Expression of RANTES by bronchoalveolar lavage cells in nonsmoking patients with interstitial lung diseases

High Interleukin-13 level is associated with disease stability in interstitial Lung disease

Purpose

Cytokines can help predict prognosis in interstitial lung disease (ILD) and to differentiate between ILD subtypes. The objectives of our study were to evaluate association of baseline cytokine levels with time to ILD progression and to compare baseline cytokine levels between ILD subtypes.

Methods

We quantified 27 cytokines using a multiplex assay in peripheral blood samples from 77 patients. Cox proportional hazards regression analysis was performed to evaluate cytokine impact on the time to progression in the total cohort and within each ILD type. We evaluated for significant differences in cytokine levels between ILD types using ANOVA, Wilcoxon signed-rank test and Tukey method.

Results

Higher IL-13 level was associated with longer time to progression (hazard ratio 0.52 [0.33-0.81], p-value 0.004). FGF-β, GM-CSF, and IL-17 levels differed significantly between fibrotic and inflammatory ILD subgroups.

Conclusion

IL-13 may be a useful biomarker predicting ILD stability.

Distinct Type 1 Immune Networks Underlie the Severity of Restrictive Lung Disease after COVID-19

The variable etiology of persistent breathlessness after COVID-19 have confounded efforts to decipher the immunopathology of lung sequelae. Here, we analyzed hundreds of cellular and molecular features in the context of discrete pulmonary phenotypes to define the systemic immune landscape of post-COVID lung disease. Cluster analysis of lung physiology measures highlighted two phenotypes of restrictive lung disease that differed by their impaired diffusion and severity of fibrosis. Machine learning revealed marked CCR5+CD95+ CD8+ T-cell perturbations in mild-to-moderate lung disease, but attenuated T-cell responses hallmarked by elevated CXCL13 in more severe disease. Distinct sets of cells, mediators, and autoantibodies distinguished each restrictive phenotype, and differed from those of patients without significant lung involvement. These differences were reflected in divergent T-cell-based type 1 networks according to severity of lung disease. Our findings, which provide an immunological basis for active lung injury versus advanced disease after COVID-19, might offer new targets for treatment.

CC Chemokines in Idiopathic Pulmonary Fibrosis: Pathogenic Role and Therapeutic Potential

Idiopathic pulmonary fibrosis (IPF), characterized by progressive worsening of dyspnea and irreversible decline in lung function, is a chronic and progressive respiratory disease with a poor prognosis. Chronic or repeated lung injury results in inflammation and an excessive injury-repairing response that drives the development of IPF. A number of studies have shown that the development and progression of IPF are associated with dysregulated expression of several chemokines and chemokine receptors, several of which have been used as predictors of IPF outcome. Chemokines of the CC family play significant roles in exacerbating IPF progression by immune cell attraction or fibroblast activation. Modulating levels of detrimental CC chemokines and interrupting the corresponding transduction axis by neutralizing antibodies or antagonists are potential treatment options for IPF. Here, we review the roles of different CC chemokines in the pathogenesis of IPF, and their potential use as biomarkers or therapeutic targets.

The matricellular protein CCN3 supports lung endothelial homeostasis and function

Aberrant vascular remodeling contributes to the progression of many aging-associated diseases, including idiopathic pulmonary fibrosis (IPF), where heterogeneous capillary density, endothelial transcriptional alterations, and increased vascular permeability correlate with poor disease outcomes. Thus, identifying disease-driving mechanisms in the pulmonary vasculature may be a promising strategy to limit IPF progression. Here, we identified Ccn3 as an endothelial-derived factor that is upregulated in resolving but not in persistent lung fibrosis in mice, and whose function is critical for vascular homeostasis and repair. Loss and gain of function experiments were carried out to test the role of CCN3 in lung microvascular endothelial function in vitro through RNAi and the addition of recombinant human CCN3 protein, respectively. Endothelial migration, permeability, proliferation, and in vitro angiogenesis were tested in cultured human lung microvascular endothelial cells (ECs). Loss of CCN3 in lung ECs resulted in transcriptional alterations along with impaired wound-healing responses, in vitro angiogenesis, barrier integrity as well as an increased profibrotic activity through paracrine signals, whereas the addition of recombinant CCN3 augmented endothelial function. Altogether, our results demonstrate that the matricellular protein CCN3 plays an important role in lung endothelial function and could serve as a promising therapeutic target to facilitate vascular repair and promote lung fibrosis resolution.

