Cynanchum atratum Ameliorates Airway Inflammation via Maintaining Alveolar Barrier and Regulating Mast Cell-Mediated Inflammatory Responses.

Asthma is a common allergic airway inflammatory disease, characterized by abnormal breathing due to bronchial inflammation. Asthma aggravates the patient's quality of life and needs continuous pharmacological treatment. Therefore, discovery of drugs for the treatment of asthma is an important area of human health. The aim of the present study was to evaluate whether Cynanchum atratum extract (CAE) modulates the asthma-like allergic airway inflammation and to study its possible mechanism of action using ovalbumin (OVA)-induced airway inflammation and lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice, as well as a mast cell-based in vitro model. The histological analysis showed that CAE reduced the airway constriction and immune cell infiltration. CAE also inhibited release of ß-hexosaminidase and expression of inflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-4, and IL-5 in bronchoalveolar lavage fluid and lung tissues. In addition, CAE reduced the OVA-specific immunoglobulin (Ig) E, total IgE, IgG1, and IgG2a levels in the serum. In the LPS-induced ALI model, CAE suppressed the LPS-induced lung barrier dysfunction and the release of proinflammatory cytokines. Because allergic airway inflammatory responses are associated with the activation of mast cells, RBL-2H3 cells were used to evaluate the underlying mechanism of CAE effects. In RBL-2H3 cells, CAE down-regulated release of ß-hexosaminidase and histamine by reducing the intracellular calcium influx. In addition, CAE suppressed the expression of proinflammatory cytokines by inhibiting nuclear translocation of nuclear factor-κB. Taken together, our findings suggest that CAE may help in the prevention or treatment of airway inflammatory diseases.

Cigarette Smoking Impairs the Bioenergetic Immune Response to Mycobacterium tuberculosis Infection.

Smoking is a major risk factor driving the tuberculosis epidemic, and smokers' alveolar macrophages (AM) demonstrate significant immune defects after infection. Recently, macrophage glycolytic reprogramming has emerged as crucial in the early host immune response to Mycobacterium tuberculosis (Mtb) infection. In the present study, we sought to compare baseline metabolic characteristics and the glycolytic response to infection of human AM from smokers and nonsmokers. AM were obtained at bronchoscopy, and extracellular flux analyses were performed to determine baseline metabolic characteristics compared with human monocyte-derived macrophages (MDM). Metabolic characterization of AM from smokers and nonsmokers was performed similarly. After infection with Mtb, differences in glycolytic response were measured by extracellular flux analyses and gene expression analyses and correlated with production of glycolysis-driven IL-1ß and prostaglandin E2. Similar experiments were performed in cigarette smoke extract-treated MDM as an alternative model. At baseline, human AM from nonsmokers have a significantly lower extracellular acidification rate/oxygen consumption rate ratio than MDM (P < 0.05), but they retain substantial glycolytic reserve. Compared with nonsmokers' AM, smokers' AM demonstrate reduced metabolic activity, reduced glycolytic reserve (P = 0.051), and reduced spare respiratory capacity (P < 0.01). After infection with Mtb, smokers' AM have significantly reduced glycolytic response, as measured by extracellular flux analyses (P < 0.05) and glycolytic gene expression analyses. Cigarette smoke extract-treated MDM similarly demonstrate reduced metabolic activity and reserves, as well as impaired glycolytic response to infection. Human AM demonstrate metabolic plasticity that allows glycolytic reprogramming to occur after Mtb infection. In smokers, this metabolic reserve is significantly attenuated, with consequent impairment of the glycolytic response to infection.

Microparticle Release from Cell Lines and Its Anti-Influenza Activity.

