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Hydroxyl radical protein footprinting (HRPF) is a powerful method for measuring protein topography, allowing researchers to monitor events that alter the solvent accessible surface of a protein (e.g., ligand binding, aggregation, conformational changes, etc.) by measuring changes in the apparent rate of reaction of portions of the protein to hydroxyl radicals diffusing in solution. Fast Photochemical Oxidation of Proteins (FPOP) offers an ultrafast benchtop method for radical generation for HRPF, photolyzing hydrogen peroxide using a UV laser to generate high concentrations of hydroxyl radicals that are consumed on roughly a microsecond time scale. The broad reactivity of hydroxyl radicals means that almost anything added to the solution (e.g., ligands, buffers, excipients, etc.) will scavenge hydroxyl radicals, altering their half-life and changing the effective radical concentration experienced by the protein. Similarly, minute changes in peroxide concentration, laser fluence, and buffer composition can alter the effective radical concentration, making reproduction of data challenging. Here, we present a simple method for radical dosimetry that can be carried out as part of the FPOP workflow, allowing for measurement of effective radical concentration in real time. Additionally, by modulating the amount of radical generated, we demonstrate that effective hydroxyl radical yields in FPOP HRPF experiments carried out in buffers with widely differing levels of hydroxyl radical scavenging capacity can be compensated on the fly, yielding statistically indistinguishable results for the same conformer. This method represents a major step in transforming FPOP into a robust and reproducible technology capable of probing protein structure in a wide variety of contexts.

This report describes the development and the biology of Sch 55700, a humanized monoclonal antibody to human IL-5 (hIL-5). Sch 55700 was synthesized using CDR (complementarity determining regions) grafting technology by incorporating the antigen recognition sites for hIL-5 onto consensus regions of a human IgG 4 framework. In vitro, Sch 55700 displays high affinity (K d = 20 pmol/l) binding to hIL-5, inhibits the binding of hIL-5 to Ba/F3 cells (IC 50 = 0.5 nmol/l) and blocks IL-5 mediated proliferation of human erythroleukemic TF-1 cells. In allergic mice, Sch 55700 (0.1-10 mg/kg, i.p. or i.m.) inhibits the influx of eosinophils in the lungs, demonstrates long duration of activity and the anti-inflammatory activity of this com- pound is additive with oral prednisolone. In allergic guinea pigs, Sch 55700 (0.03-30 mg/kg i.p.) inhibits both the pulmonary eosinophilia and airway hyperresponsiveness and at 30 mg/ kg, i.p. inhibited allergic, but not histamine-induced bronchoconstriction. In allergic rabbits, Sch 55700 blocks cutaneous eosinophilia. Sch 55700 (0.1-1 mg/kg i.p.) also blocks the pulmonary eosinophilia and neutrophilia caused by tracheal injection of hIL-5 in guinea pigs. In allergic cynomolgus monkeys, a single dose of Sch 55700 (0.3 mg/kg i.v.) blocks the pulmonary eosinophilia caused by antigen challenge for up to six months. Sch 55700 is, therefore, a potent antibody against IL-5 in vitro and in a variety of species in vivo that could be used to establish the role of IL-5 in human eosinophilic diseases such as asthma.

The Brown–Norway rat is often used to study the allergic pulmonary response. However, relatively little is known about the delayed phase reactions after allergen challenge in this species. To evaluate the temporal changes in lung function and elucidate the mechanisms involved in the delayed phase response, Brown–Norway rats were sensitized and challenged to aerosolized ovalbumin and lung functions were measured by forced expiratory maneuvers and forced oscillation for up to 10 days after a single antigen challenge. Statistically significant (P

Tachykinins are important in the development of pulmonary inflammation in mice but the tachykinin receptor subtype mediating this response has not been defined. To elucidate the role of tachykinin NK 3 -receptors on allergen-induced pulmonary inflammation, studies were performed on ovalbumin (OVA) sensitized and challenged mice with genetic disruption of the tachykinin NK 3 -receptor (NK 3 −/− ). Aerosol OVA (0.5%) challenge produced eosinophil influx into the bronchoalveolar lavage fluid and lung tissue, goblet cell hyperplasia and damage to the airway epithelium of both NK 3 −/− mice and in wild type control mice (NK 3 +/+ ). There was no difference in the magnitude of these allergic inflammatory pulmonary responses between NK 3 −/− and NK 3 +/+ mice. These results find no role for tachykinin NK 3 -receptors on the pulmonary eosinophilia and lung damage after antigen challenge in mice.

Hypotonic stimulation induces airway constriction in normal and asthmatic airways. However, the osmolarity sensor in the airway has not been characterized. TRPV4 (also known as VR-OAC, VRL-2, TRP12, OTRPC4), an osmotic-sensitive cation channel in the transient receptor potential (TRP) channel family, was recently cloned. In the present study, we show that TRPV4 mRNA was expressed in cultured human airway smooth muscle cells as analyzed by RT-PCR. Hypotonic stimulation induced Ca2+influx in human airway smooth muscle cells in an osmolarity-dependent manner, consistent with the reported biological activity of TRPV4 in transfected cells. In cultured muscle cells, 4α-phorbol 12,13-didecanoate (4-αPDD), a TRPV4 ligand, increased intracellular Ca2+level only when Ca2+was present in the extracellular solution. The 4-αPDD-induced Ca2+response was inhibited by ruthenium red (1 μM), a known TRPV4 inhibitor, but not by capsazepine (1 μM), a TRPV1 antagonist, indicating that 4-αPDD-induced Ca2+response is mediated by TRPV4. Verapamil (10 μM), an L-type voltage-gated Ca2+channel inhibitor, had no effect on the 4-αPDD-induced Ca2+response, excluding the involvement of L-type Ca2+channels. Furthermore, hypotonic stimulation elicited smooth muscle contraction through a mechanism dependent on membrane Ca2+channels in both isolated human and guinea pig airways. Hypotonicity-induced airway contraction was not inhibited by the L-type Ca2+channel inhibitor nifedipine (1 μM) or by the TRPV1 inhibitor capsazepine (1 μM). We conclude that functional TRPV4 is expressed in human airway smooth muscle cells and may act as an osmolarity sensor in the airway.

We have previously reported on a model of lipopolysaccharide (LPS)-induced pulmonary inflammation in rats, where LPS-challenged animals develop a significant pulmonary neutrophilia and mucus hypersecretion. In the current studies, we utilized whole body plethysmography and computer assisted data acquisition to examine changes in pulmonary parameters, e.g. frequency (f) tidal volume and Penh as a measure of bronchoconstriction, due to LPS-challenge in conscious rats. Compared to saline challenge, LPS-challenged rats displayed a significant increase in (f) which began within 30 min, peaked by 2 h and remained elevated up to 24 h. Mirroring this increase in (f) was a decrease in the observed tidal volume of LPS-challenged rats. Additionally, compared to saline challenge, LPS-challenge provoked a significant and spontaneous bronchoconstriction, as measured by Penh, 2 h after challenge. In order to further understand these observed LPS-induced pulmonary changes, we utilized two classes of pulmonary obstructive disease standards, namely, bronchodilators and anti-inflammatory agents, and examined their ability to affect the spontaneous bronchoconstriction and the increase in (f) seen at two discrete time points, i.e. 2 and 24 h after LPS-challenge. While ineffective on either the 2 h increase in (f) or the LPS-induced inflammation, animals pretreated with salbutamol (10 mg/kg, p.o.) were protected from the increase in (f) seen at the 24 h time point after LPS-challenge. In contrast, when animals were pretreated with theophylline (10 mg/kg, p.o.) no effect on the LPS-induced pulmonary inflammation or increase in (f) was noted. Meanwhile, in animals pretreated with either betamethasone (3 mg/kg, p.o.) or SB207499 (10 mg/kg, p.o.), a PDE4 inhibitor, doses previously shown to block the LPS-induced neutrophilic inflammation, the persistent increase in (f) seen at 24 h was attenuated, but neither compound was able to attenuate either the increase in (f) or the spontaneous bronchoconstriction seen at 2 h. In summary, the intra-tracheal LPS-challenge of rats results in pulmonary inflammation and dysfunction, which is similar to that seen in COPD patients. We conclude that the early increase in (f) and bronchoconstriction are not dependent upon airway inflammation, but airway inflammation most likely contributes to the persistent increase in (f) seen at 24 h.

