Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0032285 (pneumonia)
 54,520 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

RANTES (regulated upon activation, normally T expressed and secreted) is a chemoattractant for macrophages, memory T lymphocytes, and eosinophils. We investigated whether intrapulmonary production of the chemokine RANTES contributes to the recruitment of immune cells during lung transplantation complications. RANTES concentration was measured in bronchoalveolar lavage (BAL) fluids using an ELISA assay. It was significantly higher during CMV pneumonitis (36.2 +/- l6 pg/ml, n=12, P=0.031) and allograft rejection (31.1 +/- 8.5 pg/ml, n=27, P=0.013) than in patients without complications (9.1 +/- 2.3 pg/ml, n=22). At least some of the RANTES was produced by lung macrophages: BAL macrophages cultured for 24 hr spontaneously released larger amount of RANTES during CMV pneumonitis (140 +/- 53 pg/ml, n=8, P=0.002) and allograft rejection (84 +/- 44 pg/ml, n=11, P=0.037) than in control patients (15.2 +/- 6.5 pg/ml, n=21). Moreover, macrophages in transbronchial biopsies were labeled by an anti-RANTES mAb. RANTES production by BAL macrophages was followed in 2 patients with CMV pneumonitis. It remained high as long as CMV-induced cytopathic effects or clinical symptoms were present, but it returned to baseline as the infection was controlled. These results suggest that the intrapulmonary production of the chemokine RANTES by activated macrophages contributes to the intrapulmonary accumulation of immune cells during complications of lung transplantation.
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PMID:Intrapulmonary production of RANTES during rejection and CMV pneumonitis after lung transplantation. 868 56

In patients with impaired cell-mediated immune responses (e.g., lung transplant recipients and AIDS patients), cytomegalovirus (CMV) infection causes severe disease such as pneumonitis. However, although immunocompetency in the host can protect from CMV disease, the virus persists by evading the host immune defenses. A model of CMV infection of the endothelium has been developed in which inflammatory stimuli, such as the CC chemokine RANTES, bind to the endothelial cell surface, stimulating calcium flux during late times of CMV infection. At 96 h postinfection, CMV-infected cells express mRNA of the CMV-encoded CC chemokine receptor US28 but do not express mRNA of other CC chemokine receptors that bind RANTES (CCR1, CCR4, CCR5). Cloning and stable expression of the receptor CMV US28 in human kidney epithelial cells (293 cells) with and without the heterotrimeric G protein alpha16 indicated that CMV US28 couples to both Galphai and Galpha16 proteins to activate calcium flux in response to the chemokines RANTES and MCP-3. Furthermore, cells that coexpress US28 and Galpha16 responded to RANTES stimulation with activation of extracellular signal-regulated kinase, which could be attributed, in part, to specific Galpha16 coupling. Thus, through expression of the CC chemokine receptor US28, CMV may utilize resident G proteins of the infected cell to manipulate cellular responses stimulated by chemokines.
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PMID:Intracellular signaling by the chemokine receptor US28 during human cytomegalovirus infection. 962 Oct 10

Fibrosis, characterized by the accumulation of collagen, is a consequence of a chronic inflammatory response. The purpose of this study was to determine if the mRNA expression of the chemokines, lymphotactin (Ltn), RANTES, eotaxin, macrophage inflammatory protein (MIP)-1 alpha, -1 beta, and -2, interferon-inducible protein 10 (IP-10), and monocyte chemotactic protein-1 (MCP-1), are altered during the development of radiation-induced pneumonitis and fibrosis. Further, we wished to determine if these changes differ between two strains of mice that vary in their sensitivity to radiation fibrosis. Fibrosis-sensitive (C57BL/6) and fibrosis-resistant (C3H/HeJ) mice were irradiated with a single dose of 12.5 Gy to the thorax. Total lung RNA was prepared and hybridized utilizing RNase protection assays. Data were quantified by phosphorimaging and results normalized to a constituitively expressed mRNA L32. 8 weeks post-irradiation most chemokines measured were elevated to varying degrees. The degree of elevation of each chemokine was identical in both strains. This suggested that chemotactic activity for neutrophils, macrophages, and lymphocytes were occurring during pneumonitis. By 26 weeks post-irradiation, messages encoding Ltn, RANTES, IP-10, and MCP-1 were elevated only in fibrosis sensitive (C57BL/6) mice. In situ hybridization demonstrated that MCP-1 and RANTES transcripts were produced predominantly from macrophages and lymphocytes. These studies suggest that lymphocytic recruitment and activation are key components of radiation-induced fibrosis.
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PMID:Alterations in the expression of chemokine mRNA levels in fibrosis-resistant and -sensitive mice after thoracic irradiation. 963 54

