Growth, metastasis, and expression of CCL2 and CCL5 by murine mammary carcinomas are dependent upon Myd88

Previously we reported that lipopolysaccharide (LPS) treatment of murine mammary carcinomas resulted in decreased growth of the tumors. Here we show the decreased growth following LPS treatment was mediated through effects downstream of TLR4 and Myd88. Perhaps more notably, simply reducing TLR4 or Myd88 levels was sufficient to slow tumor growth rates. Moreover, reduced levels of Myd88 correlated with a significant reduction in lung metastasis as well as decreased CCL2 and CCL5 expression. To determine whether inhibiting Myd88 function could also alter tumor growth and chemokine expression we used a Myd88 homodimerization inhibitory peptide. Indeed, inhibiting Myd88 function in four different murine mammary carcinomas as well as the human breast cancer cell line MDA-MB-231 led to decreased growth as well as CCL2 and CCL5 expression. These data imply that Myd88 is important for growth and metastasis of breast cancer, and expression of at least two proinflammatory chemokines.

HIV-1 efficient entry in inner foreskin is mediated by elevated CCL5/RANTES that recruits T cells and fuels conjugate formation with Langerhans cells

Male circumcision reduces acquisition of HIV-1 by 60%. Hence, the foreskin is an HIV-1 entry portal during sexual transmission. We recently reported that efficient HIV-1 transmission occurs following 1 h of polarized exposure of the inner, but not outer, foreskin to HIV-1-infected cells, but not to cell-free virus. At this early time point, Langerhans cells (LCs) and T-cells within the inner foreskin epidermis are the first cells targeted by the virus. To gain in-depth insight into the molecular mechanisms governing inner foreskin HIV-1 entry, foreskin explants were inoculated with HIV-1-infeceted cells for 4 h. The chemokine/cytokine milieu secreted by the foreskin tissue, and resulting modifications in density and spatial distribution of T-cells and LCs, were then investigated. Our studies show that in the inner foreskin, inoculation with HIV-1-infected cells induces increased CCL5/RANTES (1.63-fold) and decreased CCL20/MIP-3-alpha (0.62-fold) secretion. Elevated CCL5/RANTES mediates recruitment of T-cells from the dermis into the epidermis, which is blocked by a neutralizing CCL5/RANTES Ab. In parallel, HIV-1-infected cells mediate a bi-phasic modification in the spatial distribution of epidermal LCs: attraction to the apical surface at 1 h, followed by migration back towards the basement membrane later on at 4 h, in correlation with reduced CCL20/MIP-3-alpha at this time point. T-cell recruitment fuels the continuous formation of LC-T-cell conjugates, permitting the transfer of HIV-1 captured by LCs. Together, these results reveal that HIV-1 induces a dynamic process of immune cells relocation in the inner foreskin that is associated with specific chemokines secretion, which favors efficient HIV-1 entry at this site.

15-deoxy-D12,14-prostaglandin J2 suppresses RANTES expression by inhibiting NADPH oxidase activation in Helicobacter pylori-infected gastric epithelial cells

Peroxisome proliferators-activated receptor-γ (PPAR-γ) is a ligand-activated transcription factor. 15 deoxy-(12,14) prostaglandin J(2) (15d-PGJ(2)) is a potent PPAR-γ ligand and acts as an anti-inflammatory agent via PPAR-γ-dependent and independent mechanisms. Helicobacter pylori (H. pylori) induces gastric inflammation by inducing the activation of oxidant-sensitive transcription factor NF-κB and cytokine expression in gastric epithelial cells. Since 15d-PGJ(2) inhibits NF-κB activation in various cells, it may suppress H. pylori-induced inflammatory signaling and cytokine expression in gastric epithelial cells. The present study aims to determined the effect of 15d-PGJ(2) on the activation of inflammatory mediators Jak/Stat (Janus kinase/signal transducers and activators of transcription) and induction of cytokine RANTES in H. pylori-infected gastric epithelial AGS cells. Since NADPH oxidase is a candidate for the production of reactive oxygen species in H. pylori-infected gastric epithelial cells, we determined the effect of 15d-PGJ(2) on the activation of NADPH oxdase. AGS cells were cultured in the presence of H. pylori treated with or without 15d-PGJ(2). The activations of NADPH oxidase and Jak1/Stat3, the levels of H(2)O(2) and RANTES in the medium, and DNA binding activity of Stat3 were assessed. A Jak/Stat3 specific inhibitor AG490 and an inhibitor of NADPH oxidase diphenyleneiodonium (DPI) were treated to determine the direct involvement of Jak/Stat and NADPH oxidase on the production of H(2)O(2) and RANTES in H. pylori-infected cells. H. pylori induced the production of H(2)O(2) and RANTES as well as the activations of NADPH oxidase and Jak1/Stat3, which were inhibited by the treatment of 15d-PGJ(2). DPI suppressed H. pylori-induced alterations similar to 15d-PGJ(2). However, AG490 had no effect on NADPH oxidase activation, but reduced the level of RANTES in the medium released from H. pylori-infected cells.