Among the three isoenzymes of neuraminidase (Neu) or sialidase, Neu-1 has been suggested to be induced by cell activation and to be involved in IL (interleukin)-4 biosynthesis in murine T-cells. In the present study, we found that antigen-induced airway eosinophilia, a typical response dependent on Th2 (T-helper cell type 2) cytokines, as well as mRNA expression of Th2 cytokines, including IL-4, are suppressed in Neu-1-deficient mice, thereby demonstrating the in vivo role of murine Neu-1 in regulation of Th2 cytokines. To elucidate the roles of various sialidases in human T-cell activation, we investigated their tissue distribution, gene induction and function. Neu-1 is the predominant isoenzyme at the mRNA level in most tissues and cells in both mice and humans, including T-cells. T-cells also have significant levels of Neu-3 mRNAs, albeit much lower than those of Neu-1, whereas the levels of Neu-2 mRNAs are minimal. In human T-cells, both Neu-1 and Neu-3 mRNAs are significantly induced by T-cell-receptor stimulation, as is sialidase activity against 4-methylumbelliferyl- N -acetylneuramic acid (a substrate for both Neu-1 and Neu-3) and the ganglioside G(D1a) [NeuAcalpha2-3Galbeta1-3GalNAcbeta1-4(NeuAcalpha2-3)Galbeta1-4Glcbeta1-cer] (a substrate for Neu-3, but not for Neu-1). The expression of the two sialidase genes may be under differential regulation. Western blot analysis and enzymic comparison with recombinant sialidases have revealed that Neu-3 is induced as a major isoform in activated cells. The induction of Neu-1 and Neu-3 in T-cells is unique. In human monocytes and neutrophils stimulated with various agents, the only observation of sialidase induction has been by IL-1 in neutrophils. Functionally, a major difference has been observed in Jurkat T-cell lines over-expressing Neu-1- and Neu-3. Upon T-cell receptor stimulation, IL-2, interferon-gamma, IL-4 and IL-13 are induced in the Neu-1 line, whereas in the Neu-3 line the same cytokines are induced, with the exception of IL-4. Taken together, these results suggest an important immunoregulatory role for both Neu-1 and Neu-3 in humans.

Previously, four splice variants of human cGMP-specific phosphodiesterase (PDE) 9A (PDEs 9A1, 9A2, 9A3 and 9A4) have been identified. In this study, we have cloned a cDNA representing a new human PDE9A variant (PDE9A5). PDE9A5 encodes a protein of 492 amino acids, smaller than PDEs 9A1 and 9A2 but larger than PDEs 9A3 and 9A4. The exon structure of PDE9A5 is different from those of PDEs 9A1, 9A2, 9A3 and 9A4 in that, of the 20 exons of PDE9A gene, it lacks exons 2 and 5. PDE9A5 has been characterized in comparison with PDE9A1, the longest PDE9A variant. PDEs 9A5 and 9A1 have similar enzymatic properties. They both have a high affinity for cGMP with similar Km values (0.39 and 0.25 μM, respectively), although they have slightly different Vmax values (2.55 and 0.96 μmol/min/mg, respectively). They exhibit very similar divalent metal ion dependency and inhibitor sensitivity. Real-time quantitative PCR analysis shows that PDEs 9A5 and 9A1 exhibit differential tissue distribution. They are highly expressed in immune tissues (spleen, lymph node and thymus) and are more abundant in T cells than in B cells, neutrophils and monocytes. When transiently expressed in HEK293 cells, PDEs 9A5 and 9A1 proteins exhibit differential subcellular localization. PDE9A5 localizes exclusively in the cytoplasm, whereas PDE9A1 localizes in the nucleus only. The nuclear localization of PDE9A1 is dependent on a unique pat7 motif. By Western blot analysis, native PDE9A1 is detectable in the nucleus but not in the cytoplasm of T cells. Thus, to our knowledge, PDE9A1 is the only PDE isoform found to localize exclusively in the nucleus. We speculate that the physiological role of the PDE9A diversity may be imparting cGMP-metabolizing ability to specific cellular compartments in appropriate tissues.

We present the pharmacological and pharmacokinetic profiles of a novel histamine H3 receptor antagonist, N-(3,5-dichlorophenyl)-N′-[[4-(1H-imidazol-4-ylmethyl)phenyl]-methyl]-urea (SCH 79687). The H3-receptor binding Ki values for SCH 79687 were 1.9 and 13 nM in the rat and guinea pig (GP), respectively. The Ki values for SCH 79687 at histamine H1 and H2 receptors were greater than 1 μM. SCH 79687 showed a 41- and 82-fold binding selectivity for the H3 receptor over α2A-adrenoceptors and imidazoline I2, and >500-fold H3 selectivity compared with over 60 additional receptors. The pA2 value for SCH 79687 in the GP ileum electrical field-stimulated (EFS) contraction was 9.6 ± 0.3. Similar H3 antagonist activity was observed in the EFS cryopreserved and fresh tissue isolated human saphenous vein (HSV) assays (pKb = 9.4 ± 0.3 and 10.1 ± 0.4). SCH 79687 (30 nM) did not block clonidine-induced inhibition of EFS-induced contractions in HSV. SCH 79687 (ED50 = 0.3 mg/kg i.v.) attenuated (R)-α-methylhistamine inhibition of sympathetic hypertensive responses in the GP. At the time of activity evaluation, the GP plasma SCH 79687 concentration was 25 ng/ml at the dose of 0.3 mg/kg i.v. In feline nasal studies, combined administration of SCH 79687 (3 mg/kg i.v.) and the H1-antagonist loratadine (3 mg/kg i.v.), at individual doses that do not produce decongestion, inhibited the compound 48/80-induced congestion by 47%. The α-adrenergic agonist phenylpropanolamine (PPA; 1 mg/kg i.v.) also attenuated compound 48/80 nasal responses by 42%. Unlike the H3/H1 combination that did not affect blood pressure (BP), PPA (1 mg/kg i.v.) significantly increased BP compared with control animals by a maximum of 31 mm Hg. Orally, SCH 79687 (10 mg/kg) plus loratadine (10 mg/kg) also produced decongestion without effects on BP. In pharmacokinetic studies, oral dosing with SCH 79687 in the rat (10 mg/kg) and monkey (3 mg/kg) achieved plasma Cmax and area under the curve values greater than 1.5 and 12.1 μg · h/ml, respectively. SCH 79687 is an orally active H3 antagonist with a good pharmacokinetic profile that, in combination with an H1 antagonist, demonstrates decongestant efficacy comparable with oral sympathomimetic decongestants but without hypertensive liabilities.

