Sustained activation of neutrophils in the course of Kawasaki disease: an association with matrix metalloproteinases

Kawasaki disease (KD) is an acute febrile syndrome of childhood, characterized by vasculitis of the medium-sized arteries. White blood cell counts and the inflammatory parameter C-reactive protein (CRP) are known to be elevated in the acute phase of the disease. In this study we investigated the course of inflammatory cell type-specific parameters in KD over a longer period of time. Plasma levels of human neutrophil elastase (HNE), matrix metalloproteinases-2 and -9 (MMP2, MMP9), and neutrophil gelatinase-associated lipocalin (NGAL), macrophage neopterin and CRP were measured. Plasma samples were collected in the acute, subacute and early convalescent stage, and three months after the onset of disease. Median CRP and neopterin normalized within two weeks. In contrast, six weeks and three months after onset of disease, levels of HNE were still elevated, with median values of 163 ng/ml and 156 ng/ml, respectively (control children median < 50 ng/ml; for all time-points P < 0.0001). Values of NGAL correlated with the levels of HNE (r = 0.39, P = 0.013). These results demonstrate a longer state of neutrophil activation in KD than was previously assumed. The potential relationship between this prolonged neutrophil activation, coronary artery lesion formation and their persistence, as well as the risk of premature atherosclerosis warrants further evaluation.

"Safe" Coulomb excitation of 30Mg

We report on the first radioactive beam experiment performed at the recently commissioned REX-ISOLDE facility at CERN in conjunction with the highly efficient gamma spectrometer MINIBALL. Using 30Mg ions accelerated to an energy of 2.25 MeV/u together with a thin (nat)Ni target, Coulomb excitation of the first excited 2+ states of the projectile and target nuclei well below the Coulomb barrier was observed. From the measured relative deexcitation gamma-ray yields the B(E2;0(+)gs-->2(+)1) value of 30Mg was determined to be 241(31)e2 fm4. Our result is lower than values obtained at projectile fragmentation facilities using the intermediate-energy Coulomb excitation method, and confirms the theoretical conjecture that the neutron-rich magnesium isotope 30Mg resides outside the "island of inversion."

Methodological aspects in the analysis of spontaneously produced sputum

Analysis of sputum as a specimen containing inflammatory indices has gained considerable interest during the last decade with focus on chronic bronchitis (CB) with or without airway obstruction, cystic fibrosis (CF), chronic obstructive pulmonary disease (COPD) and asthma. The nature of the specimens requires expert skill for handling them and for performing analyses. The analysis of spontaneously produced sputum has been performed less frequently than that of induced sputum. This is surprising as several studies have shown that the collection procedures and the assay methods are highly reproducible. There are several valid parameters of sputum analysis that can be applied in research on airway inflammation and in monitoring therapy of patients. Spontaneously produced sputum can be obtained in a simple and non-invasive way, which warrants further efforts to expand the range of applications of its analysis. Here, we will critically review the procedures for collecting spontaneously produced sputum, for handling the samples, and the requirements for assay of sputum components. This will imply the reproducibility of the analysis, the recovery of solutes, the validity of assays in terms of reproducibility and of linearity of the response, the validity of the assays with respect to association with other inflammatory parameters and with clinical parameters, and the usefulness of assays with respect to their response upon treatment of patients.

Airway inflammation in nonobstructive and obstructive chronic bronchitis with chronic haemophilus influenzae airway infection. Comparison with noninfected patients with chronic obstructive pulmonary disease

Nonencapsulated Haemophilus influenzae often causes chronic infections of the lower respiratory tract in both nonobstructive and obstructive chronic bronchitis. We assessed airway inflammation in clinically stable, chronically H. influenzae-infected patients with nonobstructive (CB-HI, n = 10) and in patients with obstructive chronic bronchitis (COPD-HI, n = 10) by analyses of the sol phase of spontaneously expectorated sputum (SSP). As compared with the CB-HI group, the COPD-HI group had significantly higher (p < 0.05) levels of myeloperoxidase (MPO) and tumor necrosis factor (TNF)-alpha in their SSP, whereas the degree of plasma protein leakage (SSP-to-serum ratio of plasma proteins) and the levels of interleukin (IL)-8, secretory IgA, and lactoferrin were similar in the two groups. These findings point to differences in pathophysiology in CB-HI and COPD-HI. The high level of TNF-alpha in the SSP of COPD-HI patients is in accord with the proposed role of TNF-alpha in the development of airway obstruction in COPD patients. In apparent contradiction, low levels of TNF-alpha were found in the SSP of noninfected but otherwise similar COPD patients (n = 9). This finding, however, does not exclude an exaggerated TNF-alpha response to infection or another stimulus in the airways of COPD patients. The SSP levels of MPO and IL-8, and the degree of plasma protein leakage in the COPD-HI group, were retrospectively compared with and found significantly higher than those of noninfected COPD patients, suggesting a more marked inflammatory response in COPD-HI. Whether this reflects a direct cause-and-effect relationship should be addressed in a future long-term prospective study involving repeated measurements in the same patients.

Lung epithelial H292 cells induce differentiation of immature human HMC-1 mast cells by interleukin-6 and stem cell factor

BACKGROUND

Immature mast cells migrate into tissues where they differentiate into mature mast cells under the influence of local factors. In the airways of asthmatics increased numbers of chronically activated mast cells are located nearby the airway epithelium.

OBJECTIVE

The aim of this study was to evaluate whether and, if so, which products released by epithelial cells may affect mast cell proliferation and differentiation.

METHODS

We performed in vitro studies using the human lung mucoepidermoid carcinoma-derived H292 cell line and the immature human mast cell line, HMC-1. Proliferation was assessed by 3H-thymidine incorporation. Differentiation of HMC-1 cells was inferred from tryptase production.

RESULTS

Exposure of HMC-1 cells to medium conditioned for 48 h by H292 cells resulted in a reduction of proliferation with 65 +/- 4.9% (mean +/- SEM, n = 9) at day 5. Culturing HMC-1 cells for 8 days in the presence of H292-conditioned medium resulted in morphological changes indicative of differentiation, and in a 3.0 +/- 0.4-fold increase of tryptase production (P = 0.0039, n = 9). Conditioned medium from H292 cells that were stimulated by LPS also inhibited HMC-1 proliferation. Inhibitory antibodies against two mediators from H292 cells, interleukin-6 (IL-6) and stem cell factor (SCF), abolished the increase in HMC-1 tryptase production induced by H292-conditioned medium. Recombinant human (rh) IL-6, but not rhSCF, reduced HMC-1 proliferation with 44% and 13% at day 3 and 5, respectively. Surprisingly, rhIL-6 did not increase HMC-1 tryptase production significantly whereas incubation with rhSCF did (1.5 +/- 0.1-fold, P = 0.002, n = 10) although the increase was less than observed for conditioned medium.