Pseudomonas aeruginosa, an opportunistic human pathogen, causes acute pneumonia in patients with hospital-acquired infections and is commonly associated with chronic lung disease in individuals with cystic fibrosis (CF). Evidence suggests that the pathophysiological effects of P. aeruginosa are mediated in part by virulence factors secreted by the bacterium. Among these factors is pyocyanin, a redox active compound that increases intracellular oxidant stress. We find that pyocyanin increases release of interleukin-8 (IL-8) by both normal and CF airway epithelial cell lines and by primary airway epithelial cells. Moreover, pyocyanin synergizes with the inflammatory cytokines tumor necrosis factor alpha and IL-1alpha. RNase protection assays indicate that increased IL-8 release is accompanied by increased levels of IL-8 mRNA. The antioxidant n-acetyl cysteine, general inhibitors of protein tyrosine kinases, and specific inhibitors of mitogen-activated protein kinases diminish pyocyanin-dependent increases in IL-8 release. Conversely, inhibitors of protein kinases C (PKC) and PKA have no effect. In contrast to its effects on IL-8 expression, pyocyanin inhibits cytokine-dependent expression of the monocyte/macrophage/T-cell chemokine RANTES. Increased release of IL-8, a potent neutrophil chemoattractant, in response to pyocyanin could contribute to the marked infiltration of neutrophils and subsequent neutrophil-mediated tissue damage that are observed in Pseudomonas-associated lung disease.
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PMID:Pseudomonas pyocyanin increases interleukin-8 expression by human airway epithelial cells. 982 54

Epidemiology studies associate increased pulmonary morbidity with episodes of high particulate air pollution (size range 0.1-10 microm diameter, PM10). Pneumonia, often viral in origin, is increased following episodes of high PM10 pollution. Therefore, this study was undertaken to investigate how PM10 alters airway inflammatory responses to respiratory syncytial virus (RSV), a frequent cause of viral pneumonia in infants and the elderly. Supernatants of unexposed and PM10-exposed alveolar macrophage (AM) cultured with uninfected or RSV-infected airway epithelial cells were assessed for a number of chemokines responsible for inflammatory responses in the lung. AM exposure to PM10 in the absence of infection resulted in a significant increase in interleukin (IL)-8 and macrophage inflammatory protein (MIP)-1alpha production but not in MIP-1beta or monocyte chemotactic protein (MCP)-1. AM responded to RSV infection by the production of IL-8, MIP-1alpha, MIP-1beta, and MCP-1, while RANTES was derived solely from the RSV-infected bronchial epithelial cell line BEAS-2B. In the presence of PM10, the AM response to RSV was blunted. RSV-induced MCP-1 was significantly decreased, and the levels of MIP-1 and IL-8 were lower than expected from a combined response to PM10 and RSV. Furthermore, AM analyzed for uptake of virus showed a 50% decrease in viral antigen when exposed to PM10 RSV-induced production of RANTES by epithelial cells was decreased in the presence of AM but not affected by PM10 exposure. Taken together, these results suggest that AM-regulated inflammatory responses to viral infection are altered by exposure to PM10 in a manner that may result in increased spread of infection and thus may increase viral pneumonia-related hospital admissions.
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PMID:Exposure to urban air particulates alters the macrophage-mediated inflammatory response to respiratory viral infection. 1049 14

