressing tissue after intravenous administration of the anti-FAP scFv-IL-8(72) construct. As TNF-activated PMNs are likewise producers and primary targets for IL-8, we investigated the therapeutic efficacy of co-administration of both effectors: Sequential application of scFv-IL-8(72) and dimeric IgG1-TNF fusion proteins significantly enhanced anti-tumor activity when compared either to a single effector treatment regimen or sequential application of non-targeted cytokines, indicating that the tumor-restricted sequential application of IL-8(72) and TNF is a promising approach for cancer therapy.

The interleukin-8-251 A allele is associated with increased risk of noncardia gastric adenocarcinoma in Helicobacter pylori-infected Koreans

BACKGROUND AND GOALS

Chronic inflammation associated with Helicobacter pylori infection is a risk factor of gastric adenocarcinoma. Interleukin-8 (IL-8) plays an important role in gastric mucosal inflammation induced by H. pylori infection. Recently, studies on the association of genetic polymorphisms of various proinflammatory cytokines with gastric carcinogenesis showed varying results on the basis of the ethnicity. We conducted this study to investigate the association of IL-8-251 A/T polymorphism with gastric carcinogenesis in H. pylori-infected Koreans.

STUDY

The IL-8-251 A/T polymorphism was identified by polymerase chain reaction-restriction fragment length polymorphism using DNA from a total of 605 H. pylori-infected subjects; 206 controls, 149 chronic atrophic gastritis and/or intestinal metaplasia, 97 gastric dysplasia, and 153 gastric adenocarcinoma. Degrees of gastric mucosal inflammation and mucosal IL-8 level were also assessed.

RESULTS

The IL-8-251 A carriers showed a higher risk of gastric adenocarcinoma (adjusted odds ratio 2.06, 95% confidence interval 1.16-3.68) than IL-8-251 T/T genotypes. The IL-8-251 A allele was also significantly associated with the degree of neutrophil infiltration, atrophy, and intestinal metaplasia in a younger age group. Among the chronic atrophic gastritis and/or intestinal metaplasia group, mucosal IL-8 level was significantly higher in subjects with IL-8-251 A allele than those with IL-8-251 T/T genotypes (P=0.011).

CONCLUSIONS

The IL-8-251 A allele is associated with higher IL-8 production, more severe inflammation, mucosal atrophy, and intestinal metaplasia than IL-8-251 T/T genotype in H. pylori-infected hosts. The IL-8-251 A allele may also increase the risk of gastric adenocarcinoma through an enhanced inflammatory process in H. pylori-infected Koreans.

Human IL-8 regulates smooth muscle cell VCAM-1 expression in response to endothelial cells exposed to atheroprone flow

OBJECTIVE

Interleukin-8 (IL-8) is a soluble human-specific chemokine implicated in the development of the chronic inflammatory disease atherosclerosis. Recently, we showed that atheroprone hemodynamics induced IL-8 secretion from endothelial cells (ECs) concurrent with increased EC/smooth muscle cell (SMC) VCAM-1 expression in a human hemodynamic coculture model. Despite an IL-8 association with inflammation, we show here that blocking IL-8 activity during atheroprone flow resulted in increased levels of EC/SMC VCAM-1 expression. We tested the hypothesis that IL-8 limits SMC VCAM-1 expression in response to inflammatory stimuli, either atheroprone flow or cytokine interleukin-1beta (IL-1beta) addition.

METHODS AND RESULTS

Atheroprone flow increased monocyte adhesion in both EC/SMCs, concurrent with the induction of VCAM-1 protein. VCAM-1 antisera attenuated this response. IL-1beta upregulated VCAM-1 in SMCs by 3-fold, a response inhibited by the addition of IL-8 at 24 hours. Neither IL-1beta nor IL-8 induced proliferation or migration. Neutralization of the IL-8 receptor, CXCR2, further induced VCAM-1 in the presence of IL-1beta, and phospho-p38 was required for NF-kappaB activation and VCAM-1 expression. Additionally, IL-8 reduced p38 activation and NF-kappaB activity induced by IL-1beta alone.

CONCLUSIONS

Together, these findings provide evidence for a novel role whereby IL-8 limits the inflammatory response in ECs/SMCs via VCAM-1 modulation.

