Biomedical subjects

Jan Lötvall

Publications and source records attributed to Jan Lötvall.

At least 19 recordsLinked to original sources

PubMed2006

Inhaled steroid/long-acting beta 2 agonist combination products provide 24 hours improvement in lung function in adult asthmatic patients.

BACKGROUND: The combination of inhaled corticosteroids (ICS) and long-acting beta2-agonists (LABA) is recommended by treatment guidelines for the treatment of persistent asthma. Two such combination products, salmeterol/fluticasone propionate (SFC, Seretide GSK, UK) and formoterol/budesonide (FBC, Symbicort, AstraZeneca, UK) are commercially available. OBJECTIVES: The purpose of these studies was to evaluate and compare the duration of bronchodilation of both combination products up to 24 hours after a single dose. METHODS: Two randomised, double blind, placebo-controlled, crossover studies were performed. Study A was conducted in 33 asthmatic adults receiving 400-1200 mcg of budesonide or equivalent. Serial forced expiratory volume in one second (FEV1) was measured over 24 hours to determine the duration of effect of both SFC (50/100 mcg) and FBC (4.5/160 mcg). Study B was conducted in 75 asthmatic adults receiving 800-1200 mcg of budesonide or equivalent and comprised a 4 week run-in of 400 mcg bd Becotide followed by 4 weeks treatment with either SFC 50/100 mcg bd or FBC 4.5/160 mcg bd taken in a cross-over manner. Serial 24-hour FEV1 was measured after the first dose and the last dose after each 4-weeks treatment period to determine the offset of action of each treatment. RESULTS: In study A, a single inhalation of SFC and FBC produced a sustained bronchodilation at 16 hours with an adjusted mean increase in FEV1 from pre-dose of 0.22 L (95% CI 0.19, 0.35 L) for SFC and 0.25 L (95% CI 0.21, 0.37 L) for FBC, which was significantly greater than placebo for both treatments (-0.05 L; p < 0.001). In study B, the slope of decline in FEV1 from 2-24 hours post dose was -16.0 ml/hr for SFC and -14.2 ml/hr for FBC. The weighted mean AUC over 24 hours was 0.21 Lxmin and 0.22 Lxmin and mean change from pre-dose FEV1 at 12 hours was 0.21 L for SFC and 0.20 L for FBC respectively CONCLUSION: Both SFC and FBC produced a similar sustained bronchodilator effect which was prolonged beyond 12 hours post dose and was clearly measurable at 24 h.

Administration, Inhalation↗

PubMed2006

Regulatory role of CD8+ T lymphocytes in bone marrow eosinophilopoiesis.

BACKGROUND: There is a growing body of evidence to suggest that CD8+ T lymphocytes contribute to local allergen-induced eosinophilic inflammation. Since bone marrow (BM) responses are intricately involved in the induction of airway eosinophilia, we hypothesized that CD8+ T lymphocytes, as well as CD4+ T lymphocytes, may be involved in this process. METHODS: Several approaches were utilized. Firstly, mice overexpressing interleukin-5 (IL-5) in CD3+ T lymphocytes (NJ.1638; CD3IL-5+ mice) were bred with gene knockout mice lacking either CD4+ T lymphocytes (CD4-/-) or CD8+ T lymphocytes (CD8-/-) to produce CD3IL-5+ knockout mice deficient in CD4+ T lymphocytes (CD3IL-5+/CD4-/-) and CD8+ T lymphocytes (CD3IL-5+/CD8-/-), respectively. Secondly, CD3+, CD4+ and CD8+ T lymphocytes from naïve CD3IL-5+ and C57BL/6 mice were adoptively transferred to immunodeficient SCID-bg mice to determine their effect on BM eosinophilia. Thirdly, CD3IL-5+, CD3IL-5+/CD8-/- and CD3IL-5+/CD4-/- mice were sensitized and allergen challenged. Bone marrow and blood samples were collected in all experiments. RESULTS: The number of BM eosinophils was significantly reduced in CD3IL-5+/CD8-/- mice compared to CD3IL-5+ mice and CD3IL-5+/CD4-/- mice. Serum IL-5 was significantly higher in CD3IL-5+/CD4-/- mice compared to CD3IL-5+ mice but there was no difference in serum IL-5 between CD3IL-5+/CD4-/- and CD3IL-5+/CD8-/- mice. Adoptive transfer of CD8+, but not CD4+ T lymphocytes from naïve CD3IL-5+ and C57BL/6 mice restored BM eosinophilia in immunodeficient SCID-bg mice. Additionally, allergen challenged CD3IL-5+/CD8-/- mice developed lower numbers of BM eosinophils compared to CD3IL-5+ mice and CD3IL-5+/CD4-/- mice. CONCLUSION: This study shows that CD8+ T lymphocytes are intricately involved in the regulation of BM eosinophilopoiesis, both in non-sensitized as well as sensitized and allergen challenged mice.