Prognostic significance of serum cytokines during acute exacerbation of idiopathic interstitial pneumonias treated with thrombomodulin

BACKGROUND

Acute exacerbation (AE) has been reported to herald a poor prognosis in idiopathic pulmonary fibrosis and is now thought to do so in idiopathic interstitial pneumonias (IIPs). However, the pathophysiology of AE-IIPs is not sufficiently understood. In our previously reported SETUP trial, we found better survival in patients with AE-IIPs treated with corticosteroids and thrombomodulin than in those treated with corticosteroids alone. In that study, we collected serum samples to evaluate changes in cytokine levels and retrospectively examined the prognostic significance and pathophysiological role of serum cytokines in patients with AE-IIPs.

METHODS

This study included 28 patients from the SETUP trial for whom serial serum samples had been prospectively obtained. AE-IIPs were diagnosed using the Japanese Respiratory Society criteria. All patients were treated with intravenous thrombomodulin and corticosteroids from 2014 to 2016. Serum levels of 27 cytokines were measured using Bio-Plex. The high-resolution CT pattern at the time of diagnosis of AE was classified as diffuse or non-diffuse.

RESULTS

Univariate analysis revealed that higher serum levels of interleukin (IL)-2, IL-7, IL-9, IL-12, IL13, basic fibroblast growth factor, granulocyte-macrophage colony-stimulating factor, interferon-γ inducible protein-10, platelet-derived growth factor and regulated on activation, normal T cell expressed and secreted (RANTES) at AE were significant predictors of 90-day survival. The HRCT pattern was also a significant clinical predictor of 90-day survival. Multivariate analysis with stepwise selection identified a higher serum RANTES level at AE to be a significant predictor of 90-day survival, including after adjustment for HRCT pattern. Multivariate analysis with stepwise selection suggested that a marked increase in the serum IL-10 level on day 8 could predict 90-day mortality.

CONCLUSIONS

A higher serum RANTES level at AE the time of diagnosis predicted a good survival outcome, and an elevated serum IL-10 level on day 8 predicted a poor survival outcome.

TRIAL REGISTRATION NUMBER

UMIN000014969.

Phosphodiesterase 4 inhibition reduces lung fibrosis following targeted type II alveolar epithelial cell injury

Fibrosis of the lung constitutes a major clinical challenge and novel therapies are required to alleviate the associated morbidity and mortality. Investigating the antifibrotic efficacy of drugs that are already in clinical practice offers an efficient strategy to identify new therapies. The phosphodiesterase 4 (PDE4) inhibitors, approved for the treatment of chronic obstructive pulmonary disease, harbor therapeutic potential for pulmonary fibrosis by augmenting the activity of endogenous antifibrotic mediators that signal through cyclic AMP. In this study, we tested the efficacy of several PDE4 inhibitors including a novel compound (Compound 1) in a murine model of lung fibrosis that results from a targeted type II alveolar epithelial cell injury. We also compared the antifibrotic activity of PDE4 inhibition to the two therapies that are FDA-approved for idiopathic pulmonary fibrosis (pirfenidone and nintedanib). We found that both preventative (day 0-21) and therapeutic (day 11-21) dosing regimens of the PDE4 inhibitors significantly ameliorated the weight loss and lung collagen accumulation that are the sequelae of targeted epithelial cell damage. In a therapeutic protocol, the reduction in lung fibrosis with PDE4 inhibitor administration was equivalent to pirfenidone and nintedanib. Treatment with this class of drugs also resulted in a decrease in plasma surfactant protein D concentration, a reduction in the plasma levels of several chemokines implicated in lung fibrosis, and an in vitro inhibition of fibroblast profibrotic gene expression. These results motivate further investigation of PDE4 inhibition as a treatment for patients with fibrotic lung disease.

