Release of interleukin-1 by alveolar macrophages of patients with active pulmonary sarcoidosis

Activated T-lymphocytes play a central role in the alveolitis of pulmonary sarcoidosis by recruiting monocytes, the building blocks of granulomata, to the alveolar structures. The present study suggests that the lung mononuclear phagocyte population, which is derived from blood monocytes, may play a critical role in the pathogenesis of sarcoidosis by modulating local T-cell activation. In this regard, alveolar macrophages from sarcoid patients with high-intensity alveolitis released significantly greater amounts of lymphocyte-activating factor (interleukin-1), in vitro, than did macrophages from sarcoid patients with low-intensity alveolitis, patients with idiopathic pulmonary fibrosis, or normal control subjects (p less than 0.001, each comparison). Consistent with the concept that the lungs of sarcoid patients with low-intensity alveolitis may have a low level of inflammation present, alveolar macrophages from this group released more interleukin-1 than did macrophages from the normal group (p less than 0.05). These observations suggest that in pulmonary sarcoidosis: (1) mononuclear phagocytes are activated, and this state of activation correlates with the activity of the lung disease; (2) activated lung mononuclear phagocytes may modulate lung lymphocyte function, and thus play a critical role in the pathogenesis of this disease.     

Altered immunological reactivity in alveolar macrophages from patients with sarcoidosis

Lung macrophages may play an important role in the pathogenesis of pulmonary sarcoidosis. In this study, the ability of pulmonary macrophages and blood monocytes from sarcoidosis patients, normal controls and disease controls to provide the accessory signal necessary for the concanavalin A-induced activation of normal blood T cells was examined. Blood monocytes from all groups supplied a significantly greater accessory signal than lung macrophages. The accessory capacity of lavage macrophages from sarcoidosis patients varied over a wide range and correlations were sought between these values and other parameters of disease activity. Whilst there was no correlation with clinical parameters, accessory function of alveolar macrophages correlated significantly with the percentage of T helper cells in bronchoalveolar lavage (BAL) fluid (p less than 0.05) and, more closely, with the T helper:T suppressor ratio in BAL fluid (p less than 0.01). This interrelationship between macrophage activity and the T cell infiltrate favours the probability that both cell types participate in the sarcoid disease process and raises the possibility that T cells of both helper and suppressor phenotypes contribute to the pathogenesis.     

Increased spontaneous interleukin-10 release from alveolar macrophages in active pulmonary sarcoidosis

The study was designed to determine whether alveolar macrophages (AM) in acute pulmonary sarcoidosis release in vitro the anti-inflammatory cytokine interleukin (IL)-10. To learn more about the coherence between IL-10 and proinflammatory cytokines in active sarcoidosis, the release of interferon (IFN)-gamma, macrophage inhibitory protein (MIP)-1alpha, and granulocyte-macrophage colony-stimulating factor (GM-CSF) was studied and additionally compared to normal controls and patients with pneumonia and interstitial lung fibrosis. AM were obtained by bronchoalveolar lavage from 13 patients with active sarcoidosis, 8 patients with interstitial lung fibrosis, 10 patients with bacterial pneumonia, and 14 normal controls. The spontaneous and stimulated (tumor necrosis factor [TNF]-alpha, IL-1beta) cytokine release was measured in the supernatant of cultured AM by enzyme-linked immunosorbent assay (ELISA). Unstimulated AM from sarcoidosis patients released more IL-10, IFN-gamma, MIP-1alpha, and GM-CSF than normal controls and patients with pneumonia and interstitial lung disease. Stimulation with TNF-alpha or IL-1beta increased the MIP-1alpha and GM-CSF release from AM of normal controls and patients with pneumonia and interstitial lung disease: however, no further enhancement of MIP-1alpha and GM-CSF production was observed in AM from sarcoidosis patients. Exogenous IL-10 reduced the spontaneous and stimulated MIP-1alpha and GM-CSF release in sarcoidosis to a lesser extent than in controls and patients with fibrosis and pneumonia. The up-regulated IL-10 in active pulmonary sarcoidosis may be a compensatory response to the enhanced expression of proinflammatory cytokines in order to down-regulate the inflammatory process. The results suggest an involvement of the anti-inflammatory cytokine IL-10 in the immunopathogenesis of sarcoidosis.     

Increased production of matrix metalloproteinase-2 in alveolar macrophages and regulation by interleukin-10 in patients with acute pulmonary sarcoidosis.

