The human MCP-2 gene (SCYA8): cloning, sequence analysis, tissue expression, and assignment to the CC chemokine gene contig on chromosome 17q11.2

Insights on the role of the chemokine CCL8 in pathology

Chemokine (C-C motif) ligand 8 (CCL8), also known as monocyte chemotactic protein-2 (MCP-2) is involved in immune cell recruitment, inflammation, and disease progression. While essential for host defense, dysregulated CCL8 expression and signaling contribute to the progression of infectious diseases, inflammatory disorders, and various cancers. CCL8 is also transcriptionally regulated under hypoxic conditions, linking it to the remodeling of the tumor microenvironment, placental dysfunction, and ischemic injury. In infections such as HIV, tuberculosis, and viral pneumonias, CCL8 regulates immune cell trafficking, enhancing both pathogen clearance and excessive immune activation. Inflammatory conditions such as graft-versus-host disease (GVHD), idiopathic pulmonary fibrosis (IPF), and preeclampsia are also associated with elevated CCL8 expression, promoting immune dysregulation and tissue damage. In allergic diseases such as asthma and atopic dermatitis, CCL8 contributes to Th2-driven inflammation by recruiting eosinophils and CCR8+ T cells to affected tissues. In cancer, CCL8 promotes tumor progression, metastasis, immune evasion, and therapeutic resistance through the recruitment of immunosuppressive cells such as M2 macrophages and regulatory T cells. Given its widespread role in immune modulation, CCL8 represents both a potential diagnostic biomarker and a therapeutic target. Recent advances in antibody-based therapies and ligand-directed strategies, including cytotoxic CCL8 analogs, highlight new opportunities for translational application. Further research is needed to clarify its specific mechanisms and explore targeted interventions that modulate CCL8 signaling for clinical applications.

Inflammatory chemokine (C-C motif) ligand 8 inhibition ameliorates peritoneal fibrosis

Peritoneal fibrosis (PF) is an irreversible complication of peritoneal dialysis (PD) that leads to loss of peritoneal membrane function. We investigated PD effluent and serum levels and the tissue expression of chemokine (C-C motif) ligand 8 (CCL8) in patients with PD. Additionally, we investigated their association with PF in a mouse model. Eighty-two end-stage renal disease (ESRD) patients with PD were examined. CCL8 levels were measured via enzyme-linked immunosorbent assays in PD effluents and serum and analyzed with peritoneal transport parameters. Human peritoneal mesothelial cells (hPMCs) were obtained from the PD effluents of 20 patients. Primary cultured hPMCs were treated with recombinant (r) transforming growth factor (TGF)-β, and CCL8 expression was assessed via western blotting. As the duration of PD increased, the concentration of CCL8 in PD effluents significantly increased. Correlations between peritoneal transport parameters and dialysate CCL8 levels were observed. Western blotting analysis showed that CCL8 was upregulated via rTGF-β treatment, accompanied by increases in markers of inflammation, fibrosis, senescence, and apoptosis in hPMCs after induction of fibrosis with rTGF-β. Anti-CCL8 monoclonal antibody (mAb) treatment suppressed the rTGF-β-induced increase in all analyzed markers. Immunohistochemical analysis revealed that CCL8 along with fibrosis- and inflammation-related markers were significantly increased in the PF mouse model. Functional blockade of CCL8 using a CCR8 inhibitor (R243) abrogated peritoneal inflammation and fibrosis in vivo. In conclusion, high CCL8 levels in PD effluents may be associated with an increased risk of PD failure, and the CCL8 pathway is associated with PF. CCL8 blockade can ameliorate peritoneal inflammation and fibrosis.