Downregulation of SLC7A7 Triggers an Inflammatory Phenotype in Human Macrophages and Airway Epithelial Cells

Lysinuric protein intolerance (LPI) is a recessively inherited aminoaciduria caused by mutations of SLC7A7, the gene encoding y+LAT1 light chain of system y⁺L for cationic amino acid transport. The pathogenesis of LPI is still unknown. In this study, we have utilized a gene silencing approach in macrophages and airway epithelial cells to investigate whether complications affecting lung and immune system are directly ascribable to the lack of SLC7A7 or, rather, mediated by an abnormal accumulation of arginine in mutated cells. When SLC7A7/y+LAT1 was silenced in human THP-1 macrophages and A549 airway epithelial cells by means of short interference RNA (siRNA), a significant induction of the expression and release of the inflammatory mediators IL1β and TNFα was observed, no matter the intracellular arginine availability. This effect was mainly regulated at transcriptional level through the activation of NFκB signaling pathway. Moreover, since respiratory epithelial cells are the important sources of chemokines in response to pro-inflammatory stimuli, the effect of IL1β has been addressed on SLC7A7 silenced A549 cells. Results obtained indicated that the downregulation of SLC7A7/y+LAT1 markedly strengthened the stimulatory effect of the cytokine on CCL5/RANTES expression and release without affecting the levels of CXCL8/IL8. Consistently, also the conditioned medium of silenced THP-1 macrophages activated airway epithelial cells in terms of CCL5/RANTES expression due to the presence of elevated amount of proinflammatory cytokines. In conclusion, our results point to a novel thus far unknown function of SLC7A7/y+LAT1, that, under physiological conditions, besides transporting arginine, may act as a brake to restrain inflammation.

Global DNA hypomethylation has no impact on lung function or serum inflammatory and fibrosis cytokines in asbestos-exposed population

PURPOSE

To examine the effect of asbestos exposure on global DNA methylation and determine whether lung function and inflammatory and fibrosis biomarkers are correlated with the methylation state.

METHODS

A total of 26 healthy subjects without asbestos exposure (Group 1), 47 healthy subjects with exposure (Group 2), and 52 subjects with benign asbestos-related disorders (ARDs) (Group 3) participated in this cross-sectional study. Blood global 5-methylcytosine (5mC) and serum TNF-α, collagen IV, CCL5 and CC16 concentrations were analyzed using enzyme-linked immunosorbent assay-like assays. Spirometric maneuvers were performed to assess lung function.

RESULTS

Decreased 5mC levels were observed in Groups 2 and 3 compared to Group 1, irrespective of lung function (p < 0.01). There was no significant change in 5mC between Groups 2 and 3. Overall, 5mC was negatively correlated with CCL5 and collagen IV (p < 0.05), but no significant inverse relationship was found between 5mC and CCL5 or collagen IV in each group. Additionally, both 5mC and CC16 were inversely associated with FEV1/FVC% (p = 0.001, adjusted R ² = 0.145) for non-smokers, and consistently significant inverse relationships were found between CC16 and FEV1/FVC%, independent of asbestos exposure.

CONCLUSIONS

Asbestos exposure causes global DNA hypomethylation. DNA hypomethylation has no influence on serum biomarkers and lung function in asbestos-exposed population with or without pleural and pulmonary parenchymal abnormalities.

Increased expression of CCL4/MIP-1β in CD8+ cells and CD4+ cells in sarcoidosis

Sarcoidosis is a granulomatous disease with an increased accumulation of T cells in lungs as a result of on-site proliferation and chemotaxis induced by chemokines. It has already been demonstrated that CCL3-5 levels were increased in BAL fluid of sarcoidosis patients. To analyze the expression of CCL3-5 chemokines by T-cell subtypes (CD4+, CD8+, Th1, Th2, Tc1 or Tc2) in the lungs of sarcoidosis patients, fifteen untreated sarcoidosis patients and eighteen control subjects were enrolled in this study. CD4+ and CD8+ cells were isolated from BAL fluid by positive magnetic selection. The expression of CCL3-5 and other cytokines in CD4+ and CD8+ cells were measured by flow cytometry. The percentage of CD4+ or CD8+ cells expressing CCL4 were significantly higher in sarcoidosis patients (22.3&#x0025; and 58.1&#x0025;) compared to those seen in healthy subjects (11.1&#x0025; and 16.5&#x0025;, P = 0.04 and P = 0.02, respectively). In addition, the expression of CCL3, CCL4 and CCL5 was significantly elevated in CD8+ cells (8.9&#x0025;, 58.1&#x0025; and 2.1&#x0025;) compared to CD4+ cells (2.1&#x0025;, 22.3&#x0025; and 0.7&#x0025;; P = 0.04, P = 0.009 and P = 0.04, respectively), whereas CCL4 was expressed by significantly more Tc1 than Th1 cells in sarcoidosis patients (P = 0.006). Our study shows the possible role of CD8+ cells and CD4+ cells in recruiting T cells to the site of inflammation in sarcoidosis through the release of CCL4, either alone or together with Th1/Tc1-associated cytokines.

