The fine balance of chemokines during disease: trafficking, inflammation, and homeostasis

Fractalkine/CX3CR1-Dependent Modulation of Synaptic and Network Plasticity in Health and Disease

CX3CR1 is a G protein-coupled receptor that is expressed exclusively by microglia within the brain parenchyma. The only known physiological CX3CR1 ligand is the chemokine fractalkine (FKN), which is constitutively expressed in neuronal cell membranes and tonically released by them. Through its key role in microglia-neuron communication, the FKN/CX3CR1 axis regulates microglial state, neuronal survival, synaptic plasticity, and a variety of synaptic functions, as well as neuronal excitability via cytokine release modulation, chemotaxis, and phagocytosis. Thus, the absence of CX3CR1 or any failure in the FKN/CX3CR1 axis has been linked to alterations in different brain functions, including changes in synaptic and network plasticity in structures such as the hippocampus, cortex, brainstem, and spinal cord. Since synaptic plasticity is a basic phenomenon in neural circuit integration and adjustment, here, we will review its modulation by the FKN/CX3CR1 axis in diverse brain circuits and its impact on brain function and adaptation in health and disease.

Plasma C-C Chemokine Concentrations in Intermediate Age-Related Macular Degeneration

Purpose: To determine the relationship between plasma concentrations of the C-C chemokines CCL2, CCL3, CCL4, and CCL5 and intermediate age-related macular degeneration (iAMD) patients compared with control inidividuals to further define the inflammatory pathways associated with age-related macular degeneration.

Methods: The concentrations of CCL2, CCL3, CCL4, and CCL5 were measured using multiplex assays in plasma collected from 210 patients with iAMD and 102 control individuals with no macular degeneration as defined by multi-modal imaging. Non-inflammatory data included in the analysis were: age, sex, family history of AMD, history of smoking, body mass index, presence of reticular pseudo-drusen and cardiovascular disease. Median concentrations as well as a cutoff value for each chemokine were compared between the two groups.

Results: The median concentrations of CCL2 and CCL4 did not differ between control and iAMD groups, however, CCL2 was elevated in iAMD when a cutoff comparison was used (p < 0.05). Median CCL3 and CCL5 concentrations were significantly decreased in the macular degeneration group compared with controls (p < 0.001) as well as when a cutoff value comparison was used. CCL3 and CCL5 were negatively correlated in cases and positively correlated in controls.

Conclusions: Plasma CCL3 and CCL5 concentrations were significantly decreased and CCL2 concentrations were increased in patients with iAMD compared with controls, suggesting a role for C-C chemokines in the systemic inflammatory processes associated with disease development.

Modulation of the chemokine/chemokine receptor axis as a novel approach for glioma therapy

Chemokines are a large subfamily of cytokines known for their ability to facilitate cell migration, most notably leukocytes, throughout the body. Chemokines are necessary for a functioning immune system in both health and disease and have received considerable attention for their roles in orchestrating temporal-spatial regulation of immune cell populations in cancer. Gliomas comprise a group of common central nervous system (CNS) primary tumors that are extremely challenging to treat. Immunotherapy approaches for highly malignant brain tumors offer an exciting new avenue for therapeutic intervention but so far, have seen limited successful clinical outcomes. Herein we focus on important chemokine/chemokine receptor systems in the regulation of pro- and anti-tumor mechanisms, highlighting potential therapeutic advantages of modulating these systems in malignant gliomas and other cancers.

Chemokine Profile and the Alterations in CCR5-CCL5 Axis in Geographic Atrophy Secondary to Age-Related Macular Degeneration

Purpose

Geographic atrophy (GA) secondary to age-related macular degeneration (AMD) is a progressive disease with no treatment option. Previous studies show chemokine-mediated recruitment of immune cells in the retina, and therefore we investigated systemic levels of chemokines and chemokine receptors in patients with GA.

