James Martin - Academia.edu (original) (raw)

Papers by James Martin

Frontiers in Physiology, Sep 29, 2021

Journal of Immunology, Jul 1, 2016

The Journal of Allergy and Clinical Immunology, Mar 1, 2005

The role of CD8+ T cells in the immune response to airway challenge with an allergen is poorly un... more The role of CD8+ T cells in the immune response to airway challenge with an allergen is poorly understood. The aim of this study was to test the hypothesis that resident naive CD8+ T cells modulate the magnitude of CD4+ T cell-dependent allergic airway responses. Cervical lymph node CD4+ T cells (2 x 10(6)) were harvested from ovalbumin (OVA)- or sham-sensitized rats and injected intraperitoneally into naive Brown Norway recipients. The recipients were treated with a CD8alpha mAb (OX-8) to deplete the resident CD8+ T cells (n = 12) or mouse ascites (n = 12). Two days after adoptive transfer, the recipient animals were OVA challenged, lung resistance was measured for 8 hours, and bronchoalveolar lavage (BAL) was performed. After OVA challenge, primed CD4-transferred CD8-depleted rats had larger early airway responses and late airway responses compared with primed CD4-transferred CD8-nondepleted rats (early airway responses: 158.6% +/- 19.2% vs 115.7% +/- 5.9%, P < .05; late airway responses: 8.5% +/- 1.7% vs 4.4% +/- 0.9%, P < .05). BAL eosinophilia was also greater (4.67% +/- 0.45% vs 2.34 +/- 0.26%, P < .01). The cells in BAL fluid expressing IL-4 mRNA were not significantly changed by CD8 depletion, but IL-5 mRNA+ cells were higher in number, and IFN-gamma mRNA+ cells were fewer in the CD8-depleted group. Resident CD8+ T cells downregulate the late allergic response and airway inflammation evoked by CD4+ T-cell transfers in Brown Norway rats. This downregulation does not require antigen priming.

American Journal of Respiratory and Critical Care Medicine, Sep 1, 2000

Neurokinins (NKs), which include substance P (SP) and neurokinin A (NKA), act through NK-1 and NK... more Neurokinins (NKs), which include substance P (SP) and neurokinin A (NKA), act through NK-1 and NK-2 receptors. There is considerable evidence of interaction between the neurogenic and the immune systems, and NKs are candidates for mediating such interactions. We hypothesized that selective inhibition of pulmonary NK-1 or NK-2 receptors may modulate immune responses so as to prevent the development of allergic airway responses in the atopic BN rat sensitized to ovalbumin (OA). To address this hypothesis, we have validated our animal model by showing that NK-1 and NK-2 receptors are expressed in the lungs, and that SP is released in the airways after allergen challenge. The selective NK-1 (CP-99,994) or NK-2 (SR-48968) antagonists before allergen challenge failed to reduce the allergic early airway responses. In contrast, both neurokinin antagonists decreased allergen-induced late airway responses in OA-challenged animals. However, only the NK-2 antagonist decreased the eosinophil numbers in the bronchoalveolar lavage (BAL). Likewise, the NK-2, but not NK-1, antagonist decreased both Th1 (INF-␥) and Th2 (IL-4 and-5) cytokine expression in BAL cells by in situ hybridization. These results provide initial in vivo evidence linking neurokinins to the regulation of cytokine expression in cells without discrimination as to their phenotype. We conclude that there is a dichotomy between NK receptors in the modulation of the allergic airway inflammation, which has important implications for future therapeutic strategies for asthma using the NK antagonists.

Chest, Jun 1, 2010

Though several biologic factors have been suggested to play a role in the development and persist... more Though several biologic factors have been suggested to play a role in the development and persistence of severe asthma, those associated with psychologic factors remain poorly understood. This study assessed levels of psychologic distress and a range of disease-relevant emotional and behavioral coping styles in patients with severe vs moderate asthma. Eighty-four patients (50% women, mean [M] age 46 years) with severe (n = 42) and moderate (n = 42) asthma were recruited. Severe asthma was defined according to American Thoracic Society criteria. Patients underwent demographic and medical history interviews and pulmonary function and allergy testing. Patients also completed questionnaires measuring asthma symptoms and the Millon Behavioral Medicine Diagnostic Inventory, which assesses psychologic distress and emotional/behavioral coping factors that influence disease progression and treatment. After adjustment for covariates and applying a correction factor that reduced the significant P level to…

Free Radical Biology and Medicine, Mar 1, 2011

American Journal of Respiratory Cell and Molecular Biology, 2003

The leukotriene modifiers are a novel generation of therapeutic bronchoalveolar lavage (BAL) flui... more The leukotriene modifiers are a novel generation of therapeutic bronchoalveolar lavage (BAL) fluid (BALF) of asthmatics agents in the treatment of allergic asthma. However, the mechcompared with normal subjects (4) and allergen challenge anisms by which the cysteinyl (cys) leukotrienes (LTs) particiinduces the release of LTs into the airways in several animal pate in allergen-induced airway eosinophilia and airway hypermodels of asthma (5-7). responsiveness (AHR) are still unclear. In the present study, LTB 4 induces leukocyte chemotaxis through an action we have investigated the role of cys-LTs in ovalbumin (OVA)on BLT receptors, whereas the cysteinyl (cys)-LTs (LTC 4 , induced airway responses in a murine model of asthma. Monte-LTD 4 and LTE 4) principally cause contraction of airway lukast (3 or 10 mg/kg), a selective cys-LT1 receptor antagonist, muscle, increase microvascular permeability, stimulate mureduced airway eosinophilia and AHR after OVA challenge. The cus secretion, and induce smooth-muscle cell proliferation levels of interleukin (IL)-5 and eotaxin in the bronchoalveolar (2, 5, 8). Cys-LTs have also been shown to participate in the lavage fluid (BALF) from montelukast-treated (3 mg/kg) mice induction of AHR in patients with asthma; the inhalation of were unaffected, although a decrease in IL-5 was observed with LTC 4 , LTD 4 , and LTE 4 increases the airway responsiveness a dose of 10 mg/kg. LTD 4 (50 ng) instilled intranasally to immuto histamine (9). Recent studies have shown a reduction in nized mice augmented macrophages in the BALF, but in conjunction with OVA challenge it caused BALF eosinophilia and airway eosinophilia in asthmatic subjects treated with cysneutrophilia when given before challenge and BALF neutro-LT1 receptor antagonists (10, 11), suggesting chemotactic philia but not eosinophilia when given 2 h after challenge. effects of the cys-LTs in vivo. Indeed, cys-LTs have chemo-However, there were no increases of IL-5 or eotaxin in BALF tactic activity in vitro on human eosinophils (12, 13). Similar following LTD 4 treatment. Repeated instillations of LTD 4 to imeffects have been observed in vivo, where inhaled LTD 4 or munized mice, mimicking allergen challenge, did not induce LTE 4 causes an increase of eosinophil numbers in the air-AHR but in conjunction with OVA challenge LTD 4 enhanced ways in human subjects with asthma (14, 15) and in the AHR. These results indicate that allergen-induced eosinophilia guinea-pig (16, 17). Other in vivo studies have failed to and AHR are in part mediated by the cys-LT1 receptor, and demonstrate the induction of eosinophilia by LTD 4 (18, 19), that, although LTD 4 alone has no effect on airway eosinophilia, suggesting that the effect of LTD 4 on eosinophilia may in conjunction with antigenic stimulation it potentiates the dedepend on the characteristics of the subjects, on the species, gree of airway inflammation and AHR.

