Urinary IL-6 and IL-8 as predictive markers in bladder urothelial carcinoma: A pilot study.

BACKGROUND: Cytokines are known to be a key a factor in numerous malignancies and to exert an important regulatory role in the tumor microenvironment. Interest has grown in understanding how cytokines modulate the tumor microenvironment and which cytokines may serve as markers of the tumor process; however, a complete picture of the cytokine landscape in bladder cancer remains unclear. METHODS: Fresh urine specimens with sufficient volume were collected at random intervals. The urine concentrations of IL-8 (CXCL8), CCL18, and CXCL9 were determined using the standard commercially available enzyme immunoassay. The urine concentrations of IL-6 were determined using the high sensitivity enzyme immunoassay kit. Urinary cytokine concentrations were normalized with urinary creatinine concentrations. RESULTS: Significantly elevated concentrations of IL-6 and IL-8 were detected in the urine from patients with urothelial carcinoma on follow-up compared to patients with benign follow-up. The presence of both IL-6 and IL-8 in the urine samples from the high grade urothelial carcinoma (HGUC) cohort revealed a clear discrimination when compared to samples from patients with benign follow-up. The presence of the combination of both IL-6 and IL-8 had a sensitivity of 90.0% and a specificity of 81.25%. Similar data were obtained when receiver operating characteristic analysis was performed on both IL-6 and IL-8 concentrations in the urine from patients with HGUC vs. the hematuria cohort. CONCLUSIONS: The presence of IL-6 and IL-8 in urine specimens may have predictive value for urothelial carcinoma. However, a large longitudinal study is required to statistically eliminate confounding factors and support this theory.

Elevated serum levels of IL-6 and CXCL9 in autoimmune retinopathy (AIR) patients.

Autoimmune retinopathy (AIR) is a rare immune-mediated retinopathy associated with circulating antiretinal antibodies (ARAs). Other prominent features of AIR include visual field deficits and photoreceptor dysfunction in the setting of progressive unexplained vision loss. The role of inflammation is poorly understood in AIR. Since cytokines play a central role in the initiation and development of inflammation, we evaluated the presence of proinflammatory cytokines and chemokines in AIR patient sera. We demonstrate that IL-6 and CXCL9 are both elevated in AIR patient sera. Moreover, the presence and concentration of these 2 molecules appear to correlate with AIR patient disease severity. This cytokine profile, IL-6 and CXCL9, has been described to participate in a variety of autoimmune and inflammatory diseases. Our study provides support for an activated inflammatory process in AIR and identifies possible mechanisms that can drive autoimmunity in this disease.

Consensus on the Diagnosis and Management of Nonparaneoplastic Autoimmune Retinopathy Using a Modified Delphi Approach.

PURPOSE: To develop diagnostic criteria for nonparaneoplastic autoimmune retinopathy (AIR) through expert panel consensus and to examine treatment patterns among clinical experts. DESIGN: Modified Delphi process. METHODS: A survey of uveitis specialists in the American Uveitis Society, a face-to-face meeting (AIR Workshop) held at the National Eye Institute, and 2 iterations of expert panel surveys were used in a modified Delphi process. The expert panel consisted of 17 experts, including uveitis specialists and researchers with expertise in antiretinal antibody detection. Supermajority consensus was used and defined as 75% of experts in agreement. RESULTS: There was unanimous agreement among experts regarding the categorization of autoimmune retinopathies as nonparaneoplastic and paraneoplastic, including cancer-associated retinopathy and melanoma-associated retinopathy. Diagnostic criteria and tests essential to the diagnosis of nonparaneoplastic AIR and multiple supportive criteria reached consensus. For treatment, experts agreed that corticosteroids and conventional immunosuppressives should be used (prescribed) as first- or second-line treatments, though a consensus agreed that biologics and intravenous immunoglobulin were considered appropriate in the treatment of nonparaneoplastic AIR patients regardless of the stage of disease. Experts agreed that more evidence is needed to treat nonparaneoplastic AIR patients with long-term immunomodulatory therapy and that there is enough equipoise to justify randomized, placebo-controlled trials to determine if nonparaneoplastic AIR patients should be treated with long-term immunomodulatory therapy. Regarding antiretinal antibody detection, consensus agreed that a standardized assay system is needed to detect serum antiretinal antibodies. Consensus agreed that an ideal assay should have a 2-tier design and that Western blot and immunohistochemistry should be the methods used to identify antiretinal antibodies. CONCLUSIONS: Consensus was achieved using a modified Delphi process to develop diagnostic criteria for nonparaneoplastic AIR. There is enough equipoise to justify randomized, placebo-controlled trials to determine whether patients with nonparaneoplastic AIR should be treated with long-term immunomodulatory therapy. Efforts to develop a standardized 2-tier assay system for the detection of antiretinal antibodies have been initiated as a result of this study.

