Chemokines take center stage in inflammatory ills

Toxic effects of bisphenol AF on the embryonic development of marine medaka (Oryzias melastigma)

Bisphenol AF (BPAF), an emerging environmental endocrine disruptor, has been detected in surface waters worldwide and has adverse effects on aquatic organisms. The accumulation of BPAF in oceans and its potential toxic effect on marine organisms are important concerns. In this study, the effects of BPAF (10, 100, 1, and 5 mg/L) on marine medaka (Oryzias melastigma) were evaluated, including effects on the survival rate, heart rate, hatchability, morphology, and gene expression in embryos. The survival rate of marine medaka embryos was significantly lower after treatment with 5 mg/L BPAF than in the solvent control group. Exposure to 1 mg/L and 5 mg/L BPAF significantly reduced hatchability. Low-dose BPAF (10 μg/L) significantly accelerated the heart rate of embryos, while high-dose BPAF (5 mg/L) significantly decreased the heart rate. BPAF exposure also resulted in notochord curvature, pericardial edema, yolk sac cysts, cardiovascular bleeding, and caudal curvature in marine medaka. At the molecular level, BPAF exposure affected the transcript levels of genes involved in the thyroid system (dio1, dio3a, trhr2, tg, and thra), cardiovascular system (gata4, atp2a1, and cacna1da), nervous system (elavl3 and gap43), and antioxidant and inflammatory systems (sod, pparβ, and il-8) in embryos. These results indicate that BPAF exposure can alter the expression of functional genes, induce abnormal development, and reduce the hatching and survival rates in marine medaka embryos. Overall, BPAF can adversely affect the survival and development of marine medaka embryos, and BPAF may not be an ideal substitute for BPA.

Investigation of roles of IL-8 (+ 781 C/T) and MMP-2 (-735 C/T) gene variations in early diagnosis of bladder cancer and progression

BACKGROUND

The aim of our study is to investigate the roles of IL-8 (+ 781 C/T) and MMP-2 (-735 C/T) gene variations in early diagnosis and progression of BCA.

METHODS

Polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (RFLP) methods were used to determine the genotype distributions of IL-8 (+ 781 C/T) and MMP-2 (-735 C/T) gene variations.

RESULTS

In our study, the genotype distributions of IL-8 (+ 781 C/T) and MMP-2 (-735 C/T) gene variations were not found to be significantly different between the patient and control groups. In addition, C and T allele frequencies for these gene variations were not different from the Hardy-Weinberg distribution in patient and control groups. However, when the combined genotype analyzes for these gene variations were evaluated, CC-CC and CT-CC combined genotypes for + 781 C/T / -735 C/T gene variations were observed significantly more in the patient group compared to other genotypes.

CONCLUSION

Although IL-8 (+ 781 C/T) and MMP-2 (-735 C/T) gene variations were not found to be genetic risk factors in the Thrace population in our study, CC-CC and CT-CC combined genotypes were determined as genetic risk factors for BCA susceptibility. The combined genotypes obtained as a result of the combined genotype analysis of these genetic variations that are effective in tumor progression may be considered to be important biomarkers for the early diagnosis and progression of BCA.

ASIC1a induces synovial inflammation via the Ca2+/NFATc3/ RANTES pathway

Rationale: Synovial inflammation is one of the main pathological features of rheumatoid arthritis (RA) and is a key factor leading to the progression of RA. Understanding the regulatory mechanism of synovial inflammation is crucial for the treatment of RA. Acid-sensing ion channel 1a (ASIC1a) is an H+-gated cation channel that promotes the progression of RA, but the role of ASIC1a in synovial inflammation is unclear. This study aimed to investigate whether ASIC1a is involved in the synovial inflammation and explore the underlying mechanisms in vitro and in vivo. Methods: The expression of ASIC1a and nuclear factor of activated T cells (NFATs) were analyzed by Western blotting, immunofluorescence, and immunohistochemistry both in vitro and in vivo. The Ca2+ influx mediated by ASIC1a was detected by calcium imaging and flow cytometry. The role of ASIC1a in inflammation was studied in rats with adjuvant-induced arthritis (AA). Inflammatory cytokine profile was analyzed by protein chip in RA synovial fibroblasts (RASF) and verified by a magnetic multi-cytokine assay and ELISA. The NFATc3-regulated RANTES (Regulated upon activation, normal T cell expressed and secreted) gene transcription was investigated by ChIP-qPCR and dual-luciferase reporter assay. Results: The expression of ASIC1a was significantly increased in human RA synovial tissues and primary human RASF as well as in ankle synovium of AA rats. Activated ASIC1a mediated Ca2+ influx to increase [Ca2+]i in RASF. The activation/overexpression of ASIC1a in RASF up-regulated the expression of inflammatory cytokines RANTES, sTNF RI, MIP-1a, IL-8, sTNF RII, and ICAM-1 among which RANTES was increased most remarkably. In vivo, ASIC1a promoted inflammation, synovial hyperplasia, articular cartilage, and bone destruction, leading to the progression of AA. Furthermore, activation of ASIC1a upregulated the nuclear translocation of NFATc3, which bound to RANTES promoter and directly regulated gene transcription to enhance RANTES expression. Conclusion: ASIC1a induces synovial inflammation, which leads to the progression of RA. Our study reveals a novel RA inflammation regulatory mechanism and indicates that ASIC1a might be a potential therapeutic target for RA.