CONCLUSION

Epithelial-derived IL-6 and SCF are implicated in differentiation of HMC-1 cells but additional factors are not excluded. As activated primary bronchial epithelial cells also express IL-6 and SCF, it should be considered that these cells are involved in mast cell differentiation within the airways, particularly in diseases where epithelial cells are activated, such as asthma.

IL-6 protein production by airway epithelial(-like) cells disabled in IL-6 mRNA degradation

IL-6 mRNA and protein expression in human airway epithelial-like H292 cells depends on rapid, but regulable IL-6 mRNA degradation. We restricted IL-6 mRNA degradation by partially inhibiting protein synthesis and studied the IL-6 response. Despite partial inhibition of protein synthesis, IL-6 protein production was increased and prolonged. Furthermore, the threshold concentration for stimuli of IL-6 protein production decreased and the dose-response curves became steeper. Similar findings were obtained with primary human bronchial epithelial cells. This exaggerated production may apply to other proteins encoded by labile mRNA and is likely to occur during viral infection of airway epithelial cells.

Interleukin-4 and interferon-gamma synergistically increase secretory component gene expression, but are additive in stimulating secretory immunoglobulin A release by Calu-3 airway epithelial cells

Interleukin-4 (IL-4) and interferon-gamma (IFN-gamma) synergize to express polymeric immunoglobulin receptor (pIgR) but their combined effect, and that of IL-4 alone, on secretory immunoglobulin A (sIgA) release is unknown. Recently, we have developed an airway epithelial cell model that allows assessment of the integrated effect of a stimulus on pIgR gene and protein expression and sIgA release. With this model we show here that IL-4 and IFN-gamma dose-dependently increased pIgR mRNA and protein expression, and sIgA release. IFN-gamma and IL-4 induced similar maximal expression of pIgR, but IFN-gamma enhanced sIgA release more than IL-4. When added together, IL-4 and IFN-gamma synergistically increased pIgR mRNA and protein expression, but sIgA release was stimulated in an additive manner. Thus, IL-4 and IFN-gamma may be implicated in the increase of sIgA levels as found in mucosal inflammatory diseases. In addition, our results indicate that transport and release of empty pIgR is subject to regulatory mechanisms different from those of pIgR with bound dimeric IgA.

The structure of bovine mitochondrial F1-ATPase: an example of rotary catalysis

There is now compelling evidence in support of a rotary catalytic mechanism in F1-ATPase, and, by extension, in the intact ATP synthase. Although models have been proposed to explain how protein translocation in F0 results in rotation of the gamma-subunit relative to the alpha 3/beta 3 assembly in F1 [22], these are still speculative. It seems likely that a satisfactory explanation of this mechanism will ultimately depend on structural information on the intact ATP synthase.

Triple role of platelet-activating factor in eosinophil migration across monolayers of lung epithelial cells: eosinophil chemoattractant and priming agent and epithelial cell activator

Infiltration of eosinophils into the lung lumen is a hallmark of allergic asthmatic inflammation. To reach the lung lumen, eosinophils must migrate across the vascular endothelium, through the interstitial matrix, and across the lung epithelium. The regulation of this process is obscure. In this study, we investigated the migration of human eosinophils across confluent monolayers of either human lung H292 epithelial cells or primary human bronchial epithelial cells. Established eosinophil chemoattractants (IL-8, RANTES, platelet-activating factor (PAF), leukotriene B4, and complement fragment 5a (C5a)) or activation of the epithelial cells with IL-1beta induced little eosinophil transmigration (<7% in 2 h). In contrast, addition of PAF in combination with C5a induced extensive (>20%) transepithelial migration of unprimed and IL-5-primed eosinophils. Eosinophil migration assessed in a Boyden chamber assay, i.e., without an epithelial monolayer, was only slightly increased upon addition of PAF and C5a. Preincubation of eosinophils with the PAF receptor antagonist WEB 2086 only inhibited migration of unprimed eosinophils toward PAF and C5a, whereas preincubation of epithelial cells with WEB 2086 abolished migration of both IL-5-primed and unprimed eosinophils. This latter result indicated the presence of PAF receptors on epithelial cells. Indeed, addition of PAF to epithelial cells induced an increase in cytosolic free Ca2+, which was blocked by the PAF receptor antagonists WEB 2086 and TCV-309. Our results show that PAF induces permissive changes in epithelial cells, and that PAF acts as a chemoattractant and priming agent for the eosinophils.

Superinduction of interleukin-6 mRNA in lung epithelial H292 cells depends on transiently increased C/EBP activity and durable increased mRNA stability

Restriction of eukaryotic protein synthesis affects the regulation of some transiently expressed gene transcripts resulting in their superinduction. We determined the transcriptional and post-transcriptional processes implicated in IL-6 mRNA superinduction in a human lung-derived epithelial cell line H292, and their kinetics in the absence and presence of an exogenous stimulus, tumor necrosis factor-alpha (TNF-alpha). Cycloheximide (CHI) at 10 microg/ml, which inhibited protein synthesis for 80%, caused a 80-fold induction of IL-6 mRNA level which was due predominantly to a stabilization of IL-6 mRNA (20-fold) early on. Employing transient transfection protocols we noted a small positive effect of CHI on transcription, mediated by the proximal and the distal C/EBP sites of the IL-6 promoter and paralleled by an increased C/EBP DNA-binding activity, similar to that found for exposure to TNF-alpha alone. TNF-alpha and CHI synergized on IL-6 mRNA expression (200-fold increase) which was due to an increased transcription, corresponding to a further increased C/EBP DNA-binding activity. However, the effect of CHI on IL-6 gene transcription was transient, in support of the need for ongoing protein synthesis for C/EBP activity. These findings indicate that IL-6 mRNA superinduction, at least in H292 cells, is regulated predominantly by modulating the repressive system that ensures a rapid degradation of IL-6 mRNA.