Methods

This observational prospective study was conducted at a single center. We included 122 participants with no immune disease: 41 participants with GA and no choroidal neovascularization, 51 patients with neovascular AMD, and 30 healthy control individuals. Flow cytometric analysis was used to detect expression level of C-C chemokine receptor (CCR)1, CCR2, CCR3, CCR5, and C-X-C motif chemokine receptor (CXCR)3 on peripheral blood mononuclear cells (CD14+ monocytes, CD4+ T cells, CD8+ T cells). Plasma levels of C-C motif ligand (CCL)11, C-X-C motif chemokine (CXCL)10, and CCL5 were measured by specific immunoassays. Enlargement rate of GA lesion was measured from autofluorescence images.

Results

Participants with GA have a specific chemokine profile with a higher expression of CCR5 than healthy controls in peripheral blood mononuclear cells, and a higher plasma levels of CCL-5. Further, GA was associated with higher monocytic expression of CCR2 than in neovascular AMD. We found that a high expression level of CCR5 on CD8+ T cells was associated with slower enlargement rate of atrophic lesion.

Conclusions

The study showed an association between systemic chemokine profile and GA formation. Further studies are needed to fully elucidate the possible role of systemic chemokine regulation in mediating pathogenesis of GA.

The role of chemokines and chemokine receptors in multiple sclerosis

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Summarize the study of the role of chemokines and their receptors in multiple sclerosis (MS) patients and MS animal models.

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Discuss their potential significance in inflammatory injury and repair of MS.

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Summarize the progress in the research of MS antagonists in recent years with chemokine receptors as targets.

Multiple sclerosis (MS) is a chronic inflammatory disease that is characterized by leukocyte infiltration and subsequent axonal damage, demyelinating inflammation, and formation of sclerosing plaques in brain tissue. The results of various studies in patients indicate that autoimmunity and inflammation make an important impact on the pathogenesis of MS. Chemokines are key mediators of inflammation development and cell migration, mediating various immune cell responses, including chemotaxis and immune activation, and are important in immunity and inflammation, therefore we focus on chemokines and their receptors in multiple sclerosis. In this article, we summarize the study of the role of prominent chemokines and their receptors in MS patients and MS animal modelsand discuss their potential significance in inflammatory injury and repair of MS. We have also summarized the progress in the treatment of multiple sclerosis antagonists in recent years with chemokine receptors as targets.

Maraviroc attenuates the pathogenesis of experimental autoimmune encephalitis

It has been shown that the blockade of chemokine receptor type 5 can dampen inflammatory reaction within the central nervous system (CNS). In the present study, we utilized maraviroc, a potent antagonist o CCR5, to examine whether this drug can mitigate neuroinflammation in the spinal cord of mice induced by experimental autoimmune encephalitis (EAE), considered a murine model of multiple sclerosis (MS). For this aim, mice were immunized with myelin oligodendrocyte glycoprotein 35-55 (MOG35-55), followed by pertussis toxin to induce paralysis in EAE mice. The animals intraperitoneally received various doses of maraviroc (5, 25, and 50 mg/kg body weight) when the early clinical signs of EAE appeared. The results demonstrated that the administration of maraviroc led to a marked decrease in the clinical score and improvement in behavioral motor functions. Moreover, our finding indicated that the administration of maraviroc significantly attenuates the infiltration of inflammatory cells to the spinal cord, microgliosis, astrogliosis, pro-inflammatory cytokines, and cell death in EAE mice. The flow cytometry data indicated that a decreased number of CD4+ and CD8+ T cells in the peripheral blood of mice with EAE without affecting the number of T regulatory cells (CD4 + CD25+ forkhead box protein 3+). Finally, it seems that maraviroc is well-tolerated, and targeting CCR5 could open up a new horizon in the treatment of MS.

Computer aided protein engineering to enhance the thermo-stability of CXCR1- T4 lysozyme complex

CXCR1, a member in G-protein coupled receptor (GPCR) family, binds to chemokine interleukin-8 (IL-8) specifically and transduces signals to mediate immune and inflammatory responses. Despite the importance of CXCR1, high-resolution structure determination is hindered by the challenges in crystallization. It has been shown that properly designed mutants with enhanced thermostability, together with fusion partner proteins, can be useful to form crystals for GPCR proteins. In this study, in silico protein design was carried out by using homology modeling and molecular dynamics simulations. To validate the computational modeling results, the thermostability of several mutants and the wild type were measured experimentally. Both computational results and experimental data suggest that the mutant L126W has a significant improvement in the thermostability. This study demonstrated that in silico design can guide protein engineering and potentially facilitate protein crystallography research.