Inflammatory responses of airway smooth muscle cells and effects of endothelin receptor antagonism

Endothelin receptor antagonists (ETRAs), authorized for pulmonary hypertension, have failed to prove their utility in chronic lung diseases with corticosteroid-resistant airway inflammation when applied at late disease stages with emphysema/fibrosis. Earlier administration might prove effective by targeting the interaction between airway inflammation and tissue remodeling. We hypothesized that human airway smooth muscle cells (HASMCs) participate in linking inflammation with remodeling and that associated genes become differentially suppressed by ambrisentan (A-receptor selective ETRA) and bosentan (nonselective/dual ETRA). Inflammatory responses of ex vivo-cultivated HASMCs to TNF-α were investigated by whole-genome microarray analyses. qRT-PCR and ELISA were used to test inflammatory and remodeling genes for sensitivity to bosentan and ambrisentan and to investigate differential sensitivities mechanistically. ETRA and corticosteroid effects were compared in HASMCs from patients with chronic obstructive pulmonary disease. TNF-α induced the expression of 18 cytokines/chemokines and five tissue remodeling genes involved in severe, corticosteroid-insensitive asthma, chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, and/or pulmonary hypertension. Thirteen cytokines/chemokines, MMP13, and WISP1 were suppressed by ETRAs. Eight genes had differential sensitivity to bosentan and ambrisentan depending on the endothelin-B receptor impact on transcriptional regulation and mRNA stabilization. Chemokine (C-C motif) ligands 2 and 5, granulocyte macrophage colony-stimulating factor, and MMP13 had increased sensitivity to bosentan or bosentan/dexamethasone combination versus dexamethasone alone. Suppression of cytokine and remodeling gene expression by ETRAs was confirmed in TNF-α-activated human bronchial epithelial cells. HASMCs and human bronchial epithelial cells participate in the interaction of inflammation and tissue remodeling. This interaction is targeted differentially by selective and nonselective ETRAs, which could be used in therapies of chronic lung diseases with corticosteroid-resistant airway inflammation at early disease stages to attenuate inflammation-induced airway remodeling.

Inflammatory profile and response to anti-tumor necrosis factor therapy in patients with chronic pulmonary sarcoidosis

Sarcoidosis is an inflammatory, granulomatous disease of unknown etiology that most commonly afflicts the lungs. Despite aggressive immunosuppressive therapies, many sarcoidosis patients still chronically present significant symptoms. Infliximab, a therapeutic tumor necrosis factor alpha (TNF-α) monoclonal antibody (MAb), produced a small but significant improvement in forced vital capacity (FVC) in sarcoidosis patients in a double-blind, placebo-controlled, phase II clinical trial. In the current study, serum samples from this clinical trial were assessed to evaluate the underlying hypothesis that treatment with infliximab would reduce systemic inflammation associated with sarcoidosis, correlating with the extent of clinical response. A 92-analyte multiplex panel was used to assess the expression of serum proteins in 134 sarcoidosis patients compared with sera from 50 healthy controls. A strong systemic inflammatory profile was associated with sarcoidosis, with 29 analytes significantly elevated in sarcoidosis (false-discovery rate, <0.05 and >50% higher than controls). The associated analytes included chemokines, neutrophil-associated proteins, acute-phase proteins, and metabolism-associated proteins. This profile was evident despite patients receiving corticosteroids and immunosuppressive therapies. Following infliximab treatment, sarcoidosis patients expressing the highest levels of TNF-α, who had more severe disease, had the greatest improvement in FVC and reduction in serum levels of the inflammatory proteins MIP-1β and TNF-RII. This study supports the need for further exploration of anti-TNF therapy for chronic sarcoidosis patients, particularly for those expressing the highest serum levels of TNF-α.

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.

Elevated levels of interferon ?-inducible protein-10 and epithelial neutrophil-activating peptide-78 in patients with pulmonary sarcoidosis

OBJECTIVE AND BACKGROUND

Interferon gamma-inducible protein (IP)-10 and epithelial neutrophil-activating peptide (ENA)-78 belong to the CXC chemokine family and are important factors in inflammatory lung diseases. In sarcoidosis, the potential role of IP-10 to regulate the migration and activation of T-cells towards sites of sarcoid activity has been suggested.