Histamine affects interleukin-4, interleukin-5, and interferon-gamma production by human T cell clones from the airways and blood

High levels of histamine can be found in the airways of asthma patients. This study describes the effects of histamine on anti-CD3-induced production of IL-4, IL-5, and IFN-gamma by T cell clones from subjects with allergic asthma and healthy subjects. T cell clones were obtained from bronchoalveolar lavage (BAL) fluid and blood. The number of clones tested, and the percentage of clones in which histamine inhibited or enhanced cytokine production by more than 25%, were as follows: IL-4, 47, 8.5%, and 4.3%; IL-5, 43, 14%, and 30%; and IFN-gamma, 52, 40%, and 15%. Inhibition of IL-5 and IFN-gamma production was reversed by IL-2. The enhancement of IFN-gamma production was associated with an enhancement of both IL-2 production and proliferation. In 21% of the clones a combined effect consisting of inhibition of IFN-gamma production and enhancement of IL-5 production was found. This response was reversed by H2-receptor antagonists and was significantly associated with a histamine-induced increase in intracellular levels of cAMP. The role of cAMP in mediating the histamine effects was supported by the observations that the beta2-agonist salbutamol had effects similar to histamine and that high concentrations of PGE2 mimicked the inhibitory effects of histamine. Clones from BAL fluid and blood showed similar responses, as did clones from patients with asthma and from control subjects. The enhancement of IFN-gamma production by histamine, however, was found only in clones from healthy subjects. The results warrant further investigations on the role of cAMP in the regulation of cytokine production.

Enhanced AP-1 and NF-kappaB activities and stability of interleukin 8 (IL-8) transcripts are implicated in IL-8 mRNA superinduction in lung epithelial H292 cells

Inhibition of protein synthesis may result in superinduction of short-lived transcripts and has been attributed variably to stabilization of transcripts and/or increased gene transcription. Little is known about the kinetics of these processes and relevant transcriptional elements have not been identified. In this study, we describe superinduction of interleukin 8 (IL-8) mRNA, an important inflammatory mediator, in lung epithelial-like H292 cells and identify the underlying molecular mechanisms and their kinetics. Cycloheximide (CHI, 10 microg/ml), an inhibitor of protein synthesis, maximally increased IL-8 mRNA levels 30-fold in H292 cells. Tumour necrosis factor alpha (TNF-alpha), which induced IL-8 mRNA 3-fold, synergized with CHI causing a 150-fold increase at 6 h. CHI early on increased the stability of IL-8 mRNA (from 40 min in cells cultured with medium to more than 4 h with CHI). CHI also increased transcription as shown by transfection with IL-8 promoter constructs. Truncated and mutated constructs identified NF-kappaB and AP-1 binding sites as primary cis-acting elements in IL-8 gene transcription and IL-8 mRNA superinduction. Electrophoretic mobility shift assays indicated that CHI increased NF-kappaB and prolonged AP-1 DNA-binding activities and that the synergism of TNF-alpha and CHI on IL-8 mRNA expression was paralleled by a further increase of AP-1 DNA-binding activity. This synergism was still noticed when 4 h elapsed between the addition of CHI and that of TNF-alpha. Taken together, our results indicate that CHI interferes with both post-transcriptional and transcriptional repressive mechanisms of IL-8 mRNA expression.

Persisting Haemophilus influenzae strains induce lower levels of interleukin-6 and interleukin-8 in H292 lung epithelial cells than nonpersisting strains

Nonencapsulated Haemophilus influenzae strains isolated from patients with chronic bronchitis can be divided into those that persist in the lower respiratory tract and those that do not. We tested the hypothesis that persisting and nonpersisting strains differ in the extent to which they activate epithelial cells to produce two potent inflammatory mediators, interleukin (IL)-6 and IL-8. A suspension of 10(7) and 10(8) colony forming units (cfu) x mL(-1) of H. influenzae, persisting and nonpersisting, induced a dose- and time-dependent production of IL-6 and IL-8 by the human pulmonary mucoepidermoid carcinoma-derived cell line H292, but levels of IL-6 were lower after exposure to persisting H. influenzae (p<0.05). IL-8 production showed a similar trend (p<0.02; analysis of variance). H. influenzae bacteria that adhered to H292 cells were equally distributed over persisting and nonpersisting isolates and induced IL-6 and IL-8 levels similar to their nonadhering counterparts. The difference between persisting and nonpersisting H. influenzae was not due to cytotoxic, antimetabolic or antiproliferative effects on H292 cells. Furthermore, pre-exposure of cells to persisting and nonpersisting isolates did not block subsequent IL-1beta-induced IL-6 production. We conclude that persisting clinical isolates induce less interleukin-6 and interleukin-8 in H292 cells than nonpersisting isolates, probably because they excrete lower amounts of a stimulus of H292 cells. The stimulus is heat stable, hydrophilic and nonproteinous and probably not lipopolysaccharide alone. These findings support the suggestion that some strains of Haemophilus influenzae that persist in the airways of patients, may do so because they induce only a weak inflammatory response.

Vectorial transcytosis of dimeric IgA by the Calu-3 human lung epithelial cell line: upregulation by IFN-gamma

We have developed an in vitro airway epithelial cell model for dimeric immunoglobulin (Ig) A (dIgA) transcytosis that allows the assessment of polymeric Ig receptor (pIgR) gene expression and actual dIgA transport. Tight monolayers of human lung-derived Calu-3 adenocarcinoma cells grown on permeable membranes expressed pIgR mRNA and released more secretory component (SC; P < 0.01) and secretory IgA (sIgA; P < 0.02) into the apical medium than into the basolateral medium. Transcytosis of dIgA was not due to paracellular leakage and was inhibited to approximately 20 and 30% of control values by anti-pIgR antibodies and the competitive ligand pentameric IgM, respectively. Interferon-gamma (IFN-gamma; 200 U/ml) induced pIgR mRNA expression and increased apical release of free SC and sIgA in a dose-dependent fashion (P < 0.0001). Basolateral addition of increasing amounts of dIgA dose dependently increased apical sIgA release (P < 0.0001). These data indicate that Calu-3 monolayers are capable of translocating dIgA through the pIgR. In addition, we show the integrated stimulatory effect of IFN-gamma on pIgR mRNA and protein expression and dIgA transcytosis.