Genomic variant in porcine TNFRSF1A gene and its effects on TNF signaling pathway in vitro

Our initial genome-wide association study (GWAS) revealed the presence of single nucleotide polymorphisms (SNPs) related to immune traits in the tumor necrosis factor receptor superfamily member 1A (TNFRSF1A) gene, suggesting the association of this gene with immune function in pigs. To better understand the immune functions of the TNFRSF1A gene, SNPs within the TNFRSF1A gene were detected by sequencing. One SNP (c.1394C > T) in exon 6 of TNFRSF1A was identified, and association analysis in two pig populations was subsequently performed. The results showed that this SNP was significantly associated with CD4^-CD8^-CD3^-, CD4⁺CD8^-CD3⁺, and CD4⁺/CD8⁺ (P = 0.0038, P = 0.0007, and P = 0.0076, respectively). Based on quantitative real-time polymerase chain reaction (RT-qPCR), the TNFRSF1A mRNA was shown to be widely expressed in six different tissues. Finally, functional verification of the TNFRSF1A gene was performed in vitro to better understand its role. RNAi was used to generate a porcine PK15 cell line with a silenced TNFRSF1A gene, and a vector was also constructed to assess overexpression of TNFRSF1A. RT-qPCR was then used to detect changes in the expression levels of five critical genes. Our results indicated that TNFRSF1A activated the TNF signaling pathway and inhibited the NFκB signaling pathway in vitro. These findings provide evidence for an immune-related regulatory function for porcine TNFRSF1A.

Strong association between the interleukin-8-251A/T polymorphism and coronary artery disease risk

Several reports have suggested a possible association between the interleukin (IL)-8-251A/T single-nucleotide polymorphism (SNP) and the susceptibility to coronary artery disease (CAD). Due to inconclusive results of the studies so far, we conducted a meta-analysis to systematically summarize the studies on the association between this SNP and CAD risk. A systematic literature search identified 9 case-control studies (3752 cases and 4219 controls) on the IL-8-251A/T polymorphism. We observed a significant association between different genetic forms of -251A/T SNP and CAD risk, like the allele model (A vs T: odds ratio [OR] 1.14, 95% confidence interval [CI] 1.02-1.27, P = .02), dominant model (AA + AT vs TT: OR 1.20, 95% CI 1.01-1.43, P = .042), recessive model (AA vs AT + TT: OR 1.15, 95% CI 1.03-1.27, P = .01), and homozygous model (AA vs TT: OR 1.26, 95% CI 1.01-1.56, P = .037), whereas the heterozygote model did not show any significant association (AT vs TT: OR 1.16, 95% CI 0.98-1.38, P = .091). Furthermore, significant heterogeneity was observed among studies in terms of all genetic models, except the recessive model. Analysis of the ethnic subgroups revealed a significantly higher risk of CAD in the East Asian population carrying this SNP, and the heterogeneity among the studies regarding the East Asian population was decreased after subgroup analysis. The results of this meta-analysis suggest that the IL-8-251A/T SNP may increase the risk of CAD, especially in people of East Asian ethnicity. Further large-scale, multicenter epidemiological studies are warranted to validate this finding.

Porous Se@SiO2 nanospheres attenuate ischemia/reperfusion (I/R)-induced acute kidney injury (AKI) and inflammation by antioxidative stress

Objectives

Acute kidney injury (AKI) is a growing global health concern, and is associated with high rates of mortality and morbidity in intensive care units. Se is a trace element with antioxidant properties. This study aimed to determine whether porous Se@SiO₂ nanospheres could relieve oxidative stress and inflammation in ischemia/reperfusion (I/R)-induced AKI.

Methods

Male 6- to 8-week-old C57bl/6 mice were divided into four groups: sham + saline, sham + Se@SiO₂, I/R + saline, and I/R + Se@SiO₂. Mice in the I/R groups experienced 30 minutes of bilateral renal I/R to induce an AKI. Porous Se@SiO₂ nanospheres (1 mg/kg) were intraperitoneally injected into mice in the I/R + Se@SiO₂ group 2 hours before I/R, and the same dose was injected every 12 hours thereafter. Hypoxia/reoxygenation (H/R) was used to mimic I/R in vitro. PBS was used as a control treatment. Human kidney 2 cells were seeded into 12-well plates (5×10⁵ cells/well) and divided into four groups: control + PBS group, control + Se@SiO₂ group, H/R + PBS group, and H/R + Se@SiO₂ group (n=3 wells). We then determined the expression levels of ROS, glutathione, inflammatory cytokines and proteins, fibrosis proteins, and carried out histological analysis upon kidney tissues.

Results

In vitro, intervention with porous Se@SiO₂ nanospheres significantly reduced levels of ROS (P<0.05), inflammatory cytokines (P<0.05), and inflammation-associated proteins (P<0.05). In vivo, tubular damage, cell apoptosis, and interstitial inflammation during AKI were reduced significantly following treatment with porous Se@SiO₂ nanospheres. Moreover, the occurrence of fibrosis and tubular atrophy after AKI was attenuated by porous Se@SiO₂ nanospheres.