Chemokine (C-C Motif) Ligand 8 and Tubulo-Interstitial Injury in Chronic Kidney Disease

Kidney fibrosis has been accepted to be a common pathological outcome of chronic kidney disease (CKD). We aimed to examine serum levels and tissue expression of chemokine (C-C motif) ligand 8 (CCL8) in patients with CKD and to investigate their association with kidney fibrosis in CKD model. Serum levels and tissue expression of CCL8 significantly increased with advancing CKD stage, proteinuria level, and pathologic deterioration. In Western blot analysis of primary cultured human tubular epithelial cells after induction of fibrosis with rTGF-β, CCL8 was upregulated by rTGF-β treatment and the simultaneous treatment with anti-CCL8 mAb mitigated the rTGF-β-induced an increase in fibronectin and a decrease E-cadherin and BCL-2 protein levels. The antiapoptotic effect of the anti-CCL8 mAb was also demonstrated by Annexin V/propidium iodide staining assay. In qRT-PCR analysis, mRNA expression levels of the markers for fibrosis and apoptosis showed similar expression patterns to those observed by western blotting. The immunohistochemical analysis revealed CCL8 and fibrosis- and apoptosis-related markers significantly increased in the unilateral ureteral obstruction model, which agrees with our in vitro findings. In conclusion, CCL8 pathway is associated with increased risk of kidney fibrosis and that CCL8 blockade can ameliorate kidney fibrosis and apoptosis.

The role of cancer stem cells in immunotherapy for bladder cancer: An in vitro study

OBJECTIVE

Bladder cancer is characterized by frequent recurrence and progression. CD44+ cancer stem cells (CSCs) might be one of the main reasons for recurrence. Although Bacillus Calmette Guerin (BCG) has become a gold standard immunotherapy, after treatment recurrence frequently occur. Based on this knowledge, the aim of this study was to evaluate the changes in cytokine and chemokine expressions in bladder cancer and CSCs cultures in vitro with BCG only and in combination with IL2 and lymphocyte (MNCs) applications.

MATERIAL AND METHODS

In this study, 3 cell lines of human bladder cancer cells with different characteristics (T24, 5637, and JMSU-1) and CD44+ bladder CSCs isolated by magnetic bead isolation (Miltenyl Magtech) were used. Bladder cancer cell lines and bladder CSCs in complete medium were cultured under humidified conditions of 37°C temperature in 5% CO₂. BCG only and its combination with IL2 and MNCs were applied to bladder cancer cell lines and bladder CSCs for 24, 48, and 72 hours. Annexin V-PI was used to detect the percentages of apoptotic and necrotic cells in treatment groups and control groups. After treatments, total RNAs were isolated and converted to cDNA for each group and controls. Quantitative fold changes in terms of gene expression were measured by RT2-PCR array and fold changes for expression levels of genes were compared among groups. Eighty-four genes were analyzed in standard array of chemokines and cytokines (Biorad).

RESULTS

BCG treatment with 7.32 µg/ml dose alone and in combination with IL2 (1000 IU/ml) and MNCs (1000 cells/ml) were found to be most effective on bladder cancer cells. When BCG and its combinations were applied to CSCs of the 3 cell lines, BCG treatment showed cytotoxic effect on CSCs as well as cancer cells. CSCs of 3 cell lines over expressed CXCL5, CCL8, CNTF, and CSF2 compared with cancer cells. Cancer cells over expressed IL6, TNSFF11, FASLG, and CXCL9 compared with CSCs. In all 3 cell lines, BCG application increased expression of CXCL5 and LTB and also decreased CCL20 and IL6. When BCG was combined with IL2 and MNCs, CXCL10, CXCL5, and IFNG were increased and CXCL12, IL6, and TNSF11 were decreased. BCG treatment of CSCs caused increases in ADIPOQ, CXCL10, and XCL1 and a decrease in CCL8. When IL2 and MNCs were combined with BCG, the expression of many cytokines and chemokines decreased.

CONCLUSION

BCG treatment changes the expression of many cytokines and chemokines in bladder cancer. The expression differs in 3 different cell lines and their CSCs. Immune modulation of each case differs from each other. The effectivity of BCG-based immunotherapy in bladder cancer on CSCs might decrease in combination with IL2. Our results indicate that recurrence after BCG treatment for bladder cancer may not occur mainly based on the CSCs hypothesis considering bladder cancer occurs at different loci of surface epithelium.