The Journal of Allergy and Clinical Immunology, Dec 1, 2000

Background: Little is known about the comparative kinetics of eosinophil recruitment after exposu... more Background: Little is known about the comparative kinetics of eosinophil recruitment after exposure to low-and high-molecular-weight sensitizers in subjects with occupational asthma (OA). Objectives: The aims of the study were to investigate the kinetics of changes in inflammatory mediators associated with eosinophil infiltration (IL-5 and eotaxin) and to examine the nature of the airway inflammation induced in response to different types of occupational agents. Methods: We investigated 15 subjects with OA caused by highand low-molecular-weight agents. The subjects were exposed to increasing doses of the relevant occupational agent over 3 to 4 days until a 20% fall in FEV 1 occurred. Methacholine challenge and sputum induction were performed at the end of each day of exposure. Sputum samples were assessed for differential cell counts, including eosinophils, IL-5, and eotaxin messenger RNA. Results: There was an increase in sputum eosinophils, eotaxin, and IL-5 on the day preceding the occurrence of asthmatic reaction, although there was no change in functional parameters (FEV 1 and PC 20). Increase in sputum eosinophils was more prominent in subjects exposed to low-molecular-weight agents than to high-molecular-weight agents. Conclusion: Changes in eosinophils, IL-5, and eotaxin precede functional changes after exposure to occupational agents in subjects with OA. Eosinophil inflammation is a feature of exposure to both high-and low-molecular-weight agents. Induced sputum may be a useful tool in the early diagnosis of OA.

The Journal of Allergy and Clinical Immunology, Nov 1, 2006

Background: Airway inflammation assessed by bronchial biopsies demonstrates distinct eosinophilic... more Background: Airway inflammation assessed by bronchial biopsies demonstrates distinct eosinophilic and noneosinophilic phenotypes in severe asthma, but their relationship to other biomarkers of disease (induced sputum and nitric oxide [NO]) is not clear. Objectives: We sought to compare airway inflammation using noninvasive (induced sputum, exhaled NO), and invasive (bronchial biopsies) methods in moderate and severe asthma and to assess whether induced sputum and exhaled NO would allow the identification of eosinophilic and noneosinophilic phenotypes in severe asthma. Methods: We performed a cross-sectional study of 32 subjects with severe asthma and 35 subjects with moderate asthma, from whom we obtained bronchial biopsies, induced sputum, and exhaled NO measurements. Results: Among subjects with severe asthma, we identified eosinophilic and noneosinophilic phenotypes using both bronchial biopsies and sputum cell counts. However, the vast majority of subjects with high sputum eosinophil counts did not have high mucosal eosinophil counts. Exhaled NO was increased in the eosinophilic phenotype as judged from bronchial biopsy findings, but not on the basis of induced sputum. Subjects with high sputum eosinophil counts experienced more asthma exacerbations than the subjects with low sputum eosinophil counts. In contrast, we did not find any differences in the clinical characteristics between eosinophilic and noneosinophilic phenotypes that were identified by bronchial biopsies. Conclusion: The use of sputum cell counts allowed the identification of a subgroup of subjects with severe asthma who were at risk of more frequent asthma exacerbations. Clinical implications: Monitoring sputum eosinophil counts in subjects with severe asthma may allow identifying the subjects with the greatest disease activity.

The Journal of Allergy and Clinical Immunology, Aug 1, 2004

Increased airway smooth muscle (ASM) mass is perhaps the most important component of the airway w... more Increased airway smooth muscle (ASM) mass is perhaps the most important component of the airway wall remodeling process in asthma. Known mediators of ASM proliferation in cell culture models fall into 2 categories: those that activate receptors with intrinsic receptor tyrosine kinase activity and those that have their effects through receptors linked to heterotrimeric guanosine triphosphateebinding proteins. The major candidate signaling pathways activated by ASM mitogens are those dependent on extracellular signal-regulated kinase and phosphoinositide 39-kinase. Increases in ASM mass may also involve ASM migration, and in culture, the key signaling mechanisms have been identified as the p38 mitogenactivated protein kinase and the p21-activated kinase 1 pathways. New evidence from an in vivo rat model indicates that primed CD4 + T cells are sufficient to trigger ASM and epithelial remodeling after allergen challenge. Hyperplasia has been observed in an equine model of asthma and may account for the increase in ASM mass. Reduction in the rate of apoptosis may also play a role. b 2-Adrenergic receptor agonists and glucocorticoids have antiproliferative activity against a broad spectrum of mitogens, although it has become apparent that mitogens are differentially sensitive. Culture of ASM on collagen type I has been shown to enhance proliferative activity and prevent the inhibitory effect of glucocorticoids, whereas b 2-agonists are minimally affected. There is no evidence that long-acting b 2-agonists are more effective than short-acting agonists, but persistent stimulation of the b 2-adrenergic receptor probably helps suppress growth responses. The maximum response of fluticasone propionate against thrombininduced proliferation is increased when it is combined with salmeterol.