Conclusion

Porous Se@SiO₂ nanospheres exhibited a protective effect in I/R-induced AKI by resisting oxidative stress and inflammation. This suggests that porous Se@SiO₂ nanospheres may represent a new therapeutic method for AKI.

Effects of porcine MyD88 knockdown on the expression of TLR4 pathway-related genes and proinflammatory cytokines

As a critical adapter protein in Toll-like receptor (TLR)/Interleukin (IL)-1R signalling pathway, myeloid differentiation protein 88 (MyD88) plays an important role in immune responses and host defence against pathogens. The present study was designed to provide a foundation and an important reagent for the mechanistic study of MyD88 and its role TLR/IL-1R signalling pathways in porcine immunity. Lentivirus-mediated RNAi was used to generate a porcine PK15 cell line with a silenced MyD88 gene and quantitative real-time PCR (qPCR) and Western blotting were used to detect changes in the expression of critical genes in the Toll-like receptor 4 (TLR4) signalling pathway. ELISA was used to measure the levels of seven proinflammatory cytokines–interleukin-1β (IL-1β), tumour necrosis factor-α (TNF-α), IL-6, IL-8, IL-12, macrophage inflammatory protein (MIP)-1α and MIP-1β–in cell culture supernatants after MyD88 silencing. We successfully obtained a PK15 cell line with 61% MyD88 mRNA transcript down-regulated. In PK15 cells with MyD88 silencing, the transcript levels of TLR4 and IL-1β were significantly reduced, whereas there were no significant changes in the expression levels of cluster of differentiation antigen 14 (CD14), interferon-α (IFN-α) or TNF-α. The ELISA results showed that the levels of most cytokines were not significantly changed apart from IL-8 without stimulation, which was significantly up-regulated. When cells were induced by lipopolysaccharide (LPS) (0.1 μg/ml) for 6 h, the global level of seven proinflammatory cytokines up-regulated and the level of IL-1β, TNF-α, IL-6, IL-8 and IL-12 of Blank and negative control (NC) group up-regulated more significantly than RNAi group (P<0.05), which revealed that the MyD88 silencing could reduce the TLR4 signal transduction which inhibited the release of proinflammatory cytokines and finally leaded to immunosuppression.

Searching for Chemokine Receptor Binding Antagonists by High Throughput Screening

Identification of putative drug candidates by high throughput screening is assuming enormous importance within the pharmaceutical industry, driven by increasing numbers of valid therapeutic targets from both classical and molecular biological sources. Screening is an applied discipline that requires equipment and, more importantly, thinking that is fundamentally different from more traditional, lower throughput assay methodology. This article describes the process as applied to the discovery of selective antagonists of three chemokine receptor binding systems, from the original biological targets to chemically prosecutable lead compounds, which are currently being investigated using traditional medicinal and combinatorial chemistry methods.

MiRNA-181a regulates Toll-like receptor agonist-induced inflammatory response in human fibroblasts

MicroRNAs (miRNA) regulate the synthesis of cytokines in response to Toll-like receptor (TLR) activation. Our recent microarray study comparing normal and inflamed human dental pulps showed that miRNA-181 (miR-181) family is differentially expressed in the presence of inflammation. Prior studies have reported that the dental pulp, which is composed primarily of TLR4/2+ fibroblasts, expresses elevated levels of cytokines including Interleukin-8 (IL-8) when inflamed. In this study, we employed an in-vitro model to determine the role of the miRNA 181 family in the TLR agonist-induced response in human fibroblasts. TLR4/2+ primary human dental pulp fibroblasts were stimulated with lipopolysaccharide from Porphyromonas gingivalis (Pg LPS), a known oral pathogen, and IL-8 and miR-181 expression measured. An inversely proportional relationship between IL-8 and miR-181a was observed. In-silico analysis identified a miR-181a binding site on the 3′UTR of IL-8 which was confirmed by dual-luciferase assays. MiR-181a directly binds to the 3′UTR of IL-8, an important inflammatory component of the immune response, and modulates its levels. This is the very first report demonstrating miR-181a regulation of IL-8.

Diaminocyclobutenediones as potent and orally bioavailable CXCR2 receptor antagonists: SAR in the phenolic amide region

A series of potent and orally bioavailable 3,4-diaminocyclobutenediones with various amide modifications and substitution on the left side phenyl ring were prepared and found to show significant inhibitory activities towards both CXCR2 and CXCR1 receptors.

3,4-Diamino-1,2,5-thiadiazole as potent and selective CXCR2 antagonists

A series of potent and selective 3,4-diamino-1,2,5-thiadiazoles were prepared and found to show excellent binding affinities towards CXCR2 receptor.

3,4-Diamino-2,5-thiadiazole-1-oxides as potent CXCR2/CXCR1 antagonists

A series of novel and potent 3,4-diamino-2,5-thiadiazole-1-oxides were prepared and found to show excellent binding affinities for CXCR2 and CXCR1 receptors and excellent inhibitory activity of Gro-alpha and IL-8 mediated in vitro hPMN MPO release of CXCR2 and CXCR1 expressing cell lines. On the other hand, a closely related 3,4-diamino-2,5-thiadiazole-dioxide did not show functional activity despite its excellent binding affinities for CXCR2 and CXCR1 in membrane binding assays. A detailed SAR has been discussed in these two closely related structures.