METHODS

In this study, the concentrations of IP-10 and ENA-78 in the serum and BAL fluid of patients with different stages of active pulmonary sarcoidosis (n=41) and healthy subjects (n=12) were measured by enzyme-linked immunosorbent assay to evaluate the contribution of these CXC chemokines to this disease.

RESULTS

Serum and BAL fluid concentrations of IP-10 and BAL fluid levels of ENA-78 in patients with sarcoidosis were significantly higher than those in control subjects. The serum levels of IP-10 were significantly increased only in patients with stages I and II sarcoidosis, while BAL fluid levels of ENA-78 were increased only in stage III sarcoidosis. In addition, serum concentrations of IP-10 were elevated in patients with extrapulmonary lesions compared with those without such lesions. In patients with sarcoidosis, IP-10 concentrations in BAL fluid correlated with lymphocyte proportions in BAL fluid.

CONCLUSION

IP-10 may play an important role in regulating lymphocytes into the lung and that ENA-78 may be associated with lung parenchymal disease in pulmonary sarcoidosis.

Comparison of BALF concentrations of ENA-78 and IP10 in patients with idiopathic pulmonary fibrosis and nonspecific interstitial pneumonia

BACKGROUND

Epithelial neutrophil-activating peptide 78 (ENA-78) and interferon gamma-inducible protein 10 (IP10) belong to the CXC chemokine family and are considered to be important factors in idiopathic pulmonary fibrosis (IPF). Idiopathic nonspecific interstitial pneumonia (NSIP) and IPF are the two largest subsets of idiopathic interstitial pneumonias (IIP). In patients with NSIP, the prognosis is generally good compared with IPF. Therefore, the pathogenesis of NSIP seems to be different from that of IPF, but this remains unclear. The aim of the present study was to evaluate the contribution of ENA-78 and IP10 in the two diseases.

METHODS

We measured the levels of ENA-78 and IP10 in serum and bronchoalveolar lavage fluid (BALF) of patients with IPF (n=17), idiopathic NSIP (n=10) and healthy subjects (n=12) by enzyme-linked immunosorbent assays.

RESULTS

The level of ENA-78 in BALF was significantly higher in IPF patients than in NSIP patients and controls. Serum levels of ENA-78 and BALF levels of IP10 in NSIP patients were significantly higher than in patients with IPF and controls. In BALF of patients with NSIP, IP10 level significantly correlated with the absolute number of lymphocytes. In IPF patients, BALF IP10 levels also correlated with the proportion of lymphocytes in BALF.

CONCLUSION

Our results show distinct profiles of CXC chemokines in IPF and NSIP, and suggest that these chemokines play an important role in inflammatory cell recruitment into the lung in patients with IIP.

High-BAL fluid concentrations of RANTES in nonspecific interstitial pneumonia compared with usual interstitial pneumonia

Chemokines such as regulated on activation, normal T-cell expressed and secreted (RANTES), monocyte chemoattractant protein (MCP)-1, monocyte inflammatory protein (MIP)-lalpha have been reported to play an important role in the pathogenesis of interstitial lung diseases. Among idiopathic interstitial pneumonia (IIP), nonspecific interstitial pneumonia (NSIP) has elevated percentages of Lymphocytes in bronchoalveolar lavage (BAL) fluid compared with usual interstitial pneumonia (UIP). These chemokines are candidate mediators for lymphocyte attraction to the lung in NSIR Therefore, we measured the BAL fluid levels of RANTES, MCP-1 and MIP1-alpha in 15 patients with idiopathic NSIP, 20 with idiopathic UIP, 22 with sarcoidosis and 12 healthy volunteers to evaluate the contribution of these chemokines using enzyme-linked immunosorbent assays. The levels of RANTES in BAL fluid were significantly higher in patients with NSIP compared with healthy volunteers (P < 0.01), UIP and sarcoidosis (P < 0.05). In MCP-1, the levels in BAL fluid of NSIP and UIP patients were significantly elevated compared with healthy volunteers and sarcoidosis patients (P < 0.01). These results suggest that RANTES and MCP-1 in BAL fluid may play an important role in inflammatory cell recruitment to the lung in idiopathic NSIP as well as other interstitial lung diseases.

In vitro pharmacoregulation of CC chemokine ligand 5 and its receptor CCR5 in diffuse lung diseases

BACKGROUND

CC chemokine ligand (CCL)5 and its receptor CCR5 contribute to leukocyte migration into lungs of patients with diffuse lung diseases (DLD). Pharmacological regulation of CCL5 and CCR5 expression was therefore explored in bronchoalveolar cells obtained from patients with DLD.