Pulmonary Pharmacology & Therapeutics, Dec 1, 2003

The purpose of this study was to test the therapeutic potential of monomethoxypolyethylene glycol... more The purpose of this study was to test the therapeutic potential of monomethoxypolyethylene glycol (mPEG) conjugated-allergen using a rodent model of allergic asthma. Previously, this conjugate has been shown to possess the dual capacity of inducing long-term ovalbumin (OA)-specific suppression of the antibody response and inactivating rat mast cells that have been sensitized with murine IgE to OA. Ovalbumin sensitized and challenged Brown Norway rats were studied. Fourteen days after sensitization, a test group of six rats received mPEG-OA solution intratracheally and were challenged 30 min later with aerosolized OA. Another group of seven sensitized rats was similarly challenged with OA 30 min after intratracheal administration of normal saline. A group of six sensitized rats received mPEG-OA solution intratracheally but were challenged with normal saline. Another group of seven sensitized rats received mPEG-BSA solution intratracheally and were challenged 30 min later with aerosolized OA. A final group of five unsensitized rats were neither challenged nor medicated intratracheally. Pulmonary resistance was measured before and for 8 h following inhalation challenge. mPEG-OA treatment had an inhibitory effect on the allergic late airway response, but the early response was not significantly altered. Both mPEG-OA and mPEG-BSA reduced the total cells, eosinophils and neutrophils, in bronchoalveolar lavage and decreased the expression of IL-4, IL-5 and IFN-g mRNA. In conclusion, mPEG-OA can prevent the development of allergen-induced late airway responses and reduce airway Th2-type cytokine expression whereas mPEG conjugated to an irrelevant antigen (BSA) is anti-inflammatory but does not affect the late response.

American Journal of Respiratory Cell and Molecular Biology, Nov 1, 2020

British Journal of Pharmacology, Aug 23, 2017

BACKGROUND AND PURPOSE Cysteinyl leukotrienes (CysLTs) are pro-inflammatory lipid mediators that ... more BACKGROUND AND PURPOSE Cysteinyl leukotrienes (CysLTs) are pro-inflammatory lipid mediators that exacerbate disease state in several asthma phenotypes including asthma induced by allergen, virus and exercise. However, the role of CysLTs in irritant-induced airway disease is not well characterized. The purpose of the current study was to investigate the effect of montelukast, a CysLT 1 receptor antagonist, on parameters of irritant-induced asthma induced by inhalation of chlorine in the mouse. EXPERIMENTAL APPROACH BALB/c mice were exposed to chlorine in air (100 ppm, for 5 min). Montelukast (3 mg•kg À1) or the vehicle (1% methylcellulose) was administered 24 and 1 h prior to chlorine exposure and 1 h prior to outcome measurements. Twenty-four hours after exposure, responses to inhaled aerosolized methacholine, cell composition and an array of cytokines/chemokines in bronchoalveolar lavage (BAL) fluid were measured. Neutralizing antibodies against IL-6 and VEGF were administered prior to exposures. KEY RESULTS Montelukast reduced chlorine-induced airway hyperresponsiveness (AHR) to methacholine in the peripheral lung compartment as estimated from dynamic elastance, but not in large conducting airways. Montelukast treatment attenuated chlorine-induced macrophage influx, neutrophilia and eosinophilia in BAL fluid. Chlorine exposure increased VEGF, IL-6, the chemokines KC and CCL3 in BAL fluid. Montelukast treatment prevented chlorine-induced increases in VEGF and IL-6. Anti-IL-6 antibody inhibited chlorine-induced neutrophilia and reduced AHR.

American Journal of Physiology-lung Cellular and Molecular Physiology, Jan 15, 2016

Airway exposure to organic dust (OD) from swine confinement facilities induces airway inflammatio... more Airway exposure to organic dust (OD) from swine confinement facilities induces airway inflammation dominated by neutrophils and airway hyperresponsiveness (AHR). One important neutrophilic innate defense mechanism is the induction of oxidative stress. Therefore, we hypothesized that neutrophils exacerbate airway dysfunction following OD exposure by increasing oxidant burden. BALB/C mice were given intranasal challenges with OD or PBS (1/day for 3 days). Mice were untreated or treated with a neutrophil-depleting antibody, anti-Ly6G, or the antioxidant dimethylthiourea (DMTU) prior to OD exposure. Twenty-four hours after the final exposure, we measured airway responsiveness in response to methacholine (MCh) and collected bronchoalveolar lavage fluid to assess pulmonary inflammation and total antioxidant capacity. Lung tissue was harvested to examine the effect of OD-induced antioxidant gene expression and the effect of anti-Ly6G or DMTU. OD exposure induced a dose-dependent increase of airway responsiveness, a neutrophilic pulmonary inflammation, and secretion of keratinocyte cytokine. Depletion of neutrophils reduced OD-induced AHR. DMTU prevented pulmonary inflammation involving macrophages and neutrophils. Neutrophil depletion and DMTU were highly effective in preventing OD-induced AHR affecting large, conducting airways and tissue elastance. OD induced an increase in total antioxidant capacity and mRNA levels of NRF-2dependent antioxidant genes, effects that are prevented by administration of DMTU and neutrophil depletion. We conclude that an increase in oxidative stress and neutrophilia is critical in the induction of OD-induced AHR. Prevention of oxidative stress diminishes neutrophil influx and AHR, suggesting that mechanisms driving ODinduced AHR may be dependent on neutrophil-mediated oxidant pathways.

Journal of Immunology, Nov 15, 1999

Autoimmunity induced by HgCl2 in Brown-Norway rats. I. Production of monoclonal antibodies.

Respirology, Apr 25, 2011

ABSTRACTAsthma is a chronic disorder of the airways associated in many instances with structural ... more ABSTRACTAsthma is a chronic disorder of the airways associated in many instances with structural changes of the airways, termed airway remodelling. Irritant and allergen‐induced murine models have been used to further understand the mechanisms of airway remodelling. The infiltration of the airways by inflammatory cells, such as T lymphocytes, mast cells, eosinophils, neutrophils and macrophages after repeated allergen challenges may be important effectors in the initiation and perpetuation of airway remodelling through the release of inflammatory mediators and growth factors. Interleukins‐4 and ‐13 have been widely studied in experimental models, and have been shown to play a significant role in airway remodelling. Recently, a role for Th17 cells has been established. Other mediators involved in this process are ligands of the epidermal growth factor receptor, matrix metalloproteases and cysteinyl leukotrienes. A better understanding of the mechanisms leading to airway remodelling in allergic diseases may lead to the identification of novel therapeutic strategies but validation in human subjects is required for potential targets.