Study of the CC chemokine receptor 3 (CCR3) has been limited to using radiolabeled agonist chemokines. A small molecule CCR3 antagonist, 2-[(6-amino-2-benzothiazolyl)thio]-N-[1-[(3,4-dichlorylphenyl)methyl]-4-piperidinyl]acetamide, Banyu (I), was tritiated and used for pharmacological studies. Banyu (I) has a K(d) of 5.0+/-0.4 and 4.3+/-1.8 nM on human CCR3 transfectants and eosinophils, and noncompetitively inhibits [125I]eotaxin binding and eotaxin-induced [35S]guanosine-5'-O-(3-thiotriphosphate) ([35S]GTPgammaS) binding. The proportion of [125I]eotaxin: [3H]Banyu (I) binding sites in eosinophils or transfectants was 35% or 13%, although both binding sites were overexpressed in transfectants. CCR3 spontaneously couples to G-proteins in CCR3 transfectants, demonstrated by changes in basal and eotaxin-induced [35S]GTPgammaS binding under reduced NaCl and GDP concentrations. Consequently, Banyu (I) was identified as an inverse agonist. In contrast, CCL18 and I-TAC (interferon-inducible T cell alpha-chemoattractant) were neutral antagonists, inhibiting eotaxin-induced [35S]GTPgammaS binding, with minimal effect on basal coupling of CCR3 to G proteins. Eotaxin, eotaxin-2 and monocyte chemoattractant protein (MCP)-4 are full agonists inducing [35S]GTPgammaS binding; eotaxin-3, MCP-3, RANTES (regulated on activation normal T cell expressed and secreted), vMIP-I (Kaposi's sarcoma-associated herpesvirus macrophage inflammatory protein-) and vMIP-II are partial agonists, indicating that this is a sensitive method to quantitate agonist efficacy.

1. Endogenous neuronal lipid mediator anandamide, which can be synthesized in the lung, is a ligand of both cannabinoid (CB) and vanilloid receptors (VR). The tussigenic effect of anandamide has not been studied. The current study was designed to test the direct tussigenic effect of anandamide in conscious guinea-pigs, and its effect on VR1 receptor function in isolated primary guinea-pig nodose ganglia neurons. 2. Anandamide (0.3-3 mg.ml(-1)), when given by aerosol, induced cough in conscious guinea-pigs in a concentration dependent manner. When guinea-pigs were pretreated with capsazepine, a VR1 antagonist, the anandamide-induced cough was significantly inhibited. Pretreatment with CB1 (SR 141716A) and CB2 (SR 144528) antagonists had no effect on anandamide-induced cough. These results indicate that anandamide-induced cough is mediated through the activation of VR1 receptors. 3. Anandamide (10-100 micro M) increased intracellular Ca(2+) concentration estimated by Fluo-4 fluorescence change in isolated guinea-pig nodose ganglia cells. The anandamide-induced Ca(2+) response was inhibited by two different VR1 antagonists: capsazepine (1 micro M) and iodo-resiniferatoxin (I-RTX, 0.1 micro M), indicating that anandamide-induced Ca(2+) response was through VR1 channel activation. In contrast, the CB1 (SR 141716A, 1 micro M) and CB2 (SR 144528, 0.1 micro M) receptor antagonists had no effect on Ca(2+) response to anandamide. 4. In conclusion, these results provide evidence that anandamide activates native vanilloid receptors in isolated guinea-pig nodose ganglia cells and induces cough through activation of VR1 receptors.

Experiments were performed to characterize the pharmacology of SCH 206272 [(R,R)-1'[5-[(3,5-dichlorobenzoyl)methylamino]-3-(3,4-dichlorophenyl)-4(Z)-(methoxyimino)pentyl]-N-methyl-2-oxo-[1,4'bipiperidine]-3-acetamide] as a potent and selective antagonist of tachykinin (NK) NK(1), NK(2), and NK(3) receptors. SCH 206272 inhibited binding at human tachykinin NK(1), NK(2), and NK(3) receptors (K(i) = 1.3, 0.4, and 0.3 nM, respectively) and antagonized [Ca(2+)](i) mobilization in Chinese hamster ovary (CHO) cells expressing the cloned human tachykinin NK(1), NK(2), or NK(3) receptors. SCH 206272 inhibited relaxation of the human pulmonary artery (pK(b) = 7.7 +/- 0.3) induced by the tachykinin NK(1) receptor agonist, [Met-O-Me] substance P and contraction of the human bronchus (pK(b = 8.2 +/- 0.3) induced by the tachykinin NK(2) receptor agonist, neurokinin A. In isolated guinea pig tissues, SCH 206272 inhibited substance P-induced enhancement of electrical field stimulated contractions of the vas deferens, (pK(b = 7.6 +/- 0.2), NKA-induced contraction of the bronchus (pK(b) = 7.7 +/- 0.2), and senktide-induced contraction of the ileum. In vivo, oral SCH 206272 (0.1-10 mg/kg, p.o.) inhibited substance P-induced airway microvascular leakage and neurokinin A-induced bronchospasm in the guinea pig. In a canine in vivo model, SCH 206272 (0.1-3 mg/kg, p.o.) inhibited NK(1) and NK(2) activities induced by exogenous substance P and neurokinin A. Furthermore, in guinea pig models involving endogenously released tachykinins, SCH 206272 inhibited hyperventilation-induced bronchospasm, capsaicin-induced cough, and airway microvascular leakage induced by nebulized hypertonic saline. These data demonstrate that SCH 206272 is a potent, orally active tachykinin NK(1), NK(2), and NK(3) receptor antagonist. This compound may have beneficial effects in diseases thought to be mediated by tachykinins, such as cough, asthma, and chronic obstructive pulmonary disease.

We have characterized desloratadine (5 H -benzo[5,6]cyclohepta[1,2- b ]pyridine, 8-chloro-6,11-dihydro-11-(4-piperidinylidene), CAS 100643-71-8) as a potent antagonist of the human histamine H 1 receptor. [ 3 H]Desloratadine bound to membranes expressing the recombinant human histamine H 1 receptor in Chinese hamster ovary cells (CHO-H 1 ) in a specific and saturable manner with a K d of 1.1±0.2 nM, a B max of 7.9±2.0 pmol/mg protein, and an association rate constant of 0.011 nM −1 min −1 . The K d calculated from the kinetic measurements was 1.5 nM. Dissociation of [ 3 H]desloratadine from the human histamine H 1 receptor was slow, with only 37% of the binding reversed at 6 h in the presence of 5 μM unlabeled desloratadine. Seventeen histamine H 1 -receptor antagonists were evaluated in competition-binding studies. Desloratadine had a K i of 0.9±0.1 nM in these competition studies. In CHO-H 1 cells, histamine stimulation resulted in a concentration-dependent increase in [Ca 2+ ] i with an EC 50 of 170±30 nM. After a 90-min preincubation with desloratadine, the histamine-stimulated increase in [Ca 2+ ] i was shifted to the right, with a depression of the maximal response at higher concentrations of antagonist. The apparent K b value was 0.2±0.14 nM with a slope of 1.6±0.1. The slow dissociation from the receptor and noncompetitive antagonism suggests that desloratadine may be a pseudoirreversible antagonist of the human histamine H 1 receptor. The mechanism of desloratadine antagonism of the human histamine H 1 receptor may help to explain the high potency and 24-h duration of action observed in clinical studies.

Asthma is a common respiratory disorder characterized by recurrent episodes of coughing, wheezing and breathlessness. Although environmental factors such as allergen exposure are risk factors in the development of asthma, both twin and family studies point to a strong genetic component1,2. To date, linkage studies have identified more than a dozen genomic regions linked to asthma3. In this study, we performed a genome-wide scan on 460 Caucasian families and identified a locus on chromosome 20p13 that was linked to asthma (log10 of the likelihood ratio (LOD), 2.94) and bronchial hyperresponsiveness (LOD, 3.93). A survey of 135 polymorphisms in 23 genes identified the ADAM33 gene4 as being significantly associated with asthma using case-control, transmission disequilibrium and haplotype analyses (P = 0.04–0.000003). ADAM proteins are membrane-anchored metalloproteases with diverse functions, which include the shedding of cell-surface proteins such as cytokines and cytokine receptors5. The identification and characterization of ADAM33, a putative asthma susceptibility gene identified by positional cloning in an outbred population, should provide insights into the pathogenesis and natural history of this common disease.