CONCLUSION

NADPH oxidase activation is an upstream signaling of Jak1/Stat3 activation and induction of RANTES in H. pylori-infected AGS cells. 15d-PGJ(2), inhibits the activations of NADPH oxidase and Jak1/Stat3 and RANTES expression, suggesting that 15d-PGJ(2) may be beneficial for the treatment of H. pylori-induced gastric inflammation.

Molecular cloning of the porcine RANTES promoter: functional characterization of dsDNA/dsRNA response elements in PK-15 cells

The chemokine RANTES plays an essential role in inflammation and immune response. In this study, we cloned the nucleotide sequence of the 5'-flanking region of the porcine RANTES (poRANTES) gene and characterized the regulatory elements that activate transcription. Analyses of a series of 5' deletion constructs demonstrated that a 266 bp region (-220/+46) that spanned the potential transcription start site of the poRANTES gene was sufficient to activate transcription in PK-15 cells. Furthermore, our results indicated that dsDNA/dsRNA significantly induced poRANTES promoter activity and expression of mRNA levels in a time- and dose-dependent manner. Promoter deletions and mutagenesis experiments indicated that an interferon-stimulated responsive element (ISRE) was critical for dsDNA/dsRNA-induced poRANTES transcription. In addition, porcine interferon regulatory factor 3 (IRF-3) and IRF-7 play important roles in dsDNA/dsRNA-induced poRANTES expression.

Vascular endothelial cells cultured from patients with cerebral or uncomplicated malaria exhibit differential reactivity to TNF

Plasmodium falciparum malaria is a major cause of morbidity and mortality in African children, and factors that determine the development of uncomplicated (UM) versus cerebral malaria (CM) are not fully understood. We studied the ex vivo responsiveness of microvascular endothelial cells to pro-inflammatory stimulation and compared the findings between CM and UM patients. In patients with fatal disease we compared the properties of vascular endothelial cells cultured from brain tissue to those cultured from subcutaneous tissue, and found them to be very similar. We then isolated, purified and cultured primary endothelial cells from aspirated subcutaneous tissue of patients with CM (EC(CM) ) or UM (EC(UM) ) and confirmed the identity of the cells before analysis. Upon TNF stimulation in vitro, EC(CM) displayed a significantly higher capacity to upregulate ICAM-1, VCAM-1 and CD61 and to produce IL-6 and MCP-1 but not RANTES compared with EC(UM) . The shedding of endothelial microparticles, a recently described parameter of severity in CM, and the cellular level of activated caspase-3 were both significantly greater in EC(CM) than in EC(UM) . These data suggest that inter-individual differences in the endothelial inflammatory response to TNF may be an additional factor influencing the clinical course of malaria.

Chlamydia pneumoniae induces chemokine expression by platelets in patients with atherosclerosis

OBJECTIVE

In this study, the role of Chlamydia pneumoniae in triggering platelets to induce the inflammatory potential chemokines CCL3, CCL5, CCL7 and CXCL8 in atherosclerotic patients was investigated.

SUBJECTS AND METHODS

Venous blood from control subjects (n = 35) and atherosclerotic patients (n = 35) was collected in tubes with and without EDTA. Platelets from controls and patients were separated from whole blood and then stimulated with lipopolysaccharide (LPS), live C. pneumoniae and heat-treated C. pneumoniae. The ability of C. pneumoniae and its LPS to stimulate platelets and expression of CCL3, CCL5, CCL7 and CXCL8 was assessed with immunofluorescence. Immunosorbent assays were used to detect anti-C. pneumoniae antibodies in sera from patients and healthy subjects.

RESULTS

Nonstimulated platelets from patients showed significant expression of CCL3, CCL5, CCL7 and CXCL8 compared to controls (p < 0.0001). Stimulation of platelets from patients with live and heat-treated C. pneumoniae and its LPS demonstrated significant induction of chemokines compared to similarly stimulated platelets from controls (p < 0.01). After stimulation with heat-treated C. pneumoniae chemokine expression in platelets from controls was significantly lower than after stimulation with live C. pneumoniae (p < 0.01), which was not the case when platelets from patients were stimulated. Increased levels of anti-C. pneumoniae antibodies were detected in sera from patients compared to healthy subjects, suggesting prior C. pneumoniae exposure.

CONCLUSION

Our data demonstrated an interactive link between C. pneumoniae and platelets in atherosclerotic patients, leading to induction of potential chemokines and possibly disease development.