Human eosinophils secrete two distinct ribonucleases that have antiviral activity against pathogens of the family Paramyxoviridae. To examine the role of eosinophils and their ribonucleases in host defense against paramyxovirus pathogens in vivo, we have developed a mouse model involving a viral pathogen that naturally targets a rodent host. In this work we describe infection of Balb/c mice with pneumonia virus of mice (PVM, strain J3666), a paramyxovirus pathogen found frequently among rodent populations. We show here that pulmonary eosinophilia is an immediate response to infection with PVM, with bronchoalveolar lavage fluid containing 12-14% eosinophils obtained as early as day 3 postinoculation. Infection is accompanied by the production of macrophage inflammatory protein-1-alpha (MIP-1alpha), a chemokine that has been associated with the pulmonary eosinophilia observed in response to respiratory syncytial virus infection in humans and with enhanced clearance of influenza virus in mice. Interestingly, we observed no changes in expression of the chemoattractants eotaxin and RANTES in response to PVM infection, and interleukin-5 remained undetectable throughout. These responses-clinical pathology, viral recovery, pulmonary eosinophilia, and production of MIP-1alpha-will provide a means for exploring the role of eosinophils, eosinophil secretory ribonucleases, and eosinophil chemoattractants in host defense against PVM and related paramyxovirus pathogens in vivo.
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PMID:Pulmonary eosinophilia and production of MIP-1alpha are prominent responses to infection with pneumonia virus of mice. 1075 1

RANTES and sCD30 were measured in ex vivo culture supernatants of unstimulated or stimulated PBMC in order to investigate their potential role as markers of acute immune activation. Patients in an advanced stage of HIV infection (AIDS A) were compared to AIDS patients who were evaluated for pneumonia at the time of blood withdrawal (AIDS B); HIV(+) individuals with nonprogressive infection (LTNP) and healthy donors (N) served as controls. Constitutive levels of RANTES were significantly elevated in AIDS B patients (P 0.0001), whereas spontaneous release of sCD30 was strongly correlated with the presence of both pneumonia (P 0.002) and HIV infection (P 0.004). LPS was a strong inducer of RANTES in all four categories; however, in AIDS B patients a negative and positive correlation between constitutive and induced levels was observed with LPS (P 0.0004) and IFN-gamma (P 0.006), respectively. We clearly showed that IFN-gamma reached a fourfold superinduction of sCD30 release in both HIV-positive and -negative individuals, whereas IL-6-driven production of both sCD30 and RANTES occurred only in healthy donors. Ex vivo RANTES levels may also be monitored as an index of acute immune activation under conditions of chronic activation of the immune system, whereas sCD30 release may be equally indicative of both acute and chronic processes of T cell activation. Proinflammatory stimuli differentially affected RANTES and sCD30 secretion in ex vivo PBMC cultures, suggesting complex pathways in the in vivo regulation of these two molecules.
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PMID:Ex vivo modulation of RANTES and sCD30 by proinflammatory stimuli in HIV-seropositive and -negative individuals. 1102 50

Host-derived chemoattractant factors are suggested to play crucial roles in leukocyte recruitment elicited by inflammatory stimuli in vitro and in vivo. However, in the case of acute bacterial infections, pathogen-derived chemoattractant factors are also present, and it has not yet been clarified how cross-talk between chemoattractant receptors orchestrates diapedesis of leukocytes in this context of complex chemoattractant arrays. To investigate the role of chemokine (host-derived) and formyl peptide (pathogen-derived) chemoattractants in leukocyte extravasation in life-threatening infectious diseases, we used a mouse model of pneumococcal pneumonia. We found an increase in mRNA expression of eight chemokines (RANTES, macrophage-inflammatory protein (MIP)-1alpha, MIP-1beta, MIP-2, IP-10, monocyte chemoattractant protein (MCP)-1, T cell activation 3, and KC) within the lungs during the course of infection. KC and MIP-2 protein expression closely preceded pulmonary neutrophil recruitment, whereas MCP-1 protein production coincided more closely than MIP-1alpha with the kinetics of macrophage infiltration. In situ hybridization of MCP-1 mRNA suggested that MCP-1 expression started at peribronchovascular regions and expanded to alveoli-facing epithelial cells and infiltrated macrophages. Interestingly, administration of a neutralizing Ab against MCP-1, RANTES, or MIP-1alpha alone did not prevent macrophage infiltration into infected alveoli, whereas combination of the three Abs significantly reduced macrophage infiltration without affecting neutrophil recruitment. The use of an antagonist to N-formyl peptides, N-t-Boc-Phe-D-Leu-Phe-D-Leu-Phe, reduced both macrophages and neutrophils significantly. These data demonstrate that a complex chemokine network is activated in response to pulmonary pneumococcal infection, and also suggest an important role for fMLP receptor in monocyte/macrophage recruitment in that model.
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PMID:Role of chemokines and formyl peptides in pneumococcal pneumonia-induced monocyte/macrophage recruitment. 1139 Apr 86