Melanoma and innate immunity--aActive inflammation or just erroneous attraction? Melanoma as the source of leukocyte-attracting chemokines

Unwanted growth breeds response--in the garden as well as in the tumor microenvironment. Innate immune cells mediate the earliest responses against melanoma or its precursors. However, the actual benefit by those cellular efforts is questionable. Why can early melanoma lesions actually develop in the face of rapid innate responses, and why is neutrophil- and macrophage-attracting chemokine secretion observed in melanoma? A surprisingly similar choice of chemokine receptors and chemokines are present in both innate immune cells and melanoma. Here we focus on analogies and differences between the two. Melanoma cell clusters show active chemokine signalling, with mostly tumor growth-enhancing and leukocyte-attracting effects. However, infiltrating leukocytes have only weak tumoricidal effects. Therefore, the observed leukocyte infiltration in melanoma might be at least in part an epiphenomenon of neoplastic self-stimulation rather than a full-fledged innate anti-tumor immune response.

Critical role of PBEF expression in pulmonary cell inflammation and permeability

Previous studies in our lab have identified pre-B-cell colony enhancing factor (PBEF) as a novel biomarker in acute lung injury. This study continues to elucidate the underlying molecular mechanism of PBEF in the pathogenesis of acute lung injury in pulmonary cell culture models. Our results revealed that IL-1beta induced PBEF expression in pulmonary vascular endothelial cells at the transcriptional level and a -1535 T-variant in the human PBEF gene promoter significantly attenuated its binding to an IL-1beta-induced unknown transcription factor. This may underlie the reduced expression of PBEF and thus the lower susceptibility to acute lung injury in -1535T carriers. Furthermore, overexpression of PBEF significantly augmented IL-8 secretion and mRNA expression by more than 6-fold and 2-fold in A549 cells and HPAEC, respectively. It also significantly augmented IL-1beta-mediated cell permeability by 44% in A549 cells and 65% in endothelial cells. The knockdown of PBEF expression significantly inhibited IL-1beta-stimulated IL-8 secretion and mRNA level by 60% and 70%, respectively, and the knockdown of PBEF expression also significantly attenuated IL-1beta-induced cell permeability by 29% in epithelial cells and 24% in endothelial cells. PBEF expression also affected the expression of two other inflammatory cytokines (IL-16 and CCR3 genes). These results suggest that PBEF is critically involved in pulmonary vascular and epithelial inflammation and permeability, which are hallmark features in the pathogenesis of acute lung injury. This study lends further support to our finding that PBEF is a potential new target in acute lung injury.

The role of inflammatory mediators in the pathogenesis of otitis media and sequelae

This review deals with the characteristics of various inflammatory mediators identified in the middle ear during otitis media and in cholesteatoma. The role of each inflammatory mediator in the pathogenesis of otitis media and cholesteatoma has been discussed. Further, the relation of each inflammatory mediator to the pathophysiology of the middle and inner ear along with its mechanisms of pathological change has been described. The mechanisms of hearing loss including sensorineural hearing loss (SNHL) as a sequela of otitis media are also discussed. The passage of inflammatory mediators through the round window membrane into the scala tympani is indicated. In an experimental animal model, an application of cytokines and lipopolysaccharide (LPS), a bacterial toxin, on the round window membrane induced sensorineural hearing loss as identified through auditory brainstem response threshold shifts. An increase in permeability of the blood-labyrinth barrier (BLB) was observed following application of these inflammatory mediators and LPS. The leakage of the blood components into the lateral wall of the cochlea through an increase in BLB permeability appears to be related to the sensorineural hearing loss by hindering K⁺ recycling through the lateral wall disrupting the ion homeostasis of the endolymph. Further studies on the roles of various inflammatory mediators and bacterial toxins in inducing the sensorineumral hearing loss in otitis media should be pursued.

The use of a semiocclusive dressing reduces epidermal inflammatory cytokine expression and mitigates dermal proliferation and inflammation in a rat incisional model

Occlusive wound dressings are utilized clinically to accelerate wound healing and improve the final appearance of scars. In vivo and in vitro evidence suggests that one mechanism for this effect is maintenance of normal hydration in the epidermis, although the molecular signals remain uncharacterized. We sought to elucidate histological changes and some of the molecular signals involved in this effect in a rat model of wound semiocclusion. We utilized a rat linear incision model with surgical tape occlusion. Histological stains and quantitative real-time PCR analysis were used to characterize the cellular and molecular effects of semiocclusion on the wound healing response. Semioccluded wounds demonstrated decreased epidermal thickness and cellularity and less mitotic epidermal activity when compared with nonoccluded control wounds. Associated dermal cellularity was similarly attenuated by semiocclusion. Finally, levels of proinflammatory cytokines interleukin-1-alpha and tumor necrosis factor-alpha were significantly decreased on postoperative day 3 at the transcriptional level when compared with nonoccluded wounds. Semiocclusive wound treatments significantly decrease epidermal thickness, cellularity, mitotic activity, and dermal cellularity as well as transcriptional levels of important epidermal mediators of inflammation in a rat incisional wound model.