St. John's wort attenuates irinotecan-induced diarrhea via down-regulation of intestinal pro-inflammatory cytokines and inhibition of intestinal epithelial apoptosis

Diarrhea is a common dose-limiting toxicity associated with cancer chemotherapy, in particular for drugs such as irinotecan (CPT-11), 5-fluouracil, oxaliplatin, capecitabine and raltitrexed. St. John's wort (Hypericum perforatum, SJW) has anti-inflammatory activity, and our preliminary study in the rat and a pilot study in cancer patients found that treatment of SJW alleviated irinotecan-induced diarrhea. In the present study, we investigated whether SJW modulated various pro-inflammatory cytokines including interleukins (IL-1beta, IL-2, IL-6), interferon (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) and intestinal epithelium apoptosis in rats. The rats were treated with irinotecan at 60 mg/kg for 4 days in combination with oral SJW or SJW-free control vehicle at 400 mg/kg for 8 days. Diarrhea, tissue damage, body weight loss, various cytokines including IL-1beta, IL-2, IL-6, IFN-gamma and TNF-alpha and intestinal epithelial apoptosis were monitored over 11 days. Our studies demonstrated that combined SJW markedly reduced CPT-11-induced diarrhea and intestinal lesions. The production of pro-inflammatory cytokines such as IL-1beta, IFN-gamma and TNF-alpha was significantly up-regulated in intestine. In the mean time, combined SJW significantly suppressed the intestinal epithelial apoptosis induced by CPT-11 over days 5-11. In particular, combination of SJW significantly inhibited the expression of TNF-alpha mRNA in the intestine over days 5-11. In conclusion, inhibition of pro-inflammatory cytokines and intestinal epithelium apoptosis partly explained the protective effect of SJW against the intestinal toxicities induced by irinotecan. Further studies are warranted to explore the potential for STW as an agent in combination with chemotherapeutic drugs to lower their dose-limiting toxicities.

Synthesis and structure-activity relationships of 3,4-diaminocyclobut-3-ene-1,2-dione CXCR2 antagonists

A novel series of 3,4-diaminocyclobut-3-ene-1,2-diones was prepared and found to show potent inhibitory activity of CXCR2 binding and IL-8-mediated chemotaxis of a CXCR2-expressing cell line. Microsome stability and Caco2 studies were subsequently used to show that compounds of this chemotype are predicted to have good oral bioavailability and are thus suitable for pharmaceutical development.

Protein Kinase Cα-RhoA Cross-talk in CCL2-induced Alterations in Brain Endothelial Permeability

Monocyte chemoattractant protein-1 (MCP-1 or CCL2) regulates blood-brain barrier permeability by inducing morphological and biochemical alterations in the tight junction (TJ) complex between brain endothelial cells. The present study used cultured brain endothelial cells to examine the signaling networks involved in the redistribution of TJ proteins (occludin, ZO-1, ZO-2, claudin-5) by CCL2. The CCL2-induced alterations in the brain endothelial barrier were associated with de novo Ser/Thr phosphorylation of occludin, ZO-1, ZO-2, and claudin-5. The phosphorylated TJ proteins were redistributed/localized in Triton X-100-soluble as well as Triton X-100-insoluble cell fractions. Two protein kinase C (PKC) isoforms, PKCalpha and PKCzeta, had a significant impact on this event. Inhibition of their activity using dominant negative mutants PKCalpha-DN and PKCzeta-DN diminished CCL2 effects on brain endothelial permeability. Previous data indicate that Rho/Rho kinase signaling is involved in CCL2 regulation of brain endothelial permeability. The interactions between the PKC and Rho/Rho kinase pathways were therefore examined. Rho, PKCalpha, and PKCzeta activities were knocked down using dominant negative mutants (T17Rho, PKCalpha-DN, and PKCzeta-DN, respectively). PKCalpha and Rho, but not PKCzeta and Rho, interacted at the level of Rho, with PKCalpha being a downstream target for Rho. Double transfection experiments using dominant negative mutants confirmed that this interaction is critical for CCL2-induced redistribution of TJ proteins. Collectively these data suggest for the first time that CCL2 induces brain endothelial hyperpermeability via Rho/PKCalpha signal pathway interactions.

The influence of HIV infection on the correlation between plasma concentrations of monocyte chemoattractant protein-1 and carotid atherosclerosis

BACKGROUND

Monocyte chemoattractant protein-1 (MCP-1) plays a crucial role in atherosclerosis and it has been recently proposed as a surrogate biomarker of long-term clinical outcomes in patients with acute myocardial infarction. Little is known of the factors that may influence plasma MCP-1 concentrations.

METHODS

We studied 384 healthy volunteers and 226 HIV-infected patients as a model of chronic inflammatory condition that predisposes to sub-clinical atherosclerosis.