Adoptive Transfer↗

PubMed2005

Interleukin-17 as a recruitment and survival factor for airway macrophages in allergic airway inflammation.

Recent data indicate that the proinflammatory cytokine, interleukin (IL)-17, stimulates certain effector functions of human macrophages. We evaluated whether IL-17 mediates allergen-induced accumulation of airway macrophages and, if so, whether such an effect relates to the control of macrophage recruitment and survival. BALB/c mice were sensitized and challenged with ovalbumin. Three hours before challenge an anti-mouse IL-17 mAb (a-IL-17) was administered. Sampling was conducted 24 h after the allergen challenge. In vitro chemotaxis assay for blood monocytes and culture of airway macrophages, immunocytochemistry for Fas-antigen, and matrix metalloproteinase-9 (MMP-9) were used to determine the effect of IL-17 on the recruitment, survival, and activity of airway macrophages. A-IL-17 reduced the number of airway neutrophils and macrophages after allergen challenge. In vitro, recombinant IL-17 induced migration of blood monocytes and prolonged survival of airway macrophages. A-IL-17 also increased the expression of Fas-antigen in airway macrophages in vivo. Finally, the expression of MMP-9 by airway neutrophils and macrophages in vivo was downregulated by a-IL-17. This study indicates that endogenous IL-17 mediates the accumulation of macrophages during allergen-induced airway inflammation. IL-17 exerts its effects by acting directly on airway macrophages by promoting their recruitment and survival. Furthermore, IL-17 is involved in controlling the proteolytic activity of macrophages and neutrophils in allergen-induced airway inflammation.

Animals↗

PubMed2005

Airway allergen exposure stimulates bone marrow eosinophilia partly via IL-9.

BACKGROUND: Interleukin (IL)-9 is a Th2-derived cytokine with pleiotropic biological effects, which recently has been proposed as a candidate gene for asthma and allergy. We aimed to evaluate the therapeutic effect of a neutralizing anti-IL-9 antibody in a mouse model of airway eosinophilic inflammation and compared any such effect with anti-IL-5 treatment. METHODS: OVA-sensitized Balb/c mice were intraperitoneally pretreated with a single dose (100 microg) of an anti-mouse IL-9 monoclonal antibody (clone D9302C12) or its vehicle. A third group was given 50 microg of a monoclonal anti-mouse IL-5 antibody (TRFK-5) or its vehicle. Animals were subsequently exposed to OVA on five days via airways. Newly produced eosinophils were labelled using 5-bromo-2'-deoxyuridine (BrdU). BrdU+ eosinophils and CD34+ cell numbers were examined by immunocytochemistry. After culture and stimulation with OVA or PMA+IC, intracellular staining of IL-9 in bone marrow cells from OVA-exposed animals was measured by Flow Cytometry. The Mann-Whitney U-test was used to determine significant differences between groups. RESULTS: Anti-IL-9 significantly reduced bone marrow eosinophilia, primarily by decrease of newly produced (BrdU+) and mature eosinophils. Anti-IL-9 treatment also reduced blood neutrophil counts, but did not affect BAL neutrophils. Anti-IL-5 was able to reduce eosinophil numbers in all tissue compartments, as well as BrdU+ eosinophils and CD34+ progenitor cells, and in all instances to a greater extent than anti-IL-9. Also, FACS analysis showed that IL-9 is over-expressed in bone marrow CD4+ cells after allergen exposure. CONCLUSIONS: Our data shows that a single dose of a neutralizing IL-9 antibody is not sufficient to reduce allergen-induced influx of newly produced cells from bone marrow to airways. However, in response to allergen, bone marrow cells over-express IL-9. This data suggest that IL-9 may participate in the regulation of granulocytopoiesis in allergic inflammation.