Microparticles (MPs) are vesicles that are released by budding from plasma membrane of living cells. Recently, the role of MPs in antiviral activity has been proposed. We investigated quantity and anti-influenza activity of MPs from human alveolar epithelial cells A549, human bronchial epithelial cells BEAS-2B, human colon adenocarcinoma cells HT-29, and the human lung fibroblast cells MRC-5. MPs were found from all four cell lines. However, anti-influenza activity against an H1N1 influenza virus was found only from MPs of A549 and BEAS-2B. BEAS-2B cell differentiation did not increase MP release. Methyl-ß-cyclodextrin (MßCD) increased MP release and anti-influenza activity in HT-29 and A549. MP release increased after calcium ionophore A23187 treatment in three cell lines but only in HT-29 after forskolin treatment. These findings provide in vitro data supporting the role of MPs as an innate defense against influenza virus and as an approach to enhance the defense.

Lilium lancifolium Thunb. extract attenuates pulmonary inflammation and air space enlargement in a cigarette smoke-exposed mouse model.

ETHNOPHARMACOLOGICAL RELEVANCE: Lilium lancifolium Thunb. (Liliaceae) has long been used as a traditional medicine in Korea and China to treat bronchitis, pneumonia, and other pulmonary ailments. AIM OF THE STUDY: Cigarette smoke (CS) is a major risk factor for the development of pulmonary inflammatory response; it also triggers pulmonary alveoli enlargement. In the present study, we investigate the effects of Lilium lancifolium Thunb. root extract on pulmonary inflammatory responses in a CS-exposed mouse model. MATERIALS AND METHODS: Water extract of Lilium lancifolium Thunb. root was fed to C57BL/6 mice prior CS exposure every day for 3 weeks. The numbers of macrophages and neutrophils in bronchoalveolar lavage fluid (BALF) were counted. The relative inflammatory factors, tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-1 beta (IL-1ß), monocyte chemotactic protein-1 (MCP-1), and matrix metalloproteinase-12 (MMP-12) were measured by real-time PCR, ELISA, or Western blot analysis. The average alveoli size was determined by lung histology. RESULTS: Lilium lancifolium Thunb. root extract was found to significantly inhibit the numbers of macrophages and neutrophils in BALF due to CS exposure. Lilium lancifolium Thunb. root extract also reduced the protein secretion levels of TNF-α, IL-6, IL-1ß, and MCP-1 in BALF and the RNA expression levels of TNF-α, IL-6, IL-1ß, MCP-1, and MMP-12 in lung tissue compared with mice only exposed to CS. Moreover, MMP-12 in serum was down regulated in Lilium lancifolium Thunb. root extract treated mice compared with CS-exposed mice. Finally, a morphometric analysis of the lungs of Lilium lancifolium Thunb. root extract treated mice demonstrated a significant reduction in airspace size compared to mice only exposed to CS. CONCLUSION: Our results show that Lilium lancifolium Thunb. root extract reduces lung inflammation and airspace enlargement in a CS-exposed mouse model. These data indicate that Lilium lancifolium Thunb. root extract is a therapeutic candidate for pulmonary inflammation and emphysema caused by CS.

Reactions of airway epithelial cells to birch pollen grains previously exposed to in situ atmospheric Pb concentrations: a preliminary assay of allergenicity.

A growing body of evidence suggests that interactions between pollen grains and environmental pollutants, especially air pollutants, could be of critical importance with regard to the increase in allergic responses observed in the past decades. Using birch pollen grains (BPG), a major allergy source in European countries, and lead (Pb), a highly toxic metal trace element (MTE) present in urban areas, the immune response of human epithelial cells exposed to BPG or to Pb-associated BPG was compared. The cellular response after exposure either to BPG, BPG exposed to 30 mg/L of Pb (BPG-30), or BPG exposed to 60 mg/L of Pb (BPG-60) was evaluated after two time lapses (2 and 6 h) by measuring mRNA levels of four mediators, including two inflammatory (interleukin-8 and interleukin-6) and two allergic (interleukin-5 [IL-5] and interleukin-13) cytokines. After 2 h of exposure, significant upregulation of the IL-5 gene was observed after exposure to BPG-60 in comparison with exposure to BPG and BPG-30 (N (IL-5) = 1.9, Mann-Whitney test, p = 0.003). After 6 h of exposure, significant upregulation of the IL-5 gene was observed after exposure to BPG-30 with N (IL-5) = 1.8 and to BPG-60 with N (IL-5) = 2.3 (Mann-Whitney test, p = 0.0029) in comparison with exposure to BPG. This first attempt to investigate the influence of pollution by MTE on pollen grain showed a dose-time-dependent increase in IL-5 gene expression after exposure to BPG combined to Pb.