Inflammatory cytokines regulate secretion of VEGF and chemokines by human conjunctival fibroblasts: Role in dysfunctional tear syndrome.

Ocular surface inflammation is one of the primary mechanisms associated with dysfunctional tear syndrome (DTS), also known as dry eye disease. DTS, more prevalent in older populations, causes ocular discomfort and visual disturbance due to dryness on the surface layer in the eye. We used human conjunctival fibroblast cultures (HCJVF) to investigate the effects of inflammatory cytokines IFN-γ, TNF-α and IL-1ß (ITI) on the secretions of VEGF and chemokines. Our results demonstrate the elevated secretion of angiogenic VEGF molecules by ITI without affecting anti-angiogenic molecules, PEDF, endostatin, thrombospondin and sVEGF-R1. The secretion of interferon-γ inducible chemokines, CXCL9, -10, -11 by HCJVF were significantly enhanced by ITI. Our in vitro study supports previously reported observations of elevated VEGF and chemokines in tear fluids of DTS patients, reiterating the role of inflammatory reactions in DTS.

Inflammatory Cytokines Induce Expression of Chemokines by Human Retinal Cells: Role in Chemokine Receptor Mediated Age-related Macular Degeneration.

Chemokine reeptor-3 (CCR-3) was shown to be associated with choroidal neovascularization (CNV) in age-related macular degeneration (AMD). AMD is a vision threatening retinal disease that affects the aging population world-wide. Retinal pigment epithelium and choroid in the posterior part of the retina are the key tissues targeted in the pathogenesis of CNV in AMD. We used human retinal pigment epithelial (HRPE) and choroidal fibroblast (HCHF) cells, prepared from aged adult human donor eyes, to evaluate the expression of major CCR-3 ligands, CCL-5, CCL -7, CCL-11,CCL-24 and CCL-26. Microarray analysis of gene expression in HRPE cells treated with inflammatory cytokine mix (ICM= IFN-γ+TNF-α+IL-1ß) revealed 75 and 23-fold increase in CCL-5 and CCL-7 respectively, but not CCL-11, CCL-24 and CCL-26. Chemokine secretion studies of the production of CCL5 and CCL7 by HRPE corroborated with the gene expression analysis data. When the HRPE cells were treated with either individual cytokines or the ICM, both CCL-5 and CCL-7 were produced in a dose dependent manner. Similar to the gene expression data, the ICM did not enhance HRPE production of CCL-11, CCL-24 and CCL-26. CCL-11 and CCL-26 were increased with IL-4 treatment and this HRPE production was augmented in the presence of TNF-α and IL1ß. When HCHF cells were treated with either individual cytokines or the ICM, both CCL-5 and CCL-7 were produced in a dose dependent fashion. IL-4 induced low levels of CCL-11 and CCL-26 in HCHF and this production was significantly enhanced by TNF-α. Under these conditions, neither HRPE nor HCHF were demonstrated to produce CCL-24. These data demonstrate that chronic inflammation triggers CCL-5 and CCL-7 release by HRPE and HCHF and the subsequent interactions with CCR3 may participate in pathologic processes in AMD.

Identification of α-fodrin as an autoantigen in experimental coronavirus retinopathy (ECOR).