Gene expression profiling reveals clear differences between EBV-positive and EBV-negative posttransplant lymphoproliferative disorders

Posttransplant patients are at risk of developing a potentially life-threatening posttransplantation lymphoproliferative disorder (PTLD), most often of diffuse large B cell lymphoma (DLBCL) morphology and associated with Epstein-Barr Virus (EBV) infection. The aim of this study was to characterize the clinicopathological and molecular-genetic characteristics of posttransplant DLBCL and to elucidate whether EBV(+) and EBV(-) posttransplant DLBCL are biologically different. We performed gene expression profiling studies on 48 DLBCL of which 33 arose posttransplantation (PT-DLBCL; 72% EBV+) and 15 in immunocompetent hosts (IC-DLBCL; none EBV+). Unsupervised hierarchical analysis showed clustering of samples related to EBV-status rather than immune status. Except for decreased T cell signaling these cases were inseparable from EBV(-) IC-DLBCL. In contrast, a viral response signature clearly segregated EBV(+) PT-DLBCL from EBV(-) PT-DLBCL and IC-DLBCL cases that were intermixed. The broad EBV latency profile (LMP1+/EBNA2+) was expressed in 59% of EBV(+) PT-DLBCL and associated with a more elaborate inflammatory response compared to intermediate latency (LMP1+/EBNA2-). Inference analysis revealed a role for innate and tolerogenic immune responses (including VSIG4 and IDO1) in EBV(+) PT-DLBCL. In conclusion we can state that the EBV signature is the most determining factor in the pathogenesis of EBV(+) PT-DLBCL.

Monocyte chemotactic protein-2 and -3 in amniotic fluid: relationship to microbial invasion of the amniotic cavity, intra-amniotic inflammation and preterm delivery

OBJECTIVE

To evaluate the presence of monocyte chemotactic protein (MCP)-2 and MCP-3 in cervical and amniotic fluid in women in preterm labor.

STUDY DESIGN

Cervical and amniotic fluid was sampled from women with singleton pregnancies (< or =34 weeks) in preterm labor (n = 58).

RESULTS

Monocyte chemotactic protein-2 (range: 80-583 pg/ml) and MCP-3 (range: 36-649 pg/ml) were detectable in 7/58 women in preterm labor. Monocyte chemotactic protein-3 was found significantly more often in amniotic fluid of women delivered within 7 days (P < 0.001), <34 weeks (P = 0.002), or with intra-amniotic inflammation (P < 0.001) and microbial invasion of the amniotic fluid (P = 0.003). Women in preterm labor had detectable levels of MCP-2 significantly more often if they gave birth before 34 weeks of gestation (P = 0.038) or had intra-amniotic inflammation (P = 0.042).

CONCLUSIONS

The presence of MCPs in amniotic fluid of women in preterm labor was associated with preterm birth before 34 weeks of gestation (MCP-2 and MCP-3), microbial invasion (MCP-3), and inflammation (MCP-2 and MCP-3) of the amniotic cavity.

Immune prevention of mammary carcinogenesis in HER-2/neu transgenic mice: a microarray scenario

Neoplastic transformation is a multistep process in which gene products of specific regulatory pathways are involved at each stage. Identification of these overexpressed or mutated gene products provides an unprecedented opportunity to address the immune system against defined antigens and eliminate transformed cells. Mice transgenic for these oncogenes (e.g. HER-2/neu, a prototype of deregulated oncogenic protein kinase membrane receptors) are ideal experimental models for assessing the potential of active immunization. The demonstration that vaccines can cure HER-2/neu transplantable tumors, prevent their onset and delay the progression of preneoplastic lesions in mice at risk suggests that efficient immunological inhibition of HER-2/neu carcinogenesis can be achieved by specific vaccination. To further explore this issue, halting of tumor progression in the mammary glands of BALB-neuT mice with two immunization protocols in two laboratories has been studied independently by DNA microarray analysis. Combination of the two sets of results revealed a clear correlation between them when the tumor mass was titrated by transcription profiling. It was also clear that both protocols induced a strong, polyclonal antibody response and halted tumor growth at a condition very similar to that at which the vaccination began. Differences in the expression profiles were mainly related to the expression levels of a few chemokines and T-cell-specific genes that may be in some way correlated with the efficacy of the vaccination. Last, combination of the expression data with the protection results indicated that chronic vaccination is needed to maintain an active IFN-gamma-mediated response in the mammary gland.