Airborne Asian sand dust enhances murine lung eosinophilia.

There is no experimental study demonstrating the effects of airborne Asian sand dust (AASD) on allergic lung eosinophilia. The organic substances adsorbed onto AASD collected from the atmosphere of Iki-island in Japan were excluded by heat treatment at 360°C for 30 min. The effects of AASD or heated-AASD (H-AASD) towards allergic lung inflammation were compared in murine lungs to investigate the role of organic substances. ICR mice were administrated with the two kinds of AASD and/or ovalbumin (OVA) intratracheally four times at 2-week intervals. AASD and H-AASD enhanced eosinophil recruitment induced by OVA in the alveoli and in the submucosa of the airway, which has a goblet cell proliferation in the bronchial epithelium. AASD and H-AASD synergistically increased Th2 cytokines-interleukin-13 (IL-13), eosinophil-relevant cytokine and chemokine, such as IL-5, and monocyte chemotactic protein-3 (MCP-3) induced by OVA in whole lung lavage fluid. The enhancing effects were much greater in AASD than in H-AASD. AASD induced adjuvant effects on OVA-specific immunoglobulin E (IgE) and IgG1 production. In an in vitro study using RAW264.7 cells, AASD increased the expression of Toll-like receptors 2 (TLR2) mRNA, but not TLR4 mRNA. AASD increased mRNA expression of NALP3, ASC, and IL-1ß compared with the control. H-AASD caused no expression of either mRNA. These results suggest that the aggravated lung eosinophilia in AASD is due to activation of a Th2-associated immune response and that the activation of TLR2 and NALP3 inflammasome by microbial materials could be participating in this phenomenon.

Efficacy of clarithromycin against experimentally induced pneumonia caused by clarithromycin-resistant Haemophilus influenzae in mice.

Clarithromycin is a 14-member lactone ring macrolide with potent activity against Haemophilus influenzae, including ampicillin-resistant strains. We evaluated the in vivo efficacy of clarithromycin at 40 mg/day and 100 mg/day for 3 days in the treatment of a murine model of pneumonia using a macrolide-resistant H. influenzae strain, which was also ampicillin resistant. The MIC of clarithromycin was 64 microg/ml. The viable bacterial counts in infected tissues after treatment with 100 mg clarithromycin/kg of body weight were lower than the counts obtained in control and 40-mg/kg clarithromycin-treated mice. The concentrations of macrophage inflammatory protein 2 (MIP-2) and interleukin 1beta (IL-1beta) in bronchoalveolar lavage fluid (BALF) samples from mice treated at both concentrations were lower than in the control group. Pathologically, following infection, clarithromycin-treated mice, particularly at a dose of 100 mg/kg, showed lower numbers of neutrophils in alveolar walls, and inflammatory changes had apparently improved, whereas large aggregates of inflammatory cells were observed within the alveoli of control mice. In addition, we demonstrated that clarithromycin has bacteriological effects against intracellular bacteria at levels below the MIC. Our results indicate that clarithromycin may be useful in vivo for macrolide-resistant H. influenzae, and this phenomenon may be related to the good penetration of clarithromycin into bronchoepithelial cells. We also believe that conventional drug susceptibility tests may not reflect the in vivo effects of clarithromycin.

CpG oligodeoxynucleotides promote phospholipase D dependent phagolysosome maturation and intracellular mycobacterial killing in M. tuberculosis infected type II alveolar epithelial cells.

CpG oligodeoxynucleotides have been previously shown to enhance antimycobacterial response in human monocytes/macrophages. The present study reports evidences showing the capability of CpG oligodeoxynucleotides to induce (i) host phospholipase D (PLD) activation, (ii) PLD dependent reactive oxygen intermediate production, (iii) PLD dependent phagolysosome maturation and (iv) PLD dependent intracellular mycobacterial killing in type II alveolar epithelial cells. These are the first evidences showing that alveolar epithelial cells may represent efficient effecter cells during primary innate antimycobacterial immune response.

