Soluble form of Fas and Fas ligand in serum and bronchoalveolar lavage fluid of individuals infected with human T-lymphotropic virus type 1

sFasL-The Key to a Riddle: Immune Responses in Aging Lung and Disease

By dint of the aging population and further deepened with the Covid-19 pandemic, lung disease has turned out to be a major cause of worldwide morbidity and mortality. The condition is exacerbated when the immune system further attacks the healthy, rather than the diseased, tissue within the lung. Governed by unremittingly proliferating mesenchymal cells and increased collagen deposition, if inflammation persists, as frequently occurs in aging lungs, the tissue develops tumors and/or turns into scars (fibrosis), with limited regenerative capacity and organ failure. Fas ligand (FasL, a ligand of the Fas cell death receptor) is a key factor in the regulation of these processes. FasL is primarily found in two forms: full length (membrane, or mFasL) and cleaved (soluble, or sFasL). We and others found that T-cells expressing the mFasL retain autoimmune surveillance that controls mesenchymal, as well as tumor cell accumulation following an inflammatory response. However, mesenchymal cells from fibrotic lungs, tumor cells, or cells from immune-privileged sites, resist FasL⁺ T-cell-induced cell death. The mechanisms involved are a counterattack of immune cells by FasL, by releasing a soluble form of FasL that competes with the membrane version, and inhibits their cell death, promoting cell survival. This review focuses on understanding the previously unrecognized role of FasL, and in particular its soluble form, sFasL, in the serum of aged subjects, and its association with the evolution of lung disease, paving the way to new methods of diagnosis and treatment.

IL-15 is a biomarker involved in the development of rapidly progressive interstitial lung disease complicated with polymyositis/dermatomyositis

BACKGROUND

Polymyositis/dermatomyositis (PM/DM) is an autoimmune disease that is sometimes complicated with rapidly progressive interstitial lung disease (RPILD). However, serum and lung biomarkers that can predict RPILD development remain unclear.

OBJECTIVES

To determine potential serum and lung biomarkers that can predict RPILD development in patients with PM/DM-ILD.

METHODS

In total, 49 patients with PM/DM-ILD were enrolled. We measured the serum levels of 41 cytokines/chemokines, ferritin and anti-MDA5 antibody, compared them between the RPILD (n = 23) and non-RPILD (n = 26) groups, and ranked them by their importance through random forest analysis. To distinguish the two groups, we determined biomarker combinations by logistic regression analysis. We also measured the bronchoalveolar lavage fluid (BALF) levels of 41 cytokines/chemokines. Using immunohistochemistry, we examined IL-15 expression in lung tissues. The IL-15 production was also investigated using A549 and BEAS-2B cells.

RESULTS

The RPILD group had significantly higher IL-15, IL-1RA, IL-6, CXCL10, VCAM-1, anti-MDA5 antibody and ferritin serum levels than the non-RPILD group, but it had a significantly low CCL22 level. Meanwhile, anti-MDA5 antibody, IL-15, CXCL8, CCL22, IL-1RA and ferritin were the best combination to distinguish the two groups. IL-15 and CCL22 were also predictive marker for RPILD development in anti-MDA5 antibody-positive patients. Additionally, the RPILD group had significantly high IL-15 levels in BALF. The lung tissues expressed IL-15, which increased after cytokine stimulation in the A549 cells.

CONCLUSION

This study identified a combination of biomarkers predicting PM/DM-RPILD progression, and IL-15 is an important cytokine for predicting RPILD development and reflecting ILD severity.

Human T-cell leukaemia virus type 1 associated pulmonary disease: clinical and pathological features of an under-recognised complication of HTLV-1 infection

The lung is one of several organs that can be affected by HTLV-1 mediated inflammation. Pulmonary inflammation associated with HTLV-1 infection involves the interstitium, airways and alveoli, resulting in several clinical entities including interstitial pneumonias, bronchiolitis and alveolitis, depending on which structures are most affected. Augmentation of the inflammatory effects of HTLV-1 infected lymphocytes by recruitment of other inflammatory cells in a positive feedback loop is likely to underlie the pathogenesis of HTLV-1 associated pulmonary disease, as has been proposed for HTLV-1 associated myelopathy. In contrast to the conclusions of early case series, HTLV-1 associated pulmonary disease can be associated with significant parenchymal damage, which may progress to bronchiectasis where this involves the airways. Based on our current understanding of HTLV-1 associated pulmonary disease, diagnostic criteria are proposed.