Augmentation of Pulmonary Epithelial Cell IL-8 Expression and Permeability by Pre-B-cell Colony Enhancing Factor

Background

Previous studies in our lab have identified Pre-B-cell colony enhancing factor (PBEF) as a novel biomarker in acute lung injury (ALI). The molecular mechanism of PBEF involvement in the pathogenesis of ALI is still incompletely understood. This study examined the role of PBEF in regulating pulmonary alveolar epithelial cell IL-8 expression and permeability.

Methods

Human pulmonary alveolar epithelial cells (cell line and primary cells) were transfected with human PBEF cDNA or PBEF siRNA and then cultured in the presence or absence of TNFα. PBEF and IL-8 expression were analyzed by RT-PCR and Western blotting. In addition, changes in pulmonary alveolar epithelial and artery endothelial cell barrier regulation with altered PBEF expression was evaluated by an in vitro cell permeability assay.

Results

Our results demonstrated that, in human pulmonary alveolar epithelial cells, the overexpression of PBEF significantly augmented basal and TNFα-stimulated IL-8 secretion by more than 5 to 10-fold and increased cell permeability by >30%; the knockdown of PBEF expression with siRNA significantly inhibited basal and TNFα-stimulated IL-8 secretion by 70% and IL-8 mRNA levels by 74%. Further, the knockdown of PBEF expression also significantly attenuated TNFα-induced cell permeability by 43%. Similar result was observed in human pulmonary artery endothelial cells.

Conclusion

These results suggest that PBEF may play a vital role in basal and TNFα-mediated pulmonary inflammation and pulmonary epithelial barrier dysfunction via its regulation of other inflammatory cytokines such as IL-8, which could in part explain the role of PBEF in the susceptibility and pathogenesis of ALI. These results lend further support to the potential of PBEF to serve as a diagnostic and therapeutic target to ALI.

Citrullination of CXCL8 by peptidylarginine deiminase alters receptor usage, prevents proteolysis, and dampens tissue inflammation

Biological functions of proteins are influenced by posttranslational modifications such as on/off switching by phosphorylation and modulation by glycosylation. Proteolytic processing regulates cytokine and chemokine activities. In this study, we report that natural posttranslational citrullination or deimination alters the biological activities of the neutrophil chemoattractant and angiogenic cytokine CXCL8/interleukin-8 (IL-8). Citrullination of arginine in position 5 was discovered on 14% of natural leukocyte-derived CXCL8(1-77), generating CXCL8(1-77)Cit(5). Peptidylarginine deiminase (PAD) is known to citrullinate structural proteins, and it may initiate autoimmune diseases. PAD efficiently and site-specifically citrullinated CXCL5, CXCL8, CCL17, CCL26, but not IL-1beta. In comparison with CXCL8(1-77), CXCL8(1-77)Cit(5) had reduced affinity for glycosaminoglycans and induced less CXCR2-dependent calcium signaling and extracellular signal-regulated kinase 1/2 phosphorylation. In contrast to CXCL8(1-77), CXCL8(1-77)Cit(5) was resistant to thrombin- or plasmin-dependent potentiation into CXCL8(6-77). Upon intraperitoneal injection, CXCL8(6-77) was a more potent inducer of neutrophil extravasation compared with CXCL8(1-77). Despite its retained chemotactic activity in vitro, CXCL8(1-77)Cit(5) was unable to attract neutrophils to the peritoneum. Finally, in the rabbit cornea angiogenesis assay, the equally potent CXCL8(1-77) and CXCL8(1-77)Cit(5) were less efficient angiogenic molecules than CXCL8(6-77). This study shows that PAD citrullinates the chemokine CXCL8, and thus may dampen neutrophil extravasation during acute or chronic inflammation.

Pancreatic duct cells in human islet cell preparations are a source of angiogenic cytokines interleukin-8 and vascular endothelial growth factor

OBJECTIVE

Engraftment and function of human islet cell implants is considered to be dependent on their rapid and adequate revascularization. Studies with rodent islet grafts have shown that vascular endothelial growth factor (VEGF) expression by beta-cells can promote this process. The present work examines whether human islet preparations produce VEGF as well as interleukin (IL)-8, another angiogenic protein, and assesses the role of contaminating duct cells in VEGF and IL-8-mediated angiogenesis.

RESEARCH DESIGN AND METHODS

Human islet and pancreatic duct cell preparations are compared for their respective expression and production of VEGF and IL-8 during culture as well as following transplantation in nonobese diabetic (NOD)/scid mice. The associated angiogenic effects are measured in an in vitro aortic ring assay and in an in vivo chick embryo chorioallantoic membrane assay.