A novel recombinant human lactoferrin augments the BCG vaccine and protects alveolar integrity upon infection with Mycobacterium tuberculosis in mice.

Lactoferrin, an iron binding glycoprotein, possesses multiple immune modulatory activities, including the ability to promote antigen specific cell-mediated immunity. Previous studies showed that adding bovine lactoferrin to the BCG vaccine (an attenuated strain of Mycobacterium bovis Bacillus Calmette Guerin) resulted in increased host protective responses upon subsequent challenge with virulent Erdman Mycobacterium tuberculosis (MTB) in mice. The studies outlined here investigate utility of a novel recombinant human lactoferrin to enhance the BCG vaccine and protect against alveolar injury during experimental MTB infection in mice. Sialylated and non-sialylated forms of the recombinant human lactoferrin (rhLF), glycoengineered in yeast (Pichia pastoris) and expressing humanized N-glycosylation patterns, were examined for their ability to enhance efficacy of the BCG vaccine in a murine TB model system. Results indicated that the sialylated form of the recombinant human lactoferrin generated increased antigen specific recall responses to BCG antigens. Furthermore, augmented protection was demonstrated using the sialylated lactoferrin adjuvant with BCG, resulting in significant reduction in associated pathology following challenge with virulent organisms.

Effects of sivelestat, a new elastase inhibitor, on IL-8 and MCP-1 production from stimulated human alveolar epithelial type II cells.

PURPOSE: The alveolar epithelial cell type II (AEC-II) is itself able to amplify lung inflammation by producing inflammatory cytokines and chemokines, leading to the activation and recruitment of phagocytes. Sivelestat, a new neutrophil elastase inhibitor, has been shown to attenuate acute lung injury in animal experiments. In the current study, we assessed the effects of sivelestat on the production of chemokines from cultured A549 cells, a human AEC-II-like cell line. METHODS: A549 cells were stimulated with endotoxin or tumor necrosis factor-alpha in the presence of sivelestat (1-100 microg x ml(-1)). Culture supernatant levels of interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) were determined by enzyme-linked immunosorbent assay. The expression of IL-8 and MCP-1 mRNAs in stimulated A549 cells in the presence of sivelestat (100 microg x ml(-1)) was quantified by real-time polymerase chain reaction. RESULTS: Sivelestat, at 100 microg x ml(-1) reduced the accumulation of IL-8 and MCP-1 in the culture medium. The high dose of sivelestat significantly inhibited the expression of IL-8 mRNA in A549 cells. The drug also decreased MCP-1 mRNA expression, although not significantly. CONCLUSION: These data suggest that a high dose of sivelestat regulates the production of IL-8 and MCP-1 in AEC-II.

Asian sand dust enhances ovalbumin-induced eosinophil recruitment in the alveoli and airway of mice.

Asian sand dust (ASD) containing sulfate (SO4(2-)) reportedly causes adverse respiratory health effects but there is no experimental study showing the effect of ASD toward allergic respiratory diseases. The effects of ASD and ASD plus SO4(2-) toward allergic lung inflammation induced by ovalbumin (OVA) were investigated in this study. ICR mice were administered intratracheally with saline; ASD alone (sample from Shapotou desert); and ASD plus SO4(2-) (ASD-SO4); OVA+ASD; OVA+ASD-SO4. ASD or ASD-SO4 alone caused mild nutrophilic inflammation in the bronchi and alveoli. ASD and ASD-SO4 increased pro-inflammatory mediators, such as Keratinocyte chemoattractant (KC) and macrophage inflammatory protein (MIP)-1 alpha, in bronchoalveolar lavage fluids (BALF). ASD and ASD-SO4 enhanced eosinophil recruitment induced by OVA in the alveoli and in the submucosa of the airway, which has a goblet cell proliferation in the bronchial epithelium. However, a further increase of eosinophils by addition of SO4(2-) was not observed. The two sand dusts synergistically increased interleukin-5 (IL-5) and monocyte chemotactic protein-1 (MCP-1), which were associated with OVA, in BALF. However, the increased levels of IL-5 were lower in the OVA+ASD-SO4 group than in the OVA+ASD group. ASD caused the adjuvant effects to specific-IgG1 production by OVA, but not to specific-IgE. These results suggest that the enhancement of eosinophil recruitment in the lung is mediated by synergistically increased IL-5 and MCP-1. IgG1 antibodies may play an important role in the enhancement of allergic reaction caused by OVA and sand dust. However, extra sulfate may not contribute to an increase of eosinophils.

