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Results for “Chemokine CCL4”

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At least 19 recordsLinked to original sources
PubMed2006

Genetic variation in the CCL18-CCL3-CCL4 chemokine gene cluster influences HIV Type 1 transmission and AIDS disease progression.

CCL3 (MIP-1 alpha), CCL4 (MIP-1 beta), and CCL18 (DC-CK1/PARC/AMAC-1) are potent chemoattractants produced by macrophages, natural killer cells, fibroblasts, mast cells, CD4(+) T cells, and CD8(+) T cells. CCL3 and CCL4 are natural ligands for the primary human immunodeficiency virus type 1 (HIV-1) coreceptor CCR5 and are also known to activate and enhance the cytotoxicity of natural killer cells. Genomic DNAs from >3,000 participants enrolled in five United States-based natural-history cohorts with acquired immunodeficiency syndrome (AIDS) were genotyped for 21 single-nucleotide polymorphisms (SNPs) in a 47-kb interval on chromosome 17q12 containing the genes CCL3, CCL4, and CCL18. All 21 SNPs were polymorphic in African Americans (AAs), whereas 7 of the 21 had minor-allele frequencies <0.01 in European Americans (EAs). Substantial linkage disequilibrium was observed in a 37-kb interval containing 17 SNPs where many pairwise D' values exceeded 0.70 in both racial groups, but particularly in EAs. Four and three haplotype blocks were observed in AAs and EAs, respectively. Blocks were strongly correlated with each other, and common haplotype diversity within blocks was limited. Two significant associations are reported that replicate an earlier study. First, among AA members of the AIDS Link to the Intravenous Experience cohort of injection drug users, frequencies of three correlated SNPs covering 2,231 bp in CCL3 were significantly elevated among highly exposed, persistently HIV-1-uninfected individuals compared with HIV-1-infected seroconvertors (P = .02-.03). Second, seven highly correlated SNPs spanning 36 kb and containing all three genes were significantly associated with more-rapid disease progression among EAs enrolled in the Multicenter AIDS Cohort Study cohort (P = .01-.02). These results reiterate the importance of chemokine gene variation in HIV-1/AIDS pathogenesis and emphasize that localized linkage disequilibrium makes the identification of causal mutations difficult.

Chemokine CCL3↗
PubMed2004

The beta chemokines CCL4 and CCL5 enhance adhesion of specific CD4+ T cell subsets to human brain endothelial cells.

Chemokines are key mediators of inflammation, acting as subset-specific chemoattractants and activators of leukocytes. In the present study we investigated the effects of chemokine concentration gradients on CD4+ T cell (TC4) adhesion to human brain microvessel endothelial cells (HBMECs) in vitro. CCL4 or CCL5 were placed in a double chamber chemotaxis system beneath confluent resting HBMEC monolayers or cultures co-incubated with TNF-alpha and IFN-gamma to mimic an inflammatory milieu. Chemokines readily diffused across activated HBMEC monolayers while binding to the sub-endothelial regions, establishing a chemotactic and haptotactic gradient. Naïve or resting TC4 adhered poorly to resting HBMECs compared to memory or recently activated TC4, but all subsets adhered more readily to cytokine-treated HBMECs. Chemokine gradients (10-100 ng/ml) of both CCL4 and CCL5 significantly enhanced the adhesion of memory and recently activated TC4 to cytokine-treated HBMECs, as much as doubling adhesion in a manner that correlated with chemokine receptor expression. Neither chemokine influenced adhesion to resting HBMEC monolayers nor the adhesion of resting or naïve TC4. These findings emphasize the role and importance of CNS-derived beta-chemokines in regulating the traffic of recently activated TC subsets (those previously localized to the CNS in vivo) across cytokine-activated cerebral endothelium in inflammatory diseases.

Brain↗
PubMed2004

Reduced GRK2 level in T cells potentiates chemotaxis and signaling in response to CCL4.