American Journal of Respiratory Cell and Molecular Biology, 1997

Late allergic airway responses can be transferred by CD4 + T cells in the rat. To investigate the... more Late allergic airway responses can be transferred by CD4 + T cells in the rat. To investigate the role of T-cell cytokines in these responses, we examined the expression of mRNA for Th2 (interleukin [lL]-4 and IL-5) and Thl (IL-2 and interferon')' [INF-')'D-type cytokines in Brown Norway rats that were administered either antigen-primed W3/25(CD4V or OXS(CDSV T cells. Donors were actively sensitized by subcutaneous injection of ovalbumin (OVA) in the neck and T cells were obtained from the cervical lymph nodes by immunomagnetic cell sorting for administration to unsensitized rats. Control rats received bovine serum albumin (BSA)-primed CD4 + and CDS+ T cells. Two days later, recipient rats were challenged with aerosolized OVA, and bronchoalveolar lavage (BAL) was performed Shafter challenge. BAL cells expressing mRNA for IL-2, IL-4, IL-5, and INF-')' were analyzed using the technique of in situ hybridization. Recipients of OVA-primed CD4 + T cells had an increase in the fraction of BAL cells expressing mRNA for IL-4 and IL-5 compared with BSA-primed CD4 + or OVA-primed CDS + cells (P < 0.001). Recipients of CDS+ T cells had an increase in INF-')' mRNA expression after OVA challenge compared with recipients of BSA-primed-CDS+ or OVA-primed CD4 + T cells (P < 0.001). In conclusion, T-cell-dependent allergen-induced late responses are associated with the expression of mRNA for IL-4 and IL-5, indicating Th2 cell activation. Furthermore, the increased expression of INF-')' in allergen challenge recipients of antigen-primed CDS+ T cells suggests that CDS+ T cells may be important in modulating allergic responses.

Respiratory Research, Aug 14, 2008

Accidental chlorine (Cl 2) gas inhalation is a common cause of acute airway injury. However, litt... more Accidental chlorine (Cl 2) gas inhalation is a common cause of acute airway injury. However, little is known about the kinetics of airway injury and repair after Cl 2 exposure. We investigated the time course of airway epithelial damage and repair in mice after a single exposure to a high concentration of Cl 2 gas. Mice were exposed to 800 ppm Cl 2 gas for 5 minutes and studied from 12 hrs to 10 days post-exposure. The acute injury phase after Cl 2 exposure (≤ 24 hrs post-exposure) was characterized by airway epithelial cell apoptosis (increased TUNEL staining) and sloughing, elevated protein in bronchoalveolar lavage fluid, and a modest increase in airway responses to methacholine. The repair phase after Cl 2 exposure was characterized by increased airway epithelial cell proliferation, measured by immunoreactive proliferating cell nuclear antigen (PCNA), with maximal proliferation occurring 5 days after Cl 2 exposure. At 10 days after Cl 2 exposure the airway smooth muscle mass was increased relative to controls, suggestive of airway smooth muscle hyperplasia and there was evidence of airway fibrosis. No increase in goblet cells occurred at any time point. We conclude that a single exposure of mice to Cl 2 gas causes acute changes in lung function, including pulmonary responsiveness to methacholine challenge, associated with airway damage, followed by subsequent repair and airway remodelling.

Journal of Clinical Investigation, Sep 1, 1995

Activated CD4+ helper T cells have been demonstrated in asthmatic airways and postulated to play ... more Activated CD4+ helper T cells have been demonstrated in asthmatic airways and postulated to play a central role in eliciting allergic inflammation; direct evidence of their involvement seems to be lacking. We hypothesized that CD4+ T cells have the potential to induce allergic responses to antigen challenge, and tested this hypothesis in a model of allergic bronchoconstriction, the Brown Norway rat, using the approach of adoptive transfer. Animals were actively sensitized to either ovalbumin (OVA) or BSA and were used as donors of T cells. W3/25 (CD4) + or OX8 (CD8) + T cells were isolated from the cervical lymph nodes of sensitized donors and transferred to naive BN rats. 2 d after adoptive transfer recipient rats were challenged by OVA inhalation, and changes in lung resistance (RL), bronchoalveolar lavage (BAL) cells, and serum levels of antigen-specific IgE were studied. After OVA challenge recipients of OVA-primed W3/25+ T cells exhibited sustained increases in RL throughout the entire 8-h observation period and had significant bronchoalveolar lavage eosinophilia, which was detected by immunocytochemistry using an antimajor basic protein mAb. Recipients of BSA-primed W3/25+ T cells or OVAprimed OX8+ T cells failed to respond to inhaled OVA. OVA-specific immunoglobulin E was undetectable by ELISA or skin testing in any of the recipient rats after adoptive transfer. In conclusion, antigen-induced airway bronchoconstriction and eosinophilia were successfully transferred by antigen-specific W3/25+ T cells in Brown Norway rats. These responses were dependent on antigenprimed W3/25+ T cells and appeared to be independent of IgE-mediated mast cell activation. This study provides clear evidence for T cell mediated immune mechanisms in allergic airway responses in this experimental model.

American Journal of Respiratory and Critical Care Medicine, Sep 1, 2003

Exposure to chlorine gas (Cl 2) causes occupational asthma that we hypothesized occurs through th... more Exposure to chlorine gas (Cl 2) causes occupational asthma that we hypothesized occurs through the induction of airway inflammation and airway hyperresponsiveness by oxidative damage. Respiratory mechanics and airway responsiveness to methacholine were assessed in A/J mice 24 hours after a 5-minute exposure to 100, 200, 400, or 800 ppm Cl 2 and 2 and 7 days after inhalation of 400 ppm Cl 2. Airway responsiveness was higher 24 hours after 400 and 800 ppm Cl 2. Responsiveness after inhalation of 400 ppm Cl 2 returned to normal by 2 days but was again elevated at 7 days. Airway epithelial loss, patchy alveolar damage, proteinaceous exudates, and inflammatory cells within alveolar walls were observed in animals exposed to 800 ppm Cl 2. Macrophages, granulocytes, epithelial cells, and nitrate/ nitrite levels increased in lung lavage fluid. Increased inducible nitric oxide synthase expression and oxidation of lung proteins were observed. Epithelial cells and alveolar macrophages from mice exposed to 800 ppm Cl 2 stained for 3-nitrotyrosine residues. Inhibition of inducible nitric oxide synthase with 1400W (1 mg/kg) abrogated the Cl 2-induced changes in responsiveness. We conclude that chlorine exposure causes functional and pathological changes in the airways associated with oxidative stress. Inducible nitric oxide synthase is involved in the induction of changes in responsiveness to methacholine.