Immunocytochemical and flow cytofluorimetric detection of intracellular IL-4, IL-5 and IFN-gamma: applications using blood- and airway-derived cells

We have compared an immunocytochemical and a flow cytofluorimetric method to detect intracellular IFN-gamma, IL-4 and IL-5 in T-cell clones, peripheral blood mononuclear cells (PBMC) and bronchoalveolar lavage fluid (BALF) cells. Intracellular bound cytokine-specific antibodies were visualized either with amino-ethyl carbazole (for immunocytochemistry), or with fluorescent antibodies (for flow cytofluorimetry). The staining was inhibited with recombinant cytokines and corresponded qualitatively and quantitatively to cytokine levels in the supernatants of T-helper-0 (Th0), Th1 and Th2 clones. In analysing in vitro stimulated cells, sufficient signal in the fluorimetric assay was only obtained after the addition of monensin to the cultures. We then observed a good correlation between immunocytochemical (with no monensin added) and the flow cytofluorimetric staining for all three cytokines (PBMC, IFN-gamma and IL-4, rho = 0.9, no IL-5 detectable; clones, IL-5, rho = 0.81, all three p < 0.05). However, compared to flow cytometry, a greater percentage of positively stained cells was frequently observed using immunocytochemistry. In BALF cells, the immunocytochemical method was able to detect significant percentages of positive cells without in vitro stimulation of the cells, in contrast to the flow cytofluorimetric method. In BALF cells from sarcoidosis patients, T-cells were mainly IFN-gamma-positive (immunocytochemically assessed), both with (mean +/- SEM, 39.7 +/- 9.8%), and without (3.5 +/- 1.3%) in vitro stimulation. In BALF cells from allergic subjects, the immunocytochemical method showed lymphocytes positive for IFN-gamma (40.3 +/- 8.3%), IL-4 (19.1 +/- 0.49) and IL-5 (6.1 +/- 3.1). We conclude that both methods can be used to assess the production of IFN-gamma, IL-4 or IL-5 at the single-cell level in T-cell clones, PBMC and cells from the BALF. The high sensitivity and the low number of cells required for the immunocytochemical method indicate that this method can provide detailed information on cytokine production of airway-derived cells in diseases with airway inflammation such as sarcoidosis and asthma.

Transmigration of human neutrophils across airway epithelial cell monolayers is preferentially in the physiologic basolateral-to-apical direction

To study the mechanisms involved in the movement of neutrophils from the blood stream into the lung airways, we investigated human neutrophil transmigration across a monolayer of human airway epithelial cells, both in the apical-to-basolateral direction and in the more physiologic basolateral-to-apical direction. Migration of human neutrophils across monolayers of human airway epithelial H292 cell-line cells and primary bronchial epithelial cells occured most efficiently in the basolateral-to-apical direction, both after the addition of chemoattractants to resting epithelial cells and across interleukin-1beta (IL-1beta)-stimulated epithelial cells. Blocking studies with monoclonal antibodies revealed that the migration of neutrophils was mediated by the CR3 adhesion molecule (CD11b/CD18) on the neutrophils. IL-1beta-treated epithelial cells caused neutrophil movement via the secretion of chemoattractants. The most potent chemoattractant released by the epithelial cells was found to be IL-8, because the IL-1beta-induced migration was inhibited for 75 +/- 10% by the addition of an antibody against IL-8. After apical stimulation of the epithelial cells with an optimal concentration of IL-1beta, 27 +/- 4 ng/ml IL-8 was found in the supernatant at the apical side of epithelial cells. Platelet-activating factor (PAF) synthesis by the epithelial cells did not play a role in neutrophil transmigration, as was demonstrated by the lack of inhibition of this process after addition of the PAF-receptor antagonist WEB 2086. We conclude that the movement of neutrophils across airway epithelial cell monolayers occurs preferentially in the physiologic basolateral-to-apical direction, indicating that the polarity of epithelial cells is important for neutrophil transmigration.

Neutrophil transmigration across monolayers of endothelial cells and airway epithelial cells is regulated by different mechanisms

Neutrophil recruitment from the blood stream into the airways is one of the important features of many inflammatory disorders in the lung. In this process, neutrophils migrate first from the blood across the ECs in the apical-to-basolateral direction into the tissues and then across airway epithelium in the basolateral-to-apical direction into the lung lumen. We investigated and compared the different mechanisms of neutrophil transmigration in vitro across monolayers of these two cell types in both directions. Neutrophil migration induced by chemoattractants was stronger across resting EC than across resting epithelial cells when both cell types were growing on top of the filters (i.e., migration in the apical-to-basolateral direction). Much higher neutrophil transepithelial migration was found in the physiological, basolateral-to-apical direction (cells hanging underneath the filters) than in the opposite direction across either resting or IL-1 beta-activated epithelial cells. In contrast, no significant difference was observed with EC under these conditions. After a 4-h IL-1 beta activation, neutrophil migration across EC was dependent on IL-8 and PAF. However, the migration across epithelial cells relied, to a greater extent, on IL-8 production, and not on PAF. The adhesion molecule ICAM-1 contributed much less to neutrophil migration across epithelium than that across endothelium. Our study provides evidence of different mechanisms of neutrophil transmigration across monolayers of EC and epithelial cells in vitro, indicating that different processes control neutrophil transmigration across EC and epithelial cells in vivo.

Cytokine production by T-cell clones from bronchoalveolar lavage fluid of patients with asthma and healthy subjects

Cytokines produced by T-lymphocytes play an important regulatory role in inflammation in the airways of asthmatic patients. Our aim was to analyse the cytokine production by T-cell clones from bronchoalveolar lavage fluid (BAL) of patients with allergic asthma and the cytokine production of clones from the patients' peripheral blood (PB), as well as from BAL and blood from healthy controls. In 75 randomly selected CD4+ T-cell clones, we assessed the production of interleukin (IL)-2, IL-4 and interferon-gamma (IFN-gamma). After stimulation with anti-CD3, the clones from the asthmatic patients' BAL (A-BAL) produced significantly more IL-4 and IFN-gamma (median 0.32 and 4.17 ng.mL-1, respectively) than clones from A-PB (0.11 and 1.12 ng.mL-1, respectively). No evidence was found for a dominance of a type 1 or type 2 T-helper cell (Th1- or Th2)-cytokine profile in any of the groups. In three out of nine clones tested, the stimulation with anti-CD2/CD28/phorbol myristate acetate (PMA) induced a shift of the IFN-gamma/IL-4 ratio towards a Th2-type cytokine profile. Our results suggest that the clones from the asthmatic patients' bronchoalveolar lavage were derived from a more differentiated T-cell population. In several clones, the cytokine profile was still modulated by the stimulus applied. Similarly, local conditions in the airways may be involved in directing the cytokine production of T-cells.