TNF-α and IL-1β mediate Japanese encephalitis virus-induced RANTES gene expression in astrocytes

Infection with Japanese encephalitis virus (JEV) causes neuroinfection and neuroinflammation characterized by profound neuronal destruction/dysfunction, concomitant microgliosis/astrogliosis, and production of various molecules that initiate the recruitment of immune cells to the sites of infection. Previously, we reported that glial cells expressed RANTES (regulated upon activation, normal T cell expressed and secreted) with chemotactic activity in response to JEV infection. In this study, we further demonstrated that JEV-infected microglia had an additional activity in regulating RANTES production. Both astrocytes and microglia responded to JEV infection by releasing RANTES through a process likely related to viral replication. Independent of infectious virus, supernatants of JEV-infected microglia, but not JEV-infected astrocytes, caused additional RANTES production from astrocytes. Antibody neutralization studies suggested the potential involvement of tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) in mediating additional RANTES production. Treatment of astrocyte cultures with TNF-α and IL-1β caused activation of several signaling molecules and transcription factors crucial to RANTES gene expression, including reactive oxygen species, extracellular signal-regulated kinase, NF-κB, and NF-IL6, increased RANTES gene promoter activity, and provoked RANTES production. As with RANTES, neutralization of bioactive TNF-α and IL-1β caused an attenuation of chemotactic activity from supernatants of mixed glia containing astrocytes and microglia during the course of JEV infection. In conclusion, TNF-α and IL-1β produced by JEV-infected microglia might trigger another mechanism which induces a secondary wave of RANTES gene expression by activating astrocytes. The released RANTES from glial cells might play a role in the recruitment of immune cells during JEV infection.

Rabies virus nucleoprotein functions to evade activation of the RIG-I-mediated antiviral response

The rabies virus Ni-CE strain causes nonlethal infection in adult mice after intracerebral inoculation, whereas the parental Nishigahara (Ni) strain kills mice. We previously reported that the chimeric CE(NiN) strain with the N gene from the Ni strain in the genetic background of the Ni-CE strain kills adult mice, indicating that the N gene is related to the different pathogenicities of Ni and Ni-CE strains. In the present study, to obtain an insight into the mechanism by which the N gene determines viral pathogenicity, we compared the effects of Ni, Ni-CE, and CE(NiN) infections on host gene expressions using a human neuroblastoma cell line. Microarray analysis of these infected cells revealed that the expression levels of particular genes in Ni- and CE(NiN)-infected cells, including beta interferon (IFN-beta) and chemokine genes (i.e., CXCL10 and CCL5) were lower than those in Ni-CE-infected cells. We also demonstrated that Ni-CE infection activated the interferon regulatory factor 3 (IRF-3)-dependent IFN-beta promoter and induced IRF-3 nuclear translocation more efficiently than did Ni or CE(NiN) infection. Furthermore, we showed that Ni-CE infection, but not Ni or CE(NiN) infection, strongly activates the IRF-3 pathway through activation of RIG-I, which is known as a cellular sensor of virus infection. These findings indicate that the N protein of rabies virus (Ni strain) has a function to evade the activation of RIG-I. To our knowledge, this is the first report that the Mononegavirales N protein functions to evade induction of host IFN and chemokines.

Inhibitory effects of Schefflera leucantha extract on production of allergic mediators by Langerhans cells and mast cells

BACKGROUND

Schefflera leucantha Viguier is used as a traditional medicine in Thailand and China to relieve chronic cough and asthma. However, little is known about its anti-allergic effects.

OBJECTIVE

This study was designed to investigate the effects of S leucantha ethanol extract (SLEE) on chemokine production by epidermal Langerhans cells (LCs) stimulated with peptidoglycan (PEG) from Staphylococcus aureus and histamine release from mast cells.

METHODS

LCs were purified from murine epidermal cells using the panning method with anti-IA(d) monoclonal antibody. Chemokine production by LCs was investigated by reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay (ELISA). Mast cells for histamine release assay were induced by long-term culture of mouse spleen cells. Histamine release from these mast cells was measured by a competitive ELISA.

RESULTS

Production of the eosinophil chemoattractant CCL5 and the type 2 T helper (TH2)-associated chemokine CCL17 from PEG-stimulated LCs was significantly inhibited by SLEE. Furthermore, SLEE significantly decreased the release of histamine from mast cells by IgE-mediated degranulation.

CONCLUSION

These results suggest that S leucantha may offer a new therapeutic approach for the control of atopic dermatitis associated with S aureus colonization through inhibition of the production of allergic mediators.