Animals↗

PubMed2005

Past, present and future--beta2-adrenoceptor agonists in asthma management.

The beta-adrenoceptor agonists (beta-agonists) have been used to relieve bronchoconstriction for at least 5000 years. beta-agonists are based on adrenaline and early forms, such as isoprenaline, Lacked bronchial selectivity and had unpleasant side effects. Modern beta-agonists are more selective for the beta2-adrenoceptors (beta2-receptors) located in bronchial smooth muscle and have less cardiotoxicity. Traditional beta2-adrenoceptor agonists (beta2-agonists), such as salbutamol, terbutaline and fenoterol, were characterised by a rapid onset but relatively short duration of action. While valuable as reliever medication, their short duration gave inadequate night-time relief and limited protection from exercise-induced bronchoconstriction. beta2-agonists with longer durations of action, formoterol and salmeterol, were subsequently discovered or developed. When combined with inhaled corticosteroids they improved lung function, and reduced symptoms and exacerbations more than an increased dose of corticosteroids. However, tolerance to the bronchprotective effects of long-acting beta2-agonists and cross-tolerance to the bronchodilator effects of short-acting beta2-agonists is apparent despite use of inhaled corticosteroids. The role of beta2-receptor polymorphisms in the development of tolerance has yet to be fully determined. Formoterol is unique in having both a long-lasting bronchodilator effect (> 12 h) and a fast onset of action (1-3min from inhalation), making it effective both as maintenance and reliever medication. The recent change in classification from short- and long-acting beta2-agonists to rapid-acting and/or long-acting agents reflects the ongoing evolution of beta2-agonist therapy.

Adrenergic beta-Agonists↗

PubMed2005

Ultra long-acting beta 2-agonists in development for asthma and chronic obstructive pulmonary disease.

After the discovery of formoterol and salmeterol, new candidates for long-acting beta2-adrenoceptor agonists (LABAs) have emerged from various companies. In particular, once-daily beta2-adrenoceptor agonists such as arformoterol, carmoterol, indacaterol, GSK-159797, GSK-597901, 159802, 642444 and 678007 are under development for the treatment of asthma and chronic obstructive pulmonary disease. The majority of these compounds are (R,R)-isomers in order to control desensitisation and accumulation. Several options for combination products are currently being evaluated in parallel with the development of these ultra LABAs. Once-daily dosing of an ultra LABA would be a significant convenience and probably a compliance-enhancing advantage leading to improved overall clinical outcomes in patients with asthma and chronic obstructive pulmonary disease. The only limits set for the development of a LABA with a new product profile are medical needs and marketing opportunities.

Adrenergic beta-2 Receptor Agonists↗

PubMed2005

Comparison of the bronchodilating effects of formoterol and albuterol delivered by hydrofluoroalkane pressurized metered-dose inhaler.