Frontiers in Physiology, Sep 29, 2021

Journal of Immunology, Jul 1, 2016

The Journal of Allergy and Clinical Immunology, Mar 1, 2005

The role of CD8+ T cells in the immune response to airway challenge with an allergen is poorly un... more The role of CD8+ T cells in the immune response to airway challenge with an allergen is poorly understood. The aim of this study was to test the hypothesis that resident naive CD8+ T cells modulate the magnitude of CD4+ T cell-dependent allergic airway responses. Cervical lymph node CD4+ T cells (2 x 10(6)) were harvested from ovalbumin (OVA)- or sham-sensitized rats and injected intraperitoneally into naive Brown Norway recipients. The recipients were treated with a CD8alpha mAb (OX-8) to deplete the resident CD8+ T cells (n = 12) or mouse ascites (n = 12). Two days after adoptive transfer, the recipient animals were OVA challenged, lung resistance was measured for 8 hours, and bronchoalveolar lavage (BAL) was performed. After OVA challenge, primed CD4-transferred CD8-depleted rats had larger early airway responses and late airway responses compared with primed CD4-transferred CD8-nondepleted rats (early airway responses: 158.6% +/- 19.2% vs 115.7% +/- 5.9%, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .05; late airway responses: 8.5% +/- 1.7% vs 4.4% +/- 0.9%, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .05). BAL eosinophilia was also greater (4.67% +/- 0.45% vs 2.34 +/- 0.26%, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .01). The cells in BAL fluid expressing IL-4 mRNA were not significantly changed by CD8 depletion, but IL-5 mRNA+ cells were higher in number, and IFN-gamma mRNA+ cells were fewer in the CD8-depleted group. Resident CD8+ T cells downregulate the late allergic response and airway inflammation evoked by CD4+ T-cell transfers in Brown Norway rats. This downregulation does not require antigen priming.

American Journal of Respiratory and Critical Care Medicine, Sep 1, 2000

Neurokinins (NKs), which include substance P (SP) and neurokinin A (NKA), act through NK-1 and NK... more Neurokinins (NKs), which include substance P (SP) and neurokinin A (NKA), act through NK-1 and NK-2 receptors. There is considerable evidence of interaction between the neurogenic and the immune systems, and NKs are candidates for mediating such interactions. We hypothesized that selective inhibition of pulmonary NK-1 or NK-2 receptors may modulate immune responses so as to prevent the development of allergic airway responses in the atopic BN rat sensitized to ovalbumin (OA). To address this hypothesis, we have validated our animal model by showing that NK-1 and NK-2 receptors are expressed in the lungs, and that SP is released in the airways after allergen challenge. The selective NK-1 (CP-99,994) or NK-2 (SR-48968) antagonists before allergen challenge failed to reduce the allergic early airway responses. In contrast, both neurokinin antagonists decreased allergen-induced late airway responses in OA-challenged animals. However, only the NK-2 antagonist decreased the eosinophil numbers in the bronchoalveolar lavage (BAL). Likewise, the NK-2, but not NK-1, antagonist decreased both Th1 (INF-␥) and Th2 (IL-4 and-5) cytokine expression in BAL cells by in situ hybridization. These results provide initial in vivo evidence linking neurokinins to the regulation of cytokine expression in cells without discrimination as to their phenotype. We conclude that there is a dichotomy between NK receptors in the modulation of the allergic airway inflammation, which has important implications for future therapeutic strategies for asthma using the NK antagonists.

Chest, Jun 1, 2010

Though several biologic factors have been suggested to play a role in the development and persist... more Though several biologic factors have been suggested to play a role in the development and persistence of severe asthma, those associated with psychologic factors remain poorly understood. This study assessed levels of psychologic distress and a range of disease-relevant emotional and behavioral coping styles in patients with severe vs moderate asthma. Eighty-four patients (50% women, mean [M] age 46 years) with severe (n = 42) and moderate (n = 42) asthma were recruited. Severe asthma was defined according to American Thoracic Society criteria. Patients underwent demographic and medical history interviews and pulmonary function and allergy testing. Patients also completed questionnaires measuring asthma symptoms and the Millon Behavioral Medicine Diagnostic Inventory, which assesses psychologic distress and emotional/behavioral coping factors that influence disease progression and treatment. After adjustment for covariates and applying a correction factor that reduced the significant P level to…

Free Radical Biology and Medicine, Mar 1, 2011

American Journal of Respiratory Cell and Molecular Biology, 2003

The leukotriene modifiers are a novel generation of therapeutic bronchoalveolar lavage (BAL) flui... more The leukotriene modifiers are a novel generation of therapeutic bronchoalveolar lavage (BAL) fluid (BALF) of asthmatics agents in the treatment of allergic asthma. However, the mechcompared with normal subjects (4) and allergen challenge anisms by which the cysteinyl (cys) leukotrienes (LTs) particiinduces the release of LTs into the airways in several animal pate in allergen-induced airway eosinophilia and airway hypermodels of asthma (5-7). responsiveness (AHR) are still unclear. In the present study, LTB 4 induces leukocyte chemotaxis through an action we have investigated the role of cys-LTs in ovalbumin (OVA)on BLT receptors, whereas the cysteinyl (cys)-LTs (LTC 4 , induced airway responses in a murine model of asthma. Monte-LTD 4 and LTE 4) principally cause contraction of airway lukast (3 or 10 mg/kg), a selective cys-LT1 receptor antagonist, muscle, increase microvascular permeability, stimulate mureduced airway eosinophilia and AHR after OVA challenge. The cus secretion, and induce smooth-muscle cell proliferation levels of interleukin (IL)-5 and eotaxin in the bronchoalveolar (2, 5, 8). Cys-LTs have also been shown to participate in the lavage fluid (BALF) from montelukast-treated (3 mg/kg) mice induction of AHR in patients with asthma; the inhalation of were unaffected, although a decrease in IL-5 was observed with LTC 4 , LTD 4 , and LTE 4 increases the airway responsiveness a dose of 10 mg/kg. LTD 4 (50 ng) instilled intranasally to immuto histamine (9). Recent studies have shown a reduction in nized mice augmented macrophages in the BALF, but in conjunction with OVA challenge it caused BALF eosinophilia and airway eosinophilia in asthmatic subjects treated with cysneutrophilia when given before challenge and BALF neutro-LT1 receptor antagonists (10, 11), suggesting chemotactic philia but not eosinophilia when given 2 h after challenge. effects of the cys-LTs in vivo. Indeed, cys-LTs have chemo-However, there were no increases of IL-5 or eotaxin in BALF tactic activity in vitro on human eosinophils (12, 13). Similar following LTD 4 treatment. Repeated instillations of LTD 4 to imeffects have been observed in vivo, where inhaled LTD 4 or munized mice, mimicking allergen challenge, did not induce LTE 4 causes an increase of eosinophil numbers in the air-AHR but in conjunction with OVA challenge LTD 4 enhanced ways in human subjects with asthma (14, 15) and in the AHR. These results indicate that allergen-induced eosinophilia guinea-pig (16, 17). Other in vivo studies have failed to and AHR are in part mediated by the cys-LT1 receptor, and demonstrate the induction of eosinophilia by LTD 4 (18, 19), that, although LTD 4 alone has no effect on airway eosinophilia, suggesting that the effect of LTD 4 on eosinophilia may in conjunction with antigenic stimulation it potentiates the dedepend on the characteristics of the subjects, on the species, gree of airway inflammation and AHR.