METHODS

Cells from 21 patients were co-cultivated in vitro with tumour necrosis factor-alpha and dexamethasone, cyclosporin A (CyA) or pentoxifylline. Chemokine mRNA expression and protein production was assessed by reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay, respectively.

RESULTS

Dexamethasone altered CCL5 mRNA expression and suppressed its protein levels. CyA inhibited chemokine mRNA expression but not protein production. Pentoxifylline did not affected chemokine expression. Both dexamethasone and CyA suppressed CCR5 mRNA transcripts.

CONCLUSION

In conclusion, while dexamethasone downregulates the CCL5 functional form, CyA and pentoxifylline have no effects on CCL5 protein. These data provide in vitro correlation for clinical applications of immunomodulators in therapy of DLD.

Significant involvement of CCL2 (MCP-1) in inflammatory disorders of the lung

Mounting evidence suggests that CCL2 (MCP-1) and its hematopoietic cell receptor CC chemokine receptor 2 (CCR2) are involved in inflammatory disorders of the lung. In animal models of allergic asthma, idiopathic pulmonary fibrosis (IPF), and bronchiolitis obliterans syndrome (BOS), CCL2 expression and protein production are increased and the disease process is attenuated by CCL2 immunoneutralization. Mechanisms by which CCL2 may be acting include recruitment of regulatory and effector leukocytes; stimulation of histamine or leukotriene release from mast cells or basophils; induction of fibroblast production of transforming growth factor-beta (TGF-beta) and procollagen; and enhancement of Th2 polarization. Recently, polymorphism for CCL2 has been described with increased cytokine-induced release of CCL2 by monocytes and increased risk of allergic asthma. These studies identify potentially important roles for CCL2 in these lung inflammatory disorders. While CCL2 inhibition in patients with acute respiratory distress syndrome (ARDS) may be hazardous by interfering with defense against bacteremia, future studies are needed to determine if CCL2/CCR2 antagonism will offer breakthrough therapy for patients with allergic asthma, IPF, or BOS, and to confirm the hypothesis that CCL2 polymorphism places patients at greater risk for these disorders.

Expression of the chemokine PARC mRNA in bronchoalveolar cells of patients with sarcoidosis

BACKGROUND

Chemotactic cytokines (chemokines) have been recently implicated in the pathogenesis of interstitial lung diseases. A novel chemokine called pulmonary and activation-regulated chemokine (PARC/CCL18), which attracts lymphocytes in vitro, has been detected in the human lung. We have, therefore, investigated PARC mRNA expression in bronchoalveolar lavage fluid (BALF) cells of patients with pulmonary sarcoidosis-a disease characterised by a lymphocytic infiltrate. Further, because several immunomodulators are used in the treatment of sarcoidosis, we have determined the effects of selected drugs on PARC mRNA expression in vitro.

SUBJECTS AND METHODS

BALF cells were obtained by standard bronchoalveolar lavage (BAL) from 30 patients with pulmonary sarcoidosis (S) and 16 control subjects (C). BALF cells from seven subjects were cultured in the presence of dexamethasone (Dx), cyclosporin A (CyA) and pentoxifylline (Px). PARC mRNA expression was semiquantitated by reverse-transcription polymerase chain reaction (RT-PCR) using normalisation to the expression of the beta-actin gene.

RESULTS

PARC mRNA transcripts were detected in 87% of all investigated BALF samples. The expression (ODR PARC/beta-actin; median, the first to the third quartile range) was similar in both groups tested (S, 0.60 (0.50-0.95); C, 0.59 (0.36-0.93); S vs. C: P>0.05). PARC mRNA expression was not associated with the number of lymphocytes in bronchoalveolar space. PARC mRNA expression was significantly suppressed by Dx (P=0.02); CyA and Px showed a moderate inhibitory effect which did not attain significance.

CONCLUSION

mRNA for the chemokine PARC is expressed in the lower respiratory tract in both healthy subjects and patients with pulmonary sarcoidosis. Out of the three immunomodulatory drugs tested, Dx downregulates PARC mRNA expression in BALF cells in vitro.