Targeted cellular process profiling approach for uterine leiomyoma using cDNA microarray, proteomics and gene ontology analysis

This study utilized both cDNA microarray and two-dimensional protein gel electrophoresis technology to investigate the multiple interactions of genes and proteins involved in uterine leiomyoma pathophysiology. Also, the gene ontology analysis was used to systematically characterize the global expression profiles at cellular process levels. We profiled differentially expressed transcriptome and proteome in six-paired leiomyoma and normal myometrium. Screening up to 17 000 genes identified 21 upregulated and 50 downregulated genes. The gene-expression profiles were classified into mutually dependent 420 functional sets, resulting in 611 cellular processes according to the gene ontology. Also, protein analysis using two-dimensional gel electrophoresis identified 33 proteins (17 upregulated and 16 downregulated) of more than 500 total spots, which was classified into 302 cellular processes. Of these functional profilings, downregulations of transcriptomes and proteoms were shown in cell adhesion, cell motility, organogenesis, enzyme regulator, structural molecule activity and response to external stimulus functional activities that are supposed to play important roles in pathophysiology. In contrast, the upregulation was only shown in nucleic acid-binding activity. Taken together, potentially significant pathogenetic cellular processes were identified and showed that the downregulated functional profiling has a significant impact on the discovery of pathogenic pathway in leiomyoma. Also, the gene ontology analysis can overcome the complexity of expression profiles of cDNA microarray and two-dimensional protein analysis via its cellular process-level approach. Therefore, a valuable prognostic candidate gene with relevance to disease-specific pathogenesis can be found at cellular process levels.

Persistent over-expression of specific CC class chemokines correlates with macrophage and T-cell recruitment in mdx skeletal muscle

Prior studies and the efficacy of immunotherapies provide evidence that inflammation is mechanistic in pathogenesis of Duchenne muscular dystrophy. To identify putative pro-inflammatory mechanisms, we evaluated chemokine gene/protein expression patterns in skeletal muscle of mdx mice. By DNA microarray, reverse transcription-polymerase chain reaction, quantitative polymerase chain reaction, and immunoblotting, convergent evidence established the induction of six distinct CC class chemokine ligands in adult MDX: CCL2/MCP-1, CCL5/RANTES, CCL6/mu C10, CCL7/MCP-3, CCL8/MCP-2, and CCL9/MIP-1gamma. CCL receptors, CCR2, CCR1, and CCR5, also showed increased expression in mdx muscle. CCL2 and CCL6 were localized to both monocular cells and muscle fibers, suggesting that dystrophic muscle may contribute toward chemotaxis. Temporal patterns of CCL2 and CCL6 showed early induction and maintained expression in mdx limb muscle. These data raise the possibility that chemokine signaling pathways coordinate a spatially and temporally discrete immune response that may contribute toward muscular dystrophy. The chemokine pro-inflammatory pathways described here in mdx may represent new targets for treatment of Duchenne muscular dystrophy.

Cytokines of the placenta and extra-placental membranes: biosynthesis, secretion and roles in establishment of pregnancy in women

Virtually all known cytokines have been demonstrated to be expressed in the placenta and associated fetal and maternal membranes during normal gestation. In addition to playing their traditional roles as modulators of immunological function, cytokines derived from the placenta and extraplacental membranes, together with other locally-derived growth factors, appear to be implicated in various aspects of implantation and placental development. Imbalances in the intrauterine cytokine milieu around the time of implantation and invasion may play a causative role in disorders associated with early pregnancy failure, and are also associated with the abnormal trophoblast development seen in gestational trophoblastic disease. Cytokines thus appear to be an important component of a paracrine/autocrine communication network operating within the feto-maternal interface to ensure the successful establishment of pregnancy.

Monocyte chemotactic protein-1 and -2 messenger ribonucleic acids in the ovine uterus: regulation by pregnancy, progesterone, and interferon-tau