Putative Systemic Biomarkers of Biomass Smoke-Induced Chronic Obstructive Pulmonary Disease among Women in a Rural South Indian Population

RATIONALE

Exposure to biomass smoke (BMS) has been implicated in chronic obstructive pulmonary disease (COPD). About 3 billion people worldwide use biomass fuel for cooking and heating. Women in rural communities of low- and lower-middle-income countries are disproportionately exposed to massive amounts of BMS during active cooking hours (4-6 h/day). Therefore, BMS exposure is considered as a risk factor for COPD in the same order of magnitude as tobacco smoke. In rural India, due to cultural reasons, women are the primary cook of the family and are mostly nonsmokers. Thus, BMS-induced COPD is predominant among rural Indian women. However, BMS-COPD remains a relatively unexplored health problem globally. Therefore, we investigated the serum chemokine and cytokine signatures of BMS-COPD and tobacco smoke-induced COPD (TS-COPD) patients compared to their control in a rural South Indian population for this field study.

METHODS

Concentrations of 40 serum chemokines and cytokines were measured using a multiplexed immunoassay. The study cohort consisted of BMS-COPD (female; n = 29) and BMS-exposed subjects without COPD (BMS-CONTROL; female; n = 24). For comparison, data from TS-COPD patients (male, n = 23) and tobacco smokers without COPD (TS-CONTROL; male, n = 22) were investigated. Subjects were matched for age, sex, and biomass exposure. Tobacco consumption was slightly higher in TS-COPD subjects compared to TS-CONTROL. BMS-exposed and TS-exposed subjects (currently exposed) were from the same locality with similar dwelling habits and socioeconomic status. A validated structured questionnaire-based survey and spirometry was performed. An additional control group with no tobacco and BMS exposure (TS-BMS-CONTROL; n = 15) was included. Statistical significance was set at p ≤ 0.01.

RESULTS

Serum median concentrations (pg/ml) of CCL15 [8799.35; 5977.22], CCL27 [1409.14; 1024.99], and CXCL13 [37.14; 26.03] were significantly higher in BMS-CONTROL compared to BMS-COPD subjects. Nine analytes exhibited higher concentrations in TS-CONTROL compared to TS-COPD subjects. Comparison of chemokine and cytokine concentrations among BMS-COPD versus TS-COPD and BMS-CONTROL versus TS-CONTROL subjects also revealed distinct molecular signatures.

CONCLUSION

Our data identifies CCL27 and CXCL13 as putative, plausibly homeostatic/protective biomarkers for BMS-COPD within the investigated population that warrants validation in larger and multiple cohorts. The findings further indicate exposure-specific systemic response of chemokines and cytokines.

CXCL13 polymorphism is associated with essential hypertension in Tatars from Russia

Essential arterial hypertension is a disease with distinct yet unexplored inflammatory component. Our aim was to assess the role of chemokine genes and their interaction in its development. Genotyping of polymorphic markers in six chemokine genes (CXCL13, CCL8, CCL16, CCL17, CCL18, and CCL23) was performed in the group of 522 men of Tatar ethnic origin from the Republic of Bashkortostan, Russia (213 patients with essential hypertension and 309 healthy individuals without history of cardiovascular disease). We found a strong association of CXCL13 rs355689*C allele with essential hypertension under additive (OR 0.56, P_FDR = 0.008) and dominant (OR 0.41, P_FDR 4.38 × 10^- 4) genetic model. The analysis of gene-gene interactions revealed 12 allele/genotype combinations that remained significantly associated with essential hypertension after correction for multiple testing was applied, and each of these combinations included CXCL13 rs355689 polymorphism. Our results indicate that CXCL13 rs355689 polymorphism is strongly associated with essential hypertension in the ethnic group of Tatars, alone and in combination with polymorphic markers in other chemokine genes.