The coronavirus, mouse hepatitis virus (MHV), JHM strain induces a biphasic disease in BALB/c mice that consists of an acute retinitis followed by progression to a chronic retinal degeneration with autoimmune reactivity. Retinal degeneration resistant CD-1 mice do not develop either the late phase or autoimmune reactivity. A mouse RPE/choroid DNA expression library was screened using sera from virus infected BALB/c mice. Two clones were identified, villin-2 protein and α-fodrin protein. α-Fodrin protein was used for further analysis and western blot reactivity was seen only in sera from virus infected BALB/c mice. CD4 T cells were shown to specifically react with MHV antigens and with α-fodrin protein. These studies clearly identified both antibody and CD4 T cell reactivities to α-fodrin in sera from virus infected, retinal degenerative susceptible BALB/c mice.

Resveratrol Suppresses Expression of VEGF by Human Retinal Pigment Epithelial Cells: Potential Nutraceutical for Age-related Macular Degeneration.

Age-related macular degeneration (AMD) is a sight threating retinal eye disease that affects millions of aging individuals world-wide. Choroid-retinal pigment epithelium (RPE)-neuroretina axis in the posterior compartment of the eye is the primary site of AMD pathology. There are compelling evidence to indicate association of vascular endothelial growth factors (VEGF) to AMD. Here, we report the inhibitory actions of resveratrol (RSV) on inflammatory cytokine, TGF-ß and hypoxia induced VEGF secretion by human retinal pigment epithelial cells (HRPE). HRPE cultures prepared from aged human donor eyes were used for the studies in this report. HRPE secreted both VEGF-A and VEGF-C in small quantities constitutively. Stimulation with a mixture of inflammatory cytokines (IFN-γ, TNF-α, IL-1ß), significantly increased the secretion of both VEGF-A and VEGF-C. RSV, in a dose dependent (10-50 uM) manner, suppressed VEGF-A and VEGF-C secretion induced by inflammatory cytokines significantly. RT-PCR analysis indicated that effects of RSV on VEGF secretion were possibly due to decreased mRNA levels. TGF-ß and cobalt chloride (hypoxia mimic) also upregulated HRPE cell production of VEGF-A, and this was inhibited by RSV. In contrast, RSV had no effect on anti-angiogenic molecules, endostatin and pigment epithelial derived factor secretion. Studies using an in vitro scratch assay revealed that wound closure was also inhibited by RSV. These results demonstrate that RSV can suppress VEGF secretion induced by inflammatory cytokines, TGF-ß and hypoxia. Under pathological conditions, over expression of VEGF is known to worsen AMD. Therefore, RSV may be useful as nutraceutical in controlling pathological choroidal neovascularization processes in AMD.

Differential regulation of microRNA-146a and microRNA-146b-5p in human retinal pigment epithelial cells by interleukin-1ß, tumor necrosis factor-α, and interferon-γ.