Endometrial leukocytes may play important roles during pregnancy. Because chemokines are regulators of immune cell activity and trafficking, this study determined if mRNAs for monocyte chemotactic proteins (MCP) were present in the ovine uterus and regulated by progesterone (P) and/or recombinant ovine interferon tau (roIFN-tau). Uteri of normal cycling and pregnant ewes (experiment 1) and uteri of ovariectomized ewes receiving intrauterine infusions of IFN-tau and/or i.m. injections of P (experiment 2) were used to detect MCP-1 and MCP-2 mRNA. In experiment 1, slot-blot hybridization analysis of endometrial total RNA revealed that MCP-1 and MCP-2 mRNA levels did not change during the estrous cycle but increased between Days 13 and 19 of pregnancy. Using in situ hybridization, MCP-1 and MCP-2 mRNA were localized to immune cells in the subepithelial compact stroma. Histomorphological studies and in situ hybridization for major basic protein (MBP) indicated that MCP-positive immune cells were eosinophils. In experiment 2, treatment with P and roIFN-tau increased (P < 0.05) the number of MCP-1- and MCP-2-expressing eosinophils in the endometrium compared to ewes treated with P alone. Injection of the P receptor antagonist (ZK 137,316) inhibited effects of P and/or roIFN-tau to recruit eosinophils expressing MCP-1 and MCP-2 mRNAs. Endometrial production of MCPs by eosinophils during early pregnancy may play a role(s) in central implantation and/or placentation in ewes that is crucial for successful establishment of pregnancy.

Expression of the chemokines, monocyte chemotactic protein (MCP)-1 and MCP-2 in endometrium of normal women and Norplant users, does not support a central role in macrophage infiltration into endometrium

The endometrium contains many leukocytes, including macrophages, the numbers varying with the time of the menstrual cycle and being maximal peri-menstrually. The long-acting progestogenic contraceptive Norplant, has a high rate of discontinuation due to uterine bleeding; this is associated with large numbers of endometrial macrophages. Monocyte chemotactic proteins (MCP) act to recruit and activate monocytes into sites of inflammation. This study compared the cellular localization of endometrial MCP-1 and MCP-2 across the normal menstrual cycle and in users of Norplant. Both MCP-1 and MCP-2 were present in normal endometrium, but with very different patterns of cellular location and considerable variability between individuals. MCP-1 of epithelial origin was present in 77% of tissues, while stromal staining was present in 52% and vascular staining in 34% of samples. MCP-1 was also released from both epithelial and stromal cells in culture. MCP-2 staining was predominantly epithelial and was found in 52% of tissues while stromal staining was present in only 3/56 samples. Vascular staining of MCP-2 was found in 2/56 samples. The epithelial staining was mostly punctate and sometimes within uterine secretions. No correlation of staining for MCP-1 or -2 with the phase of the cycle was found in any cellular compartment. Very little immunoreactive MCP-1 or MCP-2 was detected in endometrium from Norplant users regardless of morphological subtype. These distributions do not support a role for either MCP-1 or MCP-2 in the migration of macrophages into the endometrium and suggest that these cytokines may have other functions in this tissue.

Molecular cloning and characterization of a novel CXC chemokine macrophage inflammatory protein-2 gamma chemoattractant for human neutrophils and dendritic cells

Chemokines play important roles in leukocyte trafficking as well as function regulation. In this study, we described the identification and characterization of a novel CXC chemokine from a human dendritic cell (DC) cDNA library, the full-length cDNA of which contains an open reading frame encoding 111 aa with a putative signal peptide of 34 aa. This CXC chemokine shares greatest homology with macrophage inflammatory protein (MIP)-2alphabeta, hence is designated as MIP-2gamma. Mouse MIP-2gamma was identified by electrocloning and is highly homologous to human MIP-2gamma. Northern blotting revealed that MIP-2gamma was constitutively and widely expressed in most normal tissues with the greatest expression in kidney, but undetectable in most tumor cell lines except THP-1 cells. In situ hybridization analysis demonstrated that MIP-2gamma was mainly expressed by the epithelium of tubules in the kidney and hepatocytes in the liver. Although no detectable expression was observed in freshly isolated or PMA-treated monocytes, RT-PCR analysis revealed MIP-2gamma expression by monocyte-derived DC. Recombinant MIP-2gamma from 293 cells is about 9.5 kDa in size and specifically detectable by its polyclonal Ab developed by the immunization with its 6His-tagged fusion protein. The eukaryotically expressed MIP-2gamma is a potent chemoattractant for neutrophils, and weaker for DC, but inactive to monocytes, NK cells, and T and B lymphocytes. Receptor binding assays showed that MIP-2gamma does not bind to CXCR2. This implies that DC might contribute to the innate immunity through the production of neutrophil-attracting chemokines and extends the knowledge about the regulation of DC migration.