Chemokine receptors belong to the family of G-protein-coupled receptors (GPCR). Phosphorylation of GPCR by GPCR kinases (GRKs) is considered to play an important role in desensitization of these receptors. We have recently shown in patients with rheumatoid arthritis that the level of GRK2 in lymphocytes is reduced by approximately 50%. However, the physiological relevance of reduced GRK2 levels in lymphocytes is not known. Here, we investigated whether reduced GRK2 expression changes the chemotactic response of T cells to the chemokines CCL3, CCL4, and CCL5. Activated T cells from GRK2+/- mice, which have a 50% reduction in GRK2 protein levels, showed a significant 40% increase in chemotaxis toward the CCR5 ligand CCL4. In addition, chemotaxis toward the CCR1 and CCR5 ligands CCL3 and CCL5 was also increased. Binding of CCL4 to activated T cells from GRK2+/- and wild-type (WT) mice was similar, but agonist-induced CCR5 phosphorylation was attenuated in GRK2+/- cells. Moreover, the calcium response and phosphorylation of protein kinase B and extracellular-regulated kinase in response to CCL4 were significantly increased in GRK2+/- T cells, showing that signaling is increased when the level of GRK2 is reduced. GRK2+/- and WT cells do become refractory to restimulation with CCL4. In conclusion, a 50% decrease in T cell GRK2 expression results in increased responsiveness to CCL3, CCL4, and CCL5, suggesting that the 50% reduction in lymphocyte GRK2 level as observed during inflammation can have functional consequences for the response of these cells to chemokines.

Animals↗
PubMed2004

Functional redundancy of the human CCL4 and CCL4L1 chemokine genes.

CCL4 and CCL4L1 are two CC chemokine genes located at chromosome 17q21 whose mature proteins differ at only a single amino acid. Abundant functional information exists for CCL4, however, CCL4L1 has only recently been recognized as a distinct gene, thus information describing it is wanting. The CCL4L1 protein was synthesized in Escherichia coli and compared with the CCL4 protein. Competitive binding studies using HEK-293/CCR5 cells produced comparable EC50 values for the two proteins. Similarly, chemotaxis assays with cells expressing CCR1, CCR3, or CCR5 revealed no substantial differences. CCL4L1 was somewhat more effective at inhibiting HIV-1 replication in PBMCs than was CCL4, however the difference was not statistically significant. These data combined with the observation of individual variation in CCL4L1 gene copy number [Eur. J. Immunol. 32 (2002) 3016, Genomics 83 (2004) 735] support the contention that the CCL4 and CCL4L1 proteins have redundant functions.

Amino Acid Sequence↗
PubMed2003

Independent expression of the two paralogous CCL4 genes in monocytes and B lymphocytes.

The CCL4 chemokine is secreted by a variety of cells following stimulation. CCL4 affects several different types of cells that are important for acute inflammatory responses and are critical for the development of specific immune responses to foreign antigens. The human genome contains two genes for the CCL4 chemokine. Although highly homologous, the two genes encode slightly different proteins. We analyzed the mRNA expressed in monocytes and B lymphocytes and found that while monocytes express predominantly one CCL4 gene, known as ACT-2, peripheral blood B lymphocytes express a mixture of ACT-2 and the second CCL4 gene, lymphocyte activating gene-1 ( LAG-1). Although peripheral blood B cells, CD27(-) B cells, and CD27(+) B cells all express a mixture of LAG-1 and ACT-2, the B-cell lines that were studied regulate the two genes independently. RL, SU-DHL-6, and REH cells predominantly express LAG-1. These studies demonstrate that monocytes and B cells utilize different mechanisms to regulate expression of the two CCL4 genes and suggest that the two genes may not have identical activities.

B-Lymphocytes↗
PubMed2005

Expression of the beta chemokines CCL3, CCL4, CCL5 and their receptors in idiopathic inflammatory myopathies.