RESULTS

In healthy participants there were significant associations between plasma MCP-1 concentration and age, smoking status, and serum triglyceride concentrations that were not observed in the HIV-infected patients. The plasma concentration of MCP-1 was significantly associated with the polymorphism at position -2518 of the MCP-1 gene and, in patients, with the carotid artery intima-media thickness. There were also significant correlations indicating a close association between MCP-1 and HIV disease activity. However, in a multiple regression model, only age, the MCP-1 genotype and smoking status showed significant, and independent, associations with plasma MCP-1 concentrations.

CONCLUSION

Plasma MCP-1 concentration is genetically determined and associated with age and smoking habit and it also correlates with subclinical atherosclerosis in HIV-infected patients.

The role of cervical cerclage in obstetric practice: can the patient who could benefit from this procedure be identified?

This editorial critically examines the definition of "cervical insufficiency." The definition, the clinical ascertainment, efforts to develop an objective method of diagnosis, as well as the nature of cervical disease leading to spontaneous mid-trimester spontaneous abortion and preterm delivery are reviewed. The value and limitations of cervical sonography as a risk assessment tool for spontaneous preterm delivery are appraised. The main focus is on the role of cervical cerclage to prevent an adverse pregnancy outcome. The value of assessing the presence or absence of endocervical inflammation in the outcome of cerclage placement is discussed.

From a unique cell to metastasis is a long way to go: clues to stromelysin-3 participation

Stromelysin-3 (ST3) overexpression is associated with poor patient clinical outcome in numerous carcinomas. The ST3 is expressed by peritumoral fibroblast-like cells. Review of the literature shows that ST3 is an active partner of cancer cells along the whole natural cancer history, and is essential for optimal tumor development as it reduces death of cancer cells invading adjacent connective tissues at the primary tumor site. Paradoxically, ST3 lowers metastasis development in vivo in mice. However, this beneficial effect does not counterbalance the deleterious anti-apoptotic function of ST3.

Chemokines, innate and adaptive immunity, and respiratory disease

Selective leukocyte trafficking and recruitment is primarily regulated by a specific family of small proteins called "chemokines". This extended family shepherds and guides leukocytes through their lives, facilitating their development, regulating their interactions with other leukocyte types, and guiding their recruitment to sites of inflammation. Through the actions of chemokines, allergen sensitization is regulated in atopic asthma, through the controlled migration of dendritic cells, T- and B-lymphocytes, mast cells and basophils. Subsequently, atopic inflammation is driven by chemokine-directed recruitment of eosinophils, basophils and lymphocytes. Diseases from cancer to chronic obstructive pulmonary disease to interstitial fibrosis are all potential targets for chemokine receptor antagonism. Innate immunity (the early pattern-recognition responses to stimuli such as lipopolysaccharide, viral proteins and bacterial DNA) needs to bridge the gap to specific immunity and antibody production and immunological memory. Again, chemokines are likely to be fundamental mediators of these responses. Chemokines are fundamental regulators of leukocyte homeostasis and inflammation, and their antagonism by small molecule chemokine receptor antagonists may be of enormous importance in the future treatment of human respiratory disease.

A small molecule antagonist of chemokine receptors CCR1 and CCR3. Potent inhibition of eosinophil function and CCR3-mediated HIV-1 entry

We describe a small molecule chemokine receptor antagonist, UCB35625 (the trans-isomer J113863 published by Banyu Pharmaceutical Co., patent WO98/04554), which is a potent, selective inhibitor of CCR1 and CCR3. Nanomolar concentrations of UCB35625 were sufficient to inhibit eosinophil shape change responses to MIP-1alpha, MCP-4, and eotaxin, while greater concentrations could inhibit the chemokine-induced internalization of both CCR1 and CCR3. UCB35625 also inhibited the CCR3-mediated entry of the human immunodeficiency virus-1 primary isolate 89.6 into the glial cell line, NP-2 (IC(50) = 57 nm). Chemotaxis of transfected cells expressing either CCR1 or CCR3 was inhibited by nanomolar concentrations of the compound (IC(50) values of CCR1-MIP-1alpha = 9.6 nm, CCR3-eotaxin = 93.7 nm). However, competitive ligand binding assays on the same transfectants revealed that considerably larger concentrations of UCB35625 were needed for effective ligand displacement than were needed for the inhibition of receptor function. Thus, it appears that the compound may interact with a region present in both receptors that inhibits the conformational change necessary to initiate intracellular signaling. By virtue of its potency at the two major eosinophil chemokine receptors, UCB35625 is a prototypic therapy for the treatment of eosinophil-mediated inflammatory disorders, such as asthma and as an inhibitor of CCR3-mediated human immunodeficiency virus-1 entry.