Matrix metalloproteinases (MMPs) and cathepsins have been implicated in the pathogenesis of several interstitial lung diseases by their effects on inflammatory processes and extracellular matrix remodelling. The aim of this study was to investigate whether macrophage-derived MMPs and cathepsins are involved in the pathogenesis of sarcoidosis. Therefore the release of MMP-2, MMP-9, and cathepsins B and L from alveolar macrophages (AM) in active pulmonary sarcoidosis was studied and compared to normal controls and patients with pneumonia and fibrosis. Patients with sarcoidosis (n = 11), pulmonary fibrosis (n = 7), and pneumonia (n = 9) and normal controls (n = 10) were enrolled in the study. AM were obtained by bronchoalveolar lavage and cultured without stimulation and in presence of tumor necrosis factor alpha (TNFalpha) and interleukin-10 (IL-10). The release of cathepsins and MMPs as well as IL-10 and TNFalpha was measured in the supernatant of cultured AM by fluorimetric assays and zymography. AM of patients with sarcoidosis and pneumonia spontaneously released more MMP-2 than normal controls. Stimulation with TNFalpha showed no effects on MMP-2 and MMP-9 production. Exogenous IL-10 led partially to an inhibition of the MMP-2 and MMP-9 release. Patients with sarcoidosis produced significantly more IL-10 and TNFalpha than normal controls. This was not observed in patients with fibrosis and pneumonia. The spontaneous release of cathepsins B and L did not differ between the patient groups and normal controls and was not affected by TNFalpha and IL-10. The data show that AM of patients with sarcoidosis and pneumonia release significant amounts of MMP-2. The endogenous production of IL-10 in AM of patients with sarcoidosis and the MMP downregulation by exogenous IL-10 suggest an involvement of IL-10 in MMP regulation. Furthermore the results suggest that the production of MMP-2 is more specific for acute lung injury, rather than for a single lung disease such as sarcoidosis.     

Studies of phagocytic and killing activities of alveolar macrophages in patients with sarcoidosis

Phagocytosis and killing activities of alveolar macrophages were compared in 17 patients with stage 1 sarcoidosis and 6 healthy controls. The average total cell count of bronchoalveolar lavage fluid from patients with sarcoidosis was 7.8 ± 7.5 × 10⁶ cells; 70.4 ± 15% of these cells were alveolar macrophages and 25.9 ± 16.2% lymphocytes. Average total cell count from controls was 8.33 ± 8.6 × 10⁶ cells, with 92.7 ± 5.9% alveolar macrophages and 6.6 ± 4.4% lymphocytes. Purified alveolar macrophages were tested in in vitro antibacterial assays using S. aureus as a test microbe. Moderate decreases in the kinetics of staphylococcal ingestion were detected in the sarcoidosis group. The intracellular killing activity of macrophages was much lower in the patients with sarcoid than in control subjects. In a pilot study, intracellular killing activity of macrophages from 1 patient: with sarcoidosis was greatly enhanced by 24 hr treatment with transfer factor. In summary, alveolar macrophages from patients with radiographic stage 1 sarcoidosis have decreased bacterial ingestion and intracellular killing activities. These results suggest that macrophages undergo complex functional changes in sarcoidosis that may influence both disease development and host defenses. Offprint requests to: P. Orosi     

The immunocytochemical detection of angiotensin-converting enzyme in alveolar macrophages from patients with sarcoidosis

Angiotensin-converting enzyme (ACE) was detected in alveolar macrophages obtained by bronchoalveolar lavage (BAL), but not in lymphocytes and other cells, by immunofluorescence using anti-human ACE antibody. The enzyme was localized on the surface of plasma membrane and cytoplasmic processes of alveolar macrophages, as demonstrated by immunoelectron microscopy. The immunocytochemical staining for ACE in alveolar macrophages from patients with sarcoidosis was intense, which was consistent with the result that ACE activity in BAL cells from patients with sarcoidosis was significantly higher than in cells from normal subjects and from patients with nonsarcoid lung diseases. Part of this work was presented at the 8th Asia-Pacific Congress on Diseases of the Chest, Tokyo, July 11–15, 1983     

Spontaneous production of interleukin-1 alpha and beta by alveolar cells from patients with sarcoidosis