The idiopathic inflammatory myopathies (IIM) are a group of autoimmune diseases characterized by chronic lymphocytic and macrophagic infiltration in muscle. Because the mechanism for recruitment of these cells probably involves chemokines, we focused on the study of the expression pattern of some beta chemokines and receptors because it may provide a basis for selective immunotherapy. The expression of CCL3 (MIP-1alpha), CCL4 (MIP-1beta), CCL5 (RANTES) and their main receptors (CCR1 and CCR5) was studied by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry in a series of 16 IIM and five controls (four normal muscles and one tonsil). Except for CCL5, strong expression was observed by RT-PCR with all molecules in all IIM subtypes in comparison to control muscle. Immunohistochemistry revealed diffuse CCL4 expression in all vessels in dermatomyositis. In both polymyositis and sporadic inclusion body myositis (s-IBM) it was restricted to vessels in the vicinity of inflammatory exudates. CCL5 expression was low, restricted to a few inflammatory cells in all IIM; CCR1 expression was mainly restricted to macrophages and s-IBM endothelial cells, whereas CCR5 was localized in inflammatory cells invading non-necrotic muscle fibres. Expressions of both receptors were also recorded in few muscle fibres. In conclusion, the upregulation of beta chemokines and receptors in IIM and their differential expression by various cells may contribute to chronic inflammation and to the peculiar distribution of inflammatory exudates in these diseases.

Adolescent↗
PubMed2005

Not all tetramer binding CD8+ T cells can produce cytokines and chemokines involved in the effector functions of virus-specific CD8+ T lymphocytes in HIV-1 infected children.

In the pediatric human immunodeficiency virus type-1 (HIV-1) infection, the presence of cytotoxic T lymphocytes (CTL) is associated with a slow progression to AIDS. The secretion of cytokines by CTLs may be critical in the control of viral infection. We used the combination of cell surface and intracellular staining to study the functionality of tetramer binding CD8+ T cells recognizing two HIV-1 immunodominant epitopes, in peripheral blood mononuclear cells from HIV-1-infected children. A fraction of tetramer positive CD8+ T cells produce cytokines (IFN-gamma, TNF-alpha) or chemokines (CCL4, CCL5) after ex vivo stimulation with the cognate peptide. There was a negative correlation between the plasma viral load and the percentage of CD8+ Tetramer Gag+ T cells secreting IFN-gamma. This is the first report in the context of pediatric HIV-1 infection showing that only a fraction of HIV-1-specific CD8+ T cells have the capacity to produce cytokines and chemokines implicated in their antiviral functions.

Adolescent↗
PubMed2006

Mantle cell lymphomas acquire increased expression of CCL4, CCL5 and 4-1BB-L implicated in cell survival.

We have analyzed mantle cell lymphomas (MCLs), using high-density DNA microarrays, and confirmed the expression of differentially regulated antigens, using flow cytometry and immunohistochemistry. The results show that MCLs acquire expression of molecules that normally are involved in interaction with other immune cells and, thus, might affect the ability of the tumor to survive. The MCL signature is represented by the overexpression of the chemokine CCL4 (MIP-1beta), implicated in the recruitment of regulatory T cells, as well as CCL5 and 4-1BB-L. The latter molecules are normally involved in chemotaxis of T cells and B cell activation, respectively. Signaling through 4-1BB-L allows B cells to proliferate and the expression of its ligand, by the intra-tumoral mesh of follicular dendritic cells (FDC), could thus serve as a paracrine loop facilitating growth and survival of MCL cells.

4-1BB Ligand↗
PubMed2006

Altered thymocyte migration during experimental acute Trypanosoma cruzi infection: combined role of fibronectin and the chemokines CXCL12 and CCL4.