Glucocorticosteroids affect functions of airway- and blood-derived human T-cell clones, favoring the Th1 profile through two mechanisms

Glucocorticosteroids (GCS) are beneficial in allergic asthma. GCS therapy results in reduced mRNA expression of interleukin-4 (IL-4) and IL-5 in cells from bronchoalveolar lavage (BAL) but not of IFN-gamma. In vitro studies with blood-derived T cells, however, show inhibition of all three cytokines by GCS. We studied the effects of GCS on T cells from BAL in vitro, namely Th0-, Th1, and Th2-like clones; and we compared BAL- with blood-derived clones. Dexamethasone (DEX) inhibited the anti-CD3-induced production of IL-4, IL-5 and IFN-gamma in all 20 clones tested. IFN-gamma production was inhibited significantly less than IL-4 and IL-5. DEX enhanced the ratio IFN-gamma/IL-4 (mean +/- SEM: control, 28.7 +/- 17.6; with 10-7 M DEX, 55.0 +/- 27.5, P<0.005). Interestingly, two categories of clones were distinguished based on the effects of GCS on IL-2 production and IL-2R alpha expression and proliferation; 1) In low IL-2 producers DEX blocked IL-2 production and decreased IL-2R alpha expression and proliferation; 2) In high IL-2 producers DEX inhibited IL-2 production partially and enhanced IL-2R alpha expression and proliferation. Anti-IL-2 and anti-IL2R alpha blocked the DEX-induced increase in proliferation. High levels of added IL-2 induced the second type of response. In conclusion, the production of IL-4 and IL-5 by T-cell clones (derived either from BAL or blood) was more sensitive to inhibition by DEX than that of IFN-gamma, which may account for the therapeutic effects of glucocorticosteroids in patients with asthma. The differential effects of DEX on the proliferation of high and low IL-2 producers in vitro may implicate a selective outgrowth of Th1-like T cells in vivo in patients treated with steroids.

Interleukin-8 in airway inflammation in patients with asthma and chronic obstructive pulmonary disease

We have investigated whether IL-8 is present in airway secretions from patients with asthma and chronic obstructive pulmonary disease (COPD) to obtain information on its possible role in airway inflammation in obstructive airways disease. In the bronchoalveolar lavage fluid (BALF) from 11 clinically stable patients with asthma the levels of IL-8 were increased compared to 10 healthy subjects (median: controls 21.5 pg/ml, asthma 244 pg/ml: p < 0.005). In the patients with asthma the levels of IL-8 correlated with the percentage neutrophils in the BALF (r = 0.81; p < 0.001) and with a parameter of the permeability of the respiratory membrane, the quotient (alpha 2-macroglobulin in BALF)/(alpha 2-macroglobulin in serum) (r = 0.66; p < 0.025). In the sputum sol phase of 9 patients with symptomatic asthma the levels of IL-8 were lower than in 9 patients with COPD (asthma: 6.4 ng/ml; COPD: 16.3 ng/ml; p < 0.02) and significantly correlated with those of neutrophilic myeloperoxidase (MPO; r = 0.85; p < 0.005). The increased levels of IL-8 in the airway secretions from both patients with asthma and COPD may be markers of an ongoing inflammatory process, which is more pronounced in patients with COPD. In patients with asthma the strong correlation between the levels of IL-8 and the percentage neutrophils and/or the levels of MPO points to a role of IL-8 in the recruitment and activation of neutrophils in the airway lumen.

Plasma protein leakage and local secretion of proteins assessed in sputum in asthma and COPD. The effect of inhaled corticosteroids

Asthma and chronic obstructive pulmonary disease (COPD) are characterized by chronic airway inflammation with cell infiltration, increased plasma exudation and abnormal local secretion of proteins. We have analysed whether sputum differs in this respect between asthma (n = 9) and COPD (n = 9), and whether inflammatory markers in sputum are affected by treatment. In non-smoking asthma patients there was more plasma protein leakage, based on the relative coefficient of excretion Q alpha 2macroglobulin/QIgG (P = 0.03). There was less local secretion of sIgA and lactoferrin than in COPD (P < 0.05). Tryptase was slightly higher in sputum from asthma than from COPD (P < 0.05), whereas eosinophil cationic protein and myeloperoxidase were similar. After treatment with glucocorticosteroids, there was a reduction in the Q alpha 2macroglobulin/Qalbumin (P < 0.015), but no effect was seen on the levels of products from local cells. We conclude that sputum analysis is useful to study the local inflammatory process in asthma and COPD.

Physical interaction between lung epithelial cells and T lymphocytes

The present results support a role for epithelial cells in the activation of T cells in an apparent antigen-independent manner. The transient expression of CD25 indicates a short acting T cells activation. Possibly, this event primes T cells to respond swiftly upon antigen-specific stimulation or to synthesize mediators that affect the local milieu. The molecular mechanism of interaction, although not well defined possibly involves LFA3-CD2 interactions. In T cell activation, via LFA3-CD2 interaction, the density of presented LFA3 molecules is critical. With the increase in the level of expression of LFA3 by epithelial cells this critical density may have been reached. However, based on what is known about T cell activation and CD25 expression in particular it is likely that additional signals such as soluble mediators are required for T cell activation by epithelial cells. Whether this mode of activation occurs in vivo remains to be established by studying ex vivo and in situ material. Not much is known about the expression of LFA3 by epithelial cells in vivo, nor about the stimuli that induce the upregulation of LFA3. In preliminary experiments with fluorescence microscopy we found that neither TNF-alpha nor IL-1 beta induce LFA3 in the same fashion as IFN-gamma. In conclusion, T cell activation by epithelial cells could be an important feature in inflammatory and immunological processes in mucosal systems such as the bronchi and deserves further research.