OBJECTIVE: To compare the onset of bronchodilation with a new formoterol hydrofluoroalkane (HFA) pressurized metered-dose inhaler (pMDI) with albuterol (salbutamol) HFA pMDI. PATIENTS AND METHODS: Thirty patients with stable mild or moderate asthma (23 using inhaled corticosteroids, mean FEV(1) 82% of predicted, >or=15% reversibility to terbutaline 1mg after 30 minutes) received formoterol HFA (Oxis) 2 x 4.5microg, albuterol HFA (Ventoline) Evohaler) 2 x 100microg, or placebo at three separate visits in this randomized, double-blind, double-dummy, three-way crossover study. FEV(1) was measured before and 3, 10, 20, 30 and 60 minutes after inhalation. Change in FEV(1) at 3 minutes after inhalation was the primary variable. RESULTS: Mean baseline FEV(1) was stable on all study days (range 2.92-2.94L). FEV(1) values at 3 minutes were: formoterol 3.22L (8% increase), albuterol 3.23L (9% increase) and placebo 2.99L (both p < 0.001 vs placebo). Maximum FEV(1) increased similarly with formoterol and albuterol, with no differences observed between the active treatments at any time point. Patients rated treatment effective at 3 minutes in 15 of 30, 19 of 30 and 7 of 30 cases with formoterol, albuterol and placebo, respectively. All treatments were well tolerated. CONCLUSION: In stable, mild, or moderate asthma, formoterol 9microg and albuterol 200microg, both by HFA pMDI, provided equally rapid and effective bronchodilation.

Adolescent↗

PubMed2004

The effect of formoterol over 24 h in patients with asthma: the role of enantiomers.

The single-dose effect of formoterol racemate and enantiomers on bronchodilatation up to 24 h was determined. Forty-six reversible asthmatic patients were randomised to this double blind, crossover study. Formoterol was inhaled by nebulizer (HaloLite); 4.5 and 36 microg of the racemate (rac-formoterol), 2.25 and 18 microg of (R;R)-formoterol, 18 mirog of (S;S)-formoterol, or placebo. Airway and systemic effects were assessed by serial measurements of forced expiratory volume during the first second, FEV1 (24 h), and heart rate (4 h). Rac- and (R;R)-formoterol significantly and dose-dependently increased FEV1 with similar mean maximal effect. (S;S)-formoterol was without significant effects on FEV1 and heart rate. (R;R)- and rac-formoterol were still effective 22-24 h after single high doses, but this was associated with some systemic side effect (increased heart rate) initially. Average 22-24 h FEV1 was 8% (rac-formoterol 36 microg) and 11% ((R;R)-formoterol 18 microg) over placebo, respectively. No significant differences in effects were observed between rac- and (R;R)-formoterol. Thus, the single dose bronchodilatating effect of formoterol resides in (R;R)-formoterol. This study does not indicate a clinically important advantage of (R;R)-formoterol as acute bronchodilator compared to the racemate.

Adrenergic beta-Agonists↗

PubMed2004

A synthetic VIP peptide analogue inhibits neutrophil recruitment in rat airways in vivo.

Currently, there is no effective pharmacotherapy against exaggerated mobilisation of neutrophils in human airway diseases such as chronic obstructive pulmonary disease and asthma. We evaluated the effect of two synthetic vasoactive intestinal peptide (VIP)-like analogues on cytokine-induced neutrophil recruitment in airways in vivo. Recombinant interleukin (IL)-1 beta was administered intratracheally (i.t.) to intubated, spontaneously breathing Sprague-Dawley rats. The rats were pretreated either with a VIP synthetic peptide analogue, a pituitary adenylate cyclase-activating peptide (PACAP)-1-27 synthetic analogue, the beta(2)-adrenoceptor agonist salbutamol or vehicle, systemically or locally. Differential cell counts were performed on bronchoalveolar lavage fluid (BALf) cytospins. Effects on mean arterial blood pressure (MAP) were monitored in separate experiments. Systemic administration of the VIP analogue, the PACAP analogue and salbutamol attenuated the cytokine-induced increase in BALf neutrophil number. Local administration of the VIP analogue and salbutamol, but not the PACAP analogue, also decreased the neutrophil number in BALf. Local administration of the VIP analogue and salbutamol caused a transient decrease in MAP. Systemic or local administration of a synthetic VIP peptide analogue inhibits cytokine-induced neutrophil recruitment in airways in vivo. This action is exerted without severe, sustained cardiovascular side effects, and deserves to be further evaluated in obstructive pulmonary diseases in human.