The spontaneous production of interleukin-1 alpha and beta by alveolar cells obtained by BAL from 7 active pulmonary sarcoidosis and 5 normal volunteers was evaluated. The activity of disease in one case was considered to be highly active because of the chest X-ray pattern (diffuse micronodular shadows), highly intense Ga up take in lungs, increased number of BAL cells and high level of S-ACE. The contents of IL-1 alpha and beta were measured by ELISA in the culture supernatants of alveolar cells after 24 hours culture without any stimulus. Large amounts of IL-1 alpha and beta production were found in highly active case. No significant amount of IL-1 alpha and beta, however, was detected in 6 other active sarcoidosis cases and 5 normal volunteers. Therefore, spontaneous release of IL-1 alpha and beta in vitro from alveolar cells in sarcoidosis might be considered as an index for the necessity of systemic corticosteroid treatment and its relationship to the spontaneous remission of sarcoidosis in Japanese patients was discussed.     

Interleukin-10 secretion by alveolar macrophages and monocytes in sarcoidosis

BACKGROUND: Alveolitis and the production of proinflammatory cytokines are known features of sarcoidosis. Because of the usually spontaneous resolution of alveolitis despite local secretion of mediators causing inflammation and granuloma formation, we hypothesized that downmodulating mechanisms such as anti-inflammatory cytokines might be involved in this process. OBJECTIVE: Investigation of the secretion of the macrophage deactivating cytokines interleukin-10 (IL-10) and transforming growth factor-beta (TGF-beta) by alveolar macrophages in untreated sarcoidosis of the lung. METHODS: Fourteen consecutive and untreated patients with pulmonary sarcoidosis and 18 volunteers underwent bronchoscopy. Alveolar macrophages (AM) were obtained by bronchoalveolar lavage and the secretion of IL-10 and TGF-beta was studied. RESULTS: Spontaneous IL-10 production by AM was found in 6 of 14 patients and in 2 of 18 controls. The IL-10 level of lipopolysaccharide-stimulated AM was significantly higher in patients. Monocytes secreted significantly more IL-10 than AM, but there was no difference between sarcoid and control monocytes. No difference was found in the secretion of TGF-beta between patients and controls. CONCLUSION: Increased local secretion of IL-10 - but not TGF-beta - may represent a downmodulating mechanism involved in the spontaneous resolution of alveolitis in sarcoidosis.     

Production of interleukin-10 by alveolar macrophages from lung cancer patients.

Interleukin (IL)-10 is known to be an autoregulatory factor of functions of monocyte macrophages. The purpose of this study was to determine whether IL-10 production by alveolar macrophages (AMs) is altered in patients with lung cancer. AMs were obtained by bronchoalveolar lavage from 25 patients with lung cancer and 14 control patients. The production of IL-10 by AMs was quantitated by enzyme immunoassay with or without stimulation with lipopolysaccharide (LPS). No significant difference in spontaneous and LPS-stimulated IL-10 production by AMs was observed between lung cancer patients and control patients (mean +/- SEM; 288.0 +/- 56.7 vs. 249.6 +/- 58.4 pg ml-1). IL-10 production of LPS-stimulated AMs was not impaired even in lung cancer patients with systemic metastasis. IL-4 failed to suppress LPS-induced production of IL-10 by AMs both in control patients and in lung cancer patients. In eight patients with lung cancer, IL-10 production by AMs was estimated before and after systemic chemotherapy and IL-10 production by LPS-stimulated AMs tended to increase after systemic chemotherapy from 152.3 +/- 51.9 to 278.0 +/- 112.8 pg ml-1. As IL-10 is a potent inhibitor of tumour angiogenesis, an important process of tumour progression, these results suggest that, even in advanced cancer patients, macrophages can produce potent angiogenesis inhibitor and systemic chemotherapy may augment this inhibitory activity in the lung.     

Spontaneous production of interleukin-6 by alveolar macrophages from human immunodeficiency virus type 1-infected patients.

To test the hypothesis that the lung represents a source of interleukin (IL)-6 in human immunodeficiency virus type 1 (HIV-1)-positive subjects, alveolar macrophages (AM) obtained from the bronchoalveolar lavage (BAL) fluid of 10 HIV-1-positive patients were investigated for the expression of IL-6 mRNA and the ability to release IL-6. The presence of IL-6 in BAL fluid was also investigated. It has been demonstrated that freshly recovered AM from HIV-1-positive patients show a strong IL-6 mRNA signal. The message for IL-6 increases following culture with LPS. Supernatants obtained from AM cultured in medium alone contain high amounts of IL-6; the values are three to four times higher following culture with LPS. IL-6 has also been detected in the BAL fluid from 5 of 8 HIV-1-positive patients. Results of immunoblotting analysis were consistent with those given above. These findings suggest that the lung represents a source of IL-6 production in HIV-1-infected subjects with lung disorders.     