The roles of chemokines in rabies virus infection: overexpression may not always be beneficial

It was found previously that induction of innate immunity, particularly chemokines, is an important mechanism of rabies virus (RABV) attenuation. To evaluate the effect of overexpression of chemokines on RABV infection, chemokines macrophage inflammatory protein 1alpha (MIP-1alpha), RANTES, and IP-10 were individually cloned into the genome of attenuated RABV strain HEP-Flury. These recombinant RABVs were characterized in vitro for growth properties and expression of chemokines. It was found that all the recombinant viruses grew as well as the parent virus, and each of the viruses expressed the intended chemokine in a dose-dependent manner. When these viruses were evaluated for pathogenicity in the mouse model, it was found that overexpression of MIP-1alpha further decreased RABV pathogenicity by inducing a transient innate immune response. In contrast, overexpression of RANTES or IP-10 increased RABV pathogenicity by causing neurological diseases, which is due to persistent and high-level expression of chemokines, excessive infiltration and accumulation of inflammatory cells in the central nervous system, and severe enhancement of blood-brain barrier permeability. These studies indicate that overexpression of chemokines, although important in controlling virus infection, may not always be beneficial to the host.

Hantaan virus triggers TLR3-dependent innate immune responses

Immediately after viral infection, innate responses including expression of IFN-alpha/beta and IFN-stimulated genes (ISGs) are elicited ubiquitously by recruitment of specific pathogen recognition receptors. The velocity to induce IFN-alpha/beta and ISGs in response to an infection is often decisive for virulence. Interestingly, in primary endothelial cells ISGs are induced later by hantaviruses pathogenic to humans than those considered to be nonpathogenic or of low virulence. Here we demonstrate that pathogenic Hantaan (HTNV) and putatively nonpathogenic Prospect Hill hantavirus (PHV) differentially activate innate responses in the established cell lines A549 and HuH7. STAT1alpha phosphorylation was detectable 3 h after PHV inoculation but not within the first 2 days after HTNV inoculation. The velocity to induce the ISGs MxA and ISG15 correlated inversely with amounts of virus produced. Moreover, expression of the inflammatory chemokine CCL5 was also induced differentially. Both hantaviruses induced innate responses via TRAF3 (TNF receptor-associated factor 3), and TLR3 was required for HTNV-induced expression of MxA, but not for the MxA induction triggered by PHV. Infection of RIG-I-deficient HuH7.5 cells revealed that RIG-I (retinoic acid receptor I) was not necessary for induction of innate responses by PHV. Taken together, these data suggest that HTNV and PHV elicit different signaling cascades that converge via TRAF3. Early induction of antiviral responses might contribute to efficient elimination of PHV. Subsequent to clearance of the infection, innate responses most likely cease; vice versa, retarded induction of antiviral responses could lead to increased HTNV replication and dissemination, which might cause a prolonged inflammatory response and might contribute to the in vivo virulence.

Cigarette smoke combined with Toll-like receptor 3 signaling triggers exaggerated epithelial regulated upon activation, normal T-cell expressed and secreted/CCL5 expression in chronic rhinosinusitis

BACKGROUND

Chronic rhinosinusitis (CRS) is characterized by persistent mucosal inflammation and frequent exacerbations.

OBJECTIVE

To determine whether innate epithelial responses to cigarette smoke or bacterial or viral pathogens may be abnormal in CRS leading to an inappropriate inflammatory response.

METHODS

Primary nasal epithelial cells (PNECs) were grown from middle turbinate biopsies of 9 healthy controls and 11 patients with CRS. After reaching 80% to 90% confluence, PNECs were exposed to medium or cigarette smoke extract (CSE) 5% (vol/vol) for 1 hour, washed, then stimulated with staphylococcal lipoteichoic acid, LPS, or double-stranded RNA (dsRNA). After 24 hours, gene expression was quantified by QRT-PCR.

RESULTS

At baseline, PNECs revealed elevated TNF-alpha and growth-related oncogene-alpha (a C-X-C chemokine)/CXCL1 (GRO-alpha) (4-fold increase, P = .02; and 16-fold increase, P = .004, respectively) in subjects with CRS compared with controls with normal levels of IL-1beta, IL-6, IL-8/CXCL8, human beta-defensin-2, monocyte chemoattractant protein 2/CCL8, monocyte chemoattractant protein 3/CCL7, and regulated upon activation, normal T-cell expressed and secreted (RANTES)/CCL5. Immunostaining of nasal biopsies, however, revealed comparable epithelial staining for TNF-alpha, GRO-alpha, and RANTES. There were no differences in mRNA induction by CSE, TNF-alpha, lipoteichoic acid, LPS, or dsRNA alone. The combination of CSE+dsRNA induced exaggerated RANTES (12,115-fold vs 1500-fold; P = .03) and human beta-defensin-2 (1120-fold vs 12.5-fold; P = .05) in subjects with CRS. No other genes were differentially induced. Furthermore, CSE+dsRNA induced normal levels of IFN-beta, IFN-lambda1, and IFN-lambda2/3 mRNA in subjects with CRS.

CONCLUSION

Cigarette smoke extract plus dsRNA induces exaggerated epithelial RANTES expression in patients with CRS. We propose that an analogous response to cigarette smoke plus viral infection may contribute to acute exacerbations and eosinophilic mucosal inflammation in CRS.