RESULTS

Cultured pancreatic duct cells expressed 3- and 10-fold more VEGF and IL-8, respectively, than cultured human islet endocrine cells and released both proteins at angiogenic levels. The angiogenic effect of purified duct cells was higher than that of purified endocrine islet cells and was completely blocked by a combination of IL-8 and VEGF antibodies. Human duct cell implants under the kidney capsule of NOD/scid mice expressed higher levels of IL-8 and VEGF than human islet cell implants and induced circulating IL-8 and VEGF levels during the first day posttransplantation.

CONCLUSIONS

Human duct cell-released IL-8 and VEGF may help revascularization of currently used human islet cell grafts. Further work should examine whether and when this effect can prevail over other inflammatory and immune influences of this cell type.

Inflammation and cancer: the oncogene-driven connection

Inflammation has long been suspected to contribute to tumor growth. However, the concept that oncogenes, known for decades as responsible for cell neoplastic transformation, build up an inflammatory pro-tumorigenic microenvironment is emerging only in the last few years. The well known oncogenes RAS and MYC have been causally linked to tumor angiogenesis through different ways. Moreover, in thyroid tumors, where many of the genetic tumor-initiating events have been identified, the oncogenes driving tumorigenesis were proved able to induce an inflammatory program. This minireview will focus on growing evidence implicating the role of intrinsic, oncogene-driven pathways leading to pro-tumoral inflammation.

Structural and functional homology among chicken, duck, goose, turkey and pigeon interleukin-8 proteins

Interleukin (IL)-8-encoding regions of five avian species were cloned, sequenced and characterized. Each IL-8-encoding region is 312 nucleotides long and encodes IL-8 which is 103 amino acids. Pairwise sequence analysis showed that sequence identities of IL-8-encoding regions ranged from 87% to 100%. The IL-8 protein identities varied from 84% to 100%. Phylogenetic analysis indicated that IL-8-encoding regions and encoded proteins of chicken, duck, goose and turkey clustered together and evolved into a distinct phylogenetic lineage from that of pigeon which evolved into a second lineage. The results from binding reactivities of antiserum against each recombinant IL-8 (rIL-8) protein to homologous or heterologous rIL-8 proteins, chemotactic activities of each rIL-8 protein or reduction levels of the chemotactic activity of rIL-8 protein which was pretreated with homologous or heterlogous antiserum have suggested that all five IL-8 proteins were functionally active, and shared structural and functional identity with each other.

Characterization of epithelial IL-8 response to inflammatory bowel disease mucosal E. coli and its inhibition by mesalamine

BACKGROUND

Mucosally adherent E. coli are found in inflammatory bowel disease (IBD) and colon cancer. They promote release of the proinflammatory cytokine interleukin-8 (IL-8). We explored mechanisms for this release and its inhibition by drugs.

METHODS

IL-8 release from colon epithelial cells in response to mucosal E. coli isolates from IBD, colon cancer, and controls was characterized at the cellular and molecular level.

RESULTS

IL-8 response of HT29 cells was greater with Crohn's disease (689 +/- 298 [mean +/- SD] pg IL-8/mL at 4 hours, n = 7) and colon cancer isolates (532 +/- 415 pg/mL, n = 14) than with ulcerative colitis (236 +/- 58 pg/mL, n = 6) or control isolates (236 +/- 100 pg/mL, n = 6, P < 0.0001). Bacterial supernatants contained shed flagellin that triggered IL-8 release. For whole bacteria the IL-8 response to E. coli that agglutinate red blood cells (548 +/- 428 pg IL-8/mL, n = 16), a function that correlates with epithelial invasion, was greater than for nonhemagglutinators (281 +/- 253 pg/mL, n = 17; P < 0.0001). This was particularly marked among E. coli that, although flagellate, could not release IL-8 from TLR5-transfected HEK293 cells. IL-8 release was mediated by extracellular-regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK) and inhibited by mesalamine, but not hydrocortisone, at therapeutic concentrations.

CONCLUSIONS

Mucosa-associated E. coli shed flagellin that elicits epithelial IL-8 release but this may only become relevant when the mucosal barrier is weakened to expose basolateral TLR5. Adherent and invasive IBD and colon cancer E. coli isolates also elicit a flagellin-independent IL-8 response that may be relevant when the mucosal barrier is intact. The IL-8 release is MAPK-dependent and inhibited by mesalamine.