Physical mapping of the CC-chemokine gene cluster on the human 17q11. 2 region

Chemokines are a family of small secreted proteins that are involved in the trafficking of leukocytes by acting on G-protein-coupled receptors. Specific chemokines are also implicated in the regulation of angiogenesis and mobilization of hematopoietic cell precursors. Chemokines are subdivided into four groups on the basis of the relative positions of their conserved cysteines. For the CC-chemokine group, in which the first two (of four) conserved cysteines are adjacent, 22 members have been described so far. In this work, we have analyzed the genomic organization of these genes. We first assigned the genes encoding CC-chemokines to chromosomal regions and organized their relative positioning by using two radiation hybrid panels. Fifteen CC-chemokine genes were shown to be clustered within the 17q11.2 region of the human genome. These genes appeared to be segregated into two subclusters separated by about 2. 25 Mb (9 cR). Contigs of bacterial artificial chromosomes (BAC) covering these two subclusters were subsequently isolated and the localizations of the CC-chemokine genes within these contigs determined. The relative positioning of the BAC clones was determined with the help of fluorescence hybridization on combed genomic DNA. The cluster organization of the various CC-chemokine genes in the genome was found to be grossly consistent with their structural similarities. This map of the CC-chemokine gene cluster should facilitate the determination of the full sequence of the chromosomal region.

Differential Regulation of Eosinophil Chemokine Signaling Via CCR3 and Non-CCR3 Pathways

To investigate eosinophil stimulation by chemokines we developed a sensitive assay of leukocyte shape change, the gated autofluorescence/forward scatter assay. Leukocyte shape change responses are mediated through rearrangements of the cellular cytoskeleton in a dynamic process typically resulting in a polarized cell and are essential to the processes of leukocyte migration from the microcirculation into sites of inflammation. We examined the actions of the chemokines eotaxin, eotaxin-2, monocyte chemoattractant protein-1 (MCP-1), MCP-3, MCP-4, RANTES, macrophage inflammatory protein-1α (MIP-1α), and IL-8 on leukocytes in mixed cell suspensions and focused on the responses of eosinophils to C-C chemokines. Those chemokines acting on CCR3 induced a rapid shape change in eosinophils from all donors; of these, eotaxin and eotaxin-2 were the most potent. Responses to MCP-4 were qualitatively different, showing marked reversal of shape change responses with agonist concentration and duration of treatment. In contrast, MIP-1α induced a potent response in eosinophils from a small and previously undescribed subgroup of donors via a non-CCR3 pathway likely to be CCR1 mediated. Incubation of leukocytes at 37°C for 90 min in the absence of extracellular calcium up-regulated responses to MCP-4 and MIP-1α in the majority of donors, and there was a small increase in responses to eotaxin. MIP-1α responsiveness in vivo may therefore be a function of both CCR1 expression levels and the regulated efficiency of coupling to intracellular signaling pathways. The observed up-regulation of MIP-1α signaling via non-CCR3 pathways may play a role in eosinophil recruitment in inflammatory states such as occurs in the asthmatic lung.

Cloning and Characterization of the Guinea Pig Eosinophil Eotaxin Receptor, C-C Chemokine Receptor-3: Blockade Using a Monoclonal Antibody In Vivo

Certain C-C chemokines, signaling via the eotaxin receptor C-C chemokine receptor-3 (CCR3), are thought to be central mediators of eosinophil accumulation in allergic inflammation. To investigate the role of CCR3 in vivo, we cloned the guinea pig eotaxin receptor (guinea pig CCR3) from a genomic DNA library. We isolated a single-exon open reading frame coding for a 358-amino acid chemokine receptor protein with 67 and 69% homology to human and murine CCR3, respectively. When expressed in stable transfectants, this receptor bound 125I-labeled guinea pig eotaxin, 125I-labeled human monocyte chemotactic protein-3, and 125I-labeled human RANTES. In chemotaxis assays, guinea pig CCR3 transfectants responded only to guinea pig eotaxin, with a maximal effect at 100 nM. mAbs were raised that bound selectively to both guinea pig CCR3 transfectants and guinea pig eosinophils. One of these mAbs, 2A8, blocked both ligand binding to transfectants and their chemotaxis in response to eotaxin. The Ab also inhibited chemotaxis and the elevation of cytosolic calcium in guinea pig eosinophils in response to eotaxin. F(ab′)2 fragments of 2A8 were prepared that retained the ability to inhibit eosinophil calcium responses to eotaxin. Pretreatment of 111In-labeled eosinophils in vitro with F(ab′)2 2A8 selectively inhibited their accumulation in response to eotaxin in vivo. These data demonstrate that functional blockade of eosinophil chemokine receptors can be achieved in vivo and provide further support for the development of novel anti-inflammatory drugs targeting eosinophil recruitment through chemokine receptor antagonism.

Severity of airflow limitation is associated with severity of airway inflammation in smokers

To investigate the relationship between airflow limitation and airway inflammation in smokers, we examined paraffin-embedded bronchial biopsies obtained from 30 smokers: 10 with severe airflow limitation, eight with mild/moderate airflow limitation, and 12 control smokers with normal lung function. Histochemical and immunohistochemical methods were performed to assess the number of inflammatory cells in the subepithelium and the expression of CC chemokines macrophage inflammatory protein (MIP)-1alpha and -1beta in the bronchial mucosa. Compared with control smokers, smokers with severe airflow limitation had an increased number of neutrophils (p < 0.02), macrophages (p < 0.03), and NK lymphocytes (p < 0.03) in the subepithelium, and an increased number of MIP-1alpha+ epithelial cells (p < 0.02). When all smokers were considered together, the value of FEV1 was inversely correlated with the number of neutrophils (r = -0.59, p < 0.002), macrophages (r = -047, p < 0. 012), NK-lymphocytes (r = -0.51, p < 0.006) in the subepithelium, and with the number of MIP-1alpha+ epithelial cells (r = -0.61, p < 0.003). We conclude that in smokers the severity of airflow limitation is correlated with the severity of airway inflammation and that severe airflow limitation is associated with an increased number of neutrophils, macrophages, NK lymphocytes, and MIP-1alpha+ cells in the bronchial mucosa.