Risk factors for disease-related deterioration following diagnostic bronchoalveolar lavage procedures in diffuse lung disease: a case-control study

Background

Although the risk factors for diagnostic bronchoalveolar lavage (BAL)-induced acute exacerbations in patients with idiopathic pulmonary fibrosis (IPF) have been previously reported, no study has assessed these in patients with non-IPF. We aimed to identify the risk factors for BAL-induced disease deterioration (BAL-DD) in all types of diffuse lung disease.

Methods

Patients with diffuse lung disease who underwent BAL at our hospital from April 2012 to November 2017 were retrospectively analyzed. The patient information, laboratory data, radiological findings, and BAL fluid analysis results in patients who developed BAL-DDs were compared with those in patients who did not.

Results

BAL-DDs occurred in 14 (3.3%) of the 429 patients included the study. The BAL-DD group had a significantly poorer performance status, higher C-reactive protein level, lower partial pressure of oxygen in the arterial blood at rest, greater proportion of desaturation on exertion and cases having followed a progressive clinical course before BAL, and more extensive consolidation and ground-glass opacity on chest high-resolution computed tomography (HRCT) than the non-BAL-DD group. A high total cell concentration and an increased number of eosinophils in the BAL fluid were more frequently found in patients with BAL-DD than in those without.

Conclusions

Patients with decreased physical activity level, increased level of inflammatory markers, low oxygenation status, and extensive lung involvements on chest HRCT and following a progressive clinical course before BAL may be warned of the BAL-DD risk. Elevated eosinophil counts in the BAL fluid could be associated with the triggering of BAL-DDs.

Protective Role of Myelocytic Nitric Oxide Synthases against Hypoxic Pulmonary Hypertension in Mice

RATIONALE

Nitric oxide (NO), synthesized by NOSs (NO synthases), plays a role in the development of pulmonary hypertension (PH). However, the role of NO/NOSs in bone marrow (BM) cells in PH remains elusive.

OBJECTIVES

To determine the role of NOSs in BM cells in PH.

METHODS

Experiments were performed on 36 patients with idiopathic pulmonary fibrosis and on wild-type (WT), nNOS (neuronal NOS)^-/-, iNOS (inducible NOS)^-/-, eNOS (endothelial NOS)^-/-, and n/i/eNOSs^-/- mice.

MEASUREMENTS AND MAIN RESULTS

In the patients, there was a significant correlation between higher pulmonary artery systolic pressure and lower nitrite plus nitrate levels in the BAL fluid. In the mice, hypoxia-induced PH deteriorated significantly in the n/i/eNOSs^-/- genotype and, to a lesser extent, in the eNOS^-/- genotype as compared with the WT genotype. In the n/i/eNOSs^-/- genotype exposed to hypoxia, the number of circulating BM-derived vascular smooth muscle progenitor cells was significantly larger, and transplantation of green fluorescent protein-transgenic BM cells revealed the contribution of BM cells to pulmonary vascular remodeling. Importantly, n/i/eNOSs^-/--BM transplantation significantly aggravated hypoxia-induced PH in the WT genotype, and WT-BM transplantation significantly ameliorated hypoxia-induced PH in the n/i/eNOSs^-/- genotype. A total of 69 and 49 mRNAs related to immunity and inflammation, respectively, were significantly upregulated in the lungs of WT genotype mice transplanted with n/i/eNOSs^-/--BM compared with those with WT-BM, suggesting the involvement of immune and inflammatory mechanisms in the exacerbation of hypoxia-induced PH caused by n/i/eNOSs^-/--BM transplantation.

CONCLUSIONS

These results demonstrate that myelocytic n/i/eNOSs play an important protective role in the pathogenesis of PH.

HTLV-1-infected asymptomatic carriers compared to HAM/TSP patients over-express the apoptosis- and cytotoxicity-related molecules

HTLV-1 infection causes a chronic progressive debilitating neuroinflammatory disease which is called, HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). One of the host defense mechanisms against viral infection is apoptosis which may control HTLV-1 infection. Therefore, we aimed to investigate this process and its interaction with viral factors in HTLV-1-infected asymptomatic carriers (ACs) compared to HAM/TSP patients. Fas, FasL, TRAIL, perforin, granzyme A, granzyme B, and granulysin gene expression and serum levels of Fas, FasL, TRAIL, and granulysin in the peripheral blood of 21 sex- and age-matched healthy controls (HCs), ACs, and HAM/TSP patients were evaluated. Also, the level of granulysin secretion in the cell culture supernatant was measured. Finally, the correlation of the expression of these molecules with HTLV-1 proviral load (PVL), Tax, and HBZ mRNA expression was analyzed. ACs compared to HAM/TSP patients significantly over-expressed the Fas, FasL, TRAIL, perforin, and granzyme B molecules. Fas, FasL, TRAIL, and granulysin serum levels were not different among studied groups; whereas, the secretion of granulysin was significantly decreased in ACs and HAM/TSP patients compared to HCs. Also, HAM/TSP patients expressed higher levels of HTLV-1 PVL, Tax, and HBZ mRNA. In addition, in ACs, inverse correlations between the Fas, FasL, TRAIL, perforin, granzyme B, and granulysin levels with HBZ mRNA expression were seen. ACs compared to HAM/TSP patients over-expressed the apoptosis- and cytotoxicity-related molecules. It could be concluded that successful control of the HTLV-1 infection and suppression of HAM/TSP development stem from the strong apoptosis and cytotoxic activity in the peripheral blood of ACs.