Bladder cancer angiogenesis and metastasis--translation from murine model to clinical trial

In the majority of cases, death from bladder cancer results from metastatic disease. Understanding the closely linked mechanisms of invasion, metastasis and angiogenesis in bladder cancer has allowed us to develop new therapeutic strategies that harbor the promise of decisive improvements in patient survival. The essential link between cell based experiments and the translation of novel agents into human patients with bladder cancer is the animal model. With emphasis on the orthotopic xenograft model, this review outlines some key mechanisms relevant to angiogenesis and the development of metastasis in bladder cancer. We highlight especially pathways related to MMP-9, IL-8, VEGF and EGFR. Most commonly, expression patterns of these markers in patients have correlated to disease progression and patient survival, which has led to laboratory investigations of these markers and eventually novel targeted therapies that are translated back into the clinic by means of clinical trials. Although imperfect in their translatability into clinical efficacy, animal models remain a critical tool in bladder cancer research.

Urinary trypsin inhibitor reduces inflammatory response in kidney induced by lipopolysaccharide

Human urinary trypsin inhibitor (UTI), a serine protease inhibitor, has been widely used in Japan as a drug for patients with acute inflammatory disorders such as septic shock and pancreatitis. Lipopolysaccharide (LPS) triggers the sepsis syndrome by activating monocytes to produce proinflammatory cytokines, including tumor necrosis factor alpha (TNFalpha), which potently stimulate the activation of neutrophils. The inhibitory mechanism of UTI on the systemic inflammatory response induced by the intraperitoneal injection of LPS in the kidney is unclear. This study was undertaken to examine the inhibitory effects of UTI on renal injury associated with the systemic inflammatory response induced by LPS stimulation, with emphasis on systemic TNFalpha and the activation of neutrophils in rat kidney. The systemic inflammatory response syndrome was induced by LPS treatment. Serum and renal TNFalpha, renal cytokine-induced neutrophil chemoattractant-1 (CINC-1) and myeloperoxidase (MPO) levels, as well as renal function after LPS stimulation, were evaluated. UTI (50,000 U/kg) inhibited LPS-induced increases in the serum and renal tissue levels of TNFalpha, as well as the renal tissue levels of CINC-1 and MPO after LPS stimulation. UTI (50,000 U/kg) also inhibited the production of serum TNFalpha associated with the systemic inflammatory response syndrome induced by LPS stimulation, thereby attenuating neutrophil infiltration into renal tissues and subsequent neutrophil-mediated renal injury. These findings may have important implications in understanding the biologic functions of UTI. UTI may prove useful in protecting against acute renal injury associated with a systemic inflammatory response.

Transactivation of vascular endothelial growth factor receptor-2 by interleukin-8 (IL-8/CXCL8) is required for IL-8/CXCL8-induced endothelial permeability

Interleukin-8 (IL-8/CXCL8) is a chemokine that increases endothelial permeability during early stages of angiogenesis. However, the mechanisms involved in IL-8/CXCL8-induced permeability are poorly understood. Here, we show that permeability induced by this chemokine requires the activation of vascular endothelial growth factor receptor-2 (VEGFR2/fetal liver kinase 1/KDR). IL-8/CXCL8 stimulates VEGFR2 phosphorylation in a VEGF-independent manner, suggesting VEGFR2 transactivation. We investigated the possible contribution of physical interactions between VEGFR2 and the IL-8/CXCL8 receptors leading to VEGFR2 transactivation. Both IL-8 receptors interact with VEGFR2 after IL-8/CXCL8 treatment, and the time course of complex formation is comparable with that of VEGFR2 phosphorylation. Src kinases are involved upstream of receptor complex formation and VEGFR2 transactivation during IL-8/CXCL8-induced permeability. An inhibitor of Src kinases blocked IL-8/CXCL8-induced VEGFR2 phosphorylation, receptor complex formation, and endothelial permeability. Furthermore, inhibition of the VEGFR abolishes RhoA activation by IL-8/CXCL8, and gap formation, suggesting a mechanism whereby VEGFR2 transactivation mediates IL-8/CXCL8-induced permeability. This study points to VEGFR2 transactivation as an important signaling pathway used by chemokines such as IL-8/CXCL8, and it may lead to the development of new therapies that can be used in conditions involving increases in endothelial permeability or angiogenesis, particularly in pathological situations associated with both IL-8/CXCL8 and VEGF.

Anti-chemokine therapy for inflammatory diseases

Chemokines are inflammatory proteins acting via G-protein coupled chemokine receptors that trigger different signaling pathways. Monocyte chemoattractant protein-1 (CCL2/MCP-1) and regulated on activation, normal T expressed and secreted (CCL5/RANTES) are the two major members of the CC chemokine beta subfamily. The roles of RANTES and MCP-1 are emerging in regulating the recruitment of inflammatory cells into tissue during inflammation. The inhibition of MCP-1 and RANTES with corresponding antibodies or other inhibitors may provide benefits in different clinical scenarios including cancer, inflammation, CNS disorders, parasitic disease, autoimmune and heart diseases. RANTES and MCP-1 may represent targets for diagnostic procedures and therapeutic intervention, and may be useful as a prognostic factor in the above diseases.