PURPOSE: The inflammatory response of the retinal pigment epithelium (RPE) is implicated in the pathogenesis of age-related macular degeneration. The microRNAs miR-146a and miR-146b-5p can regulate the inflammatory process by attenuating cytokine signaling via the nuclear factor-κB pathway. The aim of the present study is to investigate the expression of miR-146a and miR-146b-5p in human RPE cells and their response to proinflammatory cytokines. METHODS: Confluent cultures of RPE cells established from adult human donor eyes were treated with the proinflammatory cytokines interferon (IFN)-γ, tumor necrosis factor (TNF)-α, and interleukin (IL)-1ß. The expression of microRNAs was analyzed by real-time PCR using total RNA fraction. The retinal pigment epithelial cell line ARPE-19 was employed to analyze the promoter activity of the genes encoding miR-146a and miR-146b-5p. STAT1-binding activity of oligonucleotides was analyzed by electrophoretic mobility shift assay. ARPE-19 cells were transiently transfected with miR-146a and miR-146b-5p mimics for the analysis of IRAK1 expression by western immunoblotting. RESULTS: Real-time PCR analysis showed that miR-146a and 146b-5p are expressed in RPE cells. The cells responded to proinflammatory cytokines (IFN-γ + TNF-α + IL-1ß) by highly increasing the expression of both miR-146a and miR-146b-5p. This was associated with an increase in the expression of transcripts for CCL2, CCL5, CXCL9, CXCL10, and IL-6, and a decrease in that for HMOX1. The miR-146a induction was more dependent on IL-1ß, since its omission from the cytokine mix resulted in a greatly reduced response. Similarly, the induction of miR-146b-5p was more dependent on IFN-γ, since its omission from the cytokine mix minimized the effect. In addition, the increase in MIR146B promoter activity by the cytokine mix was effectively blocked by JAK inhibitor 1, a known inhibitor of the JAK/STAT signaling pathway. The expression of IRAK1 protein was decreased when ARPE-19 cells were transiently transfected with either miR-146a mimic or miR-146b-5p mimic. CONCLUSIONS: Our results clearly show that both miR-146a and miR-146b-5p are expressed in human RPE cells in culture and their expression is highly induced by proinflammatory cytokines (IFN-γ + TNF-α + IL-1ß). The induction of miR-146a showed a dependency on IL-1ß, while that of miR-146b-5p on IFN-γ. Our results show for the first time that miR-146b-5p expression is regulated by IFN-γ, potentially via the JAK/STAT pathway. These two microRNAs could play a role in inflammatory processes underlying age-related macular degeneration or other retinal degenerative diseases through their ability to negatively regulate the nuclear factor-κB pathway by targeting the expression of IRAK1.

Transforming growth factor-ß regulates the expression of anosmin (KAL-1) in human retinal pigment epithelial cells.

In a microarray analysis of human retinal pigment epithelial cells (HRPE) treated with TGF-ß, in addition to the alteration of a number of known Extracellular matrix (ECM)-related genes regulated by TGF-ß, we found a significant increase in the expression of Kallmann Syndrome (KAL)-1 gene, that codes for the protein anosmin-1. Enhanced expression of KAL-1 by TGF-ß was validated by real-time PCR analysis. In in vitro experiments, TGF-ß receptor inhibitor abolished TGF-ß-induced expression of KAL-1. Immunofluorescence staining showed increased presence of anosmin-1 in TGF-ß treated HRPE cells, with distinct localization at the intercellular junctions. Treatment of HRPE cells with TGF-ß enhanced secretion of anosmin-1 and the release of anosmin-1 was further augmented by heparin sulfate. Enhanced secretion of anosmin-1 in the presence of TGF-ß and heparin was also observed in other ocular cells such as corneal epithelial and corneal fibroblast cultures. The role of anosmin-1, a protein with adhesion functions, in retinal structure, function and pathology has not been known and remains to be investigated.

Inhibition of HSV-1 by chemoattracted neutrophils: supernatants of corneal epithelial cells (HCE) and macrophages (THP-1) treated with virus components chemoattract neutrophils (PMN), and supernatants of PMN treated with these conditioned media inhibit viral growth.

The role of PMNs (neutrophils) in corneal herpes was studied using an in vitro system. Human corneal cells (HCE) and macrophages (THP-1) infected with HSV-1 or treated with virus components (DNA or virus immune complexes) released chemokines, which attracted PMNs. Highly reactive oxygen species were detected in PMNs. PMNs inhibited HSV when overlaid onto infected HCE cells (50:1). PMNs incubated with the supernatants of HCE cells treated with virus components released H(2)O(2) and myeloperoxidase. These inhibited virus growth. PMNs released NO and MIG, which may differentiate CD4 T cells to Th1. PMNs participate in innate immune responses, limit virus growth, and initiate immunopathology.

Regulation of VEGF expression in human retinal cells by cytokines: implications for the role of inflammation in age-related macular degeneration.