[Effect of mycophenolate mofetil on the expression of early inflammatory reaction in diabetic rats]

OBJECTIVE

To investigate the effect of mycophenolate mofetil(MMF) on early inflammatory reaction of renal lesion in streptozotocin(STZ)-induced diabetic rats.

METHODS

Thirty-six male Sprague-Dawley rats were randomly divided into 3 groups after uninephrectomy: normal control group, diabetic model group, and MMF-treated group. Six rats in each group were sacrificed at the 4th week and 14th week after STZ injection. Twenty-four hour urinary protein (24 h Upro) count was measured before death. The expressions of regulated on activation of normal T expressed and secreted (RANTES),ectodermal dysplasia (ED-1)and Col-IV protein in the renal tissue were detected by immunohistochemistry. The expression of RANTES mRNA in the renal tissue was detected by RT-PCR.

RESULTS

MMF prevented the increasing of 24h Upro in diabetic rats,and the expressions of RANTES,ED-1,Col-IV protein and RANTES mRNA in the kidney of MMF-treated rats were significantly decreased.

CONCLUSION

MMF plays an early renal protective role in diabetic nephropathy, possibly through inhibition of early inflammatory reaction.

Concomitant expression of the chemokines RANTES and MCP-1 in human breast cancer: a basis for tumor-promoting interactions

The chemokines RANTES (CCL5) and MCP-1 (CCL2) were suggested to contribute, independently, to breast malignancy. In the present study, we asked if the two chemokines are jointly expressed in clinical samples of breast cancer patients, and do they interact in breast tumor cells. We found that RANTES and MCP-1 were expressed by breast tumor cells in primary tumors of Ductal Carcinoma In Situ and of Invasive Ductal Carcinoma, but minimally in normal breast epithelial duct cells. The chemokines were also detected in metastases and pleural effusions. Novel findings showed that co-expression of RANTES and MCP-1 in the same tumor was associated with more advanced stages of disease, suggesting that breast tumors "benefit" from interactions between the two chemokines. Accordingly, MCP-1 significantly promoted the release of RANTES from endogenous pre-made vesicles, in an active process that depended on calcium from intracellular and extracellular sources, and on intracellular transport of RANTES towards exocytosis. Our findings show a chemokine-triggered release of stored pro-malignancy chemokine from breast tumor cells. These observations support a major tumor-promoting role for co-expression of the chemokines in breast malignancy, and agree with the significant association of joint RANTES and MCP-1 expression with advanced stages of breast cancer.

Signal transduction involved in CTGF-induced production of chemokines in mesangial cells

OBJECTIVE AND DESIGN

This study investigates the regulatory role of connective tissue growth factor (CTGF) on production of fractalkine, monocyte-chemoattractant protein-1 (MCP-1) and regulated on activation, normal T cell expressed and secreted (RANTES) in human mesangial cells, and explore the mechanisms of CTGF action.

METHODS

Cultured human mesangial cells were treated with CTGF. Expressions of mRNA and proteins of fractalkine, MCP-1 and RANTES were analyzed by real-time polymerase chain reaction (PCR) and by enzyme-linked immunosorbent assay, respectively. Expressions of phosphorylated extracellular signal-regulated kinase 1/2 (ERK1/2), phosphoinositide 3-kinase (PI3-K) and protein kinase B (PKB) were assessed by Western blotting. Activities of nuclear factor-KB (NF-KB) were determined by NF-kappaB luciferase reporter assay.

RESULTS

CTGF enhanced the mRNA expressions and protein release of fractalkine, MCP-1 and RANTES, and the expressions of phosphorylated ERK1/2, PI3-K and PKB, and activities of NF-KB. Blockade of ERK1/2 inhibited the CTGF-induced expression ofphosphorylated ERK1/2 and NF-kappaB, and partially decreased the expressions of the above chemokines. PI3-K blockade downregulated the CTGF-stimulated expressions of phosphorylated PI3-K, PKB and NF-kappaB but not phosphorylated ERK1/2, partially decreased the expressions of the above chemokines. NF-kappaB blockade abrogated the CTGF-activated NF-kappaB and partially decreased the expressions of the above chemokines. Soluble heparin and K252a, an inhibitor of Trk, blocked CTGF-induced production of the above chemokines and the activation of the above signaling proteins.

CONCLUSION

These results demonstrated that CTGF induces production of fractalkine, MCP-1 and RANTES via ERK1/2 and PI3-K/PKB/NF-kappaB-dependent signal pathway mediated by cell surface heparin sulfate proteoglycans and the tyrosine kinase receptor TrkA in human mesangial cells.