Elevated α-defensin levels in plasma and bronchoalveolar lavage fluid from patients with myositis-associated interstitial lung disease

BACKGROUND

Interstitial lung disease (ILD) is a prognostic indicator of poor outcome in myositis. Although the pathogenesis of myositis-associated ILD is not well understood, neutrophils are thought to play a pivotal role. Neutrophils store azurophil granules that contain defensins, which are antimicrobial peptides that regulate the inflammatory response. Here, we evaluated levels of the human neutrophil peptides (HNPs) α-defensin 1 through 3 in patients with myositis-associated ILD to determine whether HNPs represent disease markers and play a role in the pathogenesis of myositis-associated ILD.

METHODS

HNP levels were measured in the plasma and bronchoalveolar lavage fluid (BALF) of 56 patients with myositis-associated ILD and 24 healthy controls by enzyme-linked immunosorbent assay.

RESULTS

Analysis revealed significantly higher HNP levels in plasma and BALF samples from patients with myositis-associated ILD as compared to those of healthy controls; however, plasma HNPs were significantly correlated with total cell counts in BALF. Additionally, BALF HNP levels were positively correlated with serum surfactant protein-A and the percentage of neutrophils in BALF, and BALF HNP levels correlated with the percentage of reticular opacities in high-resolution computed tomography results for patients with anti-aminoacyl-tRNA synthetase (ARS) antibody positive myositis-associated ILD. Survival did not differ between patients with higher and lower levels of plasma and BALF HNPs.

CONCLUSIONS

Plasma and BALF HNPs might reflect the disease activities of myositis-associated ILD, especially in patients with anti-ARS antibody positive myositis-associated ILD. However further studies are necessary to clarify whether HNPs represent disease markers and play roles in disease pathogenesis.

Risk factors for an acute exacerbation of idiopathic pulmonary fibrosis

Background

Acute exacerbations of idiopathic pulmonary fibrosis are major causes of morbidity and mortality among patients with idiopathic pulmonary fibrosis. However, acute exacerbations remain unpredictable. The aim of this study was to investigate risk factors for acute exacerbations of idiopathic pulmonary fibrosis.

Methods

We performed a retrospective cohort study of patients with idiopathic pulmonary fibrosis who visited our institutions from January 1999 to September 2014. We investigated risk factors for acute exacerbations in patients with idiopathic pulmonary fibrosis diagnosed retrospectively based on the official 2011 idiopathic pulmonary fibrosis ATS/ERS/JRS/ALAT Update Statement.

Results

The idiopathic pulmonary fibrosis study cohort included 65 subjects. The median follow-up period was 2.6 years. During follow-up, 24 patients (36.9 %) experienced acute exacerbations. A Kaplan-Meier curve demonstrated that the 1-year, 2-year, and 3-year incidences of acute exacerbation were 9.6, 19.2 and 31.0 %, respectively. Acute exacerbation exerted a significant impact on overall survival among those with the disease. A log-rank test showed that baseline cardiovascular diseases, higher GAP (gender, age, physiology) stage (≥II), higher serum lactate dehydrogenase level (≥180 U/L), higher serum surfactant protein-D level (≥194.7 ng/mL), higher neutrophil (≥1.77 %) and eosinophil (≥3.21 %) percentages in bronchoalveolar lavage fluid samples, and treatment with an immunosuppressive agent after diagnosis were associated with poor acute exacerbation-free probability. In the Cox analysis adjusted for treatment with an immunosuppressive agent, baseline cardiovascular diseases, higher GAP stage (≥II), and higher eosinophil percentage (≥3.21 %) in bronchoalveolar lavage fluid samples were predictors of an acute exacerbation of idiopathic pulmonary fibrosis.