Chronic inflammation is implicated in the pathogenesis of age-related macular degeneration (AMD). Choroidal neovascularization (CNV) observed in exudative form of AMD results in vision loss. Human retinal pigment epithelial cell (HRPE) layer and choroidal tissue are the primary pathological sites in AMD. Pathological and therapeutic evidences have strongly indicated the vascular endothelial growth factor (VEGF) molecules as critical components in CNV pathogenesis. In these studies, we used human primary HRPE and choroidal fibroblast cells (HCHF) prepared from adult donor eyes. The effects of inflammatory cytokine (IFN-γ+ TNF-α+IL-1ß) mix (ICM) on global gene expression profiles in HRPE cells, revealed 10- and 9-fold increase in VEGF-A and VEGF-C expression, respectively. The microarray results were validated by quantitative RT-PCR and secretion of VEGFs proteins. IL-1ß is the most potent in inducing VEGFs secretion followed by IFN-γ and TNF-α, and the secretion was more effective in the presence of 2 and 3 cytokines. NF-κB and JAK-STAT pathway, but not HIF-1α, Sp-1, Sp-3, and STAT-3, transcription factors were upregulated and translocated to nucleus by ICM treatment. The mRNA levels of VEGF-A and VEGF-C and secretion of these proteins were also significantly enhanced by ICM in HCHF cells. The secretion of other angiogenic molecules, PEDF, SDF-1α, endostatin, and angiopoietins was not affected by ICM. Our results show that the inflammatory cytokines enhance secretion of VEGF-A and VEGF-C by HRPE and HCHF cells. These studies indicate that VEGFs secreted by these cells initiate and promote pathological choroidal and retinal noevascularization processes in AMD.

Beta interferon suppresses the development of experimental cerebral malaria.

Cerebral malaria (CM) is a major complication of Plasmodium falciparum infection, particularly in children. The pathogenesis of cerebral malaria involves parasitized red blood cell (RBC)-mediated vascular inflammation, immune stimulation, loss of blood-brain barrier integrity, and obstruction of cerebral capillaries. Therefore, blunting vascular inflammation and immune cell recruitment is crucial in limiting the disease course. Beta interferon (IFN-ß) has been used in the treatment of diseases, such as multiple sclerosis (MS) but has not yet been explored in the treatment of CM. Therefore, we sought to determine whether IFN-ß also limits disease progression in experimental cerebral malaria (ECM). Plasmodium berghei-infected mice treated with IFN-ß died later and showed increased survival, with improved blood-brain barrier function, compared to infected mice. IFN-ß did not alter systemic parasitemia. However, we identified multiple action sites that were modified by IFN-ß administration. P. berghei infection resulted in increased expression of chemokine (C-X-C motif) ligand 9 (CXCL9) in brain vascular endothelial cells that attract T cells to the brain, as well as increased T-cell chemokine (C-X-C motif) receptor 3 (CXCR3) expression. The infection also increased the cellular content of intercellular adhesion molecule 1 (ICAM-1), a molecule important for attachment of parasitized RBCs to the endothelial cell. In this article, we report that IFN-ß treatment leads to reduction of CXCL9 and ICAM-1 in the brain, reduction of T-cell CXCR3 expression, and downregulation of serum tumor necrosis factor alpha (TNF-α). In addition, IFN-ß-treated P. berghei-infected mice also had fewer brain T-cell infiltrates, further demonstrating its protective effects. Hence, IFN-ß has important anti-inflammatory properties that ameliorate the severity of ECM and prolong mouse survival.

Role of human herpes virus 6 in corneal inflammation alone or with human herpesviruses.