Statins but not thiazolidinediones attenuate albumin-mediated chemokine production by proximal tubular cells independently of endocytosis

BACKGROUND

Proximal tubular epithelial cells (PTEC) secrete chemokines under proteinuric conditions. Both statins and thiazolidinediones (TZDs) possess pleiotropic anti-inflammatory effects. This study examined the ability of statins and TZDs and the natural peroxisome proliferator activated receptor-gamma (PPARgamma) agonist 15-deoxy-Delta(12,14)-prostaglandin J(2) (PGJ(2)) to attenuate the proteinuria-induced pro-inflammatory phenotype of PTEC.

METHODS

Mouse PTEC were treated with statins, TZDs and PGJ(2 )and effects on uptake and binding of FITC-albumin determined. PTEC were incubated with fatty acid free bovine serum albumin with or without statins/TZDs/PGJ(2), and the release of MCP-1 and RANTES measured.

RESULTS

Statins and TZDs significantly inhibited PTEC albumin endocytosis. PGJ(2 )had no effect. Incubation of PTEC with albumin significantly stimulated production of MCP-1 and RANTES. Co-treatment with statins and PGJ(2) significantly reduced albumin-stimulated chemokine production, an effect reversed by the addition of mevalonate and geranylgeranyl pyrophosphate. In contrast, TZDs had no effect on albumin-mediated chemokine production.

CONCLUSION

Statins and PGJ(2), but not TZDs, prevent the development of a PTEC pro-inflammatory phenotype in response to albumin. Albumin endocytosis is not a prerequisite for PTEC chemokine production, and inhibition of albumin endocytosis alone is insufficient to attenuate chemokine production. These studies suggest a therapeutic role for statins and some PPARgamma ligands in proteinuric renal disease.

Suppression of CCL2/MCP-1 and CCL5/RANTES expression by nociceptin in human monocytes

The receptor designated Opioid Receptor-Like 1 (ORL1) is abundantly expressed in the central nervous system (CNS) as well as by cells of the immune system. While much is known about the function of ORL1 in the CNS, there is little information in the literature about the role of ORL1 in the immune response. There have been numerous reports documenting the effects of GPCR activation on the expression of chemokines crucial in mediating inflammatory events in biological systems. The aim of the present work was to examine the effect of nociceptin administration on the pro-inflammatory chemokine expression of human monocytes. We report here that human CD14(+) monocytes expresses the mRNA for ORL1. Our results also demonstrate that nociceptin can suppress the production of CCL2/MCP-1 and CCL5/RANTES chemokine protein in both primary CD14(+) human monocytes and monocyte-like cell lines. However, nociceptin does not appear to regulate the expression of these chemokines at the level of transcription, as CCL2/MCP-1 and CCL5/RANTES mRNA levels following nociceptin treatment of monocytes were essentially normal. Although the mechanism of chemokine regulation by nociceptin is as yet unknown, it is evident that the ORL1/nociceptin system plays a role in regulating chemotactic responses of leukocytes through chemokine suppression. Finally, these data may provide the initial basis for the development of ORL1 agonists and antagonists for therapeutic treatment of inflammatory disease.

[RANTES expression in venous ulceration of lower limbs]

OBJECTIVE

To investigate the expression of RANTES in venous ulceration.

METHODS

From patients with lower limb venous ulceration, patients with non-ulcerous venous insufficiency, and healthy individuals, peripheral blood was collected from the lower limb veins for measurement of RANTES mRNA using RT-PCR.

RESULTS

In the ulceration group, the expression of RANTES mRNA was significantly increased as compared with the other two groups (P<0.01). RANTES mRNA expression was also significant higher in the non-ulcerous group than the control group (P<0.01).

CONCLUSION

High expression of RANTES mRNA may be one of the important mechanisms of venous ulceration.

Chemokine profile among human immunodeficiency virus-1 (HIV-1) infected individuals from southern India

BACKGROUND & OBJECTIVE

Individuals infected with HIV-1 have higher levels of chemokine producing cells compared to uninfected individuals. It is important to know the changes in chemokine levels associated with rate of progression of disease. There is a paucity of information on the plasma chemokines in HIV-1 infected individuals from India. We therefore carried out this study to estimate the levels of three chemokines namely macrophage inflammatory protein alpha (MIP1alpha), MIP1beta and RANTES, in relation to disease status in HIV-1 infected individuals and compared with uninfected individuals.

METHODS

RANTES and MIP1alpha were estimated using ELISA in 114 HIV-1 infected and 30 controls, whereas MIP1beta was estimated in 101 HIV infected individuals only and 30 controls. The values were compared to the T cell subsets, HIV-1 viral loads and plasma cytokines (interferon gamma and interleukin-10).