The Journal of Allergy and Clinical Immunology, Dec 1, 2000

Background: Little is known about the comparative kinetics of eosinophil recruitment after exposu... more Background: Little is known about the comparative kinetics of eosinophil recruitment after exposure to low-and high-molecular-weight sensitizers in subjects with occupational asthma (OA). Objectives: The aims of the study were to investigate the kinetics of changes in inflammatory mediators associated with eosinophil infiltration (IL-5 and eotaxin) and to examine the nature of the airway inflammation induced in response to different types of occupational agents. Methods: We investigated 15 subjects with OA caused by highand low-molecular-weight agents. The subjects were exposed to increasing doses of the relevant occupational agent over 3 to 4 days until a 20% fall in FEV 1 occurred. Methacholine challenge and sputum induction were performed at the end of each day of exposure. Sputum samples were assessed for differential cell counts, including eosinophils, IL-5, and eotaxin messenger RNA. Results: There was an increase in sputum eosinophils, eotaxin, and IL-5 on the day preceding the occurrence of asthmatic reaction, although there was no change in functional parameters (FEV 1 and PC 20). Increase in sputum eosinophils was more prominent in subjects exposed to low-molecular-weight agents than to high-molecular-weight agents. Conclusion: Changes in eosinophils, IL-5, and eotaxin precede functional changes after exposure to occupational agents in subjects with OA. Eosinophil inflammation is a feature of exposure to both high-and low-molecular-weight agents. Induced sputum may be a useful tool in the early diagnosis of OA.

The Journal of Allergy and Clinical Immunology, Nov 1, 2006

Background: Airway inflammation assessed by bronchial biopsies demonstrates distinct eosinophilic... more Background: Airway inflammation assessed by bronchial biopsies demonstrates distinct eosinophilic and noneosinophilic phenotypes in severe asthma, but their relationship to other biomarkers of disease (induced sputum and nitric oxide [NO]) is not clear. Objectives: We sought to compare airway inflammation using noninvasive (induced sputum, exhaled NO), and invasive (bronchial biopsies) methods in moderate and severe asthma and to assess whether induced sputum and exhaled NO would allow the identification of eosinophilic and noneosinophilic phenotypes in severe asthma. Methods: We performed a cross-sectional study of 32 subjects with severe asthma and 35 subjects with moderate asthma, from whom we obtained bronchial biopsies, induced sputum, and exhaled NO measurements. Results: Among subjects with severe asthma, we identified eosinophilic and noneosinophilic phenotypes using both bronchial biopsies and sputum cell counts. However, the vast majority of subjects with high sputum eosinophil counts did not have high mucosal eosinophil counts. Exhaled NO was increased in the eosinophilic phenotype as judged from bronchial biopsy findings, but not on the basis of induced sputum. Subjects with high sputum eosinophil counts experienced more asthma exacerbations than the subjects with low sputum eosinophil counts. In contrast, we did not find any differences in the clinical characteristics between eosinophilic and noneosinophilic phenotypes that were identified by bronchial biopsies. Conclusion: The use of sputum cell counts allowed the identification of a subgroup of subjects with severe asthma who were at risk of more frequent asthma exacerbations. Clinical implications: Monitoring sputum eosinophil counts in subjects with severe asthma may allow identifying the subjects with the greatest disease activity.

The Journal of Allergy and Clinical Immunology, Aug 1, 2004

Increased airway smooth muscle (ASM) mass is perhaps the most important component of the airway w... more Increased airway smooth muscle (ASM) mass is perhaps the most important component of the airway wall remodeling process in asthma. Known mediators of ASM proliferation in cell culture models fall into 2 categories: those that activate receptors with intrinsic receptor tyrosine kinase activity and those that have their effects through receptors linked to heterotrimeric guanosine triphosphateebinding proteins. The major candidate signaling pathways activated by ASM mitogens are those dependent on extracellular signal-regulated kinase and phosphoinositide 39-kinase. Increases in ASM mass may also involve ASM migration, and in culture, the key signaling mechanisms have been identified as the p38 mitogenactivated protein kinase and the p21-activated kinase 1 pathways. New evidence from an in vivo rat model indicates that primed CD4 + T cells are sufficient to trigger ASM and epithelial remodeling after allergen challenge. Hyperplasia has been observed in an equine model of asthma and may account for the increase in ASM mass. Reduction in the rate of apoptosis may also play a role. b 2-Adrenergic receptor agonists and glucocorticoids have antiproliferative activity against a broad spectrum of mitogens, although it has become apparent that mitogens are differentially sensitive. Culture of ASM on collagen type I has been shown to enhance proliferative activity and prevent the inhibitory effect of glucocorticoids, whereas b 2-agonists are minimally affected. There is no evidence that long-acting b 2-agonists are more effective than short-acting agonists, but persistent stimulation of the b 2-adrenergic receptor probably helps suppress growth responses. The maximum response of fluticasone propionate against thrombininduced proliferation is increased when it is combined with salmeterol.