Lungkine, a Novel CXC Chemokine, Specifically Expressed by Lung Bronchoepithelial Cells

We describe a novel mouse CXC chemokine that is selectively expressed in lung epithelial cells and up-regulated in various lung inflammation models. Although this chemokine clusters with other ELR-CXC chemokines, none of them can confidently be assigned to be its human homologue based on sequence identity. In addition, the highly restricted mRNA tissue distribution of this chemokine differentiates it from all previously described chemokines: Lungkine could not be detected in any of the 70 cDNA libraries analyzed corresponding to specific murine cell populations and tissues. High levels of Lungkine mRNA were specifically detected in the lung and at lower levels in fetal lung tissue by Northern blot and in situ hybridization, suggesting a potential role for this chemokine during lung development. Moreover, Lungkine protein is secreted into the airway spaces and induces the in vitro and in vivo migration of neutrophils, suggesting that it is involved in lung-specific neutrophil trafficking. Using fluorescent in situ hybridization, we show that Lungkine maps to mouse chromosome 5.

Organization of the chemokine gene cluster on human chromosome 17q11.2 containing the genes for CC chemokine MPIF-1, HCC-2, HCC-1, LEC, and RANTES

To understand the organization of the human CC chemokine gene cluster on chromosome 17q11.2, we determined the nucleotide sequence of a region 181 kb long containing five CC chemokine genes, MPIF-1 (SCYA23), HCC-2 (SCYA15), HCC-1 (SCYA14), LEC (SCYA16), and RANTES (SCYA5), by the random shot-gun method. The four CC chemokine genes, MPIF-1, HCC-2, HCC-1, and LEC, are clustered within a region 40 kb long, whereas the RANTES gene is located approximately 10 kb apart from the four chemokine gene minicluster. These chemokine genes are arranged in the same orientation, and their sizes are relatively long, 3.1 (HCC-1)-8.8 kb (RANTES) when compared with other CC chemokine genes, such as MIP-1alpha/LD78alpha (SCYA3) (1.9 kb) and MCP-1 (SCYA2) (1.5 kb). In contrast to most other human CC chemokine genes that consist of three exons, the MPIF-1 and HCC-2 genes, separated by 12 kb, have four exons. When the nucleotide sequences of the MPIF-1 and HCC-2 genes are compared, they are well conserved, including introns and flanking sequences, except for the middle region of the long first intron, indicating that they have been generated recently in evolutionary terms by duplication. In addition to the CC chemokine genes, more than 30 exons are identified in the sequenced region by similarity search against expressed sequence tags (ESTs) and also by the gene prediction program GenScan. This indicates that the chemokine cluster sequenced in this study is a gene-rich region in the human genome.

The MCP/eotaxin subfamily of CC chemokines

Migration of leukocytes from the bone marrow to the circulation, the primary lymphoid organs and inflammatory sites is directed by chemokines and specific receptor interactions. Besides the role of this group of low molecular weight cytokines in leukocyte attraction and activation, anti-HIV and hematopoietic activities were also attributed to chemokines. On the basis of the number and arrangement of the conserved cysteines, chemokines are subdivided in two multi-member families, namely the CXC and CC chemokines, whereas fractalkine (CX3C) and lymphotactin (C) are unique relatives. The CC chemokines possess four cysteines of which the first two are adjacent. Functionally, they form a rather heterogeneous family. Here, the focus is on the monocyte chemotactic proteins and eotaxin which, on a structural basis, can be considered as a CC chemokine subfamily. Not only the protein sequences, but also the gene structures, chromosomal location, biological activities and receptor usage exhibit considerable similarities. The review is complemented with a comparison of the biological functions of the MCP/eotaxin-subfamily in physiology and pathology.