Albuterol↗

PubMed2004

Allergen-induced traffic of bone marrow eosinophils, neutrophils and lymphocytes to airways.

We evaluated whether bone marrow (BM) inflammatory cells have capacity to traffic into the airways following allergen exposure in a mouse model of allergen-induced airway inflammation. We also evaluated the effect of IL-5 overexpression on (i) the production of eosinophils in BM, (ii) the accumulation of eosinophils, neutrophils and lymphocytes in blood and airways and (iii) the changes in CD34+ cell numbers in BM, blood and airways. Bromodeoxyuridine (BrdU) was used to label cells produced during the exposure period. Furthermore, CD3 splenocytes were adoptively transferred to investigate the BM inflammatory response. Allergen exposure induced traffic of BM eosinophils, neutrophils and lymphocytes to the airways and increased the number of BrdU+ eosinophils, neutrophils, lymphocytes and CD34+ cells in BALf. IL-5 overexpression enhanced the eosinophilopoiesis and increased the presence of BrdU+ eosinophils and CD34+ cells in airways and enhanced the number of CD34+ cells in BM and blood after allergen exposure. Adoptive transfer of CD3 lymphocytes overexpressing IL-5 caused increased BM eosinophilia. In conclusion, allergen exposure induces traffic of not only newly produced eosinophils but also newly produced neutrophils and lymphocytes into the airways.

Adoptive Transfer↗

PubMed2004

Eotaxin-2 regulates newly produced and CD34 airway eosinophils after allergen exposure.

BACKGROUND: Eosinophils develop from CD34+ bone marrow progenitors, and evidence increasingly suggests that these progenitors are recruited to the airways in atopic asthmatics after allergen challenge. Moreover, it has been shown that the number of CD34+ progenitors in bronchial tissue correlates with asthma severity. To date, however, little is known about how these cells are recruited into the airways. OBJECTIVE: Our aim was to evaluate the role of 2 chemokines, eotaxin-I and/or eotaxin-2, in the recruitment of newly produced and CD34+ eosinophils to the airways after allergen exposure. METHODS: BALB/c mice sensitized and exposed to ovalbumin were pretreated intraperitoneally or intranasally with a neutralizing anti-eotaxin-1 and/or anti-eotaxin-2 antibody.A thymidine analogue, 5-bromo-2'-deoxyuridine (BrdU), was used to mark newly produced cells. Bronchoalveolar lavage (BAL), blood, and bone marrow were collected 24 hours after the final exposure. RESULTS: Anti-eotaxin-1 and/or anti-eotaxin-2 given intranasally(ie, locally to airways) significantly decreased BAL eosinophils. This decrease was paralleled with a decrease in both BrdU+and CD34+ eosinophils. In contrast, systemically administered(ie, intraperitoneally) anti-eotaxin-1 and/or anti-eotaxin-2 resulted in a significant decrease in BAL eosinophils only when the combined treatment was of a sufficiently high dosage to produce measurable concentrations in the airways.Furthermore, neither of the treated groups showed any significant decrease in blood or bone marrow eosinophils. CONCLUSION: Both eotaxin-1 and eotaxin-2 are involved locally within the airways in the regulation of the recruitment of newly produced and CD34+ eosinophils after allergen exposure.

Allergens↗

PubMed2004

Combination therapy in asthma--fixed or variable dosing in different patients?