We previously showed migration disturbances in the thymus during experimental infection with Trypanosoma cruzi, the causative agent of Chagas disease. These changes were related to the enhanced expression of extracellular matrix ligands and receptors, leading to the escape of immature cells to the periphery. Here, we analyzed the expression and role of selected chemokines (CXCL12 and CCL4) and their receptors (CXCR4 and CCR5) in regulating thymocyte migration in conjunction with extracellular matrix during acute T. cruzi infection. We found increased chemokine deposition in the thymus of infected mice when compared to controls, accompanied by enhanced co-localization with fibronectin as well as up-regulated surface expression of CXCR4 and CCR5 in thymocytes. We also noticed altered thymocyte migration towards the chemokines analyzed. Such an enhancement was even more prominent when fibronectin was added as a haptotatic stimulus in combination with a given chemokine. Our findings suggest that thymocyte migration results from a combined action of chemokines and extracellular matrix (ECM), which can be altered during pathological conditions such as T. cruzi infection, and may be at the origin of the changes in the T cell repertoire seen in this pathological process.

Animals↗
PubMed2006

Up-regulation of osteopontin, chemokines, adhesion molecule, and heat shock proteins in 1-hour biopsy from cardiac death donor kidneys.

AIMS: Since April 1979, 471 kidneys were retrieved from donors after cardiac death (DCD) using an in situ regional cooling technique, with excellent renal function and good long-term graft survival. However, the precise cascade of events following transplantation of DCD kidneys and the influence of ischemia-reperfusion injury remain unclear. In this study, we performed gene expression profiling using 1-hour biopsy samples from DCD kidneys versus those from living sources. METHODS: All kidney grafts were procured at our center using an in situ regional cooling technique from DCD. Living donor kidneys (LD) were harvested by open nephrectomy. All graft biopsies were performed 1 hour after reperfusion (DCD n = 8, LD n = 9). We analyzed the expression profile of 20,173 genes. RESULTS: One hundred seventy eight genes were up-regulated (>2-fold difference and DCD/LD > 1.5) and 120 down-regulated (<1/2-fold and LD/DCD > 1.5) in DCD kidneys. Expression of osteopontin (22.5 +/- 2.6-fold DCD vs 7.7 +/- 1.7 LD; P < .001), chemokines (CCL4 4.4 +/- 0.7 vs 2.5 +/- 0.3; P < .01), (CCL2 6.0 +/- 1.3 vs 2.8 +/- 0.5), CXCL1 (9.5 +/- 0.4 vs 2.0 +/- 0.2), and CXCL2 (16.7 +/- 5.3 vs 4.8 +/- 1.3; P < .05), adhesion molecule (ICAM-1 4.7 +/- 0.7 vs 2.5 +/- 0.4; P < .05), and heat shock proteins (HSPA1L 6.7 +/- 0.7 vs 1.6 +/- 0.3, HSPA1A 17.7 +/- 2.6 vs 2.4 +/- 0.5, HSPA1B 13.3 +/- 0.2 vs 3.0 +/- 0.7, HSPA5 6.7 +/- 0.8 vs 3.2 +/- 0.3, HSPB1 2.9 +/- 0.2 vs 1.0 +/- 0.1, and HSPH1 19.4 +/- 3.0 vs 5.9 +/- 1.1; P < .001) were up-regulated in the kidneys from DCD. CONCLUSION: This report analyzed global gene expression using 1-hour biopsy samples from DCD kidneys. These results may provide new insight into the identification of novel target genes for the development of therapeutic approaches and for determining graft viability of kidneys from DCD.

Biopsy↗
PubMed2000

Topical soluble tumor necrosis factor receptor type I suppresses ocular chemokine gene expression and rejection of allogeneic corneal transplants.