Asian pear pectin administration during presensitization inhibits allergic response to ovalbumin in BALB/c mice.

OBJECTIVE: A type of respiratory disorder resembling some aspects of human allergic asthma can be induced in mice using ovalbumin. The factors that influence the etiology of asthma are poorly understood even though cytokines are known to play a pivotal role. The purpose of this study was to test the hypothesis whether an administration of Asian pear pectin during presensitization could suppress allergic response to ovalbumin in BALB/c mice. DESIGN: High-dose (100 microg) of pectin-sol was used and values were compared to those from the control. Ovalbumin and aluminum hydroxide were utilized for sensitization while ovalbumin aerosol was used for provocation 2 weeks later. The bronchoalveolar lavage (BAL) and assessment of tracheal smooth muscle responsiveness to electrical field stimulation or acetylcholine were performed 1 day after ovalbumin provocation. Two main cytokines of interferon (IFN)-gamma and interleukin (IL)-5, and serum immunoglobulin E (IgE) were assayed. SETTINGS: Laboratory of the Chosun University Medical School SUBJECT: Male BALB/c mice RESULTS: Antigen dose of 5 microg for sensitization generated TH1 type cytokines in the lungs with a high level of IFN-gamma and a low level of IL-5. In contrast, TH2 type cytokines were produced in splenocytes including a high level of IL-5 and a low level of IFN-gamma. Asian pear pectin-sol administration during presensitization significantly inhibited (p < 0.05) sensitivity of airway smooth muscle to electrical field stimulation and acetylcholine. Further, IFN-gamma production significantly decreased (p < 0.05) in BAL fluids while it significantly increased (p < 0.05) in splenic cells. On the other hand, IL-5 production significantly increased (p < 0.05) in BAL fluids while it was a significant decrease (p < 0.05) in splenic cells. For the histopathologic changes in the lung, pear pectin-sol recovered ovalbumin (OVA)-induced abnormal signs to an almost normal state. As a correlate, IgE production significantly decreased (p < 0.05) in pectin-sol-treated animals compared to the control. CONCLUSIONS: It is possible from these data that BALB/c mice have different susceptibilities to different doses of OVA regulated by pulmonary TH1 and TH2 type cytokines, independent of splenic TH1 and TH2 type cytokines production. These results also indicate that administration of Asian pear pectin-sol in presensitized mice suppresses allergic asthmatic reaction.

Pulmonary edema fluid from patients with acute lung injury augments in vitro alveolar epithelial repair by an IL-1beta-dependent mechanism.

Efficient alveolar epithelial repair is crucial for the restoration of the injured alveolar epithelial barrier in patients with acute lung injury (ALI) and the acute respiratory distress syndrome (ARDS). We hypothesized that pulmonary edema fluid from patients with ALI /ARDS would inhibit alveolar epithelial repair as measured in an in vitro epithelial wound-repair model using the human alveolar epithelial-like cell line A549. In contrast to our initial hypothesis, pulmonary edema fluid from patients with ALI/ARDS increased alveolar epithelial repair by 33 +/- 3% compared with pooled plasma from healthy donors (p < 0.01). By contrast, the plasma and the pulmonary edema fluid from patients with hydrostatic pulmonary edema, and the plasma from patients with ALI/ARDS had similar effects on epithelial repair as pooled plasma from healthy donors. Inhibition of interleukin-1beta (IL-1beta) activity by IL-1 receptor antagonist reduced alveolar epithelial repair induced by ALI/ARDS edema fluid by 46 +/- 4% (p < 0.001), indicating that IL-1beta contributed significantly to the increased epithelial repair. In summary, pulmonary edema fluid collected early in the course of ALI/ARDS increased alveolar epithelial repair in vitro by an IL-1beta-dependent mechanism. These data demonstrate a novel role for IL-1beta in patients with ALI/ARDS, indicating that IL-1beta may promote repair of the injured alveolar epithelium.