The introduction of combination products, for the coadministration of an inhaled corticosteroid (ICS) with a long-acting beta2-agonist in a single inhaler, has greatly simplified asthma therapy. The two combination inhalers currently available, Symbicort (budesonide/formoterol in a single inhaler) and Seretide (salmeterol/fluticasone), comply with Step 3 of international guidelines that recommend the addition of a long-acting beta2-agonist to ICS in patients who are inadequately controlled on ICS alone. Importantly, combination inhalers ensure that patients cannot neglect their ICS maintenance therapy in favour of the long-acting beta2-agonist--which may improve adherence and overall asthma control. In vitro experiments suggest that ICS and long-acting beta2-agonists may interact beneficially when they are administered via one inhaler. The efficacy and tolerability of budesonide/formoterol and salmeterol/fluticasone have been demonstrated. There are currently two approaches for treating asthma using combination therapy--fixed and adjustable dosing. Fixed dosing with budesonide/formoterol or salmeterol/fluticasone provides effective asthma control in line with guideline goals. However, given the inherent variability of asthma, there is increasing evidence that adjusting the dose of ICS according to fluctuations in symptoms is beneficial. Findings from a series of studies comparing fixed and adjustable symptom-guided dosing regimens demonstrate that adjustable dosing may improve asthma control at an overall lower steroid dose. Ultimately, if adjustable dosing proves to be an effective treatment option, it may be possible to use budesonide/formoterol for both maintenance therapy and symptom relief, thereby overcoming the need for a separate reliever inhaler. This is because formoterol has a more rapid onset and greater dose-related effects than salmeterol in salmeterol/fluticasone. Given that all patients are different, with different disease severities and treatment preferences, both fixed and adjustable dosing strategies are likely to be important in the long-term management of asthma. It is possible that different treatment options will be used for different patients, depending on their disease severity, personality and ability to adhere to therapy.

Adrenal Cortex Hormones↗

PubMed2003

Allergen exposure-induced differences in CD34+ cell phenotype: relationship to eosinophilopoietic responses in different compartments.

We hypothesized that the allergen-induced increased number of airway eosinophils results from increased recruitment of eosinophils from bone marrow (BM) and local development of CD34(+) cells into eosinophils. We also assumed that the phenotype of airway eosinophils depends on whether these cells have differentiated within BM or airway. C57BL/6 mice were sensitized and subsequently exposed to ovalbumin (OVA) on 5 consecutive days. Newly produced cells were labeled with a thymidine analog. Clonogenic activity and interleukin 5 (IL-5) release from bronchoalveolar lavage fluid (BALf) CD34(+) cells were evaluated by using cell-culture techniques. Allergen exposure induces increase in CD135(+) primitive myeloid progenitors within the BM CD34(+) cell population, without significant changes in total number of CD34(+) cells or newly produced CD34(+) cells. CD34(+)/IL-5R alpha(+) cells in the first stage of cell differentiation were found only in BM, arguing that early commitment of CD34(+) cells into the eosinophil lineage is restricted to the BM compartment. Allergen exposure induces a shift in differentiation of BM, blood, and BALf eosinophillineage-committed CD34(+) cells toward mature eosinophils and recruitment of these cells via blood into airway. We further demonstrate in vitro that ability to multiply persists in BALf CD34(+) cells but not CD34(-) cells, likely via autocrine IL-5 release and IL-5-induced up-regulation of IL-5R alpha.

Allergens↗

PubMed2003

Regulation of bone marrow and airway CD34+ eosinophils by interleukin-5.