A Chip for Estrogen Receptor Action: Detection of Biomarkers Released by MCF-7 Cells through Estrogenic and Anti-Estrogenic Effects

The fluorescence-based multi-analyte chip platform for the analysis of estrogenic and anti-estrogenic substances is a new in vitro tool for the high throughput screening of environmental samples. In contrast to existing tools, the chip investigates the complex action of xenoestrogens in a human cell model by characterizing protein expression. It allows for the quantification of 10 proteins secreted by MCF-7 cells, representing various biological and pathological endpoints of endocrine action and distinguishing between estrogen- and anti-estrogen-dependent secretion of proteins. Distinct protein secretion patterns of the cancer cell line after exposure to known estrogen receptor agonists ß-estradiol, bisphenol A, genistein, and nonylphenol as well as antagonists fulvestrant and tamoxifen demonstrate the potential of the chip. Stimulation of cells with Interleukin-1ß shifts concentrations of low abundant biomarkers towards the working range of the chip. In the non-stimulated cell culture, Matrix Metalloproteinase 9 (MMP-9) and Vascular Endothelial Growth Factor (VEGF) show differences upon treatment with antagonists and agonists of the estrogen receptor. In stimulated MCF-7 cells challenged with receptor agonists secretion of Monocyte Chemoattractant Protein (MCP-1), Interleukin-6 (IL-6), Rantes, and Interleukin-8 (IL-8) significantly decreases. In parallel, the proliferating effect of endocrine-disrupting substances in MCF-7 cells is assessed in a proliferation assay based on resazurin. Using ethanol as a solvent for test substances increases the background of proliferation and secretion experiments, while using dimethyl sulfoxide (DMSO) does not show any adverse effects. The role of the selected biomarkers in different physiological processes such as cell development, reproduction, cancer, and metabolic syndrome makes the chip an excellent tool for either indicating endocrine-disrupting effects in food and environmental samples, or for screening the effect of xenoestrogens on a cellular and molecular level.

Chemokines and their receptors: insights from molecular modeling and crystallography

Chemokines are small secreted proteins that direct cell migration in development, immunity, inflammation, and cancer. They do so by binding and activating specific G protein coupled receptors on the surface of migrating cells. Despite the importance of receptor:chemokine interactions, their structural basis remained unclear for a long time. In 2015, the first atomic resolution insights were obtained with the publication of X-ray structures for two distantly related receptors bound to chemokines. In conjunction with experiment-guided molecular modeling, the structures suggest a conserved receptor:chemokine complex architecture, while highlighting the diverse details and functional roles of individual interaction epitopes. Novel findings promote the development and detailed structural interpretation of the canonical two-site hypothesis of receptor:chemokine recognition, and suggest new avenues for pharmacological modulation of chemokine receptors.

CXCL12/CXCR4 axis induces proliferation and invasion in human endometrial cancer

OBJECTIVE

Since that we have previously found CXCL12/CXCR4, an important biological axis is highly transcribed in several cancer cells. We aim to investigate whether CXCL12/CXCR4 axis regulates critical processes in neoplastic transformation that affects endometrial cancer cell biology.

METHODS

The expression levels of CXCR4 were analyzed in human normal endometrial tissue, simple hyperplasia, atypical hyperplasia and endometrial cancer cells by immunohistochemistry and reverse transcriptase-polymerase chain reaction (RT-PCR). Serum CXCL12 was measured by Enzyme-Linked Immunosorbent Assay (ELISA) in Ishikawa endometrial cancer cell line. To study the biological function of CXCL12/CXCR4 in endometrial cancer, short interfering RNA silencing of CXCR4 was established to analyze the roles of CXCL12/CXCR4 in proliferation, migration, invasion and apoptosis of Ishikawa cells in vitro.

RESULTS

The expression level of CXCR4 in endometrial cancer tissue was higher as compared to atypical hyperplasia, simple hyperplasia and normal cycling endometrium cells. Ishikawa cells secreted CXCL12 spontaneously and continuously for 96 hrs in culture. The proliferation, migration and invasion of Ishikawa cells was significantly induced, and the apoptosis was significantly reduced by CXCL12 in combination with CXCR4. Moreover, CXCR4 silencing could significantly antagonize all these functions.