PURPOSE: : The purpose of this study was to determine the association of human herpes virus 6 (HHV-6) and/or other human herpesviruses in corneal inflammation using polymerase chain reaction (PCR). METHODS: : We collected tear films, conjunctival smears, and a corneal button of inflamed cornea, and the presence of HHV-6 and other herpesviruses in these samples were assessed by a nested PCR. RESULTS: : In tear films collected from 3 of 9 patients with dendritic keratitis, HHV-6 DNA was positive twice, together with herpes simplex virus (HSV) or varicella zoster virus DNA most often, during the acute phase of the disease. Two other patients in this group were either positive for HSV-1 and varicella zoster virus or for HSV-1 and Epstein-Barr virus DNA but negative for HHV-6. When another 12 patients' smear samples from corneal ulcer or keratouveitis were examined, 9 were positive for HHV-6 DNA. Of these, 4 were positive for HSV-1 simultaneously, whereas the remaining 5 patients were negative for HSV-1. One patient's smear was positive for HSV-1 but not for HHV-6. In the corneal button, both HSV and HHV-6 DNAs were positive by nested PCR. HHV-6 was also positive by nested PCR in the conjunctival swab obtained from the contralateral inflamed eye of the patient. CONCLUSIONS: : In 22 patients with corneal inflammation, HHV-6 was positive in 14 of 22 patients and HSV-1 was found in 9 of those patients. These data indicated that the association of HHV-6 with disease was more frequent than with other herpesviruses and that HHV-6 may be another sole causative agent for corneal inflammation.

Inflammatory cytokines regulate microRNA-155 expression in human retinal pigment epithelial cells by activating JAK/STAT pathway.

Inflammatory response of the retinal pigment epithelium plays a critical role in the pathogenesis of retinal degenerative diseases such as age-related macular degeneration. Our previous studies have shown that human retinal pigment epithelial (HRPE) cells, established from adult donor eyes, respond to inflammatory cytokines by enhancing the expression of a number of cytokines and chemokines. To investigate the role of microRNA (miRNA) in regulating this response, we performed microarray analysis of miRNA expression in HRPE cells exposed to inflammatory cytokine mix (IFN-γ+TNF-α+IL-1ß). Microarray analysis revealed ∼11-fold increase in miR-155 expression, which was validated by real-time PCR analysis. The miR-155 expression was enhanced when the cells were treated individually with IFN-γ, TNF-α or IL-1ß, but combinations of the cytokines exaggerated the effect. The increase in miR-155 expression by the inflammatory cytokines was associated with an increase in STAT1 activation as well as an increase in protein binding to putative STAT1 binding elements present in the MIR155 gene promoter region. All these activities were effectively blocked by JAK inhibitor 1. Our results show that the inflammatory cytokines increase miR-155 expression in human retinal pigment epithelial cells by activating the JAK/STAT signaling pathway.

Immune regulation in the retina.

Immune reactivity in the retina can be critically important in inflammation and infections, but regulation of this response is essential. The retinal pigment epithelial (RPE), a unique retinal cell, displays a number of essential functions to support the health of the retina. In this review, we highlight how the RPE cell plays a pivotal role in immune defense. The RPE cell orchestrates both innate and adaptive immunity since it expresses TLRs, complement components, MHC class I and II molecules, and serves as an antigen presenting cell. Moreover, both of these immune responses result in the production of a plethora of cytokines, mainly proinflammatory. In order to counteract these inflammatory factors and silence unwanted immune reactivity, the RPE cell also generates suppressive molecules. Recently, chronic immune reactivity has been implicated in a number of retinal diseases, such as age-related macular degeneration (AMD). Current evidence suggests that the generation of excessive retinal inflammation may be the consequence of a loss of RPE immunosuppressive factors. Herein, we summarize the varied interactions of the RPE cell with the immune response and highlight how the RPE cell survives and participates in this dynamic environment.

IL-11 expression in retinal and corneal cells is regulated by interferon-gamma.

Interleukin-11 (IL-11) is an anti-apoptotic, anti-inflammatory cytokine with hematopoietic potential. The expression and protective actions of IL-11 have not been explored in the eye. The expression of IL-11 in primary cultures of human retinal pigment epithelial (HRPE) and human corneal fibroblast (HCRF) cells were evaluated in these studies. Constitutive secretion of IL-11 was not observed in either HRPE or HCRF. TNF-alpha+IL-1 induced IL-11 secretion and this production was inhibited by NFkappaB pathway inhibitors. IFN-gamma significantly inhibited TNF-alpha and IL-1 induced IL-11 secretion and inhibitors of JAK-STAT pathway reversed this inhibition. TGF-beta induced IL-11 secretion that was blocked by TGF-beta receptor 1 inhibitor but not by IFN-gamma. RT-PCR analysis confirmed the effects of IL-1, TNF-alpha, IFN-gamma and TGF-beta on IL-11 secretion at mRNA levels. Our results demonstrate that IL-11 is dramatically up regulated in retina and cornea cells and that IFN-gamma is a physiological inhibitor of IL-11 expression.