Immunomodulatory potential of thymulin-Zn(2+) in the alveolar epithelium: amelioration of endotoxin-induced cytokine release and partial amplification of a cytoprotective IL-10-sensitive pathway.

The immunomodulatory potential of thymulin in the perinatal epithelium is not well characterized. In an in vitro model of fetal alveolar type II epithelial cells, we investigated the exhibition of an anti-inflammatory activity of this peptide hormone. Thymulin selectively ameliorated, in a dose-dependent manner, the endotoxin-induced release of IL-1 beta (IC(50) = 657 ng. ml(-1)), but showed no inhibitory effect on IL-6 and TNF-alpha. Zinc, an anti-inflammatory antioxidant, which is required for the biological activity of thymulin, reduced the secretion of IL-1 beta (IC(50) = 62 microM), TNF-alpha (IC(50) = 1000 microM), and, to a lesser extent, IL-6. This cation (100 microM) amplified the effect of thymulin on IL-1 beta and TNF-alpha (IC(50) < 0.1 ng. ml(-1)), but not on IL-6. Analysis of whether thymulin is up-regulating a counterpart anti-inflammatory signaling loop revealed the involvement of an IL-10-sensitive pathway. These results indicate that thymulin acts as a novel dual immunoregulator by enhancing an anti-inflammatory cytoprotective response and depressing an inflammatory signal, an effect synergistically amplified, in part, by cationic zinc.

Effects of inhalation of red phosphorus/butyl rubber combustion products on aveolar macrophage responses in rats.

The effects of inhalation of red phosphorus/butyl rubber (RP/BR) used as an obscurant smoke in tactical environments was examined. Sprague-Dawley male rats were exposed to 1000 mg/m3 of RP/BR for 3.5 h in single exposures, while in subsequent intermediate and subchronic studies the animals were exposed to concentrations ranging from 300 to 1200 mg/m3 for 2.25 h/day, 4 consecutive days/week for 4 and 13 weeks, respectively. Pulmonary bactericidal activity to inhaled [35S]-Klebsiella pneumoniae was depressed after the acute and the 13-week subchronic exposures but was unchanged after the 4-week exposures. The pulmonary free cells collected by lavage showed decreasing trends in total numbers, increased ATP levels and decreased ectoenzyme activity for 5'-nucleotidase after most of the exposures. Mild-to-moderate-to-severe terminal broncheolar fibrosis was observed in all rats after 4- and 13-week exposures to greater than or equal to 750 mg/m3 of RP/BR. The severity of the lesions increased with the severity of the exposure conditions. Except for the fibrosis, most changes were reversible.

Reduction of influenza virus pathogenesis by exposure to 0.5 ppm ozone.

Continuous exposure to 0.5 ppm ozone during the course of murine influenza A/PR8/34 virus infection reduced the severity of the disease as quantitated by histologic (morphometric), biochemical (serum albumin in lavage fluid), and gravimetric (lung wt/dry weight ratios) parameters of lung injury. The ozone-mediated abatement of the lung injury was independent of peak pulmonary virus titers. However, determination of the sites of virus multiplication indicated that exposure to ozone resulted in a less widespread infection of the lung parenchyma. Furthermore, ozone exposure reduced the antiviral immune response as shown by reduced numbers of phenotypically quantitated T- and B-lymphocytes recovered from lung tissues and reduction of serum antibody titers. Since the pathogenesis of influenza virus infection depends on both the site of viral replication and the antiviral immune response, these studies suggest that redistribution of virus growth in murine lungs and immunosuppressive mechanisms are factors in the ozone-reduced disease severity.