RESULTS

Compared to controls the mean MIP1alpha and RANTES level among the HIV-1 infected individuals was higher while MIP1beta level was lower in HIV infected individuals except CDC C groups. There was a significant positive correlation for MIP1á with HIV-1 viral load and IFNgamma, for MIP1alpha with viral load and IL10. There was a significant negative correlation between MIP1alpha with CD4 count and CD4: CD8 ratio and MIP1beta with CD4 count and CD8 count. There was a negativecorrelation between RANTES values and CD8 per cent.

INTERPRETATION & CONCLUSION

In conclusion, our study showed a significantly higher level of beta chemokines in south Indian HIV-1 infected individuals compared to controls. These beta chemokines may have the inhibitory effect on HIV-1 only during the initial period and with the progression of disease this inhibitory effect wanes as shown by the positive correlation of beta chemokines with HIV-1 viral load.

Antigen stimulation induces HIV envelope gp120-specific CD4(+) T cells to secrete CCR5 ligands and suppress HIV infection

CD4(+) T cells are critical for effective immune responses against HIV, but they are also the main cell type targeted by the virus. To investigate the key factors that could protect these cells from infection, we evaluated the capacity of HIV gp120-specific human CD4(+) T cells to produce chemokines that inhibit HIV and determined their contribution in suppressing infection in the cells. Antigen stimulation of the CD4(+) T cells elicited production of high amounts of CCR5 chemokines MIP-1alpha (CCL3), MIP-1beta (CCL4), and RANTES (CCL5). Production of these CCR5 ligands was more readily and reproducibly detected than that of IFN-gamma or IL-2. Importantly, in association with secretion of the CCR5 ligands, antigen stimulation made these CD4(+) T cells more resistant to CCR5-tropic HIV-1. Conversely, in the absence of antigen stimulation, the cells were readily infected by the virus, and after infection, their capacity to produce MIP-1beta and IFN-gamma rapidly declined. Thus, vaccines that trigger HIV-specific CD4(+) T cells to elicit robust and rapid production of anti-viral chemokines would be advantageous. Such responses would protect virus-specific CD4(+) T cells from HIV infection and preserve their critical functions in mounting and maintaining long-lasting immunity against the virus.

Activation of human monocytes after infection by human coronavirus 229E

Human coronaviruses (HCoV) are recognized respiratory pathogens that may be involved in other pathologies such as central nervous system (CNS) diseases. To investigate whether leukocytes could participate in respiratory pathologies and serve as vector for viral spread towards other tissues, the susceptibility of human leukocytic cell lines and peripheral blood mononuclear cells (PBMC) to HCoV-229E and HCoV-OC43 infection was investigated. Human primary monocytes/macrophages were susceptible to HCoV-229E infection, but strongly restricted HCoV-OC43 replication. Moreover, productive HCoV-229E infection of primary monocytes and of the THP-1 monocytic cell line led to their activation, as indicated by the production of pro-inflammatory mediators, including TNF-alpha, CCL5, CXCL10 and CXCL11 and MMP-9. Moreover, an in vitro chemotaxis assay showed that motility towards chemokines of THP-1 cells and primary monocytes was increased following an acute or persistent HCoV-229E infection. Taken together, these results suggest that infected monocytes could serve as a reservoir for HCoV-229E, become activated, participate in the exacerbation of pulmonary pathologies, as well as serve as potential vectors for viral dissemination to host tissues, where it could be associated with other pathologies.

Degradation of nuclear factor kappa B during foot-and-mouth disease virus infection

We have previously shown that the leader proteinase (L(pro)) of foot-and-mouth disease virus (FMDV) interferes with the innate immune response by blocking the translation of interferon (IFN) protein and by reducing the immediate-early induction of beta IFN mRNA and IFN-stimulated genes. Here, we report that L(pro) regulates the activity of nuclear factor kappaB (NF-kappaB). Analysis of NF-kappaB-dependent reporter gene expression in BHK-21 cells demonstrated that infection with wild-type (WT) virus has an inhibitory effect compared to infection with a genetically engineered mutant lacking the leader coding region. The expression of endogenous NF-kappaB-dependent genes tumor necrosis factor alpha and RANTES is also reduced in WT virus-infected primary porcine cells. This inhibitory effect is neither the result of a decrease in the level of the mRNA of p65/RelA, a subunit of NF-kappaB, nor a block on the nuclear translocation of p65/RelA, but instead appears to be a consequence of the degradation of accumulated p65/RelA. Viral L(pro) is localized to the nucleus of infected cells, and there is a correlation between the translocation of L(pro) and the decrease in the amount of nuclear p65/RelA. By using a recombinant cardiovirus expressing L(pro), we demonstrate that the disappearance of p65/RelA takes place in the absence of any other FMDV product. The observation that L(pro) disrupts the integrity of NF-kappaB suggests a global mechanism by which FMDV antagonizes the cellular innate immune and inflammatory responses to viral infection.