Varicella-zoster virus infection induces the secretion of interleukin-8

Interleukin-8 (IL-8) is an important mediator in neutrophil-mediated acute inflammation but has also a wide range of actions on various cells types. We demonstrated that infection of melanoma cells and fibroblasts with cell-associated varicella-zoster virus (VZV) and infection of a T cell line with cell-free VZV resulted in an induction of IL-8 secretion in vitro. The inhibition of the VZV replication with a drug interfering with its DNA replication had no effect on the IL-8 release. Since the IL-8 promoter contains binding sites for NF-kappaB and AP-1, melanoma cells and the T cell line were treated with inhibitors of NF-kappaB, JNK/SAPK or p38/MAPK prior to infection. In melanoma cells, the JNK/SAPK pathway was shown to be important for the IL-8 secretion during the VZV replication, whereas in the T cell line, not only the JNK/SAPK but also the p38/MAPK pathways were required for IL-8 secretion. The neutralisation of the IL-8 bioactivity had no significant consequence on the VZV replication, suggesting that IL-8 acts neither as a proviral nor as an antiviral cytokine during the VZV replication in vitro.

IL-8 expression by biliary epithelial cells is associated with neutrophilic infiltration and reactive bile ductules

BACKGROUND/AIMS

Reactive bile ductule is a non-specific feature of various hepatobiliary diseases, and is not infrequently accompanied by neutrophilic infiltration. Recently, biliary epithelial cells have been shown to secrete cytokines and chemokines and to express components of the mucosal immune system such as Toll-like receptors.

METHODS AND RESULTS

We examined the expression of a neutrophil chemo-attractant, interluekin (IL)-8, in bile ductular cells to clarify the histogenesis of reactive bile ductules with neutrophilic infiltration using human liver tissues (eight cases of chronic viral hepatitis, seven cases of liver cirrhosis (LC), seven cases of sepsis, 11 cases of extrahepatic biliary obstruction (EBO), three cases of fulminant hepatitis (FH), five cases of primary biliary cirrhosis, and three cases of primary sclerosing cholangitis). Human neutrophil peptides 1-3 (HNP1-3) were used as markers of neutrophils. Immunohistochemically, IL-8 was detected in bile ductules in various diseased livers. HNP1-3-positive neutrophils were significantly dense around IL-8-positive bile ductules compared with IL-8-negative ductules in septic liver, LC, EBO, and FH. Experiments in vitro showed that cultured human biliary epithelial cells expressed and secreted IL-8 in response to lipopolysaccharide and also IL-1beta and tumour necrosis factor-alpha.

CONCLUSIONS

Neutrophilic infiltration around reactive bile ductules may be related to the IL-8 expressed in bile ductular epithelia, possibly induced by bacterial components and proinflammatory cytokines released locally.

The effect of covalently immobilized rhIL-1ra-ELP fusion protein on the inflammatory profile of LPS-stimulated human monocytes

The objective of this research was to investigate whether immobilized anti-inflammatory cytokines will signal changes in the inflammatory profile of cultured monocytes. A fusion protein of recombinant human IL-1 receptor antagonist and elastin-like peptide (IL-1ra-ELP) was expressed in Escherichia coli. THP-1 human monocytes were cultured on either carboxyl-terminated self-assembled monolayers (SAMs), or SAMs with either covalently immobilized or soluble IL-1ra-ELP. LPS-stimulated monocytes exposed to either soluble or immobilized IL-1ra-ELP were prevented from cell differentiation, showed attenuated expression of pro-inflammatory cytokines, and had increased production of anti-inflammatory and pro-wound healing cytokines. These results suggest that immobilized anti-inflammatory cytokines have the potential to be immunomodulatory biomaterials.

Expression of interleukin 8 in synovial tissues in patients with internal derangement of the temporomandibular joint and its relationship with clinical variables

OBJECTIVES

The objectives of this study were to assay interleukin 8 (IL-8) in synovial tissues of the temporomandibular joint (TMJ) with symptomatic internal derangement, and to assess its relationship with clinical variables.

STUDY DESIGN

Forty-six joints in 44 patients were examined using an immunohistochemical technique. As controls, 8 joints in 7 subjects with habitual dislocation without pain were also examined.

RESULTS

IL-8 was expressed mainly in the blood vessels beneath the lining cells in 37 of the 46 joints (80%) with internal derangement and in 2 of the 8 control joints. The percentage of IL-8-positive cells was significantly higher in the internal derangement group than in the control group (P = .004). The percentage of IL-8-positive cells showed no correlation with joint pain or number of infiltrating cells.