Cough is an important defensive pulmonary reflex that removes irritants, fluids or foreign materials from the airways. However, often cough is non-productive and requires suppression. Opioid mu receptor agonists, such as codeine are commonly used as antitussive agents and are among the most widely administered drugs in the world. Codeine suppresses the responsiveness of one or more components of the central reflex pathway for cough and is an efficacious antitussive drug for cough due to diverse aetiologies. However, opioids produce side effects that include sedation, addiction potential and constipation. Therefore, novel cough suppressant therapies should maintain or improve upon the antitussive efficacy profile of opioids. Moreover, these novel therapies should have a safety profile significantly better than current antitussive therapies. Presently, we discuss preclinical findings showing that activation of the 'opioid-like' receptor (NOP(1)) inhibits cough in the guinea pig and cat.

Background: The role of IL-5–induced eosinophilia in airway hyperresponsiveness has been questioned. In addition, eosinophil-independent IL-5–induced airway hyperresponsiveness has been demonstrated in animals. Objective: In this study, IL-5 was investigated for direct effects on human bronchial responsiveness. Methods: Human muscle preparations were isolated from organ donor and surgical tissue. Bronchus, jejunum, and saphenous vein were incubated for 24 hours in vitro with recombinant human (rh) IL-5. Contractility to acetylcholine (bronchus, jejunum) and phenylephrine (saphenous vein) was then investigated. RT-PCR was used to evaluate IL-5 receptor α (IL-5Rα) expression in various tissues and to assess bronchus and saphenous vein eosinophils through use of CCR3 expression. Results: rhIL-5 primed bronchus for an exaggerated contraction to acetylcholine. The acetylcholine concentration that produced 50% of the control maximum response was reduced 17- to 20-fold in bronchus treated with 1 and 10 nmol/L rhIL-5. The lower concentration of 0.1 nmol/L rhIL-5 had no effect. The rhIL-5 effect on bronchial contractility was attenuated by antibodies to IL-5 (TRFK-5; 100 nmol/L) and human IL-5Rα (100 nmol/L). rhIL-5 (10 nmol/L) did not enhance contractility of saphenous vein or jejunum. When RT-PCR was used, IL-5Rα expression was strong in bronchus muscle, weak in trachealis, saphenous vein, and atrial muscle, and undetectable in jejunum, urinary bladder, and pulmonary and renal artery muscle. Comparable weak expression of CCR3 was identified in bronchus and saphenous vein. Conclusion: The findings are consistent with an airway tissue–selective expression of the IL-5 receptor that mediates IL-5–induced airway hyperresponsiveness independent of eosinophils. In asthma, in which IL-5 expression is elevated, IL-5 might directly induce bronchial hyperresponsiveness. (J Allergy Clin Immunol 2002;109:404-9.)

Background We have recently demonstrated that the transfer of interleukin (IL)-5-producing CD4 + T cell clones into unprimed mice is sufficient for the development of eosinophilic inflammation in the bronchial mucosa upon antigen inhalation. Objective The aim of this study was to elucidate the possible contribution of mast cells in eosinophilic inflammation and bronchial hyper-responsiveness (BHR), and to discriminate between the roles of CD4 + T cells and mast cells. Methods Mast cell-deficient mice (WBB6F1-W/W v ) and their congenic normal littermates (WBB6F1-+/+) were immunized with ovalbumin and challenged by inhalation with the relevant antigen. Results Airway eosinophilia was induced with equivalent intensity in +/+ and W/W v mice 6, 24, 96 and 216 h after antigen inhalation. In contrast, 48 h after antigen challenge, eosinophilic infiltration into the bronchial mucosa was significantly less pronounced in W/W v mice than in +/+ mice. Anti-CD4 monoclonal antibody (mAb), anti-IL-5 mAb, and cyclosporin A were administered next, demonstrating that the airway eosinophilia of W/W v mice induced 48 h after antigen challenge was almost completely inhibited by each of these three treatments, but that of +/+ mice was significantly less susceptible. Bronchial responsiveness to acetylcholine was increased 48 h after antigen challenge and was not significantly different between +/+ and W/W v mice. Administration of anti-IL-5 mAb completely inhibited the development of BHR in both +/+ and W/W v mice. Conclusion These results indicate that, in mice, mast cells do have a supplemental role in the development of pulmonary eosinophilia but not BHR. CD4 + T cells totally regulate these responses by producing IL-5.

Interleukin (IL)-9 is a T-cell-derived cytokine with pleiotropic activities on T helper 2 cells, B cells, and mast cells. IL-9 may therefore play an important role in the development of allergic pulmonary inflammatory diseases. In this study, an antimouse IL-9 (anti-mIL-9) antibody (Ab) was evaluated against pulmonary eosinophilia, histopathologic changes in lung tissues, serum immunoglobulin (Ig) E levels, and airway hyperresponsiveness (AHR) to methacholine in mice sensitized and challenged with ovalbumin (OVA). Additionally, steady-state levels of IL-4, IL-5, IL-13, and interferon-gamma messenger RNA (mRNA) in the lungs were measured. The anti-mIL-9 Ab (200 microg/mouse, intraperitoneally) was given as either four doses during the sensitization period or as a single dose before OVA challenge. Sensitized mice challenged with OVA displayed marked pulmonary eosinophilia, epithelial damage, and goblet cell hyperplasia. OVA challenge also increased mRNA levels of IL-4, IL-5, and IL-13 in the lungs. AHR was also increased twofold in sensitized, challenged mice. Treatment of sensitized, challenged mice with four doses of anti-mIL-9 Ab significantly reduced pulmonary eosinophilia, serum IgE levels, goblet cell hyperplasia, airway epithelial damage, and AHR, but had no effect on IL-4, IL-5, and IL-13 mRNA levels in the lungs. A single dose of the antibody was ineffective on all measures. These results indicate that an antibody to mIL-9 inhibits the development of allergic pulmonary inflammation and AHR in mice.

Introduction: This study describes a method to measure the cough reflex in dogs that is simple to perform, requires no surgical intervention, and can be used to profile efficacy and side effect liabilities of antitussive drugs. Methods: Experiments were performed in propofol-anesthetized dogs in which cardiopulmonary functions were noninvasively monitored before and after the induction of cough produced by spraying 0.75 ml of distilled water into the trachea. Results: The magnitude of the cough response, measured by the frequency and amplitude, was not different for individual dogs performed with repeated trials on different days. Treatment with the opioid antitussive drug, torbutrol (0.055–0.0055 mg/kg sc), inhibited the cough frequency but not the amplitude induced by the water challenge. Furthermore, side effects of torbutrol were identified as mild respiratory depression and an anesthetic-sparing effect with propofol. Discussion: This method offers many distinct advantages to evaluate efficacy of antitussive drugs including the fact that no surgery is required, it takes only 15–20 min to complete an experiment, and it can be used to simultaneously profile antitussive and side effect liabilities of drugs developed for the treatment of cough.

Mast cell histamine (HA) and cysteinyl leukotrienes (CysLT) account for most of the early phase bronchospasm in asthma. However, activation of the smooth muscle CysLT1-receptor plays a major role in asthmatic bronchospasms. CysLT-receptor antagonists or CysLT-synthesis inhibitors are efficacious in asthma but do not completely abolish asthmatic bronchospasms. A recent clinical study showed that combined antagonists loratadine (H1) and zafirlukast (CysLT1) were more effective against allergic bronchospasms than either drug alone. We examined the combined efficacy of H1- and CysLT1-receptor antagonists in allergic human bronchus. The H1- and CysLT1-receptor antagonists chlorpheniramine (CTM; 1 microM) and MK-571 (0.03 microM), were tested alone and in combination, against anti-human IgE antibody (Ab)-induced contractions of passively sensitized isolated human bronchus. Ab-induced allergic contractions were reduced 15% and 36% by CTM (1 microM) and MK-571 (0.03 microM), respectively. Combined CTM (1 microM) and MK-571 (0.03 microM) significantly inhibited the Ab response by 87%. Mechanistic investigations in isolated human bronchus and cultured human cord blood mast cells suggest that H1- and CysLT-receptor interactions likely occur at the airway smooth muscle level. CTM and MK-571 synergistically inhibited human allergic bronchospasm in the present in vitro model. The mechanism underlying this synergistic activity requires further investigation.