Pulmonary Pharmacology & Therapeutics, Dec 1, 2003

The purpose of this study was to test the therapeutic potential of monomethoxypolyethylene glycol... more The purpose of this study was to test the therapeutic potential of monomethoxypolyethylene glycol (mPEG) conjugated-allergen using a rodent model of allergic asthma. Previously, this conjugate has been shown to possess the dual capacity of inducing long-term ovalbumin (OA)-specific suppression of the antibody response and inactivating rat mast cells that have been sensitized with murine IgE to OA. Ovalbumin sensitized and challenged Brown Norway rats were studied. Fourteen days after sensitization, a test group of six rats received mPEG-OA solution intratracheally and were challenged 30 min later with aerosolized OA. Another group of seven sensitized rats was similarly challenged with OA 30 min after intratracheal administration of normal saline. A group of six sensitized rats received mPEG-OA solution intratracheally but were challenged with normal saline. Another group of seven sensitized rats received mPEG-BSA solution intratracheally and were challenged 30 min later with aerosolized OA. A final group of five unsensitized rats were neither challenged nor medicated intratracheally. Pulmonary resistance was measured before and for 8 h following inhalation challenge. mPEG-OA treatment had an inhibitory effect on the allergic late airway response, but the early response was not significantly altered. Both mPEG-OA and mPEG-BSA reduced the total cells, eosinophils and neutrophils, in bronchoalveolar lavage and decreased the expression of IL-4, IL-5 and IFN-g mRNA. In conclusion, mPEG-OA can prevent the development of allergen-induced late airway responses and reduce airway Th2-type cytokine expression whereas mPEG conjugated to an irrelevant antigen (BSA) is anti-inflammatory but does not affect the late response.

American Journal of Respiratory Cell and Molecular Biology, Nov 1, 2020

British Journal of Pharmacology, Aug 23, 2017

BACKGROUND AND PURPOSE Cysteinyl leukotrienes (CysLTs) are pro-inflammatory lipid mediators that ... more BACKGROUND AND PURPOSE Cysteinyl leukotrienes (CysLTs) are pro-inflammatory lipid mediators that exacerbate disease state in several asthma phenotypes including asthma induced by allergen, virus and exercise. However, the role of CysLTs in irritant-induced airway disease is not well characterized. The purpose of the current study was to investigate the effect of montelukast, a CysLT 1 receptor antagonist, on parameters of irritant-induced asthma induced by inhalation of chlorine in the mouse. EXPERIMENTAL APPROACH BALB/c mice were exposed to chlorine in air (100 ppm, for 5 min). Montelukast (3 mg•kg À1) or the vehicle (1% methylcellulose) was administered 24 and 1 h prior to chlorine exposure and 1 h prior to outcome measurements. Twenty-four hours after exposure, responses to inhaled aerosolized methacholine, cell composition and an array of cytokines/chemokines in bronchoalveolar lavage (BAL) fluid were measured. Neutralizing antibodies against IL-6 and VEGF were administered prior to exposures. KEY RESULTS Montelukast reduced chlorine-induced airway hyperresponsiveness (AHR) to methacholine in the peripheral lung compartment as estimated from dynamic elastance, but not in large conducting airways. Montelukast treatment attenuated chlorine-induced macrophage influx, neutrophilia and eosinophilia in BAL fluid. Chlorine exposure increased VEGF, IL-6, the chemokines KC and CCL3 in BAL fluid. Montelukast treatment prevented chlorine-induced increases in VEGF and IL-6. Anti-IL-6 antibody inhibited chlorine-induced neutrophilia and reduced AHR.

American Journal of Physiology-lung Cellular and Molecular Physiology, Jan 15, 2016

Airway exposure to organic dust (OD) from swine confinement facilities induces airway inflammatio... more Airway exposure to organic dust (OD) from swine confinement facilities induces airway inflammation dominated by neutrophils and airway hyperresponsiveness (AHR). One important neutrophilic innate defense mechanism is the induction of oxidative stress. Therefore, we hypothesized that neutrophils exacerbate airway dysfunction following OD exposure by increasing oxidant burden. BALB/C mice were given intranasal challenges with OD or PBS (1/day for 3 days). Mice were untreated or treated with a neutrophil-depleting antibody, anti-Ly6G, or the antioxidant dimethylthiourea (DMTU) prior to OD exposure. Twenty-four hours after the final exposure, we measured airway responsiveness in response to methacholine (MCh) and collected bronchoalveolar lavage fluid to assess pulmonary inflammation and total antioxidant capacity. Lung tissue was harvested to examine the effect of OD-induced antioxidant gene expression and the effect of anti-Ly6G or DMTU. OD exposure induced a dose-dependent increase of airway responsiveness, a neutrophilic pulmonary inflammation, and secretion of keratinocyte cytokine. Depletion of neutrophils reduced OD-induced AHR. DMTU prevented pulmonary inflammation involving macrophages and neutrophils. Neutrophil depletion and DMTU were highly effective in preventing OD-induced AHR affecting large, conducting airways and tissue elastance. OD induced an increase in total antioxidant capacity and mRNA levels of NRF-2dependent antioxidant genes, effects that are prevented by administration of DMTU and neutrophil depletion. We conclude that an increase in oxidative stress and neutrophilia is critical in the induction of OD-induced AHR. Prevention of oxidative stress diminishes neutrophil influx and AHR, suggesting that mechanisms driving ODinduced AHR may be dependent on neutrophil-mediated oxidant pathways.

Journal of Immunology, Nov 15, 1999

Autoimmunity induced by HgCl2 in Brown-Norway rats. I. Production of monoclonal antibodies.

Respirology, Apr 25, 2011

ABSTRACTAsthma is a chronic disorder of the airways associated in many instances with structural ... more ABSTRACTAsthma is a chronic disorder of the airways associated in many instances with structural changes of the airways, termed airway remodelling. Irritant and allergen‐induced murine models have been used to further understand the mechanisms of airway remodelling. The infiltration of the airways by inflammatory cells, such as T lymphocytes, mast cells, eosinophils, neutrophils and macrophages after repeated allergen challenges may be important effectors in the initiation and perpetuation of airway remodelling through the release of inflammatory mediators and growth factors. Interleukins‐4 and ‐13 have been widely studied in experimental models, and have been shown to play a significant role in airway remodelling. Recently, a role for Th17 cells has been established. Other mediators involved in this process are ligands of the epidermal growth factor receptor, matrix metalloproteases and cysteinyl leukotrienes. A better understanding of the mechanisms leading to airway remodelling in allergic diseases may lead to the identification of novel therapeutic strategies but validation in human subjects is required for potential targets.