Binding of anti-basement membrane antibody to alveolar basement membrane after intratracheal gasoline instillation in rabbits.

A possible causal relationship has been suggested between hydrocarbon (gasoline, solvents, etc.) exposure and development of anti-basement membrane antibody-associated Goodpasture's syndrome in man. The authors evaluated the effect of hydrocarbons on pulmonary capillary permeability and binding of heterologous anti-basement membrane antibodies in the lungs after intratracheal instillation of minute amounts of unleaded gasoline into rabbits. The anti-glomerular basement membrane (GBM) antibodies used reacted with the alveolar basement membrane (ABM) in vitro by indirect immunofluorescence. The gasoline treatment altered pulmonary capillary permeability, judging from the increased accumulation of systemically administered radioiodinated bovine serum albumin in the alveolar and extravascular spaces of lungs; it also induced focal macroscopic and microscopic pulmonary histologic lesions. The gasoline caused focal in vivo binding of the anti-GBM antibodies to the ABM detectable by immunofluorescence microscopy. No binding was observed in lungs from control rabbits given saline instillations when assayed by immunofluorescence. The paired label radioisotope technique confirmed the increased antibody binding to lungs injured with gasoline (1.08 +/- 0.03 micrograms) versus 0.37 +/- 0.07 microgram after saline (P less than 0.001). These results indicate that gasoline exposure damages a pulmonary barrier that normally prevents binding of anti-GBM/ABM antibody to ABM and suggest that hydrocarbon exposure may be one of perhaps several pneumotoxic events that contribute to the episodic pulmonary hemorrhage in Goodpasture's syndrome by temporarily allowing ABM binding of anti-basement membrane antibodies.

Defective chemotactic response of human alveolar and colostral macrophages.

This report describes the chemotactic response of human alveolar macrophages (AM luminal diameter) and milk macrophages (MM luminal diameter) to a panel of chemotactic agents: endotoxin (EAS) and zymosan (ZAS) activated serum, lymphocyte derived chemotactic factor (LDCF) and formylated synthetic peptides. The locomotion studies were compared with the responses of peripheral blood monocytes. Both AM luminal diameter and MM luminal diameter exhibited an extremely poor chemotactic response to all agents in comparison with the monocytic response. When monocytes were cultured for long periods, a defective response was likewise demonstrated. The chemotactic response was significantly higher in AM luminal diameter from smokers. The stimulated locomotion was not increased by the addition of a surfactant lipoprotein to the AM luminal diameter suspension. Moreover, monocytes incubated with fat- and cell-free human milk exhibited lower chemotactic responses than normal monocytes and practically in the same range as that obtained with MM luminal diameter.

The biosynthesis of leukotriene B4, the predominant lipoxygenase product in rabbit alveolar macrophages, is enhanced during immune activation.

Rabbit alveolar macrophages synthesize prostaglandins in response to various stimuli. We have previously shown that prostaglandin production was decreased in immunologically activated (live Bacillus Calmette-Guérin (BCG)-injected) animals. (Hsueh, W., Lamb, R. and Gonzalez-Crussi, F. (1982) Biochim. Biophys. Acta 710, 406-414). In the present study, we examined the lipoxygenase products of alveolar macrophages from normal and immunologically activated rabbits injected intravenously with live BCG or complete Freund's adjuvant. We found: unstimulated lung macrophages produced no detectable leukotrienes; the predominant lipoxygenase product upon stimulation was leukotriene B4; alveolar macrophages did not significantly degrade leukotriene B4 into its 20-hydroxy derivative, and the total degradation of leukotriene B4 during 90 min of incubation was minimal; the production of leukotriene B4 reached the peak at 30 min after A23187 stimulation, while zymosan caused a much slower and smaller release; following stimulation, immunologically activated lung macrophages produced more leukotriene B4 than resident macrophages. It is possible that the increased leukotriene B4 production in immunologically activated lung macrophages was related to the immunoregulatory function of this substance, such as enhancing cytotoxicity, interferon production and proliferation of suppressor-cytotoxic T cells.