Patients receiving thoracic radiation often develop pulmonary injury and fibrosis. Currently, there are no effective measures to prevent or treat these conditions. We tested whether blockade of the chemokine, CC chemokine ligand (CCL) 3, and its receptors, CC chemokine receptor (CCR) 1 and CCR5, can prevent radiation-induced lung inflammation and fibrosis. C57BL/6J mice received thoracic radiation, and the interaction of CCL3 with CCR1 or CCR5 was blocked using genetic techniques, or by pharmacologic intervention. Lung inflammation was assessed by histochemical staining of lung tissue and by flow cytometry. Fibrosis was measured by hydroxyproline assays and collagen staining, and lung function was studied by invasive procedures. Irradiated mice lacking CCL3 or its receptor, CCR1, did not develop the lung inflammation, fibrosis, and decline in lung function seen in irradiated wild-type mice. Pharmacologic treatment of wild-type mice with a small molecule inhibitor of CCR1 also prevented lung inflammation and fibrosis. By contrast, mice lacking CCR5 were not protected from radiation-induced injury and fibrosis. The selective interaction of CCL3 with its receptor, CCR1, is critical for radiation-induced lung inflammation and fibrosis, and these conditions can be largely prevented by a small molecule inhibitor of CCR1.

Findings from conference interpreting research in the Chinese context have suggested that interpreters barely produce extra-textual additions in rigidly structured press conferences, and that adding connectives and intensifiers is only required to help the English-speaking audience capture the logic embedded in implicit Chinese interclausal relations. Previous research in the Chinese context has tended to draw data almost exclusively from the Chinese Premier's Press Conference interpreting, which features interpreting from Chinese into English. In order to enrich conference interpreting corpora in Asia and to examine additions in the opposite interpreting direction for the same language pair, this study drew on authentic materials of six interpreted press conferences held at the American Institute in Taiwan (AIT). Contrary to previous research, our results showed that conference interpreters exhibited a certain degree of "visibility" through producing extra-textual additions, which is typical of interpreting in various community-based settings. Moreover, the addition of extra connectives and intensifiers that are common in Chinese-to-English interpreting was also identified. It is proposed that the interpreters' production of extra-textual additions is connected with the specific context of the AIT, whereas the connective and emphasizing additions are to a large extent caused by the grammaticalization process wherein particular linguistic devices change into discourse markers to fulfill the communicative needs in both English and Chinese.

The murine carotid artery ligation (CAL) model has been widely used in the research of intimal hyperplasia, a major pathological process in vascular diseases, such as atherosclerosis and restenosis after angioplasty. Using a variety of gene knockout or transgenic mice and different pharmacological interventions, these studies have yielded significant new findings that contribute not only to unraveling the basic molecular mechanisms involved in the pathogenesis of intimal hyperplasia, but also to the identification of novel targets for intervention of these diseases. The current review outlines the findings derived from the murine CAL model, including studies run by the authors, covering the impacts of hyperlipidemia, pro-inflammatory factors, endothelial dysfunction, protease activity and growth mediators on neointimal hyperplasia.

In this study, we report the first example of a nonpeptide chemokine receptor agonist, 2-{2-[4-(3-phenoxybenzyl)piperazin1-yl]ethoxy}ethanol (ZK 756326), for the CC chemokine receptor CCR8. ZK 756326 inhibited the binding of the CCR8 ligand I-309 (CCL1), with an IC50 value of 1.8 mu M. Furthermore, ZK 756326 was a full agonist of CCR8, dose-responsively eliciting an increase in intracellular calcium and cross-desensitizing the response of the receptor to CCL1. In addition, ZK 756326 stimulated extracellular acidification in cells expressing human CCR8. The ability of ZK 756326 to induce a response was receptor-specific and mediated through G alpha(i), because it could be blocked by treatment with pertussis toxin. The CCR8 agonist activated cells expressing murine CCR8, eliciting their chemotaxis and inducing phosphorylation of extracellular signal-regulated kinase ERK1/2. Like CCL1, ZK 756326 inhibited human immunodeficiency virus (HIV) fusion of cells expressing CD4 and CCR8. Finally, unlike mCCL1, ZK 756326 bound to and activated a form of mCCR8 that was mutated to eliminate O-linked sulfation at tyrosines 14 and 15. Therefore, ZK 756326 is most probably not binding in the same manner as CCL1 but can activate the switch mechanism involved in transducing signaling events. In summary, we have identified a nonpeptide agonist of CCR8. This compound may be useful in evaluating the physiological role of CCR8 in HIV infection, as well as in the general study of CCR8 biology without the constraints inherent to the use of protein agonists such as its natural ligand.

The identification and evaluation of aryl-[1,4]diazepane ureas as functional antagonists of the chemokine receptor CXCR3 are described. Specific examples exhibit IC(50) values of approximately 60 nM in a calcium mobilization functional assay, and dose-dependently inhibit CXCR3 functional response to CXCL11 (interferon-inducible T-cell alpha chemoattractant/I-TAC) as measured by T-cell chemotaxis, with a potency of approximately 100 nM.

Receptor-ligand binding analyses have generally used soluble components to measure thermodynamic binding constants. In their biological context, adhesion receptors bind to an immobile ligand and the binding reaction is confined to the cell-substrate contact zone. We have developed a new procedure based on the spinning disk technology to measure the number of receptor-ligand bonds in the contact zone. Application of this methodology to the CX3CR1-fractalkine and the CXCR1-IL-8 receptor-ligand systems demonstrated that the level of binding to an immobilized ligand is reduced by several orders of magnitude in comparison to solution binding. A comparison of the solution binding and contact zone binding constants shows that the effect of ligand immobilization was similar for each system. In contrast, although the CXCR1-IL-8 bond had the higher affinity, the average bond strength was only 10% of that for the CX3CR1 bond. Because fractalkine can be expressed as a cell surface-bound protein, CX3CR1 has been proposed to function as an adhesion receptor. The higher bond strength suggests that the bond architecture has also evolved to serve an adhesion function.

Recent studies in transplant biology have demonstrated a role for chemokines in the migration of leukocytes into transplanted tissue. There is further evidence that modulation of the action of chemokines at their receptors can improve the outcome of acute rejection as well as long-term graft survival. A number of clinical therapies, based on both small molecules and biologicals, are currently under investigation with the potential for selective immunosupression. This article discusses the chemokines and receptors identified as the best characterized molecular targets, as well as the therapies under investigation for these targets.

Leukocyte trafficking at the endothelium requires both cellular adhesion molecules and chemotactic factors. Fractalkine, a novel transmembrane molecule with a CX3C-motif chemokine domain atop a mucin stalk, induces both adhesion and migration of leukocytes. Here we identify a seven-transmembrane high-affinity receptor for fractalkine and show that it mediates both the adhesive and migratory functions of fractalkine. The receptor, now termed CX(3)CR1, requires pertussis toxin-sensitive G protein signaling to induce migration but not to support adhesion, which also occurs without other adhesion molecules but requires the architecture of a chemokine domain atop the mucin stalk. Natural killer cells predominantly express CX(3)CR1 and respond to fractalkine in both migration and adhesion. Thus, fractalkine and CX(3)CR1 represent new types of leukocyte trafficking regulators, performing both adhesive and chemotactic functions.