CONCLUSIONS

CXCL12/CXCR4 axis plays an important role in the proliferation, invasion and metastasis of endometrial cancer, indicating that CXCR4 could be the target for the treatment of endometrial cancer.

Insights into the Role of Chemokines, Damage-Associated Molecular Patterns, and Lymphocyte-Derived Mediators from Computational Models of Trauma-Induced Inflammation

SIGNIFICANCE

Traumatic injury elicits a complex, dynamic, multidimensional inflammatory response that is intertwined with complications such as multiple organ dysfunction and nosocomial infection. The complex interplay between inflammation and physiology in critical illness remains a challenge for translational research, including the extrapolation to human disease from animal models.

RECENT ADVANCES

Over the past decade, we and others have attempted to decipher the biocomplexity of inflammation in these settings of acute illness, using computational models to improve clinical translation. In silico modeling has been suggested as a computationally based framework for integrating data derived from basic biology experiments as well as preclinical and clinical studies.

CRITICAL ISSUES

Extensive studies in cells, mice, and human blunt trauma patients have led us to suggest (i) that while an adequate level of inflammation is required for healing post-trauma, inflammation can be harmful when it becomes self-sustaining via a damage-associated molecular pattern/Toll-like receptor-driven feed-forward circuit; (ii) that chemokines play a central regulatory role in driving either self-resolving or self-maintaining inflammation that drives the early activation of both classical innate and more recently recognized lymphoid pathways; and (iii) the presence of multiple thresholds and feedback loops, which could significantly affect the propagation of inflammation across multiple body compartments.

FUTURE DIRECTIONS

These insights from data-driven models into the primary drivers and interconnected networks of inflammation have been used to generate mechanistic computational models. Together, these models may be used to gain basic insights as well as serving to help define novel biomarkers and therapeutic targets.

Modulation of cellular signaling by herpesvirus-encoded G protein-coupled receptors

Human herpesviruses (HHVs) are widespread infectious pathogens that have been associated with proliferative and inflammatory diseases. During viral evolution, HHVs have pirated genes encoding viral G protein-coupled receptors (vGPCRs), which are expressed on infected host cells. These vGPCRs show highest homology to human chemokine receptors, which play a key role in the immune system. Importantly, vGPCRs have acquired unique properties such as constitutive activity and the ability to bind a broad range of human chemokines. This allows vGPCRs to hijack human proteins and modulate cellular signaling for the benefit of the virus, ultimately resulting in immune evasion and viral dissemination to establish a widespread and lifelong infection. Knowledge on the mechanisms by which herpesviruses reprogram cellular signaling might provide insight in the contribution of vGPCRs to viral survival and herpesvirus-associated pathologies.

The proangiogenic effect of iroquois homeobox transcription factor Irx3 in human microvascular endothelial cells

Angiogenesis is a dynamic process required for embryonic development. However, postnatal vascular growth is characteristic of multiple disease states. Despite insights into the multistep process in which adhesion molecules, extracellular matrix proteins, growth factors, and their receptors work in concert to form new vessels from the preexisting vasculature, there remains a lack of insight of the nuclear transcriptional mechanisms that occur within endothelial cells (ECs) in response to VEGF. Iroquois homeobox gene 3 (Irx3) is a transcription factor of the Iroquois family of homeobox genes. Irx homeodomain transcription factors are involved in the patterning and development of several tissues. Irx3 is known for its role during embryogenesis in multiple organisms. However, the expression and function of Irx3 in human postnatal vasculature remains to be investigated. Here we show that Irx3 is expressed in human microvascular endothelial cells, and expression is elevated by VEGF stimulation. Genetic Irx3 gain and loss of function studies in human microvascular endothelial cells resulted in the modulation of EC migration during wound healing, chemotaxis and invasion, and tubulogenesis. Additionally, we observed increased delta-like ligand 4 (Dll4) expression, which suggests an increase in EC tip cell population. Finally, siRNA screening studies revealed that transient knockdown of Hey1, a downstream Notch signaling mediator, resulted in increased Irx3 expression in response to VEGF treatment. Strategies to pharmacologically regulate Irx3 function in adult endothelial cells may provide new therapies for angiogenesis.