Conclusions

This study demonstrated that baseline cardiovascular diseases, higher GAP stage (≥II), and higher eosinophil percentage (≥3.21 %) in bronchoalveolar lavage fluid samples were associated with the onset of an acute exacerbation of idiopathic pulmonary fibrosis.

Association of elevated α-defensin levels with interstitial pneumonia in patients with systemic sclerosis

Background

Interstitial lung disease (ILD) is the leading cause of mortality in patients with systemic sclerosis (SSc). Although the pathogenesis of SSc-ILD is not well understood, neutrophils may play a pivotal role in this process. Neutrophils store azurophil granules that contain defensins, antimicrobial peptides that function in regulating the inflammatory response, and IL-8, a potent chemoattractant for neutrophils. The present study evaluated the levels of defensins and IL-8 in patients with SSc-ILD to determine their roles in disease pathogenesis.

Methods

Defensins (also known as human neutrophil peptides, HNPs) and IL-8 levels were measured in the serum and bronchoalveolar lavage fluid (BALF) of 33 patients with SSc-ILD and in 20 healthy controls by using ELISA.

Results

BALF analysis revealed a significant increase in HNPs in SSc-ILD patients (median; 240.0 pg/mL) than that of healthy controls (79.7 pg/mL). Additionally, IL-8 levels were higher in SSc-ILD patient serum and BALF as compared to healthy controls (16.4 pg/mL vs. 5.8 pg/mL and 15.4 pg/mL vs. 14.5 pg/mL, respectively). However, plasma HNPs levels were relatively unchanged. HNP and IL-8 levels in patient BALF displayed a significant positive correlation significantly correlated (r = 0.774, p <0.01), and which also correlated with clinical disease parameters—such as ILD biomarkers, pulmonary function tests, ratio of neutrophils and eosinophils in BALF, tricuspid regurgitation peak gradient (TRPG), and the extent of high-resolution computed tomography (HRCT) findings in the lung. Levels of plasma HNPs and serum IL-8 did not show a significant correlation with any clinical parameter. SSc-ILD progression was evaluated by pulmonary function tests, but no association was observed between VC change ratios and HNPs or IL-8 levels.

Conclusions

BALF levels of HNPs and IL-8 were higher in SSc-ILD than in healthy controls, and are associated with various clinical disease parameters. Further studies are needed to clarify the role of defensins and IL-8 in SSc-ILD pathogenesis.

Serum heat shock protein 47 levels in patients with drug-induced lung disease

Background

Heat shock protein (HSP) 47 is a collagen-specific molecular chaperone that is required for molecular maturation of various types of collagens. We recently reported that HSP47 serum levels were markedly higher in patients with acute exacerbations of idiopathic pulmonary fibrosis (IPF) when compared with patients with stable IPF, suggesting that serum HSP47 levels correlate with interstitial pneumonia activity. The aim of this study was to evaluate serum HSP47 levels in patients with drug-induced lung disease (DILD).

Methods

Findings from high-resolution computed tomographic chest scans of 47 patients with DILD were classified into one of four predominant patterns: organizing pneumonia (OP) (n = 4), nonspecific interstitial pneumonia (NSIP) (n = 24), hypersensitivity pneumonitis (HP) (n = 11), and diffuse alveolar damage (DAD) (n = 8). Serum levels of HSP47, Krebs von den Lungen-6 (KL-6), surfactant protein (SP)-A, and SP-D were measured in these patients.

Results

The PaO₂/fraction of inspired oxygen (FiO₂) (P/F) ratios were significantly lower and the alveolar-arterial difference of oxygen (A-a DO₂) was significantly higher in the DAD group than in the other groups. Patients with DAD had the worst outcomes among the different subgroups. Patients in the DAD group had significantly higher serum HSP47 levels than those in other groups. Receiver operating characteristic curves revealed that HSP47 was superior to KL-6, SP-A, and SP-D for discriminating between the DAD group and the other groups. The cut-off level for HSP47 that resulted in the highest diagnostic accuracy was 1711.5 pg/mL. The sensitivity, specificity, and diagnostic accuracy were 87.5%, 97.4%, and 95.7%, respectively. Serum levels of HSP47 in the group of patients requiring glucocorticoids were significantly higher than those in patients who experienced clinical improvement without glucocorticoid administration. Serum HSP47 levels also significantly correlated with various respiratory parameters.

Conclusion

This study demonstrated that serum HSP47 levels were elevated in patients with DILD with a DAD pattern who had the worst outcomes among the different subgroups, and that this was correlated with P/F ratio and A-a DO₂.