Potential implications of chemokines in reproductive function: an attractive idea

Chemokines are a new family of cytokines specialised in attracting leukocytes, acting in physiological conditions and in pathological processes. A wide variety of cell types in response to exogenous irritants or endogenous mediators of the inflammatory reaction produce them. Pivotal parts of reproductive function are based on inflammatory like processes wherein different leukocytes subsets are recruited and activated to produce paracrine autocrine effects in which cytokines and growth factors are implicated. Since chemokines control leukocyte trafficking and belong to the cytokine superfamily, in this review we analyze the implications of these molecules and related cells in ovulation, embryonic implantation, menstruation, parturition and their role in pathological process such as preterm delivery, endometriosis, ovarian hyperstimulation syndrome and HIV infection.

Activation of transcription factors and IL-8 expression in neutrophils stimulated with lipopolysaccharide from Porphyromonas gingivalis

DNA binding activity of NF-kappa B and AP-1 were examined in neutrophils stimulated with LPS purified from P. gingivalis, a major pathogenic bacteria of periodontitis lesion. Porphyromonas gingivalis LPS enhanced the activity reaching a peak at a concentration of 500 ng/ml in the absence of serum. The NF-kappa B activation stimulated with 10 ng/ml of P. gingivalis LPS was suppressed approximately 44% by treatment of neutrophils with anti-CD14 antibody under the presence of serum. Increase in the steady-state IL-8 mRNA level was concomitantly observed by stimulation of neutrophils with 500 ng/ml of P. gingivalis LPS under the absence of serum. These results indicate that P. gingivalis LPS activates NF-kappa B and AP-1 in both serum-dependent and -independent manners, followed by increased IL-8 transcription in neutrophils, and suggested a role for P. gingivalis LPS in IL-8 synthesis by neutrophils in inflamed gingiva and GCF.

Immunopharmacology of oral betalactams

Among the oral beta-lactam antibiotics only cefaclor has demonstrated a consistent in vitro and in vivo immunopharmacological effect which favors phagocytic chemotaxis and antimicrobial potential by inducing a T-helper 1 or pro-inflammatory response. Together with cefpimizole, cefaclor significantly reduces the minimum bactericidal concentration (MBC) against some bacterial species when cultured together with a suspension of polymorphonuclear leukocytes, as opposed to some other oral beta-lactams, co-amoxiclav and cefixime, which do not show this effect. The pro-inflammatory component of cefaclor's activity explains the clinical success of this antibiotic in a high percentage of cases, even when laboratory tests indicate in vitro resistance by the pathogen.

The central role of chemokines (chemotactic cytokines) in the immunopathogenesis of ulcerative colitis and Crohn's disease

The final composition of leukocytes present in a site of inflammation in response to chemokine stimulation and activation may depend on both the nature of the secreted chemokines as well as the relative expression of the multitude of specific chemokine cell surface receptors on many different cell types. Because related receptors with different affinities and cross-reactive binding capabilities are present on each type of leukocyte, relative differences in receptor distribution and receptor affinity for specific chemokines may significantly influence which cells are ultimately attracted to and activated by each individual chemokine. Production of IL-8, MCP-1, and ENA-78 by endothelial cells, LPMNC, and epithelial cells in IBD could establish a chemotactic gradient capable of influencing the increased migration of monocytes/macrophages, granulocytes, and lymphocytes from the blood stream through the endothelium into both the mucosa and submucosa during chronic IBD. The ability of chemokines to induce chemotaxis, leukocyte activation, granule exocytosis, increased production of metalloenzymes, and up-regulation of respiratory burst activity indicates that there may be a variety of different mechanisms by which chemokines could markedly increase chronic inflammation and chronic intestinal tissue destruction in IBD.

Chemokine gene expression in the brains of mice with lymphocytic choriomeningitis

Chemokines are pivotal in the trafficking of leukocytes. In the present study, we examined the expression of multiple chemokine genes during the course of lymphocytic choriomeningitis (LCM) in mice. In noninfected mice, no detectable chemokine gene expression was found in the brain; however, by day 3 postinfection, the induction of a number of chemokine mRNAs was observed as follows (in order from the greatest to the least): cytokine responsive gene-2 or interferon-inducible 10-kDa protein (Crg-2/IP-10), RANTES, monocyte chemotactic protein-1 (MCP-1), macrophage inflammatory protein-1 (MIP-1beta), and MCP-3. At day 6 postinfection, the expression of these chemokine mRNAs was increased, and low expression of lymphotactin, C10, MIP-2, and MIP-1alpha mRNAs was detectable. Transcript for T-cell activation-3 was not detectable in the brain at any time following LCM virus (LCMV) infection. With some exceptions, a pattern of chemokine gene expression similar to that in the brain was observed in the peripheral organs of LCMV-infected mice. Mice that lacked expression of gamma interferon developed LCM and had a qualitatively similar but quantitatively reduced cerebral chemokine gene expression profile. In contrast, little or no chemokine gene expression was detectable in the brains of LCMV-infected athymic mice which did not develop LCM. Expression of Crg-2/IP-10 RNA was localized to predominantly resident cells of the central nervous system (CNS) and overlapped with sites of viral infection and immune cell infiltration. These findings demonstrate the expression of a number of chemokine genes in the brains of mice infected with LCMV. The pattern of chemokine gene expression in LCM may profoundly influence the characteristic phenotype and response of leukocytes in the brain and contribute to the immunopathogenesis of this fatal CNS infection.