The aim of this study was to evaluate the effect of a neutralizing anti-interleukin (IL)-5 monoclonal antibody (TRFK-5) on bone marrow and airway CD34(+) and immature eosinophils. A focus was to determine the effect of the timing of treatment. Balb/c mice were ovalbumin-sensitized and subsequently exposed to ovalbumin for 5-10 d via airway route. Animals were treated intraperitoneally with TRFK-5 or its isotype control (50 microg) once at different time points. Newly produced eosinophils were labeled using 5-bromo-2'-deoxyuridine (BrdU). BrdU(+) and CD34(+) eosinophil numbers were examined by immunocytochemistry. TRFK-5 reduced bone marrow immature eosinophils within 3 d. This effect was closely related to a reduction of BrdU(+) and CD34(+) bone marrow eosinophils, and reduced numbers of blood eosinophils. However, bronchoalveolar lavage (BAL) eosinophilia was not attenuated to the same degree. The effect of TRFK-5 was most prominent in the extended allergen-exposure protocol, where the treatment was given in the middle of the exposure, with strongly reduced bone marrow CD34(+) and immature bone marrow eosinophils, blood eosinophils as well as BAL BrdU(+) eosinophils, and BAL CD34(+) eosinophils. These data argue that anti-IL-5 downregulates eosinophilopoiesis within 3 d by action in the bone marrow, by inhibition of the early stages of eosinophil maturation from CD34(+) cells.

Allergens↗

PubMed2003

Endogenous IL-17 as a mediator of neutrophil recruitment caused by endotoxin exposure in mouse airways.

We have previously demonstrated that administration of the recently described cytokine IL-17 in rat airways in vivo recruits and activates neutrophils locally. In the current study, we examined whether endogenous IL-17 is involved in mediating neutrophil recruitment caused by endotoxin exposure in mouse airways. Our in vivo data show that local endotoxin exposure causes the release of free, soluble IL-17 protein 6 h later. Systemic pretreatment with a neutralizing anti-IL-17 Ab almost completely inhibits neutrophil recruitment 24 h, but not 6 h, after endotoxin exposure in the airways. Pretreatment with neutralizing anti-IL-6 and anti-macrophage inflammatory protein (MIP)-2 Abs inhibits neutrophil recruitment caused by local endotoxin exposure and IL-17, respectively. Our in vitro data show that endotoxin exposure stimulates the release of soluble IL-17 protein in T lymphocytes harvested from lung and spleen, respectively, and that this cytokine release requires coculture with airway macrophages. Intracellular IL-17 protein is detected in T lymphocytes from spleen but not in airway macrophages after coculture and stimulation of these two cell types. Finally, anti-IL-17 does not alter endotoxin-induced release of IL-6 and MIP-2 from T lymphocytes and airway macrophages in coculture. In conclusion, our results indicate that endotoxin exposure causes the release of IL-17 from T lymphocytes and that this cytokine release requires the presence of macrophages. Once released, endogenous IL-17 acts in part by inducing local release of neutrophil-mobilizing cytokines such as IL-6 and MIP-2, from nonlymphocyte, nonmacrophage cells, and this contributes to recruitment of neutrophils in the airways. These IL-17-related mechanisms constitute potential targets for pharmacotherapy against exaggerated neutrophil recruitment in airway disease.

Administration, Intranasal↗

PubMed2003

Pharmacological modulation of interleukin-17-induced GCP-2-, GRO-alpha- and interleukin-8 release in human bronchial epithelial cells.