CONCLUSIONS

IL-8 was up-regulated in inflamed synovial tissues in patients with internal derangement. Because IL-8 has no significant correlation with clinical variables, IL-8 may play a secondary role in the pathogenesis of the internal derangement of the TMJ.

Pre-B-cell Colony-enhancing Factor (PBEF/Visfatin) Gene Expression is Modulated by NF-κB and AP-1 in Human Amniotic Epithelial Cells

A localized intrauterine inflammatory response is often associated with the initiation of normal human parturition, whereas infection causes a similar but more florid response initiating preterm labor. Pre-B-cell colony-enhancing factor (PBEF) is expressed in the human fetal membranes and is up-regulated by labor, severe infection and inflammatory stimuli. The aim of this study was to determine the involvement of the transcription factors NF-kappaB and AP-1 in the response of PBEF to an inflammatory stimulus and compare it with IL-8. The results showed that this treatment of amniotic epithelial-like cells (WISH) and primary amniotic epithelial cells increased expression of PBEF and IL-8, but IL-8 responded 100-fold more than PBEF. IL-1beta treatment together with a panel of NF-kappaB and AP-1 inhibitors demonstrated the involvement of these transcription factors in the up-regulation of PBEF. These data show that an inflammatory stimulus in the fetal membranes inducing NF-kappaB and AP-1 would up-regulate PBEF as well as IL-8.

Bacterial translocation in small intestinal ischemia-reperfusion injury and efficacy of Anti-CINC antibody treatment

The involvement of bacterial translocation in small intestinal ischemia-reperfusion injuries and the efficacy of using anti-CINC antibodies for treatment were investigated. A model for ischemia-reperfusion injury of the small intestine was constructed by clamping the supramesenteric artery (for 90 min) in rats. Anti-CINC antibodies and saline were given just before the induction of ischemia in the treatment group and the control group, respectively. Six hours after reperfusion, bacteria were detected in the mesenteric lymph nodes, but the 'bacteria-positive' rate was significantly lower in the treatment group than in the control group. Bacterial cultures and endotoxins in the blood were negative in both groups up to 24 h later. The plasma cytokine levels showed similar variations, although the increases were significantly lower after reperfusion in the treatment group. In addition, the degrees of neutrophil infiltration and mucosal injury were attenuated in the small intestine, and the structure of the liver was maintained. Furthermore, the 1-week survival was improved. These results suggest that bacterial translocation occurred predominantly via the lymphatic system and that anti-CINC antibody treatment exerted a protective effect against small intestinal ischemia-reperfusion injury.

Stimulated production of interleukin-8 covaries with psychosocial risk factors for inflammatory disease among middle-aged community volunteers

A growing literature suggests that psychosocial factors, such as chronic stress and depression, are associated with increased vulnerability to inflammatory disease; however, the mechanisms of this effect remain unclear. One possibility is that these psychosocial characteristics are associated with activation of innate inflammatory pathways. Here, we explore relationships between a range of psychosocial risk factors for inflammatory disease and a measure of inflammatory potential, lipopolysaccharide-induced production of the monocyte-derived proinflammatory cytokines/chemokines interleukin (IL)-1beta, IL-6, TNF-alpha, and IL-8 among a community sample of 183 healthy adults aged 30-54 years. After controlling for demographic factors, health behavior practices, blood pressure, and white blood cell count, hierarchical regression analyses revealed a positive relationship between production of IL-8 and symptoms of depression, trait negative affect, and perceived stress. In contrast, there was an inverse relationship between IL-8 production and perceived social support. Relationships between IL-8 and symptoms of depression and perceived stress were attributable primarily to dispositional differences in NA. The relationship between negative affect measures and IL-8 was independent of social support. Although there were significant univariate associations between higher IL-6 production and symptoms of depression and less social support, these relationships did not withstand adjustment for demographic controls. There were no significant associations between IL-1beta or TNF-alpha and any of the psychosocial parameters. Our findings suggest that individuals at greater psychosocial risk for the development of inflammatory diseases, including cardiovascular disease, also show greater stimulated production of the proinflammatory chemokine, IL-8. Further exploration of this potential psychophysiological pathway is warranted.