Analysis of plasma-protein leakage and local secretion in sputum from patients with asthma and chronic obstructive pulmonary disease

In order to assess the usefulness of sputum analysis in studying plasma-protein exudation and local secretion of proteins in the airways, we measured specific proteins in the sputum sol phase (SSP) and sputum gel phase (SGP) from patients with stable asthma or chronic obstructive pulmonary disease (COPD). Protein levels in SSP showed relatively small variations between two subsequent visits of each patient (n = 22), as also reflected by intraclass correlation coefficients above 0.79. Protein levels differed between SSP and SGP, but inclusion of the SGP data did not affect the variation of protein levels in sputum. The degree of plasma-protein leakage was estimated from the relative coefficients of excretion (RCE) of alpha 2-macroglobulin and albumin (QA2M/QALB), and of alpha 2-macroglobulin and ceruloplasmin (QA2M/QCP), which do not depend on variable dilution of sputum. Despite the heterogeneity of the study group of 26 patients with asthma (atopic [13] smokers [13], including five patients using inhaled steroids), QA2M/QALB and QA2M/QCP correlated both with bronchial hyperreactivity (Spearman rank: r = -0.45 and r = -0.36, p < 0.05) and with blood eosinophil counts (r = 0.37 and 0.56, p < 0.05). We conclude that protein levels in SSP are relatively constant in patients with stable asthma or COPD; in patients with asthma, the plasma-protein leakage, as measured with the RCE in SSP, appears to correlate with indirect indices of airway inflammation.

Expression of activation markers by human lung T cells after adherence to lung epithelial cells

Both increased T cell numbers and their increased activation state have implicated an important role for T cells in chronic inflammatory reactions seen in the airways of (allergic) asthmatics. Airway epithelial cells are frequently exposed to stimuli that cause the release of mediators and the expression of cell adhesion molecules. We have examined whether human airway epithelial cells can activate lung-derived T cells. Clonal lung T cells showed an increased adherence to transformed airway epithelial cells that had been exposed previously for 2 h to human recombinant interferon-gamma (IFN-gamma; 100 U/ml). After an additional 16-24 h of culturing in the absence or presence of epithelial cells, T cells expressed increased levels of both the alpha-chain of the interleukin-2 receptor (IL-2R, CD25) and the transferrin receptor (CD71), both markers of T cell activation. T cells apparently activated by epithelial cells, however, did not produce IFN-gamma or IL-4 nor showed an increased proliferation on the addition of IL-2 (5-50 U/ml). The induced adherence to and the activation of T cells by epithelial cells is mediated largely by CD2 and its ligand lymphocyte functional antigen-3, a pathway known to up- and downregulate T cell functions.

Structure at 2.8 A resolution of F1-ATPase from bovine heart mitochondria

In the crystal structure of bovine mitochondrial F1-ATPase determined at 2.8 A resolution, the three catalytic beta-subunits differ in conformation and in the bound nucleotide. The structure supports a catalytic mechanism in intact ATP synthase in which the three catalytic subunits are in different states of the catalytic cycle at any instant. Interconversion of the states may be achieved by rotation of the alpha 3 beta 3 subassembly relative to an alpha-helical domain of the gamma-subunit.

F1F0-ATP synthase from bovine heart mitochondria: development of the purification of a monodisperse oligomycin-sensitive ATPase

A new procedure for the isolation of ATP synthase from bovine mitochondria has been developed, with the primary objective of producing enzyme suitable for crystallization trials. Proteins were extracted from mitochondrial membranes with dodecyl-beta-D-maltoside, and the ATP synthase was purified from the extract in the presence of the same detergent by a combination of ion-exchange and gel-filtration chromatography and ammonium sulphate precipitation. This simple and rapid procedure yields 20-30 mg of highly pure and monodisperse enzyme, evidently consisting of 14 different subunits, amongst them, in apparently stoichiometric amounts with the established subunits, subunit e, a recently discovered subunit of unknown function. The enzyme preparation has an oligomycin-sensitive ATP hydrolysis activity, and so the F1 domain is functionally associated with the membrane domain, F0. In contrast with the N-termini of some of the subunits of bovine mitochondrial F1-ATPase, those of the F1F0-ATP synthase are not degraded by proteolysis during the isolation procedure. This preparation therefore satisfies prerequisites for crystallization trials.

Organization and sequences of genes for the subunits of ATP synthase in the thermophilic cyanobacterium Synechococcus 6716

The sequences of the genes for the nine subunits of ATP synthase in the thermophilic cyanobacterium Synechococcus 6716 have been determined. The genes were identified by comparison of the encoded proteins with sequences of ATP synthase subunits in other species, and confirmed for subunits alpha, beta, delta and epsilon, by determining their N-terminal sequences. They are arranged at three separate loci. Six of them are in one cluster in the order a: c: b': b: delta: alpha, and those for the beta and epsilon subunits form a second and separate cluster. The gene for the gamma-subunit is at a third site. As in other bacteria, the gene for subunit a is immediately preceded by a gene coding for a small hydrophobic protein of unknown function, known as uncI in Escherichia coli. The gene orders in Synechococcus 6716 are related to the orders of ATP synthase genes in the plastid genomes of higher plants, and particularly of a red alga and a diatom. The sequences of the subunits are similar to those of chloroplast ATP synthase, the alpha, beta and c subunits being particularly well conserved. Differences in the primary structures of the Synechococcus 6716 and chloroplast gamma subunits probably underlie different mechanisms of activation of ATP synthase. The nucleotide sequences that are presented also contain 12 other open reading frames. One of them encodes a protein sequence related to the E. coli DNA repair enzyme, photolyase, and another codes for a protein that contains internal repeats related to sequences in the myosin heavy chain.

Heterogeneous effects of histamine on proliferation of lung- and blood-derived T-cell clones from healthy and asthmatic persons

We have studied the effects of histamine on the proliferation and the intracellular cyclic adenosine monophosphate (cAMP) levels of T-lymphocyte clones (TLC) generated from bronchoalveolar lavage fluid (BALF) or peripheral blood (PB) from healthy and asthmatic persons. TLC from either compartment and from both groups of donors were heterogeneous in their response to histamine. In BALF-derived TLC, three types of responses were observed: histamine inhibited, stimulated, or did not modulate the anti-CD3-induced proliferation. Histamine directly and dose dependently inhibited the anti-CD3-induced proliferation of six (two asthmatic) of 12 CD4+ BALF TLC, stimulated two BALF TLC (both nonasthmatic), and did not modulate the proliferation of four BALF TLC. The maximal inhibition was 70%, the maximal stimulation 200%, both at 10(-3) M histamine. The stimulation of proliferation was associated with increased interleukin-2 (IL-2) production, whereas the inhibition of proliferation was associated with decreased IL-2 production and downregulation of IL-2 receptor expression. The inhibitory effects could be partly reversed by H2-receptor antagonists and could be mimicked by an H2-receptor agonist. In contrast, the stimulatory effect was not reversed or mimicked by H1 or H2 antagonists or agonists. The majority of CD4+ TLC responded to histamine with a rise in the intracellular cAMP levels. A rise in cAMP, however, was often but not always associated with an inhibition of proliferation. In addition, stimulation of proliferation occurred in the absence of a rise in cAMP. We compared cAMP rises in panels of TLC obtained with high cloning efficiencies from the PB from a healthy person and from an asthmatic person.(ABSTRACT TRUNCATED AT 250 WORDS)