American Journal of Respiratory Cell and Molecular Biology, 1997

Late allergic airway responses can be transferred by CD4 + T cells in the rat. To investigate the... more Late allergic airway responses can be transferred by CD4 + T cells in the rat. To investigate the role of T-cell cytokines in these responses, we examined the expression of mRNA for Th2 (interleukin [lL]-4 and IL-5) and Thl (IL-2 and interferon')' [INF-')'D-type cytokines in Brown Norway rats that were administered either antigen-primed W3/25(CD4V or OXS(CDSV T cells. Donors were actively sensitized by subcutaneous injection of ovalbumin (OVA) in the neck and T cells were obtained from the cervical lymph nodes by immunomagnetic cell sorting for administration to unsensitized rats. Control rats received bovine serum albumin (BSA)-primed CD4 + and CDS+ T cells. Two days later, recipient rats were challenged with aerosolized OVA, and bronchoalveolar lavage (BAL) was performed Shafter challenge. BAL cells expressing mRNA for IL-2, IL-4, IL-5, and INF-')' were analyzed using the technique of in situ hybridization. Recipients of OVA-primed CD4 + T cells had an increase in the fraction of BAL cells expressing mRNA for IL-4 and IL-5 compared with BSA-primed CD4 + or OVA-primed CDS + cells (P < 0.001). Recipients of CDS+ T cells had an increase in INF-')' mRNA expression after OVA challenge compared with recipients of BSA-primed-CDS+ or OVA-primed CD4 + T cells (P < 0.001). In conclusion, T-cell-dependent allergen-induced late responses are associated with the expression of mRNA for IL-4 and IL-5, indicating Th2 cell activation. Furthermore, the increased expression of INF-')' in allergen challenge recipients of antigen-primed CDS+ T cells suggests that CDS+ T cells may be important in modulating allergic responses.

Respiratory Research, Aug 14, 2008

Accidental chlorine (Cl 2) gas inhalation is a common cause of acute airway injury. However, litt... more Accidental chlorine (Cl 2) gas inhalation is a common cause of acute airway injury. However, little is known about the kinetics of airway injury and repair after Cl 2 exposure. We investigated the time course of airway epithelial damage and repair in mice after a single exposure to a high concentration of Cl 2 gas. Mice were exposed to 800 ppm Cl 2 gas for 5 minutes and studied from 12 hrs to 10 days post-exposure. The acute injury phase after Cl 2 exposure (≤ 24 hrs post-exposure) was characterized by airway epithelial cell apoptosis (increased TUNEL staining) and sloughing, elevated protein in bronchoalveolar lavage fluid, and a modest increase in airway responses to methacholine. The repair phase after Cl 2 exposure was characterized by increased airway epithelial cell proliferation, measured by immunoreactive proliferating cell nuclear antigen (PCNA), with maximal proliferation occurring 5 days after Cl 2 exposure. At 10 days after Cl 2 exposure the airway smooth muscle mass was increased relative to controls, suggestive of airway smooth muscle hyperplasia and there was evidence of airway fibrosis. No increase in goblet cells occurred at any time point. We conclude that a single exposure of mice to Cl 2 gas causes acute changes in lung function, including pulmonary responsiveness to methacholine challenge, associated with airway damage, followed by subsequent repair and airway remodelling.

Journal of Clinical Investigation, Sep 1, 1995

Activated CD4+ helper T cells have been demonstrated in asthmatic airways and postulated to play ... more Activated CD4+ helper T cells have been demonstrated in asthmatic airways and postulated to play a central role in eliciting allergic inflammation; direct evidence of their involvement seems to be lacking. We hypothesized that CD4+ T cells have the potential to induce allergic responses to antigen challenge, and tested this hypothesis in a model of allergic bronchoconstriction, the Brown Norway rat, using the approach of adoptive transfer. Animals were actively sensitized to either ovalbumin (OVA) or BSA and were used as donors of T cells. W3/25 (CD4) + or OX8 (CD8) + T cells were isolated from the cervical lymph nodes of sensitized donors and transferred to naive BN rats. 2 d after adoptive transfer recipient rats were challenged by OVA inhalation, and changes in lung resistance (RL), bronchoalveolar lavage (BAL) cells, and serum levels of antigen-specific IgE were studied. After OVA challenge recipients of OVA-primed W3/25+ T cells exhibited sustained increases in RL throughout the entire 8-h observation period and had significant bronchoalveolar lavage eosinophilia, which was detected by immunocytochemistry using an antimajor basic protein mAb. Recipients of BSA-primed W3/25+ T cells or OVAprimed OX8+ T cells failed to respond to inhaled OVA. OVA-specific immunoglobulin E was undetectable by ELISA or skin testing in any of the recipient rats after adoptive transfer. In conclusion, antigen-induced airway bronchoconstriction and eosinophilia were successfully transferred by antigen-specific W3/25+ T cells in Brown Norway rats. These responses were dependent on antigenprimed W3/25+ T cells and appeared to be independent of IgE-mediated mast cell activation. This study provides clear evidence for T cell mediated immune mechanisms in allergic airway responses in this experimental model.

American Journal of Respiratory and Critical Care Medicine, Sep 1, 2003

Exposure to chlorine gas (Cl 2) causes occupational asthma that we hypothesized occurs through th... more Exposure to chlorine gas (Cl 2) causes occupational asthma that we hypothesized occurs through the induction of airway inflammation and airway hyperresponsiveness by oxidative damage. Respiratory mechanics and airway responsiveness to methacholine were assessed in A/J mice 24 hours after a 5-minute exposure to 100, 200, 400, or 800 ppm Cl 2 and 2 and 7 days after inhalation of 400 ppm Cl 2. Airway responsiveness was higher 24 hours after 400 and 800 ppm Cl 2. Responsiveness after inhalation of 400 ppm Cl 2 returned to normal by 2 days but was again elevated at 7 days. Airway epithelial loss, patchy alveolar damage, proteinaceous exudates, and inflammatory cells within alveolar walls were observed in animals exposed to 800 ppm Cl 2. Macrophages, granulocytes, epithelial cells, and nitrate/ nitrite levels increased in lung lavage fluid. Increased inducible nitric oxide synthase expression and oxidation of lung proteins were observed. Epithelial cells and alveolar macrophages from mice exposed to 800 ppm Cl 2 stained for 3-nitrotyrosine residues. Inhibition of inducible nitric oxide synthase with 1400W (1 mg/kg) abrogated the Cl 2-induced changes in responsiveness. We conclude that chlorine exposure causes functional and pathological changes in the airways associated with oxidative stress. Inducible nitric oxide synthase is involved in the induction of changes in responsiveness to methacholine.