Association of plasma adiponectin concentrations with chronic lymphocytic leukemia and myeloproliferative diseases

Adiponectin, an adipocyte-secreted hormone, is an important negative regulator in the immune system and hematopoiesis. In this study, we investigated the association of adiponectin levels with chronic lymphocytic leukemia (CLL) and myeloproliferative diseases (MPDs). We measured adiponectin levels in 19 patients with CLL and 30 patients with MPD (chronic myelogenous leukemia, 15; polycythemia vera, 9; myelofibrosis, 4; essential thrombocythemia, 2). The data were (chronic myelogenous leukemia, 15; polycythemia vera, 9; myelofibrosis, 4; essential thrombocythemia, 2). The data were compared with results from a control group of healthy volunteers who were matched according to age, sex, and body mass index. The adiponectin levels in patients with CLL were lower than in the controls (4.71 +/- 1.33 microg/mL versus 16.61 +/- 3.91 microg/mL; P <.001). They were also significantly lower in patients with MPD than in the controls (8.95 +/- 1.33 microg/mL versus 16.16 +/- 4.77 microg/mL; P <.001). In addition, we compared the adiponectin levels of MPD patients who were treated with interferon (IFN) to the levels of patients who were not treated with IFN. Adipnectin levels were significantly higher in IFN-treated patients (11.03 +/- 1.39 microg/mL versus 6.87 +/- 1.79 microg/mL; P <.001). These results suggest that lymphopoiesis and myelopoiesis negatively influence adiponectin levels. Adiponectin may be related to inflammatory cytokine release. IFN therapy appears to have a positive influence on adiponectin secretion by suppressing inflammatory cytokines. Future studies are needed to prove causality and to provide insight about this hormone's mechanism of action and its potential role regarding the etiology and progression of CLL and MPD.

Differential expression of retinal pigment epithelium (RPE) IP-10 and interleukin-8

Interferon-gamma induced protein of 10 kDa (IP-10) is a C-X-C chemokine that attracts T lymphocytes and inhibits angiogenesis. In this study, we investigated the expression of IP-10 by human retinal pigment epithelial cells (HRPE) and compared IP-10 expression to that of interleukin-8 (IL-8), which is a leukocytic chemoattractant and pro-angiogenic factor. Cultured HRPE cells were incubated with either IL-1 beta (0.2-20 ng/ml) or tumor necrosis factor (TNF)-alpha (0.2-20 ng/ml) alone or in combination with interferon-gamma (IFN-gamma) (1000 U/ml). HRPE cells were also incubated with: (1) media conditioned by activated human T lymphocytes (CM), or (2) the same CM treated with neutralizing antibodies to IL-1, TNF, and/or IFN-gamma. IL-8 and IP-10 protein levels were measured by ELISA and mRNA levels by Northern blot analysis of HRPE cells. HRPE cells produced very high levels of IP-10 in response to either IL-1 beta/IFN-gamma, TNF-alpha/IFN-gamma or CD3-activated T-lymphocyte CM. The levels of IP-10 were at least tenfold higher (p<.001) than IL-8 measured in the same samples. Neutralizing antibodies to TNF and IFN-gamma, but not to IL-1, abrogated the ability of the CD3-activated T lymphocytes CM to induce HRPE IP-10 (p<.001). HRPE cells produce differential levels of IP-10 and IL-8 in response to various combinations of recombinant and T-lymphocyte-secreted pro-inflammatory cytokines. This may be important in evolving inflammatory and angiogenic ocular responses.

Associations of Classic Kaposi Sarcoma with Common Variants in Genes that Modulate Host Immunity

Classic Kaposi sarcoma (CKS) is an inflammatory-mediated neoplasm primarily caused by Kaposi sarcoma-associated herpesvirus (KSHV). Kaposi sarcoma lesions are characterized, in part, by the presence of proinflammatory cytokines and growth factors thought to regulate KSHV replication and CKS pathogenesis. Using genomic DNA extracted from 133 CKS cases and 172 KSHV-latent nuclear antigen-positive, population-based controls in Italy without HIV infection, we examined the risk of CKS associated with 28 common genetic variants in 14 immune-modulating genes. Haplotypes were estimated for IL1A, IL1B, IL4, IL8, IL8RB, IL10, IL12A, IL13, and TNF. Compared with controls, CKS risk was decreased with 1235T/-1010G-containing diplotypes of IL8RB (odds ratio, 0.49; 95% confidence interval, 0.30-0.78; P = 0.003), whereas risk was increased with diplotypes of IL13 containing the promoter region variant 98A (rs20541, alias +130; odds ratio, 1.88; 95% confidence interval, 1.15-3.08; P = 0.01) when considered in multivariate analysis. Risk estimates did not substantially vary by age, sex, incident disease, or disease burden. Our data provide preliminary evidence for variants in immune-modulating genes that could influence the risk of CKS. Among KSHV-seropositive Italians, CKS risk was associated with diplotypes of IL8RB and IL13, supporting laboratory evidence of immune-mediated pathogenesis.