OBJECTIVE: To determine the effect of topical soluble tumor necrosis factor receptor type I (sTNFR-I) on survival of murine orthotopic corneal transplants and on ocular chemokine gene expression after corneal transplantation. METHODS: BALB/c mice (N = 50) were used as recipients of multiple minor H-disparate corneal transplants from B10.D2 donors. After orthotopic corneal transplantation, mice were randomized in a masked fashion to receive either topical sTNFR-I or vehicle 3 times daily, and all grafts were evaluated for signs of rejection and neovascularization by slitlamp biomicroscopy for 8 weeks. Ocular chemokine gene expression in sTNFR-I- and vehicle only-treated groups was determined using a multiprobe ribonuclease protection assay. RESULTS: Hosts treated with topical sTNFR-I experienced significantly enhanced corneal allograft survival compared with animals treated with vehicle alone (P =.01). Moreover, postoperative messenger RNA levels of RANTES and macrophage inflammatory protein-1beta in sTNFR-I-treated eyes were substantially suppressed compared with vehicle-treated eyes. Vehicle-treated eyes bearing rejected allografts expressed higher levels of messenger RNA for both chemokines than control eyes bearing accepted allografts. CONCLUSIONS: Topical treatment with sTNFR-I promotes the acceptance of allogeneic corneal transplants and inhibits gene expression of 2 chemokines (RANTES and macrophage inflammatory protein-1beta) associated with corneal graft rejection. CLINICAL RELEVANCE: Our findings support the feasibility of a topical anticytokine strategy as a means of reducing corneal allograft rejection without resorting to the use of potentially toxic immunosuppressive drugs.

Administration, Topical↗
PubMed2003

High expression of chemokines Gro-alpha (CXCL-1), IL-8 (CXCL-8), and MCP-1 (CCL-2) in inflamed human corneas in vivo.

OBJECTIVE: To investigate in vivo expression of chemokines in normal and inflamed human corneas, to determine whether chemokines are responsible for the recruitment of inflammatory cells. METHODS: In situ hybridization of the CXC chemokines growth-related oncogene-alpha (Gro-alpha) (CXCL-1), interleukin 8 (CXCL-8), macrophage interferon-gamma inducible gene (CXCL-9), and interferon-gamma inducible protein 10 (CXCL-10) and of the CC chemokines macrophage chemoattractant protein 1 (MCP-1) (CCL-2), macrophage inflammatory protein 1alpha (CCL-3), and regulated on activation, normal T-cell expressed and secreted (CCL-5) was performed to localize chemokine messenger RNA. Immunohistochemistry was used to identify the cellular infiltrate within the cornea. Three normal human eyes were compared with eyes enucleated because of chronic inflammation (n = 10), secondary to perforating injuries. RESULTS: In normal corneas, no chemokine expression was detected. In inflamed lesions, a high intensity of signals from Gro-alpha (CXCL-1) and MCP-1 (CCL-2) messenger RNA was observed in limbal epithelium and from Gro-alpha (CXCL-1), interleukin 8 (CXCL-8), and MCP-1 (CCL-2) in corneal stroma. The Gro-alpha (CXCL-1) was the only chemokine expressed by central corneal epithelium. All other examined chemokines were only moderately expressed in limbus and corneal stroma, or barely detectable. CONCLUSIONS: These cytokines are important agents in the cytokine network and contribute to the cell-specific and spatially restricted recruitment of neutrophils and mononuclear cells in acute inflammatory lesions of the human cornea. Clinical Relevance Understanding the role of chemokines in corneal inflammation may lead to the development of a selective receptor blockage of highly expressed chemokines to inhibit the recruitment of leukocyte subsets.

Antibodies, Monoclonal↗
PubMed1998

Distinct patterns of chemokine expression are associated with leukocyte recruitment in alcoholic hepatitis and alcoholic cirrhosis.

Alcoholic liver disease is associated with three histologically distinct processes: steatosis (parenchymal fat accumulation), alcoholic hepatitis (characterized by parenchymal infiltration by neutrophil polymorphs), and alcoholic cirrhosis (in which chronic inflammation and fibrosis dominate). Chemokines are cytokines that promote subset-specific leukoycte recruitment to tissues and could therefore play a crucial role in determining which leukocyte subsets are recruited to the liver in alcoholic liver disease. This paper reports that chemokine expression is increased in the liver of patients with alcoholic liver disease and, moreover, that distinct patterns of chemokine expression are associated with the different inflammatory responses to alcohol. Interleukin-8 (IL-8), monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory protein-1 alpha (MIP-1 alpha), and MIP-1 beta were all detected in the parenchyma at sites of inflammation in alcoholic hepatitis, whereas in alcoholic cirrhosis, chemokines were restricted to inflammatory cells and endothelium in the fibrous septa and portal tracts. In alcoholic hepatitis, chemokine transcription was localized to sinusoidal cells, leukocytes, and fibroblasts in areas of parenchymal inflammation, but hepatocytes, despite staining strongly for chemokine protein, were negative. In alcoholic cirrhosis, chemokine mRNA was detected in portal tract endothelium, leukocytes, and fibroblasts. Thus, alcoholic hepatitis and alcoholic cirrhosis are associated with distinct patterns of chemokine expression that are likely to be important factors in determining whether a patient develops acute parenchymal inflammation and alcoholic hepatitis, or chronic septal inflammation and alcoholic cirrhosis.