Massive infiltration of basophilic cells in inflamed tissue after injection of RANTES

Regulated upon activation normal T expressed and secreted (RANTES) is a new inducible protein member of the human C-C branch of chemokines. RANTES is a potent monocyte and lymphocyte chemoattractant and is a mediator of inflammatory responses. In these studies we found that RANTES 10 ng/50 microl chemoattracts basophilic cells in a dose-dependent manner 4 h after an intradermal injection in rat skin sites, as revealed by optic microscopy. Moreover, in biopsy specimens from rat skin injection sites histamine release was significantly higher (P < 0.05) than in controls (PBS 50 microl) after 4 h from RANTES treatment. The presence of basophilic cells in rat skin injection sites after RANTES-treatment was also confirmed by electron microscopy studies. In addition, histidine decarboxylase (HDC) mRNA was increased in rat skin sites injected with RANTES compared to sites injected with PBS (controls). Our report describes additional biological activities for RANTES, suggesting that this human chemoattractant protein may play a fundamental role in histamine and HDC generation, along with basophilic cell recruitment.

Leukocyte adhesion--structure and function of human leukocyte beta2-integrins and their cellular ligands

Leukocyte adhesion is of pivotal functional importance and this has resulted in extensive research and rapid development in the field. Leukocyte adhesion involves members of three molecular families: integrins, members of the immunoglobulin superfamily and carbohydrate binding selectins and sialoadhesins. Recently, considerable structural information on leukocyte integrins and members of the immunoglobulin superfamily of adhesion molecules has been obtained. This fact, combined with the identification of several novel adhesion molecules, has increased our understanding of how they function at the molecular level. Furthermore, the important issue of how integrins are activated to become adhesive is rapidly advancing. It is clearly evident that the knowledge accumulated from basic research will increasingly be applied in clinical medicine. In this review we focus on two important families of adhesion molecules, the leukocyte-specific beta2-integrins and their ligands, the intercellular adhesion molecules. Emphasis is put on their structural/functional relationships, their mode of regulation and on novel adhesion molecules recently discovered.

The structure of MCP-1 in two crystal forms provides a rare example of variable quaternary interactions

The X-ray crystal structure of recombinant human monocyte chemoattractant protein (MCP-1) has been solved in two crystal forms. One crystal form (P), refined to 1.85 A resolution, contains a dimer in the asymmetric unit, while the other (I) contains a monomer and was refined at 2.4 A. Although both crystal forms grow together in the same droplet, the respective quaternary structures of the protein differ dramatically. In addition, both X-ray structures differ to a similar extent from the solution structure of MCP-1. Such extent of variability of quaternary structures is unprecedented. In the crystal structures, the well-ordered N termini of MCP-1 form 3(10)-helices. Comparison of the three MCP-1 structures revealed a direct correlation between the main-chain conformation of the first two cysteine residues and the quaternary arrangements. These data can be used to explain the structural basis for the assignment of residues responsible for biological activity.

Interleukin-8 and de novo mammalian angiogenesis

In the rat mesenteric-window angiogenesis assay (MWAA), the test tissue is natively vascularized, lacks significant physiological angiogenesis and its homeostasis is unperturbed by surgical intervention. Using the rat MWAA, it is shown here that interleukin-8 (IL-8), administered at approximately physiological doses, is able to induce de novo angiogenesis. Human recombinant IL-8 was administered intraperitoneally at two daily doses of 25 pM, 250 pM and 2.5 nM for 5 consecutive days (days 0-4). Using microscopic, computer-aided techniques including image analysis, the de novo angiogenic response was quantified in groups of animals on days 7, 14 and 21 in terms of the relative vascularized area (VA), a measure of the microvascular spatial extension, and the microvascular length (MVL), a measure of microvascular density or length. The total microvascular length (TMVL) was computed from VA x MVL. A statistically significant angiogenic effect was found in terms of MVL on day 7 and in terms of VA and TMVL on day 14 following the treatment with 2.5 nM, whereas MVL was significantly increased in statistical terms on day 14 following the treatment with IL-8 at the low dose of 25 pM. Notably, IL-8 at the intermediate dose of 250 pM did not induce a statistically significant angiogenic effect in terms of VA, MVL or TMVL on any observation occasion, thereby suggesting that the dose-related angiogenic effect of IL-8 may be nonlinear. This appears to be the first paper showing that IL-8 is able to induce de novo angiogenesis in normally vascularized mammalian tissue.