We studied the central and peripheral antitussive effect of ORL1 receptor activation with nociceptin/orphanin FQ in conscious guinea-pigs. In guinea-pig cough studies, nociceptin/orphanin FQ (10, 30, and 90 μg) given directly into the CNS by an intracerebroventricular (i.c.v.) route inhibited cough elicited by capsaicin exposure by approximately 23, 29 and 52%, respectively. The antitussive activity of nociceptin/orphanin FQ (90 μg, i.c.v.) was blocked by the selective ORL1 antagonist [Phe1γ(CH2-NH)Gly2]nociceptin-(1-13)-NH2 (180 μg, i.c.v.) and J113397 (10 mg kg−1, i.p.) but not by the opioid antagonist, naltrexone (3 mg kg−1, i.p.). Furthermore, intravenous (i.v.) nociceptin/orphanin FQ (1.0 and 3.0 mg kg−1) also inhibited cough approximately by 25 and 42%, respectively. These findings indicate that selective ORL1 agonists display the potential to inhibit cough by both a central and peripheral mechanism, and potentially represent a novel therapeutic approach for the treatment of cough. British Journal of Pharmacology (2001) 132, 1175–1178; doi:10.1038/sj.bjp.0703954

Nonselective adrenergic α-agonists such as phenylpropanolamine and d-pseudoephedrine are widely used as decongestants to treat nasal congestion associated with a variety of nasal diseases. Although the activity of these drugs is well established in clinical studies, a direct comparison of their nasal decongestant effect as determined by changes in nasal cavity dimensions and nasal architecture has not been studied. Using acoustic rhinometry, we evaluated the effects of these drugs on nasal cavity volume, minimum cross-sectional area (Amin), and the distance from the nosepiece to the Amin (Dmin) in a feline, pharmacological model of nasal congestion. Administration of topical compound 48/80 (1%), a mast cell histamine liberator, into the left nasal passageway decreased nasal volume by 66%, reduced Amin by 51%, and increased Dmin by 116%. The congestive responses to compound 48/80 (1%) were reproducible through six weeks. In a subset of cats, the nasal cavity volume effect of repetitive exposure to compound 48/80, given once every two weeks for six weeks, was not different from the nasal responses after the initial exposure to compound 48/80. Pretreatment with oral phenylpropanolamine (10 mg/kg) or oral d-pseudoephedrine (10 mg/kg) attenuated the nasal effects of compound 48/80, but were associated with a pronounced increase in systolic blood pressure of +51 and +82 mmHg, respectively. A similar decongestant profile was observed with phenylpropanolamine (1%) and d-pseudoephedrine (1%) when given topically. Topical phenylpropanolamine (1%) and d-pseudoephedrine (1%) 45 minutes after dosing increased blood pressure +44 and +17 mmHg, respectively, over control animals. We conclude that oral and topical phenylpropanolamine and d-pseudoephedrine display equieffective nasal decongestant activity and produce similar cardiovascular profiles characterized by significant increases in blood pressure.

The relationship between CD4(+) T cell-mediated airway eosinophilic inflammation and bronchial hyper-responsiveness (BHR) was investigated. Ovalbumin-reactive T(h)0 clones were adoptively transferred to unprimed BALB/c mice and then the mice were challenged by inhalation of the relevant antigen. Upon antigen provocation, infused T(h) clones infiltrated into the airways, followed by the accumulation and degranulation of eosinophils, goblet cell hyperplasia, edema and increase in bronchial responsiveness to acetylcholine. Transfer of several clones that differed in the levels of IL-5 production revealed that the magnitude of in vivo eosinophilia strongly correlated with the IL-5-producing capacity of the infused T(h) clones. Administration of anti-IL-5 mAb almost completely suppressed antigen-induced eosinophilic inflammation and BHR. Administration of anti-IL-4 mAb or anti-IFN-gamma mAb enhanced the eosinophilia and BHR, whereas anti-IL-2 mAb did not affect them. The number of accumulated eosinophils significantly correlated with the intensity of BHR. Our present results clearly demonstrated that CD4(+) T cells induced BHR as a result of eosinophilic inflammation. IL-5 totally regulated both responses.

Human interleukin (IL)-5 gene transcription is regulated by several transcription factor binding sites, including CLE 0, GATA, and a region from position -123 to -92 known as response element (RE)-II. By expression cloning, a partial protein was identified that bound to concatamers of RE-II. Recombinant protein derived from this initial complementary DNA (cDNA) encoding the partial protein specifically bound to RE-II-containing oligonucleotides in electromobility shift assays. The complete sequence (3,649 bp) was determined by 5' rapid amplification of cDNA ends and comparisons to existing ESTs, and found to be identical to the 3' half of Wolf-Hirschhorn syndrome candidate 1, (WHSC1; also known as Multiple Myeloma SET domain [MMSET]). The full-length protein contains an SET domain and two plant homeodomain-type zinc fingers. Transcription initiation of RE-II binding protein (RE-IIBP) messenger RNA (mRNA) uniquely occurred within the middle of WHSC1 near a region that exhibits complex mRNA splicing. RE-IIBP reactive polyclonal antisera identified proteins in human T-cell nuclear protein extracts of 62 and 66 kD that were consistent with the length of the longest open reading frame in RE-IIBP. In contrast, WHSC1 is predicted to encode a protein of 136 kD. In activated human Jurkat and murine D10.G4.1 T cells, expression of full-length and truncated forms of RE-IIBP repressed RE-II promoter activity of a 5X-RE-II luciferase reporter construct by as much as 75%. In addition, RE-IIBP expressed in activated D10.G4.1 T cells inhibited endogenous murine IL-5 production. The repressor activity of RE-IIBP is consistent with the presence of an SET domain that is found in other proteins that act as gene silencers.

Here we determine for norepinephrine, (5-bromo-6-(2-imidazolin-2-ylamino)quinoxaline) (UK14,304), 5,6,7,8-tetrahydro-6-(2-propenyl)-4 H -thiazolo[4,5- d ]azepin-2-amine dihydrochloride (BHT-920), (2-[3-hydroxy-2,6-dimethyl-4- t -butylbenzyl]-2-imidazoline) (oxymetazoline), and (( R )-3-Hydroxy-α-[(methylamino)methyl]-benzenemethanol hydrochloride) (phenylephrine), affinities using a radiolabeled agonist and antagonist, and potency and efficacy values in membrane [ 35 S]guanosine-5′- O -(3-thiotriphosphate) ([ 35 S]GTPγS) binding and cAMP cellular inhibition assays, in Chinese hamster ovary cells (CHO-K1) expressing the human α 2c -adrenoceptor. These cells express a high ratio of receptor to G-protein because each agonist, but not several antagonists, displaced [ 3 H]UK14,304 with higher affinity than [ 3 H]rauwolscine. The rank order of potency of high affinity K i and EC 50 in both functional assays was norepinephrine ≥UK14,304>BHT-920>oxymetazoline>phenylephrine. The receptor reserve of G-protein activation and cAMP responses was measured with the irreversible antagonist, benextramine; K A values of norepinephrine or UK14,304 were similar (289, 271 or 150, 163 nM, respectively). A 20-fold greater receptor occupancy was required for agonist-induced half-maximal [ 35 S]GTPγS binding compared to cAMP inhibition, indicating significant signal amplification in cells. Therefore, the G-protein activation assay is better at distinguishing full and partial agonists.