Polymorphism in RANTES chemokine promoter affects extent of sarcoidosis in a Japanese population

RANTES, a member of C-C chemokine, is known to be produced at sites of granulomatous reactions in the lung of sarcoidosis. RANTES is a potent eosinophil and lymphocyte attractant with particular preference for CD45RO+ T cells and eosinophils. Polymorphism of the RANTES promoter has recently been shown to be related to allergic and infectious diseases; atopic dermatitis, asthma, and polymyalgia rheumatica. Considering that this might affect sarcoidosis, we studied polymorphism of the RANTES gene in 114 patients with sarcoidosis and 136 healthy control subjects. Their genotypes were determined using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). Although no difference in the genotype distribution between healthy control subjects and sarcoidosis patients was identified, the difference in the frequencies of the patients with three or more organ involvement was significant (P<0.01) with the frequency of those in AA genotype being elevated (P<0.05). BAL findings in 48 out of 114 patients who underwent bronchoscopy were reviewed. The CD4/8 ratio of lymphocytes in bronchoalveolar lavage fluid in the patients with AA genotype was significantly increased (P<0.05). From the results, we suggest that in RANTES gene polymorphism the homozygous A allele might be a genetic risk factor for extent disease of sarcoidosis.

Impairment of bleomycin-induced lung fibrosis in CD28-deficient mice

Lung fibrosis is an important pulmonary disease with a high mortality rate, but its pathophysiological mechanism has not been fully clarified. Various types of cells have been implicated in the development of lung fibrosis, including T cells. However, the contribution of functional molecules expressed on T cells to the development of lung fibrosis remains largely unknown. In this study, we determined whether costimulation via CD28 on T cells was crucial for the development of lung fibrosis by intratracheally administering bleomycin into CD28-deficient mice. Compared with wild-type mice, the CD28-deficient mice showed markedly impaired lung fibrosis after injection with low doses of bleomycin, as judged by histological changes and hydroxyproline content in the lungs. In addition, bleomycin-induced T cell infiltration into the airways and production of several cytokines and chemokines including IL-5 were also impaired in the CD28-deficient mice. Furthermore, adoptive transfer of CD28-positive T cells from wild-type mice recovered the impaired bleomycin-induced lung fibrosis in CD28-deficient mice. These findings suggest that the CD28-mediated T cell costimulation plays a critical role in the development of lung fibrosis, possibly by regulating the production of cytokines and chemokines in the lung. Thus, manipulation of the CD28-mediated costimulation could be a potential therapeutic strategy for the prevention of lung fibrosis.

Sarcoidosis 2001

In every decade, sarcoidosis makes a chameleon-like change so its profile needs to be updated. It was first recognised as a dermatological curiosity which evolved into a multisystem disorder with bone cysts, uveitis, and intrathoracic involvement. New dimensions were uncovered by biochemistry and immunology, bringing it still nearer the elusive enigma, namely the cause of sarcoidosis. Aetiology includes an understanding of a genetic predisposition and environmental trigger factors. What was left undone in the 20th century will become evident in the 21st century with more sophisticated technology. Likewise, conventional treatments of the past will be superseded by cytokines and other magic bullets of the millennium.

Modulatory roles of RANTES in IL-4 production by human blood CD4(+)T cells

An increase in serum IgE levels has been reported in several thrombotic cardiovascular diseases. Since such diseases are associated with the activation of platelets, we hypothesized that platelets are implicated in a mechanism leading to heightened IgE synthesis. To this end, we performed an in vitro investigation of the effects on IL-4 production caused by several bioactive substances potentially released from platelets. Human blood CD4(+)T cells from blood donors were stimulated with anti-CD3 antibody and costimulatory signals delivered via CD58 and CD80 in the presence or absence of IL-4. One of the following test substances was also included in the culture: platelet factor-4, beta-thromboglobulin, platelet-derived growth factor, serotonin, platelet activating factor, or RANTES. The cells were restimulated in the absence of IL-4 and test substances. Among the six substances, RANTES alone exhibited significant effects on IL-4 production. RANTES enhanced IL-4 production in the presence of IL-4, whereas it suppressed IL-4 production in the absence of IL-4. The enhancing effect of RANTES was positively correlated with plasma IgE levels in the donors. We concluded that RANTES may induce IgE synthesis by increasing IL-4 production in individuals predisposed to high IgE responses. Our observations indicate a link between platelets and immune phenomena associated with increased IgE responses.