The cytokine interleukin-17 may play a role in the recruitment of airway neutrophils, and interleukin-17 protein is increased in the airways of patients with asthma. In this study, we characterised the effect of interleukin-17 on the release of the neutrophil-recruiting cytokines granulocyte chemotactic protein (GCP)-2, growth-related oncogene (GRO)-alpha and interleukin-8 in human bronchial epithelial (HBE) cells. We also characterised the involvement of mitogen-activated protein (MAP) kinases as well as the effect of beta-adrenoceptor and glucocorticoid receptor stimulation and calcineurin and P-glycoprotein inhibition on these epithelial responses to interleukin-17. We found that interleukin-17 (1-1000 ng/ml) increased the release of GCP-2, GRO-alpha and interleukin-8 in a concentration-dependent manner. This interleukin-17-induced release of C-X-C chemokines was sensitive to inhibition of the p38 MAP kinase pathway and to stimulation of glucocorticoid receptors. In contrast, stimulation of beta-adrenoceptors increased the release of interleukin-8 and did not markedly alter the release of GCP-2 and GRO-alpha. Inhibition of calcineurin and of P-glycoproteins did not exert any substantial effect on the release of C-X-C chemokines. In conclusion, interleukin-17 bears the potential to increase neutrophil recruitment into the airways by releasing several, different C-X-C chemokines, including GCP-2, GRO-alpha and interleukin-8 in human bronchial epithelial cells. Inhibition of the p38 MAP kinase pathway and glucocorticoid receptor stimulation constitute two credible therapeutic strategies against this interleukin-17-induced release of neutrophil-recruiting cytokines.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2002

Intranasal fluticasone propionate inhibits allergen induced bone marrow eosinophilia in mice.

Local corticosteroids are currently the most efficient safe anti-allergic treatment, which attenuate eosinophilic tissue inflammation through several mechanisms. We evaluated the effect of local airways corticosteroid on repeated allergen exposure-induced bone marrow activation and airway eosinophilia using the number of eosinophils in bone marrow, bronchoalveolar lavage fluid (BALf) and airways tissue as study end-points. Male BALB/c mice were sensitized by intraperitoneal injections of aluminum-precipitated ovalbumin (OVA) on two different days (5 days apart). Eight days after the second sensitization, the animals were challenged intranasally with OVA or phosphate-buffered saline (PBS) on 5 consecutive days. Concomitantly with challenges mice were treated with fluticasone propionate or respective vehicle. OVA exposures induced a significant increase in eosinophil numbers in bone marrow, BALf and airways tissue (P<0.005). Treatment with fluticasone propionate significantly reduced the increase of absolute number of mature bone marrow eosinophils (P=0.014) and showed a tendency towards decrease in the immature bone marrow eosinophil number (P=0.057) compared to controls. However, fluticasone propionate had no significant effect on BALf and airways tissue eosinophils (P=0.28 and 0.07, respectively). In this murine allergy model intranasal corticosteroid reduced number of bone marrow mature eosinophils, but did not significantly affect airways cell populations.

Allergens↗

PubMed2002

Comparison of effects of anti-IL-3, IL-5 and GM-CSF treatments on eosinophilopoiesis and airway eosinophilia induced by allergen.

Allergic inflammation is dominated by eosinophils. IL-3, IL-5, and GM-CSF are involved in production and activation of eosinophils. IL-5 has been reported to be crucial for the induction of airway eosinophilia. However, the contribution of IL-3 and GM-CSF to allergic airway inflammation remains to be determined. To address this issue, ovalbumin-sensitized Balb/c mice were repeatedly exposed to allergen via airway route. Animals were pretreated intraperitoneally with neutralising anti-IL-3, anti-IL-5 and/or anti-GM-CSF antibodies. Newly produced inflammatory cells were pulse-labelled with the thymidine analogue 5-bromo-2'-deoxyuridine (BrdU), which is incorporated into DNA during the cell mitosis. BAL and bone marrow cells were collected 24 h after the last allergen exposure, and differential cell counts and immunocytochemical detection of BrdU-labelled cells were performed. Anti-IL-5 strongly reduced both BAL and bone marrow eosinophilia, as well as the number of BrdU-positive BAL-granulocytes. In contrast, anti-IL-3 and anti-GM-CSF alone had little and no inhibitory effect on these responses, respectively. Even the combined treatment with anti-IL-3 and anti-GM-CSF showed only a non-significant tendency to attenuate these responses. These data suggest that the efficacy of treatments with anti-IL-3 and anti-GM-CSF is much weaker than that with anti-IL-5. IL-5 may be the preferred target to block eosinophilia in allergic diseases.

Allergens↗