The isolated perfused guinea pig lung was used to investigate the effect of nociceptin against bronchoconstriction elicited by endogenous and exogenous tachykinins. The opioid receptor-like 1 (ORL1) receptor agonist, nociceptin/orphanin FQ (0.001-1 microM) produced a dose-related inhibition of the capsaicin-induced bronchoconstriction (10(-5)-10(3) microg) in isolated guinea pig lung (P

A novel pharmacological study of CCR3 receptor reserve in a CCR3-transfected cell (CREM3) and human eosinophils was done; functional responses measured were increases in intracellular calcium and chemotaxis. Eotaxin, eotaxin-2, monocyte chemoattractant protein-4 (MCP-4), RANTES, and MCP-3 induced similar maximal eosinophil chemotaxis, whereas MCP-3 and RANTES induced submaximal calcium responses in eosinophils compared to eotaxin, MCP-4, and eotaxin-2. This suggested a receptor reserve in the chemotaxis response. Receptor reserve was quantitated for eotaxin. Occupancy of all CCR3 receptors was required for a maximal calcium response in both CREM3 and eosinophils (reserve = 1.0 or 0.17, respectively); the stimulus-calcium response relationship was linear, indicating no receptor reserve. In contrast, in eosinophils a large receptor reserve (6.5) was found for chemotaxis, where occupancy of 15% receptors drove half-maximal responses. These studies indicate that CCR3 interacts with G-proteins that are poorly coupled to the calcium response, whereas coupling efficiency and/or amplification to the chemotaxis apparatus in human eosinophils is significantly greater. J. Leukoc. Biol. 67: 441–447; 2000.

Several small molecule non-peptide antagonists of the NK-1 and NK-2 receptors have been developed. Mutational analysis of the receptor protein sequence has led to the conclusion that the binding site for these non-peptide antagonists lies within the bundle created by transmembrane domains IV-VII of the receptor and differs from the binding sites of peptide agonists and antagonists. The current investigation uses site-directed mutagenesis of the NK-1 and NK-2 receptors to elucidate the amino acids that are important for binding and functional activity of the first potent dual NK-1/NK-2 antagonist MDL103,392. The amino acids found to be important for MDL103,392 binding to the NK-1 receptor are Gln-165, His-197, Leu-203, Ile-204, Phe-264, His-265 and Tyr-272. The amino acids found to be important for MDL103,392 binding to the NK-2 receptor are Gln-166, His-198, Tyr-266 and Tyr-289. While residues in transmembrane (TM) domains IV and V are important in both receptors (Gln-165/166 and His-197/198), residues in TM V and VI are more important for the NK-1 receptor and residues in TM VII play a more important role in the NK-2 receptor. These data are the first report of the analysis of the binding site of a dual tachykinin receptor antagonist and indicate that a single compound (MDL103,392) binds to each receptor in a different manner despite there being a high degree of homology in the transmembrane bundles. In addition, this is the first report in which a model for the binding of a non-peptide antagonist to the NK-2 receptor is proposed.

Identification of chemokine receptors and their associated ligands is crucial to the understanding of most immune reactions. Three human chemokines [I-309, thymus and activation-regulated chemokine (TARC) and macrophage inflammatory protein-1beta (MIP-1beta)] have been reported to be ligands for CC-chemokine receptor 8 (CCR8). In this report, we present evidence that TARC and MIP-1beta did not bind to or induce chemotaxis through CCR8 on a stable transfected cell line (1D-21) and did not bind to CCR8 on in vitro differentiated human CD4(+) Th(2) cell cultures. Also, I-309-dependent calcium mobilization in 1D-21 cells and in Th(2) cells was desensitized by I-309 but not by MIP-1beta or TARC. These results provide strong evidence that, at physiologically relevant concentrations, I-309 is the only known human ligand for CCR8. These data also provide a framework for suggesting minimum requirements for the assignment of chemokine receptor-ligand pairs.

We studied the pharmacological actions of combined histamine H1/H3 receptor blockade on the increase in nasal airway resistance (NAR) and decrease in nasal cavity volume produced by nasal exposure to compound 48/80, a mast cell degranulator. In the anesthetized cat compound 48/80 (1%) produced a maximum increase in NAR of 9.1 ± 0.7 cmH20·L/minute. The increase in NAR in animals pretreated with a combination of the H1 antagonist, chlorpheniramine (CTM; 0.8 mg/kg i.v.) and increasing doses of the H3 antagonist, thioperamide (THIO; 1.0, 3.0, and 10.0 mg/kg i.v.) were 6.1 ± 2.1, 4.2 ± 1.0 and 2.2 ± 0.7 cmH20·L/minute, respectively. A second H3 antagonist, clobenpropit (CLOB; 0.03, 0.3, and 1.0 mg/kg i.v.) combined with CTM (0.8 mg/kg i.v.) also inhibited the nasal effects of compound 48/80. When the nonsedating H1 antihistamine, loratadine (3.0 mg/kg i.v.), was substituted for CTM, it also reduced nasal congestion when given in combination with THIO (10 mg/kg i.v.). In contrast, treatment with CTM (1.0 mg/kg i.v.) and the H2 antagonist, ranitidine (RAN; 1.0 mg/kg i.v.) were without activity. Loratadine, CTM, CLOB, RAN, or THIO administered alone were inactive. The α-adrenergic agonist, phenylpropanolamine (PPA; 1.0 mg/kg i.v.) demonstrated decongestant effects, but in contrast to H1/H3 blockade, PPA produced a significant hypertensive effect. Using acoustic rhinometry (AcR) we found that combined i.v. CTM (1.0 mg/kg) and THIO (10 mg/kg) and combined oral CTM (10 mg/kg) and THIO (30 mg/kg) blocked the decrease in nasal cavity volume produced by intranasal compound 48/80 (1%, 50 μL). We conclude that combined H1/H3 histamine receptor blockade enhances the efficacy of an H1 antagonist by conferring decongestant activity to the H1 antihistamine. We propose that the decongestant activity of combined H1/H3 blockade may provide a novel approach for the treatment of allergic nasal congestion without the hypertensive liability of current therapies.

Characterization of the histamine H3 receptor in rodent species has been extensive but limited characterization has been done with primate or human tissue. We have characterized the binding of [ 3 H ]N∝-methylhistamine to cynomolgus monkey and human brain membranes to determine whether there are any significant differences among species' pharmacology. In monkey, [ 3 H ]N∝-methylhistamine bound, in a guanine nucleotide-sensitive fashion, to an apparently homogeneous class of sites at equilibrium (KD=1.4 nM, Bmax=34 fmol/mg protein). The profile of binding was broadly similar to that of rodents, with a couple of significant differences. Most notably, the potency of the histamine H3-receptor-specific antagonist thioperamide (Ki=240 nM) was substantially less than reported for rodents and under assay conditions that yield a two-site curve fit in rodents only a single class of thioperamide binding sites was detected in monkey. Burimamide, however, yielded a two-site curve fit (KiH=6.7 nM, KiL=1100 nM) independent of the presence of sodium in the assay, as it does in rodents. Characterization of the human brain histamine H3 receptor showed that it was similar to the monkey and not rodent receptor. Our findings indicate that differences between primate and rodent histamine H3 receptors of potentially serious importance for the discovery of antagonists active in humans do exist.

We compared the effects of cyclosporin A (CSA) and a macrotetrolide antibiotic, dinactin, on human T-cell proliferation and cytokine production induced by stimulation of the T-cell receptor alone (monoclonal antibody [mAb] directed against CD3) or in combination with costimulatory signals (mAbs directed against CD3 and CD28). These agents were also examined in a murine model of interleukin (IL)-5-mediated pulmonary inflammation. Dinactin inhibited T-cell proliferation induced by IL-2, by mAb to CD3, and by mAbs to CD3 plus alpha-CD28 with identical dose-response curves (IC50 = 10-20 ng/ml). Dinactin inhibited cytokine production with IC50 values of 10 ng/ml for IL-4 and IL-5 and 30 or 60 ng/ml for interferon-gamma or IL-2, respectively. Unlike CSA, exogenous IL-2 did not alter the dinactin-mediated effects on T cells, and nuclear run-on and steady-state messenger RNA (mRNA) analysis showed that dinactin inhibited cytokine production through a post-transcriptional mechanism. CSA selectively blocked T-cell receptor-induced T-cell proliferation and cytokine production (IC50 = 10 ng/ml). Under costimulatory conditions, IL-5 synthesis was only minimally inhibited by high concentrations of CSA, and at CSA concentrations of less than 125 ng/ml, IL-5 was significantly increased above control values. Dinactin and CSA reduced pulmonary eosinophilia when administered within 1 d of airway antigen challenge. Of the cytokine mRNAs examined in the lungs of CSA-pretreated, antigen-challenged mice, IL-5 mRNA levels were the least reduced, paralleling the resistance of IL-5 to CSA observed in vitro and suggesting a role for CD28 in the in vivo induction of IL-5.