己酮可可碱对肺结节病患者肺泡巨噬细胞释放细胞因子的作用

目的　研究己酮可可碱 (POF)对肺结节病患者肺泡巨噬细胞 (AM)产生细胞因子的作用 ,并与地塞米松 (DEX)的作用相比较。方法　收集 1 4例活动期肺结节病患者的AM ,以 1 0 %RPMI为培养液 (含有 1 0 %热灭活胎牛血清、2mmol/LL 谷氨酰胺、2 0 0kU/L青霉素及 2 0 0mg/L链霉素 ) ;或1 0 %RPMI加内毒素 (LPS ,1 0 0 μg/L) ;或分别加入浓度为 0 0 1mmol/L、0 1mmol/L和1mmol/L的POF ;或加入 0 1mmol/LDEX进行AM培养 2 4h。用酶联免疫吸附 (ELISA)法测定培养上清液中细胞因子含量。结果　POF对结节病患者AM自发释放的肿瘤坏死因子α(TNF α)有剂量依赖性抑制作用 (P <0 0 0 1 ) ,而对其他自发释放的细胞因子无影响。 0 1mmol/LDEX抑制自发释放的TNF α、可溶性肿瘤坏死因子受体 (sTNFR 2 )、白细胞介素 (IL) 1 β和IL 1 0 (P <0 0 0 1或 <0 0 5 或 <0 0 1 )。除sTNFR 1外 ,POF亦抑制这些由LPS刺激的AM释放的细胞因子 (P <0 0 5或 <0 0 0 1 )。与POF相似 ,0 1mmol/LDEX同样抑制这些LPS刺激的细胞因子释放 (P <0 0 5或 <0 0 0 1 ) ,但对sTNFR 1和IL 1 β无影响。 结论　与DEX相比 ,POF有更宽的治疗窗。用在结节病治疗上可以减少皮质激素用量或可将其替代。然而POF治疗结节病及其他肺部疾病的临床价     

Increased expression of apoptosis signalling receptors by alveolar macrophages in sarcoidosis.

The Fas receptor (FasR) and the tumour necrosis factor (TNF) receptor 55/60 kDa (TNFR1) are recognized as apoptosis signalling receptors. They are known to be expressed by lymphocytes in association with immune regulation and immunological disorders. This study aimed to investigate the expression of FasR and TNFR1 by alveolar macrophages (AM) in patients with sarcoidosis. Bronchoalveolar lavage (BAL) was performed in 12 patients with active sarcoidosis and 11 control subjects. BAL cells were characterized by monoclonal antibodies using a peroxidase-antiperoxidase method. Both FasR and TNFR1 were expressed on a higher percentage of AM in sarcoidosis with respect to control subjects (mean +/-sem 40.8+/-3.1% versus 14.9+/-1.7%, p<0.001 and 61.9+/-3.3% versus 23.1+/-4.1%, p<0.001, respectively). There was a close relationship between the expression of FasR and TNFR1 on AM (r = 0.86, p<0.001). The percentages of FasR+ AM and TNFR1+ AM were in direct proportion to the percentage of BAL lymphocytes (r = 0.75 and 0.84), the CD4/CD8 ratio (r = 0.78 and 0.78), and the percentage of the CD14+ AM subset (r = 0.77 and 0.87), p<0.001 for all correlations. This study indicates that alveolar macrophages expressing apoptotic receptors are increased in patients with active sarcoidosis. Further studies are required to determine whether these alveolar macrophages from patients with sarcoidosis undergo apoptosis more readily than those from control subjects.     

Clinical study on soluble interleukin-2 receptor in patients with sarcoidosis]

Levels of soluble IL-2 receptor in sera of 18 patients with sarcoidosis were measured by a sandwich ELISA method established by the authors and were found to be significantly higher than those in sera of normal subjects. Levels of soluble IL-2 receptor in sera of sarcoidosis cases of bilateral hilar lymphadenopathy (BHL) were significantly higher than those in sera of sarcoidosis cases without BHL. In patients with sarcoidosis, levels of soluble IL-2 receptor did not differ in relation to the presence or absence of ocular lesions, or in relation to positive or negative response to protein purified derivative of tuberculosis (PPD).     