Chemokine CCL2↗
PubMed1997

Chemokines induce migrational responses in human breast carcinoma cell lines.

Chemokines have been shown to chemoattract and activate different leukocyte populations. Here we report the in vitro effect of macrophage inflammatory protein (MIP)-1alpha, MIP-1beta, regulated on activation, normal T-cells, expressed and secreted (RANTES), monocyte chemotactic protein-1 (MCP-1), interleukin-8 (IL-8), interferon inducible protein-10 (IP-10), neutrophil-activating peptide-2 (NAP-2), growth-related protein (GRO)-alpha and GRO-gamma, on the migration of 3 human breast carcinoma cell lines, MCF-7, T47D and ZR-75-1, using a microchemotaxis chamber to assess migration across fibronectin-coated polycarbonate membranes. MCF-7 cells responded chemotactically to all chemokines tested in a pattern which was dose and time dependent, although responses to the different chemokines were variable. ZR-75-1 responded to MIP-1beta and GRO-alpha, giving maximum migration indices of 3.7 and 5.3, respectively, and exhibited a migratory response to MIP-1alpha, IL-8 and MCP-1 although to a lower degree. T47D was unresponsive to the chemokines tested, but both MCF-7 and T47D cells bound radiolabelled ligands with binding constants (Kd) ranging from 0.6 to 2.2 nM and 0.6 to 2.1 nM, respectively. The specificity of the chemotactic response of MCF-7 to MIP-1alpha and MIP-1beta was confirmed using chemokine-specific neutralising antibodies and heat denaturation, and was demonstrated to involve G protein and cyclic AMP signalling pathways. MIP-1beta and MIP-1alpha were shown to induce changes in the organisation of the actin cytoskeleton and the level of F-actin in MCF-7 cells, as determined using flow cytometric analysis and confocal microscopy. Our results show that breast carcinoma cells can respond to chemokines, and suggests a potential role for these molecules in the process of tumour cell migration, invasion and metastasis.

Actins↗
PubMed1996

Chemokine expression in rat stab wound brain injury.

A traumatic injury to the adult mammalian central nervous system (CNS) results in reactive astrogliosis and the migration of hematogenous cells into the damaged neural tissue. Chemokines, a novel class of chemoattractant cytokines, are now being recognized as mediators of the inflammatory changes that occur following injury. The expression of MCP-1 (macrophage chemotactic peptide-1), a member of the beta family of chemokines, has recently been demonstrated in trauma in the rat brain (Berman et al.: J Immunol 156:3017-3023, 1996). Using a stab wound model for mechanical injury, we studied the expression of two other beta chemokines: RANTES (Regulated on Activation, Normal T cell Expressed and Secreted) and MIP-1 beta (macrophage inflammatory protein-1 beta) in the rat brain. The stab wound injury was characterized by widespread gliosis and infiltration of hematogenous cells. Immunohistochemical staining revealed the presence of RANTES and MIP-1 beta in the injured brain. RANTES and MIP-1 beta were both diffusely expressed in the necrotic tissue and were detected as early as 1 day post-injury (dpi). Double-labeling studies showed that MIP-1 beta, but not RANTES, was expressed by reactive astrocytes near the lesion site. In addition, MIP-1 beta staining was also detected on macrophages at the site of injury. The initial expression of the chemokines closely correlated with the appearance of inflammatory cells in the injured CNS, suggesting that RANTES and MIP-1 beta may play a role in the inflammatory events of traumatic brain injury. This study also demonstrates for the first time MIP-1 beta expression in reactive astrocytes following trauma to the rat CNS.