The proximal mouse IL-5 promoter was examined using a mouse TH2 clone stimulated through the T cell receptor using anti-CD3 monoclonal antibody. DNase I protection defined four protein binding regions [IL-5RE-A, -69/-45; -B, (-90/-76); -C, (-154/-130); and -D (-176/-157)]. Stimulation-dependent binding, which was seen in the IL-5RE-B, -D regions and the 5' end of tIL-5RE-A, did not require new protein synthesis inhibitor during cell activation. EMSA using probes targeted to the IL-5RE-B, -C, -D regions demonstrated the multimeric nature of the bound proteins. By transfection analysis using a series of truncated IL-5 promoter-luciferase constructs, IL-5RE-C and -D contributed little to constitutive or inducible activity. The CLE0 site in the IL-5RE-A region contributed to full transcriptional activity but was not sufficient to mediate full activity. Full stimulation-dependent activity required the IL-5RE-B region and/or the GATA site (-70/-60).

Interleukin-5 (IL-5) is a potent eosinophilopoietic factor implicated in the chronic inflammatory cell accumulation accompanying bronchial asthma. However, its role in stimulating eosinophil differentiation within the bone marrow following allergen exposure remains to be elucidated. The aims of our study were to determine the expression of IL-5 within the bone marrow of sensitized and control mice after allergen exposure, and to investigate the cellular phenotype of IL-5-producing cells. Sensitized Balb/c mice were challenged with either ovalbumin (OVA) or sterile saline. After 6 h, the mice were exsanguinated and the bone marrow prepared for cytospins. Bone marrow-derived cells from OVA-sensitized mice exhibited an increase in IL-5 immunoreactivity and mRNA compared with those from nonsensitized control mice (p0. 05). After allergen challenge, there was a further increase in IL-5 expression (p0.05) within the bone marrow. Both sensitization and allergen challenge resulted in an increase in the number of cells expressing major basic protein (MBP) (p0.05). In nonsensitized mice, the IL-5 mRNA was expressed predominantly by CD34-positive (CD34+) progenitor cells. Following sensitization and allergen challenge, CD3-positive (CD3+) T lymphocytes were the major source of this cytokine. These results demonstrate the presence of IL-5 within the bone marrow of normal Balb/c mice. After sensitization and allergen challenge, the increase in IL-5-producing cells within the bone marrow is attributed by T lymphocytes.

Interleukin-5 (IL-5) transcriptional activation and mRNA stability were investigated in a human TH0 T-cell clone (SP-B21) and in nonclonal CD4 TH2 cells, differentiated in vitro from peripheral blood T cells. Cells were stimulated with alpha-CD3 monoclonal antibody (mAb) with and without alpha-CD28 mAb. Comparison to other cytokine genes revealed aspects of mRNA regulation unique to IL-5. The half-life (t1/2) of IL-5 mRNA, determined by addition of actinomycin D (ActinoD) or cyclosporin A (CSA) was longer (by >= 2 h) than that of IL-2, IL-3, IL-4, interferon-gamma, or granulocyte/macrophage colony-stimulating factor. With the exception of IL-5, t1/2 values were significantly shorter with CSA as the transcriptional inhibitor than with ActinoD. The t1/2 value of IL-5 mRNA, but not the other cytokine transcripts, determined with either ActinoD or CSA, was longer than predicted from the kinetics of steady-state mRNA decline. Co-stimulation of both cell types with alpha-CD28 mAb increased the stability of cytokine transcripts weakly, and IL-5 remained the most stable transcript. Thus, the degradation pathway that targets IL-5 is distinct from the other cytokine transcripts measured and involves proteins whose transcription is blocked by ActinoD and CSA. From examination of the levels of transcription initiation (nuclear run-on assay) and steady-state mRNA attained in cultures stimulated in the presence of the protein synthesis inhibitor, cycloheximide, only IL-5 transcription initiation had an absolute dependency on new protein synthesis.

High affinity receptor for IL-5 (IL-5R), a predominant eosinophil maturation factor, is composed of an IL-5-binding α-chain (IL-5Rα) and a signal-transducing β-chain that is shared by IL-3 and granulocyte-macrophage CSF (GM-CSF) receptors (IL-3R and GM-CSFR). By Northern blot analysis of mRNAs obtained from normal human blood eosinophils, we show in this report that the hematopoietic cytokines IL-5, IL-3, and GM-CSF down-regulate IL-5Rα mRNA while up-regulating α-chain mRNAs for both IL-3R and GM-CSFR as well as the β-chain mRNA. More detailed characterization reveals that the down-regulation of IL-5Rα mRNA is specific to IL-3, IL-5, and GM-CSF; occurs very rapidly (reaching maximum inhibition within 2 h); is cytokine dose dependent; and does not require protein synthesis. Nuclear run-on and mRNA stability experiments demonstrate that cytokine-induced inhibition of IL-5Rα mRNA accumulation occurs at the level of IL-5Rα gene transcription, whereas enhanced accumulation of mRNAs for IL-3Rα and the β-chain results from reduced mRNA degradation. We suggest from these experiments that in human blood eosinophils, IL-5Rα gene transcription and IL-5Rα mRNA metabolism can be regulated by mechanisms that are distinct from those used for IL-3Rα and GM-CSFRα.

Asthma is characterized by acute episodes of nonspecific airway hyperreactivity and chronic pulmonary inflammation exacerbated by stimuli including allergen exposure. In order to reproduce the physiologic and immunologic responses that occur in asthmatic patients, we have characterized a model of antigen-induced inflammation in which allergic mice (B6D2F1) that had been challenged once with aerosolized ovalbumin and had developed a pulmonary cellular infiltrate were rechallenged 1 wk later. Pulmonary inflammation in rechallenged mice was substantially greater than that in single-challenged mice. Eosinophils and activated-memory T cells (CD44+, CD45RBlo) in bronchoalveolar lavage (BAL) fluid accumulated to higher levels and with faster kinetics in response to the second challenge than in response to the first challenge. Eosinophils in lung tissue also accumulated to higher levels but with similar kinetics in response to the second challenge than in response to the first challenge. Similarly, interleukin (IL)-4 and IL-5 steady-state mRNA levels in lung tissue increased after the second challenge and were higher than those measured after a single challenge. Furthermore, treatment of mice with an anti-IL-5 monoclonal antibody 2 h prior to rechallenge inhibited antigen induced eosinophil accumulation in the lungs. In mice challenged twice, peak in vivo bronchoconstrictor responsiveness to acetylcholine was increased following the second challenge compared with that observed following the initial challenge. In contrast, ex vivo tracheal smooth muscle contractile responsiveness to acetylcholine was not altered. Although mucus accumulation and epithelial damage in pulmonary tissue were evident in mice challenged twice, these parameters were slightly reduced compared with those seen at similar times in mice challenged once. Therefore, although these mice exhibit only slight bronchial epithelial damage, the presence of significant inflammation and airway hyperreactivity to acetylcholine as well as slightly increased baseline reactivity demonstrate important similarities with the pathophysiology of asthma.