Acid phosphatase (EC 3.1.3.2) activity in alveolar macrophages from patients with active sarcoidosis.

Five main acid phosphatase (AcP) zones have been recognized and studied by polyacrylamide-gel electrophoresis. Band 5 represents the only tartrate-resistant form and is present in bone osteoclasts and in human alveolar macrophages (AMs). This study was carried out to quantify the presence of total and tartrate-resistant AcP (TrAcP) in AMs from bronchoalveolar lavage (BAL) of 11 patients with first stage sarcoidosis and in 13 nonsmokers and 16 smokers serving as control healthy subjects. The AMs from smokers showed an increase in total AcP activity (115.9 +/- 77.8 mU/10(6)); on the contrary, macrophages of patients with sarcoidosis revealed a consistent decrease in total AcP (27.8 +/- 7.0 mU/10(6)) and particularly the TrAcP subtype (14.8 +/- 3.7 mU/10(6)) in comparison with control nonsmokers (AcP = 42.2 +/- 18.9 mU/10(6) [p = NS]; TrAcP = 35.1 +/- 15.1 mU/10(6) [p less than 0.005]). The decrease in TrAcP activity was inversely correlated with the lymphocyte number (r = -0.75; p less than 0.01), lymphocyte percentage (r = -0.62; p less than 0.05), and CD4/CD8 ratio (r = -0.61; p less than 0.05). After six months of follow-up, the cytologic BAL picture returned completely to normal in five patients with full spontaneous regression of sarcoidosis; and also at the same time, normal values of TrAcP activity were restored. Since TrAcP activity can be easily detected, its possible use, along with the lymphocyte count and CD4/CD8 ratio, as a prognostic indicator of the clinical course of sarcoidosis deserves further investigation.     

Glucocorticoid receptor mRNA expression in pulmonary alveolar macrophages in sarcoidosis

The presence of the glucocorticoid receptor was demonstrated by immunocytochemistry in pulmonary alveolar macrophages obtained by bronchoalveolar lavage. Also, GR mRNA content was determined by solution hybridization in PAM from 12 healthy volunteers and in 6 patients with sarcoidosis. No significant differences with regard to GR mRNA expression was detected between the two groups examined. For comparison, lung tissue from three patients undergoing thoracic surgery was examined and found to contain GR mRNA levels in the same range. As an indication of GR function, we also determined the mRNA levels of a glucocorticoid-regulated gene, metallothionein IIA, during basal conditions and after in vitro incubation of PAM with dexamethasone. Neither the control sample nor the dexamethasone-stimulated MTII mRNA values in PAMs differed significantly between the two groups. Solution hybridization is a rapid, sensitive and convenient assay which enables accurate and specific quantitation of GR mRNA in PAM. The GR mRNA content and basal as well as dexamethasone-induced MTII mRNA levels in PAM from patients with sarcoidosis is not significantly different from those in healthy volunteers.     

Cigarette smoking decreases interleukin-8 secretion by human alveolar macrophages

Cigarette smoking can impair pulmonary immune function, and hence influences the development of lung diseases. Interleukin-8 (IL-8) is a proinflammatory peptide and a potent chemotactic factor for neutrophils, and is produced by both immune and non-immune cells including monocytes and alveolar macrophages (AM). We investigated the effect of cigarette smoking on the secretion of IL-8 by human AM. The IL-8 concentration in bronchoalveolar lavage fluid (BALF) was much higher in smokers than in non-smokers (18.4 +/- 3.9 vs 4.1 +/- 1.0 pg ml-1; P < 0.005). However, spontaneous IL-8 secretion by cultured AM was lower in smokers than in non-smokers (46.8 +/- 12.7 vs 124.1 +/- 24.0 ng ml-1; P < 0.01). When stimulated with lipopolysaccharide (LPS), AM from smokers secreted significantly less IL-8 than those from non-smokers at all tested concentrations of LPS. In contrast, the amount of IL-8 secreted by peripheral blood monocytes with or without LPS stimulation was comparable in smokers and non-smokers. These observations indicate that smoking decreases IL-8 secretion by AM, which may modify or decrease the inflammatory response in the lung.