Coptis chinensis and Myrobalan (Terminalia chebula) Can Synergistically Inhibit Inflammatory Response In Vitro and In Vivo

Objectives. To investigate the anti-inflammatory effect of Coptis chinensis plus myrobalan (CM) in vitro and in vivo. Methods. The inflammation in mouse peritoneal macrophages was induced by lipopolysaccharide (LPS). Animal models were established by using ear swelling and paw edema of mouse induced by xylene and formaldehyde, respectively. In vitro, cytotoxicity, the phagocytosis of macrophages, the levels of nitric oxide (NO), induced nitric oxide synthase (iNOS), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) in cell supernatant were detected. In vivo, swelling rate and edema inhibitory rate of ear and paw were observed using CM-treated mice. Results. At 150–18.75 μg·mL⁻¹, CM had no cytotoxicity and could significantly promote the growth and the phagocytosis of macrophages and inhibit the overproduction of NO, iNOS, TNF-α, and IL-6 in macrophages induced by LPS. In vivo, pretreatment with CM, the ear swelling, and paw edema of mice could be significantly inhibited in a dose-dependent manner, and the antiedema effect of CM at high dose was better than dexamethasone. Conclusion. Our results demonstrated that Coptis chinensis and myrobalan possessed synergistically anti-inflammatory activities in vitro and in vivo, which indicated that CM had therapeutic potential for the prevention and treatment of inflammation-mediated diseases.

Structural analysis of a novel small molecule ligand bound to the CXCL12 chemokine

CXCL12 binds to CXCR4, promoting both chemotaxis of lymphocytes and metastasis of cancer cells. We previously identified small molecule ligands that bind CXCL12 and block CXCR4-mediated chemotaxis. We now report a 1.9 Å resolution X-ray structure of CXCL12 bound by such a molecule at a site normally bound by sY21 of CXCR4. The complex structure reveals binding hot spots for future inhibitor design and suggests a new approach to targeting CXCL12-CXCR4 signaling in drug discovery.

Plasma CX3CL1 levels and long term outcomes of patients with atrial fibrillation: the West Birmingham Atrial Fibrillation Project

BACKGROUND

There is growing evidence that chemokines are potentially important mediators of the pathogenesis of atherosclerotic disease. Major atherothrombotic complications, such as stroke and myocardial infarction, are common among atrial fibrillation (AF) patients. This increase in risk of adverse events may be predicted by a score based on the presence of certain clinical features of chronic heart failure, hypertension, age 75 years or greater, diabetes and stroke (the CHADS2 score). Our objective was to assess the prognostic value of plasma chemokines CCL2, CXCL4 and CX3CL1, and their relationship with the CHADS2 score, in AF patients.

METHODS

Plasma CCL2, CXCL4 and CX3CL1 were measured in 441 patients (59% male, mean age 75 years, 12% paroxysmal, 99% on warfarin) with AF. Baseline clinical and demographic factors were used to define each subject's CHADS2 score. Patients were followed up for a mean 2.1 years, and major adverse cardiovascular and cerebrovascular events (MACCE) were sought, being the combination of cardiovascular death, acute coronary events, stroke and systemic embolism.

RESULTS

Fifty-five of the AF patients suffered a MACCE (6% per year). Those in the lowest CX3CL1 quartile (≤ 0.24 ng/ml) had fewest MACCE (p = 0.02). In the Cox regression analysis, CX3CL1 levels >0.24 ng/ml (Hazard ratio 2.8, 95% CI 1.02-8.2, p = 0.045) and age (p = 0.042) were independently linked with adverse outcomes. The CX3CL1 levels rose directly with the CHADS2 risk score (p = 0.009). The addition of CX3CL1 did not significantly increased the discriminatory ability of the CHADS2 clinical factor-based risk stratification (c-index 0.60 for CHADS2 alone versus 0.67 for CHADS2 plus CX3CL1 >0.24 ng/ml, p = 0.1). Aspirin use was associated with lower levels of CX3CL1 (p = 0.0002) and diabetes with higher levels (p = 0.031). There was no association between CXCL4 and CCL2 plasma levels and outcomes.