Inherent asymmetry of the structure of F1-ATPase from bovine heart mitochondria at 6.5 A resolution

ATP synthase, the assembly which makes ATP in mitochondria, chloroplasts and bacteria, uses transmembrane proton gradients generated by respiration or photosynthesis to drive the phosphorylation of ADP. Its membrane domain is joined by a slender stalk to a peripheral catalytic domain, F1-ATPase. This domain is made of five subunits with stoichiometries of 3 alpha: 3 beta: 1 gamma: 1 delta: 1 epsilon, and in bovine mitochondria has a molecular mass of 371,000. We have determined the 3-dimensional structure of bovine mitochondrial F1-ATPase to 6.5 A resolution by X-ray crystallography. It is an approximately spherical globule 110 A in diameter, on a 40 A stem which contains two alpha-helices in a coiled-coil. This stem is presumed to be part of the stalk that connects F1 with the membrane domain in the intact ATP synthase. A pit next to the stem penetrates approximately 35 A into the F1 particle. The stem and the pit are two examples of the many asymmetric features of the structure. The central element in the asymmetry is the longer of the two alpha-helices in the stem, which extends for 90 A through the centre of the assembly and emerges on top into a dimple 15 A deep. Features with threefold and sixfold symmetry, presumed to be parts of homologous alpha and beta subunits, are arranged around the central rod and pit, but the overall structure is asymmetric. The central helix provides a possible mechanism for transmission of conformational changes induced by the proton gradient from the stalk to the catalytic sites of the enzyme.

Crystallization of F1-ATPase from bovine heart mitochondria

Crystals of the F1-ATPase sector of the ATP synthase complex from bovine heart mitochondria have been grown from solutions containing polyethylene glycol 6000. The crystals diffract to 2.9 A resolution on a laboratory X-ray source. They are orthorhombic and belong to the space group P2(1)2(1)2(1). The unit cell axes are a = 285 A, b = 108 A, c = 140 A. There is one molecule of F1-ATPase in the asymmetric unit.

Surfactant protein A in bronchoalveolar lavage fluid

We measured surfactant protein A and phosphatidylcholine in the bronchoalveolar lavage fluid from healthy volunteers and several groups of patients with lung diseases to obtain information on surfactant in the lung. We developed three types of enzyme-linked immunosorbent assays that used combinations of polyclonal antiserum and monoclonal antibodies. Phosphatidylcholine was assessed by enzymatic measurement. The median amounts of surfactant protein A in bronchoalveolar lavage fluid determined by the enzyme-linked immunosorbent assay with monoclonal antibodies were as follows: control subjects (n = 10), 2.82 mg/L (range, 0.92 to 5.17 mg/L); patients with asthma (n = 13), 1.89 mg/L (range, 0.45 to 2.95 mg/L); and patients with pulmonary sarcoidosis (n = 20), 2.98 mg/L (range, 0.68 to 7.02 mg/L). The median phosphatidylcholine concentrations in the bronchoalveolar lavage fluid were as follows: control subjects (n = 10), 20 mumol/L (range, 3 to 37 mumol/L); patients with asthma (n = 12), 24 mumol/L (range, 3 to 55 mumol/L); and patients with pulmonary sarcoidosis (n = 20), 26 mumol/L (range, 4 to 76 mumol/L). As a group, the patients with asthma had less surfactant protein A in bronchoalveolar lavage fluid than did the control subjects (Mann-Whitney U test, p less than 0.05). The surfactant protein A levels measured by the enzyme-linked immunosorbent assay with polyclonal antiserum and by a competitive enzyme-linked immunosorbent assay were also lower in bronchoalveolar lavage fluid from patients with asthma than in that from control subjects. The phosphatidylcholine concentrations in all groups were similar.(ABSTRACT TRUNCATED AT 250 WORDS)

Identification of the subunits of F1F0-ATPase from bovine heart mitochondria

An oligomycin-sensitive F1F0-ATPase isolated from bovine heart mitochondria has been reconstituted into phospholipid vesicles and pumps protons. this preparation of F1F0-ATPase contains 14 different polypeptides that are resolved by polyacrylamide gel electrophoresis under denaturing conditions, and so it is more complex than bacterial and chloroplast enzymes, which have eight or nine different subunits. The 14 bovine subunits have been characterized by protein sequence analysis. They have been fractionated on polyacrylamide gels and transferred to poly(vinylidene difluoride) membranes, and N-terminal sequences have been determined in nine of them. By comparison with known sequences, eight of these have been identified as subunits beta, gamma, delta, and epsilon, which together with the alpha subunit form the F1 domain, as the b and c (or DCCD-reactive) subunits, both components of the membrane sector of the enzyme, and as the oligomycin sensitivity conferral protein (OSCP) and factor 6 (F6), both of which are required for attachment of F1 to the membrane sector. The sequence of the ninth, named subunit e, has been determined and is not related to any reported protein sequence. The N-terminal sequence of a tenth subunit, the membrane component A6L, could be determined after a mild acid treatment to remove an alpha-N-formyl group. Similar experiments with another membrane component, the a or ATPase-6 subunit, caused the protein to degrade, but the protein has been isolated from the enzyme complex and its position on gels has been unambiguously assigned. No N-terminal sequence could be derived from three other proteins. The largest of these is the alpha subunit, which previously has been shown to have pyrrolidonecarboxylic acid at the N terminus of the majority of its chains. The other two have been isolated from the enzyme complex; one of them is the membrane-associated protein, subunit d, which has an alpha-N-acetyl group, and the second, surprisingly, is the ATPase inhibitor protein. When it is isolated directly from mitochondrial membranes, the inhibitor protein has a frayed N terminus, with chains starting at residues 1, 2, and 3, but when it is isolated from the purified enzyme complex, its chains are not frayed and the N terminus is modified. Previously, the sequences at the N terminals of the alpha, beta, and delta subunits isolated from F1-ATPase had been shown to be frayed also, but in the F1F0 complex they each have unique N-terminal sequences.(ABSTRACT TRUNCATED AT 400 WORDS)