Interaction of PRP4 with Kruppel-like factor 13 regulates CCL5 transcription

Activation of resting T lymphocytes initiates differentiation into mature effector cells over 3-7 days. The chemokine CCL5 (RANTES) and its major transcriptional regulator, Krüppel-like factor 13 (KLF13), are expressed late (3-5 days) after activation in T lymphocytes. Using yeast two-hybrid screening of a human thymus cDNA library, PRP4, a serine/threonine protein kinase, was identified as a KLF13-binding protein. Specific interaction of KLF13 and PRP4 was confirmed by reciprocal coimmunoprecipitation. PRP4 is expressed in PHA-stimulated human T lymphocytes from days 1 and 7 with a peak at day 3. Using an in vitro kinase assay, it was found that PRP4 phosphorylates KLF13. Furthermore, although phosphorylation of KLF13 by PRP4 results in lower binding affinity to the A/B site of the CCL5 promoter, coexpression of PRP4 and KLF13 increases nuclear localization of KLF13 and CCL5 transcription. Finally, knock-down of PRP4 by small interfering RNA markedly decreases CCL5 expression in T lymphocytes. Thus, PRP4-mediated phosphorylation of KLF13 plays a role in the regulation of CCL5 expression in T lymphocytes.

IFN-gamma-induced protein 10 is a novel biomarker of rhinovirus-induced asthma exacerbations

Background

Rhinovirus-induced acute asthma is the most frequent trigger for asthma exacerbations.

Objective

We assessed which inflammatory mediators were released from bronchial epithelial cells (BECs) after infection with rhinovirus and then determined whether they were also present in subjects with acute virus-induced asthma, with the aim to identify a biomarker or biomarkers for acute virus-induced asthma.

Methods

BECs were obtained from bronchial brushings of steroid-naive asthmatic subjects and healthy nonatopic control subjects. Cells were infected with rhinovirus 16. Inflammatory mediators were measured by means of flow cytometry with a cytometric bead array. Subjects with acute asthma and virus infection were recruited; they were characterized clinically by using lung function tests and had blood taken to measure the inflammatory mediators identified as important by the BEC experiments.

Results

IFN-γ–induced protein 10 (IP-10) and RANTES were released in the greatest quantities, followed by IL-6, IL-8, and TNF-α. Dexamethasone treatment of BECs only partially suppressed IP-10 and TNF-α but was more effective at suppressing RANTES, IL-6, and IL-8. In acute clinical asthma serum IP-10 levels were increased to a greater extent in those with acute virus-induced asthma (median of 604 pg/mL compared with 167 pg/mL in those with non–virus-induced acute asthma, P < .01). Increased serum IP-10 levels were predictive of virus-induced asthma (odds ratio, 44.3 [95% CI, 3.9-100.3]). Increased serum IP-10 levels were strongly associated with more severe airflow obstruction (r = −0.8; P < .01).

Conclusions

IP-10 release is specific to acute virus-induced asthma.

Clinical implications

Measurement of serum IP-10 could be used to predict a viral trigger to acute asthma.

Relationship between eosinophilia and levels of chemokines (CCL5 and CCL11) and IL-5 in bronchoalveolar lavage fluid of patients with mustard gas-induced pulmonary fibrosis

OBJECTIVE

Therefore, this study was designed to analyze the bronchoalveolar lavage (BAL) fluid concentrations of IL-5, RANTES (CCL5) and eotaxin (CCL11) and also to examine the relationship between the percentage and absolute number of the BAL eosinophils and these measured chemokines in patients with sulfur mustard (SM) gas-induced pulmonary fibrosis (PF).

PATIENTS

Fifteen veterans with mustard gas-induced PF and 14 normal veterans as control group.

INTERVENTION

Pulmonary function tests, tests for D(LCO), computed tomography scans of the chest, analyses of BAL fluids for RANTES (CCL5), eotaxin (CCL11), and IL-5 were performed in all cases.

RESULTS

Eosinophilic alveolitis was the predominant feature (p < 0.0001). There were significant differences in CCL5, CCL11, and IL-5 levels of BAL fluid between patients with PF and controls (p < 0.0001, p < 0.0001, and p = 0.001, respectively). The concentrations of CCL5 and CCL11 showed positive correlations with percentage (r = 0.57 and p = 0.03; r = 0.52 and p = 0.04, respectively) and absolute counts (r = 0.54 and p = 0.04, r = 0.53 and p = 0.04, respectively) of BAL eosinophils. There were significant positive correlations between the concentrations of IL-5 and the proportion and total cell number of eosinophils in BAL (r = 0.67 and p = 0.01; r = 0.59 and p = 0.02, respectively) too.

CONCLUSION

A significant correlation between BAL CCL5, CCL11, and IL-5 levels and eosinophils in patients with pulmonary fibrosis due to SM gas inhalation has been demonstrated, suggesting that these C-C chemokines and IL-5 contribute to the recruitment of eosinophils cells in the lung in these victims.