Genomic organization, sequence analysis and transcriptional regulation of the human MCP-4 chemokine gene (SCYA13) in dermal fibroblasts: a comparison to other eosinophilic beta-chemokines

The eosinophil chemotactic beta-chemokine MCP-4 is assumed to be involved in the accumulation of eosinophils characteristic for eosinophilic inflammatory diseases. We here describe the genomic organisation (3 exons of 138, 115 and 578 bp, 2 introns of 867 and 437 bp and 1.4 kb of regulatory sequences from the immediate 5' upstream region), sequence (genomic and transcribed) and mRNA expression of the human MCP-4 gene in dermal fibroblasts. Among the promoter elements potentially regulating MCP-4 gene expression and/or mediating the effects of anti-inflammatory drugs we identified consensus sequences known to interact with nuclear factors like NF-IL6, AP-2, a NF-kappaB like consensus sequence, gamma-interferon- response and YY-1 elements as well as glucocorticoid response elements. Like MCP-3, MCP-4 mRNA expression in dermal fibroblasts is upregulated by TNF-alpha, IL-1alpha, IFN-gamma or IL-4 and differs from RANTES and eotaxin mRNA expression in its response to IFN-gamma and/or IL-4.

Opportunities for novel therapeutic agents acting at chemokine receptors

Chemokines are proinflammatory mediators that primarily control leukocyte migration into selected tissues and upregulation of adhesion receptors. They also have a role in pathological conditions that require neovascularization and are implicated in the suppression of viral replication. By interaction with their respective G-protein-coupled receptor, chemokines have a profound influence over the selective recruitment of specific cell types in acute inflammatory disease and, hence, inhibition of their action should be of therapeutic benefit. Only now are small molecule inhibitors becoming available to validate this speculation. In this review, without seeking to be comprehensive, the authors provide an introduction to chemokines, their receptors and their role in certain disease processes. Also, recent disclosures claiming novel nonpeptide ligands for chemokine receptors are summarized.

MCP-1, MCP-2 and MCP-3 expression in multiple sclerosis lesions: an immunohistochemical and in situ hybridization study

Chemokines are low molecular weight chemotactic cytokines that have been shown to play a central role in the perivascular transmigration and accumulation of specific subsets of leukocytes at sites of tissue damage. Two major families have been defined depending on the positioning of four conserved cysteines. The CXC chemokines predominantly attract neutrophils, whereas the CC chemokines predominantly attract monocytes and other leukocyte cell types. Members of the monocyte chemotactic protein (MCP)-1 family form a major component of the CC family of chemokines and are considered the principal chemokines involved in the recruitment of monocytes/macrophages and activated lymphocytes. In this study we addressed the expression and distribution of MCP-1, -2 and -3 in multiple sclerosis (MS) lesions of differing ages and levels of inflammatory activity using immunohistochemistry and in situ hybridization. In acute and chronic-active MS lesions immunoreactivity for MCP-1, -2 and -3 was prominent throughout the lesion center with reactivity diminishing abruptly at the lesion edge. Hypertrophic astrocytes were strongly reactive and inflammatory cells showed variable reactivity. Outside of the lesion only hypertrophic astrocytes were reactive. The results obtained by in situ hybridization for MCP-1 were in agreement with those obtained by immunostaining. In more chronic lesions immunoreactivity for MCP-1, -2 and -3 was considerably diminished, and in chronic-silent lesions immunoreactivity was restricted to a few scattered reactive astrocytes. Normal control brains showed no immunoreactivity for MCP-1, -2 and -3. Although the cellular distribution of all three members of this family was similar, antibodies to MCP-3 gave prominent staining of the extracellular matrix that was not noted for MCP-1 and -2. These results support the conclusion that members of the MCP family of chemokines are involved in the development of MS lesions in the central nervous system.

Genomic organization, sequence, and transcriptional regulation of the human eotaxin gene

Eotaxin is an eosinophil specific beta-chemokine assumed to be involved in eosinophilic inflammatory diseases such as atopic dermatitis, allergic rhinitis, asthma and parasitic infections. Its expression is stimulus- and cell-specific. We here describe the genomic organisation (3 exons of 132, 112 and 542 bp and 2 introns of 1211 and 378 bp) and sequence including 3 kb of DNA from the immediate 5' upstream region of the human eotaxin gene. Among the regulatory promoter elements potentially regulating eotaxin gene expression and/or mediating the effects of anti-inflammatory drugs we identified consensus sequences known to interact with nuclear factors like NF-IL6, AP-1, a NF-kappa-B like consensus sequence and gamma-interferon- as well as glucocorticoid response elements.