Structural aspects of proton-pumping ATPases

ATP synthase is found in bacteria, chloroplasts and mitochondria. The simplest known example of such an enzyme is that in the eubacterium Escherichia coli; it is a membrane-bound assembly of eight different polypeptides assembled with a stoichiometry of alpha 3 beta 3 gamma 1 delta 1 epsilon 1 a1b2c10-12. The first five of these constitute a globular structure, F1-ATPase, which is bound to an intrinsic membrane domain, F0, an assembly of the three remaining subunits. ATP synthases driven by photosynthesis are slightly more complex. In chloroplasts, and probably in photosynthetic bacteria, they have nine subunits, all homologues of the components of the E. coli enzyme; the additional subunit is a duplicated and diverged relation of subunit b. The mammalian mitochondrial enzyme is more complex. It contains 14 different polypeptides, of which 13 have been characterized. Two membrane components, a (or ATPase-6) and A6L, are encoded in the mitochondrial genome in overlapping genes and the remaining subunits are nuclear gene products that are translated on cytoplasmic ribosomes and then imported into the organelle. The sequence of the proteins of ATP-synthase have provided information about amino acids that are important for its function. For example, amino acids contributing to nucleotide binding sites have been identified. Also, they provide the basis of models of secondary structure of membrane components that constitute the transmembrane proton channel. An understanding of the coupling of the transmembrane potential gradient for protons, delta mu H+, to ATP synthesis will probably require the determination of the structure of the entire membrane bound complex. Crystals have been obtained of the globular domain, F1-ATPase. They diffract to a resolution of 3-4 A and data collection is in progress. As a preliminary step towards crystallization of the entire complex, we have purified it from bovine mitochondria and reconstituted it into phospholipid vesicles.

A new method for detecting endocytosed proteins

A new reagent, DPSgt, is described which has been designed to label cell surface proteins at 0 degree C. The reagent is easily made; it is water soluble and contains a reactive impermeant ester at one end, a tyrosine which can be radioiodinated at the other, and a disulphide in-between. The label can be removed from cells by cleaving the disulphide linkage in it with glutathione at 0 degree C. When cells are warmed to 37 degrees C between labelling and reduction, labelled proteins which are endocytosed acquire resistance to reduction. This provides a simple way of measuring the endocytosis of surface proteins. The intracellular pools of transferrin and LDL receptors in K562 cells and fibroblasts have been estimated. The results indicate that intracellular receptors are in non-reducing compartments, and that uptake of average cell surface (by non-coated pit processes) in K562 cells is small.

Cytochrome b deficiency in an autosomal form of chronic granulomatous disease. A third form of chronic granulomatous disease recognized by monocyte hybridization

Three patients (two sisters and a brother) in one family are described with chronic granulomatous disease. The granulocytes of these patients did not respond with a metabolic burst to various stimuli and failed to kill catalase-positive microorganisms. The magnitude of the cytochrome b signal in the optical spectrum of the patients' granulocytes was less than 4% of the normal value, whereas the amount of noncovalently bound flavin in these cells was normal. The mode of inheritance of the genetic defect in this family is autosomal because the granulocytes of both parents (first cousins) and a nonaffected sister of the patients expressed 70-80% of the normal cytochrome b signal, showed low-normal or subnormal oxidative reactions during stimulation, and did not display mosaicism in the stimulated nitroblue-tetrazolium slide test. Somatic cell hybridization was performed between the monocytes from the affected boy in this family with monocytes from either a cytochrome b-negative male patient with X-linked chronic granulomatous disease or a cytochrome b-positive male patient with the classic autosomal form of this disease. In both combinations, monocyte hybrids were observed with nitroblue tetrazolium reductase activity after stimulation with phorbol myristate acetate. This complementation of the oxidase activity required protein synthesis. Our results prove that the defect in this family is genetically distinct from that in the other two forms of chronic granulomatous disease. Moreover, our results also indicate that the expression of cytochrome b in human phagocytes is coded by at least two loci, one on the X chromosome and one on an autosome.

Purification and partial characterization of the b-type cytochrome from human polymorphonuclear leukocytes

Polymorphonuclear leukocytes contain an oxidase system that can be activated to produce superoxide radicals and hydrogen peroxide. A nonmitochondrial b cytochrome, functioning in the generation of these oxygen species, has been purified to apparent homogeneity from human polymorphonuclear phagocytes. After solubilization of the cytochrome with Triton X-100, the cell extract was subsequently chromatographed on Blue Sepharose and Sephacryl S-300. The final preparation was maximally purified 170-fold with a specific content of 5.33 +/- 2.03 nmol mg-1 of protein (mean +/- S.D.; n = 7) and a yield of 21 +/- 13% (n = 5). The apparent molecular mass of the nondenatured cytochrome was estimated by gel filtration to be 235 kDa. Upon polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate, a single polypeptide was found with a molecular mass of 127 kDa. From the pyridine hemochrome spectrum 1 protoheme IX/polypeptide was calculated. The light absorbance bands of the dithionite-reduced cytochrome were found to be at 558.5 (alpha), 529 (beta), and 426 nm (Soret), and that of the oxidized cytochrome at 413.5 nm. The difference absorbance coefficients are delta epsilon (426.5 - 440 nm) = 160.6 +/- 11 mM-1 cm-1 and delta epsilon (558.5 - 542 nm) = 29.3 +/- 2 mM-1 cm-1 (mean +/- S.D.; n = 5). Carbon monoxide binds to the cytochrome in a time-dependent fashion (maximum binding after 50-60 min). The midpoint potential of the solubilized nonpurified cytochrome is identical to the cytochrome in situ (Em7.0 = -218 +/- 7 mV (mean +/- S.D.; n = 5)). However, purified cytochrome b shows a significantly decreased midpoint potential, estimated at -407 +/- 18 mV (n = 4). The protein does not contain noncovalently bound FAD or FMN, and no spectral evidence was obtained for the presence of covalently bound flavin. Preliminary amino acid analysis of the cytochrome shows a high content of hydrophilic residues.