HSV immune complex (HSV-IgG: IC) and HSV-DNA elicit the production of angiogenic factor VEGF and MMP-9.

Angiogenesis and inflammatory mediators are critical pathogenic factors in herpetic stromal keratitis (HSK). Since disease progresses without infectious virus, HSV-DNA and HSV-IgG complexes (HSV-IC) may contribute to HSK by triggering these factors. Production of VEGF and MMP-9 was studied in vitro using corneal epithelial cells (HCE), fibroblasts (HCRF) and macrophages (THP-1). VEGF was elevated in HCRF and THP-1 following treatment with HSV-DNA and HSV-IC. MMP-9 was elevated in THP-1 but not in corneal cells. When anti-HSV-IgG(Fab')2 complexes stimulated THP-1, MMP-9 was reduced to control levels. Pretreatment of THP-1 with anti-TLR-2 and -3 inhibited MMP-9 production. Thus, HSV-IC may stimulate THP-1 through the Fc receptor and TLRs. Proinflammatory cytokines (IL-1b, IL-6, and TNF-alpha) increased VEGF and MMP-9 in corneal cells and macrophages. These studies indicate that the continued presence of HSV-DNA and HSV-IC contribute to angiogenesis and inflammation in HSK. Thus, cytokines and TLRs may be potential targets for intervention.

Functional identification of a novel transport system for endogenous and synthetic opioid peptides in the rabbit conjunctival epithelial cell line CJVE.

PURPOSE: To investigate whether conjunctival epithelial cells express transport processes for opioid peptides. METHODS: We monitored the uptake of [(3)H]deltorphin II and [(3)H]DADLE, two hydrolysis-resistant synthetic opioid peptides, in the rabbit conjunctival epithelial cell line CJVE and elucidated the characteristics of the uptake process. RESULTS: CJVE cells express robust uptake activity for deltorphin II and DADLE. Both opioid peptides compete with each other for transport. Several endogenous and synthetic opioid peptides, but not non-peptide opioid antagonists, are recognized by the transport process. Though various peptides inhibit the uptake of deltorphin II and DADLE in a similar manner, the uptake of deltorphin II is partly Na(+)-dependent whereas that of DADLE mostly Na(+)-independent. The transport process shows high affinity for many endogenous/synthetic opioid peptides. Functional features reveal that this transport process may be distinct from the opioid peptide transport system described in the retinal pigment epithelial cell line ARPE-19 and also from the organic anion transporting polypeptides, which are known to transport opioid peptides. CONCLUSIONS: CJVE cells express a novel, hitherto unknown transport process for endogenous/synthetic opioid peptides. This new transport process may offer an effective delivery route for opioid peptide drugs to the posterior segment of the eye.

The need for standardization of antiretinal antibody detection and measurement.

PURPOSE: To review the current literature on the detection and measurement of antiretinal antibodies. DESIGN: Collaborative essay. METHODS: Literature review and interpretation. RESULTS: There is strong evidence to suggest a role for antiretinal antibodies, particularly those targeting recoverin and alpha-enolase, in the pathogenesis of autoimmune retinopathy (AIR). Additionally, numerous other autoantibodies have been described as putative mediators of retinal degeneration and more remain to be discovered. However, assay methods described in the literature by many laboratories for the detection of circulating antiretinal antibodies have been varied and diverse, making it difficult to interpret and compare their results. CONCLUSIONS: There is currently little standardization of laboratory methods used to detect and monitor antiretinal antibodies. To measure and monitor levels of circulating antiretinal antibodies optimally in patients with AIR, development of standardized assays with stringent internal controls is required. A multicenter collaborative and validation effort is encouraged to reach a consensus on this issue.