Animals↗
PubMed1999

Chemokines induce migration and changes in actin polymerization in adult rat brain microglia and a human fetal microglial cell line in vitro.

Microglia, the resident macrophages of the central nervous system, are the primary cells to respond to injury in the brain, both in inflammation, e.g., in multiple sclerosis, and trauma. Chemokines are potential mediators of microglial cell recruitment to sites of injury; thus, the ability of microglia to migrate in response to a number of chemokines was assessed. The chemokines monocyte chemoattractant protein 1, macrophage inflammatory protein 1alpha, macrophage inflammatory protein 1beta, RANTES (regulated upon activation normal T cell expressed and secreted), interleukin 8, and IP-10 (interferon gamma inducible protein-10), induce migration and changes in the distribution of f-actin in adult rat microglia and a human microglial cell line, CHME3, in vitro. Both cell types show a significant migration response, above control levels, to all the chemokines tested in a typical dose-dependent manner. These chemokines also induced a reorganization of the actin cytoskeleton of the cells. This study indicates that chemokines play an important role in the recruitment of microglia to areas of central nervous system inflammation.

Actins↗
PubMed2000

Distinct patterns of stimulus-inducible chemokine mRNA accumulation in human fetal astrocytes and microglia.

Interferon-gamma-inducible 10 kd protein (IP-10) is an ELR (Glu-Leu-Arg)(-) alpha chemokine with known chemotactic effects on T cells and monocytes, as well as anti-viral, anti-angiogenic, and anti-tumor effects. Previous studies have demonstrated that in cultured rat astrocytes and microglia, stimulation with LPS or virus can induce the expression of IP-10. In this study, we determined the pattern of IP-10 gene induction in primary human microglia and astrocytes by cytokines and LPS using ribonuclease protection assay. The expression of IP-10 mRNA was compared with that of other alpha (IL-8) and beta chemokines. The results showed that in human microglia, IP-10 expression was induced equally potently by LPS, IFNbeta or IFNgamma. "Proinflammatory" cytokines IL-1beta or TNFalpha also induced small amounts of IP-10 mRNA. "Anti-inflammatory" cytokines IL-4, IL-10 and TGFbeta were ineffective in inducing IP-10 in microglia. In human astrocytes, induction of IP-10 mRNA by cytokines was similar to that in microglia. LPS, however, was ineffective in inducing IP-10 in human astrocytes. The monocyte chemoattractant beta-chemokine I-309 mRNA was induced in human astrocytes and microglia by IFNbeta or IFNgamma, or by LPS in microglia, showing a tight co-regulation with IP-10 mRNA expression. In contrast to the potent induction of IP-10 and I-309 by IFNs in human glia, the ELR(+) alpha chemokine IL-8 mRNA was induced by IL-1beta and TNFalpha, and to a lesser extent by IFNbeta in microglia. IFNbeta but not IFNgamma was effective in inducing the expression of beta chemokines MIP-1alpha and MIP-1beta in human microglia, with the levels of mRNA similar to those induced by IL-1beta or TNFalpha. Neither MIP-1alpha nor MIP-1beta mRNAs were induced by any stimulation in human astrocytes. The induction of RANTES mRNA in microglia by IFNbeta, IL-1beta or TNFalpha was variable, showing no to low level expression depending on the case, whereas LPS provided a consistent inducing signal. In astrocytes, only cytokine combinations (IFN + IL-1beta) effectively induced the RANTES mRNA. These results demonstrate that distinct sets of chemokine genes are induced in human glial cells by cytokines and interferons. These results may have wide implications for inflammatory, vascular and neoplastic diseases of the CNS.

Astrocytes↗