CONCLUSION

There is an independent association between low plasma CX3CL1 levels and low risk of major cardiovascular events in AF patients, as well as a linear association between CX3CL1 plasma levels and CHADS2-defined cardiovascular risk. The potential for CX3CL1 in refining risk stratification in AF patients merits consideration.

Caught in the cross fire: p53 in inflammation

The p53 transcription factor is a major tumor suppressor, whose diverse activities serve to ensure genome stability and inhibit neoplastic processes. In recent years, it is becoming increasingly clear that p53 also plays a broader role in maintaining cellular homeostasis, as well as contributing to tissue homeostasis in a non-cell-autonomous fashion. Chronic inflammation is a potential cancer-promoting condition, and as such is also within the radar of p53, which mounts a multifaceted attempt to prevent the escalation of chronic tissue imbalance into neoplasia. Recent understanding of the p53 pathway and other family members reveals a broad interaction with inflammatory elements such as reactive oxygen and nitrogen species, cytokines, infectious agents and major immune-regulatory pathways like nuclear factor-kappaB. This complex cross talk is highly dependent on p53 status, as different p53 isoforms and p53 mutants can mediate different responses and even promote chronic inflammation and associated cancer, acting in the tumor cells as well as in the stromal and immune compartments.

IL-32γ induces chemotaxis of activated T cells via dendritic cell-derived CCL5

Interleukin (IL)-32 has been associated with a variety of inflammatory diseases including rheumatoid arthritis, vasculitis and Crohn's disease. We have previously reported that IL-32γ, the IL-32 isoform with the highest biological activity, could act as an immune modulator through regulation of dendritic cell (DC) functions in immune responses. Cell locomotion is crucial for induction of an effective immune response. In this study, we investigated the effect and underlying mechanisms of IL-32γ on recruitment of T cells. IL-32γ upregulated the expression of several chemokines including CCL2, CCL4, and CCL5 in the DCs. In particular, IL-32γ significantly increased CCL5 expression in a dose-dependent manner. Treatment with JNK and NF-κB inhibitors suppressed IL-32γ-induced CCL5 expression in DCs, indicating that IL-32γ induced CCL5 production through the JNK and NF-κB pathways. Furthermore, supernatants from IL-32γ-treated DCs showed chemotactic activities controlling migration of activated CD4(+) and CD8(+) T cells, and these activities were suppressed by addition of neutralizing anti-CCL5 antibody. These results show that IL-32γ effectively promotes migration of activated T cells via CCL5 production in DCs. The chemotactic potential of IL-32γ may explain the pro-inflammatory effects of IL-32 and the pathologic role of IL-32 in immune disorders such as rheumatoid arthritis.

Chemokine CXCL-1 expression in the subretinal fluid during rhegmatogenous retinal detachment

PURPOSE

To investigate the expression of chemokine CXCL-1 in the subretinal fluid (SRF) during rhegmatogenous retinal detachment (RRD) and identify potential correlations with number of quadrants involved and duration of the detachment.

METHODS AND RESULTS

Inclusion criteria were patients aged 18 years or older and primary RRD possibly complicated by proliferative vitreoretinopathy (PVR). CXCL-1 levels were measured in 36 SRF samples from 36 RRD patients. Mean CXCL-1 levels (102 ± 37 pg/mL) were significantly higher (p = 0.050) compared to controls. CXCL-1 levels correlated significantly with age (p = 0.001) and RRD duration (p = 0.002). Maximum CXCL-1 levels coincided with total RRD, 29- to 60-day duration and PVR grade C.

CONCLUSIONS

The findings of this study may contribute to increased understanding regarding the role of CXCL-1 during the onset and progression of the wound healing process in the context of RRD and PVR.