Infection with the pathogens human cytomegalovirus (HCMV) or Chlamydia pneumonia (CP) is linked to the development of vascular disease, including atherosclerosis. The role of pathogens in vasculopathies has been controversial. However, animal models have demonstrated a direct link between infection with CP and herpesviruses and the development of vascular disease. Clinical studies have shown a direct association of HCMV and CP with the acceleration of vascular disease. This article will review the evidence supporting the role for CP and HCMV in the development of vascular disease and will suggest a potential mechanism for HCMV acceleration of the disease process. Vascular diseases are the result of either mechanical or immune-related injury followed by inflammation and subsequent smooth muscle cell (SMC) proliferation and/or migration from the vessel media to the intima, which culminates in vessel narrowing. A number of in vitro and in vivo models have provided potential mechanisms involved in pathogen-mediated vascular disease. Recently, we have demonstrated that HCMV infection of arterial but not venous SMC results in significant cellular migration in vitro. Migration was dependent on expression of the HCMV-encoded chemokine receptors, US28, and the presence of the chemokines, RANTES or MCP-1. Migration involved chemotaxis and provided the first evidence that viruses may induce migration of SMC toward sites of chemokine production through the expression of a virally encoded chemokine receptor in infected SMC. Because SMC migration into the neointimal space is the hallmark of vascular disease, these observations provide a molecular link between HCMV and the development of vascular disease.
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PMID:Do pathogens accelerate atherosclerosis? 1158 10

Current design strategies for vaccines against certain microbial pathogens, including Chlamydia trachomatis, require the induction and targeting of specific immune effectors to the local sites of infection known as the mucosal effector sites. Chemokines and their receptors are important mediators of leukocyte trafficking and of the controlled recruitment of specific leukocyte clonotypes during host defense against infections and during inflammation. We analyzed the dynamics of chemokine and chemokine receptor expression in genital mucosae during genital chlamydial infection in a murine model to determine how these molecular entities influence the development of immunity and the clearance of infection. A time course study revealed an increase of up to threefold in the levels of expression of RANTES, monocyte chemotactic protein 1 (MCP-1), gamma-interferon-inducible protein 10 (IP-10), macrophage inflammatory protein 1alpha (MIP-1alpha), and intercellular adhesion molecule type 1 (ICAM-1) after genital infection with the C. trachomatis agent of mouse pneumonitis. Peak levels of expression of RANTES, MCP-1, and MIP-1alpha occurred by day 7 after primary infection, while those of IP-10 and ICAM-1 peaked by day 21. Expression levels of these molecules decreased by day 42 after primary infection, by which time all animals had resolved the infection, suggesting an infection-driven regulation of expression. A rapid upregulation of expression of these molecules was observed after secondary infection. The presence of cells bearing the chemokine receptors CCR5 and CXCR3, known to be preferentially expressed on Th1 and dendritic cells, was also synchronous with the kinetics of immune induction in the genital tract and clearance of infection. Results demonstrated that genital chlamydial infection is associated with a significant induction of chemokines and chemokine receptors that are involved in the recruitment of Th1 cells into the site of infection. Future studies will focus on how selective modulation of chemokines and their receptors can be used to optimize long-term immunity against CHLAMYDIA:
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PMID:Chemokine and chemokine receptor dynamics during genital chlamydial infection. 1179 19


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