Elevated levels of tenascin-C in patients with cryptogenic organizing pneumonia

OBJECTIVE

Idiopathic interstitial pneumonias (IIPs) comprises a group of diffuse parenchymal lung diseases of unknown etiology with varying degrees of inflammation and fibrosis including cryptogenic organizing pneumonia (COP), idiopathic pulmonary fibrosis (IPF) and nonspecific interstitial pneumonia (NSIP). Tenascin-C is an extracellular matrix molecule that is expressed during wound healing in various tissues. The present study was aimed to investigate the role of tenascin-C in the pathogenesis of IIPs.

METHODS

We used enzyme-linked immunosorbent assays to measure levels of tenascin-C in serum and bronchoalveolar lavage fluid (BALF) from 17 patients with IPF, 12 with NSIP, 15 with COP and from 23 healthy individuals.

RESULTS

Serum levels of tenascin-C were significantly elevated in patients with COP compared with those in all other participants, whereas those in patients with IPF and NSIP were not significantly elevated compared with healthy individuals. The levels of tenascin-C in BALF from patients with COP and NSIP were significantly higher than those of healthy individuals. In addition, serum tenascin-C was significantly correlated with levels of serum C-reactive protein, which is a serum acute phase protein.

CONCLUSION

Systemic inflammation in the lung with IIPs might be associated with tenascin-C. These results suggest that tenascin-C is responsible for the pathogenesis of IIPs especially via inflammation, and that it might serve as a serum marker of COP.

Fas/FasL interaction: a novel immune therapy approach with immobilized biologicals

Systemically applied agents to modulate the Fas/FasL system, e.g., by stimulation of Fas on activated leukocytes or tumor cells failed as strategies in immune therapy due to severe toxic effects in the host. Recently, a novel strategy has been developed by using immobilized immune active biologicals in a medical device that may allow immune management without expensive systemic therapy. This review reports on the potential role of Fas/FasL in immune therapy and summarizes current experimental and clinical data with the leukocyte inhibition module (LIM), an immobilized anti-Fas antibody containing device yet used in extracorporeal blood circulation. This proof of principal may stimulate the development of other devices based on the regulation of Fas/FasL or other targets relevant for immune disorders.

Transfection of apoptosis related gene Fas ligand in human hepatocellular carcinoma cells and its significance in apoptosis

AIM: To evaluate the expression of apoptosis related gene Fas ligand (FasL) in human hepatocellular carcinoma (HCC) cells HepG2 and its significance in apoptosis.

METHODS: Levels of soluble Fas ligand (sFasL) in a group of patients with hepatitis B virus (HBV)-induced chronic hepatitis, HBV-positive liver cirrhosis and HCC were evaluated. In a further study, the recombinant eukaryotic expression plasmid pcDNA3.1hisB-FasL was transfected into HCC cells HepG2 by lipofection, and then soluble FasL was examined in the supernatant of culture cells by EIA, FasL expression in HepG2 cells was detected by immuohistochemistry. After being stained by annexin V and propidium iodine, cells were passed through a flow cytometer and examined by a fluorescence microscope and a laser scanning microscope.

RESULTS: The sFasL levels were significantly lower in patients with HCC when compared to the patients with hepatitis or liver cirrhosis. In comparison with untransfected cells, the soluble FasL could be detected in the supernatant of transfected cells. FasL was expressed on the membranes and cytoplasm of transfected cells. The apoptotic cell rate was 36.30% in transfected cells, and was 11.53% in untransfected cells. Moreover, the different stage of apoptotic cells could be distinguished by annexin V and propidium iodine staining.

CONCLUSION: Fas ligand is an apoptotic pathway of HCC cells.

cDNA cloning and expression of human CD95 ligand and its role in apoptosis of HepG2 cell lines

AIM: To investigate CD95 ligand and its physiological function in liver neoplasms.

METHODS: The levels of soluble Fas ligand (sFasL) were evaluated in a group of patients affected by hepatitis B virus (HBV)-induced chronic hepatitis, HBV-positive liver cirrhosis and hepatocellular carcinoma (HCC).To further study, we constructed recombinant eukaryotic expression vector pcDNA3.1 hisB-CD95L, which was then tranfected into human hepatoma cell line HepG2 by lipofection.After stained by annexin V and propidium iodine, HepG2 cells were detected by flow cytometer.

RESULTS: CD95L levels were significantly decreased in patients with HCC when compared to the patients with hepatitis or liver cirrhosis.The correct recombinant pcDNA3.1hisB-CD95L was selected by PCR and restriction endonuclease digestion and confirmed by DNA sequencing respectively.Subsequently a significant proportion of cells became apoptotic, as evidenced by positive annexin staining.

CONCLUSION: CD95-CD95 ligand system can induce apoptosis of hepatoma cells.