Pivotal role of CCR1-positive leukocytes in bleomycin-induced lung fibrosis in mice

We have investigated the involvement of chemokine receptor CCR1-positive cells in bleomycin-induced lung injury, a model of pulmonary fibrosis. After bleomycin challenge in C57BL/6J mice, the expression of CCR1 mRNA increased and peaked at day 7, which paralleled to the expression of its ligands, macrophage-inflammatory protein-1 alpha and RANTES. Immunohistochemical study showed that CCR1-positive cells accumulated in the interstitial inflammatory site. Furthermore, the treatment of anti-CCR1 Ab significantly reduced the accumulation of inflammatory cells and collagen deposition, resulting in dramatic improvement of survival. These results suggest that CCR1-positive cells play significant roles in the pathogenesis of pulmonary fibrosis subsequent to bleomycin-induced lung injury, and that CCR1 could be a novel molecular target for intervention therapy against pulmonary fibrosis.

New pathogenetic insights into the sarcoid granuloma

Although the most important enigma of sarcoidosis, ie, its etiology, remains an unsolved problem, the past few years have seen remarkable advances in understanding general immunologic and molecular aspects of the mechanisms leading to granuloma formation in sarcoidosis. It is now clear that during the sarcoid inflammatory process several cytokines are secreted at sites of disease activity; in addition, high affinity receptors for cytokines participating in the granuloma development have been recently identified. This article provides a detailed description of recent data that have clarified cellular interactions governing the dynamics of granuloma formation in sarcoidosis. Together, these new results provide important insights that can refocus efforts at developing immunotherapeutic methods of inhibiting cytokine production at sites of granuloma formation.

Increased levels in vivo of mRNAs for IL-8 and macrophage inflammatory protein-1 alpha (MIP-1 alpha), but not of RANTES mRNA in peripheral blood mononuclear cells of patients with atopic dermatitis (AD)

Chemokines play an important role in the selective movement of leucocytes into inflammatory areas and they also activate various cells in inflamed tissues. However, it is unclear which cells are the main sources of chemokines in actual inflammatory diseases, even though both mononuclear cells and non-inflammatory resident cells are able to produce chemokines in vitro and the former cells are also the main target of chemokines. To clarify the roles of chemokines that are produced by mononuclear cells in AD, we measured levels in vivo of mRNA for IL-8 and MIP-1 alpha, as well as the level of regulated upon activation normal T cell expressed and secreted (RANTES) mRNA in freshly isolated peripheral blood mononuclear cells from patients with AD. We compared the results with those from psoriatic patients, and patients without AD who were suffering from other cutaneous diseases and eosinophilia. Levels of mRNAs were determined by semiquantitative reverse transcriptase-polymerase chain reactions. Levels of IL-8 and MIP-1 alpha mRNA were elevated not only in atopic patients but also in non-atopic patients with inflammatory skin disease associated with eosinophilia, compared with levels in psoriatic patients and healthy controls. Levels of RANTES mRNA were similar in atopic patients but they were lower in the other two groups of patients when compared with levels in healthy controls. In atopic patients, the levels of both IL-8 and MIP-1 alpha mRNAs but not of RANTES mRNA decreased with improvements in symptom scores after therapy. These findings suggest that mononuclear cells are not only the target of chemokines but might also play an important role in the pathogenesis of AD by producing IL-8 and MIP-1 alpha.

The role of the C-C chemokine receptor 2 gene polymorphism V64I (CCR2-64I) in sarcoidosis in a Japanese population

A number of chemokines are produced by alveolar cells in the course of inflammatory reactions of sarcoidosis. C-C chemokine receptor 2 (CCR2) is a prominent receptor for the monocyte chemoattractant protein (MCP) group of C-C chemokines. A transition causing a valine to isoleucine substitution in transmembrane domain I of the CCR2 gene (CCR2-64I) that has a protective effect against the progression of human immunodeficiency virus-1 (HIV-1) disease has been described. To elucidate the role of this CCR2 polymorphism in sarcoidosis, we investigated the distribution of the CCR2-64I in 100 subjects with sarcoidosis (40.2 +/- 18.6 yr [mean +/- SD], 37:63 [male:female]) and 122 healthy control subjects (44.4 +/- 14.1 yr, 75:47). The distribution of the CCR2-64I allele was significantly different between subjects with sarcoidosis and healthy control subjects (p < 0.001). The presence of the CCR2-64I allele conferred a lower risk for the development of sarcoidosis (adjusted odds ratio = 0.369, 95% CI = 0.203 to 0.673). Our study suggests that this polymorphism may play a role in the pathogenesis of sarcoidosis, and further studies are needed to define the role of CCR2-64I.

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

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