This study identifies three regions of the human interleukin (IL)-5 promoter involved in binding nuclear factors from activated T cells. DNase I footprinting and mobility shift assays with nuclear proteins from the human T cell clone, SP-B21, demonstrated protein interactions with each of these response elements (REs), located between positions -79 and -45 (RE-I), -123 and -92 (RE-II), and -170 and -130 (RE-III). Two of these regions, RE-II and RE-III, have not previously been described to regulate IL-5 expression in T cells. The RE-II site was shown to be critical for inducible IL-5 promoter activity in transient transfection assays in D10.G4.1 T cells, while the RE-III site functions as a negative regulatory element. The activity of the RE-II site was specifically inhibited by cyclosporin A, and transfection assays with IL-5 constructs containing mutations in the RE-II site showed greatly reduced reporter gene activity. We have defined the sequence involved in stimulation-dependent transcription and have identified constitutive as well as inducible DNA-binding protein complexes that bind to RE-II. Antibodies against at least two members of the nuclear factor of activated T cells (NFAT) family of transcription factors are capable of binding to the IL-5 RE-II complexes, although they can be distinguished from previously identified NFAT-specific complexes by several characteristics.

Interleukin-5 (IL-5) is a critical cytokine for the maturation of eosinophil precursors to eosinophils in the bone marrow and those eosinophils then accumulated in the lungs during asthma. We have studied anti IL-5 antibodies on allergic responses in mice, guinea pigs and monkeys and are extending this experiment into humans with a humanized antibody. In a monkey model of pulmonary inflammation and airway hyperreactivity, we found that the TRFK-5 antibody blocked both responses for three months following a single does of 0.3 mg/kg, i.v. This antibody also blocked lung eosinophilia in mice by inhibiting release from the bone marrow. To facilitate multiple dosing and to reduce immunogenicity in humans, we prepared Sch 55700, a humanized antibody against IL-5. Sch 55700 was also active against lung eosinophilia in allergic monkeys and mice and against pulmonary eosinophilia and airway hyperresponsiveness in guinea pigs. Furthermore, as opposed to steroids, Sch 55700 did not cause immunosuppression in guinea pigs. Studies with this antibody in humans will be critical to establishing the therapeutic potential of IL-5 inhibition.

Pulmonary inflammation is characterized by the accumulation of eosinophils and other leukocytes in the lungs of individuals challenged with antigen. Cytokines released by the Th2 lymphocyte subset, especially interleukin-4 (IL-4) and interleukin-5 (IL-5), are also present and thought to play an important role in this process. Previously, we used a model of aerosolized antigen challenge of sensitized mice to show that T cells were necessary for the accumulation of eosinophils and the production of cytokine steady-state messenger ribonucleic acid (mRNA). T cells were isolated from lung tissue at a time (4 h) when high levels of IL-4 and IL-5 mRNAs had accumulated, and from bronchoalveolar lavage fluid (BALF) and lung tissue at a later time (24 h), when inflammation could be detected by lavage. Lung-derived lymphocytes from sensitized challenged mice consisted of approximately 40% Thyl+ T cells (20% CD4+, 13% CD8+, and 6% CD4+/CD8+) and 30% B220+ B cells. Both BALF- and lung-derived T lymphocytes exhibited a similar activated/memory phenotype (CD44+ CD45RBlo), although lung tissue also contained less differentiated cells (CD44+ CD45RBhi). Thyl+ BALF cells isolated by magnetic bead-mediated separation accounted for approximately 88% of the IL-5 mRNA, 21% of the interferon-gamma (IFN-gamma) mRNA, and2% of the IL-4 mRNA detected in unseparated samples by reverse transcriptase-polymerase chain reaction (RT-PCR). Thyl+ T cells from lung tissue accounted for approximately 98% and 89% of IL-5 mRNA, 56% and 80% of IFN-gamma mRNA, and 23% and 40% of IL-4 mRNA at 4 h and 24 h after challenge, respectively. These experiments demonstrate that isolated T cells from BALF and lung are responsible for most of the IL-5 mRNA, but not all of the IFN-gamma or IL-4 mRNAs, detected in this model. These results are consistent with human studies indicating T cells as the major source of IL-5 mRNA in the lungs of asthmatic patients.

To investigate the role of interleukin-5 (IL-5) on airway hyperreactivity and pulmonary inflammation in nonhuman primate airways, the effect of a neutralizing monoclonal antibody to murine IL-5 (TRFK-5) was investigated in a cynomolgus monkey model of allergic asthma. Anesthetized Ascaris-sensitive monkeys underwent bronchoalveolar lavage (BAL) to assess the granulocyte content of this fluid before and 24 h after aerosolized Ascaris suum extract inhalation. Airway reactivity was assessed by the concentration of inhaled histamine required to produce a 40% reduction in dynamic lung compliance (Cdyn40). Exposure to A. suum extract produced an increase in airway reactivity (Cdyn40 = 0.065 +/- 0.024% before Ascaris; Cdyn40 = 0.014 +/- 0.004% after Ascaris) and an inflammatory reaction in the airways characterized by an increase in BAL eosinophils (0.05 +/- 0.03 x 10(3) cells/ml before Ascaris; 176 +/- 76 x 10(3) cells/ml after Ascaris) and neutrophils (3 +/- 1 x 10(3) cells/ml before Ascaris; 406 +/- 211 x 10(3) cells/ml after Ascaris). In contrast, only small nonsignificant changes in airway reactivity and granulocyte influx into the BAL occurred after aerosolized saline as a sham challenge. When the monkeys were treated 1 h before Ascaris challenge with the TRFK-5 antibody (0.3 mg/kg, intravenously), there was no increase in airway reactivity after Ascaris challenge (Cdyn40 = 0.032 +/- 0.016% before Ascaris; Cdyn40 = 0.217 +/- 0.196% after Ascaris) and there were only small increases in the number of eosinophils and neutrophils in the BAL after Ascaris challenge. The inhibition of this pulmonary eosinophilia and bronchial hyperresponsiveness by TRFK-5 was seen for up to 3 mo after treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

The effects of interferon-alpha (IFN-alpha) on the interleukin-6 (IL-6) receptor in a multiple myeloma cell line, U266, have been examined. IFN-alpha inhibits [3H]thymidine incorporation in U266 cells in a time- and dose-dependent manner. Furthermore, IFN-alpha inhibits the ability of IL-6 to induce increases in [3H]thymidine incorporation. While IFN-alpha suppresses the ability of 125I-IL-6 to bind to the IL-6 receptor on U266 cells, this effect is not due to competition of IFN-alpha with IL-6 for the IL-6 receptor. Although IFN-alpha induces IL-6 synthesis in the U266 cell, inhibition of IL-6 binding occurs when IL-6 synthesis is minimal. Furthermore, after pretreatment of U266 cells with neutralizing anti-IL-6 antibodies, IFN-alpha still inhibits 125I-IL-6 binding. These data suggest that IFN-alpha inhibition of 125I-IL-6 binding does not involve IL-6 synthesis. IFN-alpha reduces 125I-IL-6 binding without affecting its affinity, suggesting that IFN-alpha inhibits IL-6 receptor expression. Although pretreatment with cycloheximide inhibits 125I-IL-6 binding, IFN-alpha does not cause a selective decrease in the levels of gp130 or IL-6 receptor mRNA at times when 125I-IL-6 binding is inhibited. These observations indicate that IFN-alpha lowers IL-6 receptor density on U266 cells by mechanisms other than competitive binding or lowering IL-6 receptor mRNA production. Receptor down-regulation may be a mechanism of IFN-alpha-induced inhibition of growth in U266 cells.

Our previous studies in human monocytes have demonstrated that interleukin (IL)-10 inhibits lipopolysaccharide (LPS)-stimulated production of inflammatory cytokines, IL-1 beta, IL-6, IL-8, and tumor necrosis factor (TNF)-alpha by blocking gene transcription. Using electrophoretic mobility shift assays (EMSA), we now show that, in monocytes stimulated with LPS or TNF alpha, IL-10 inhibits nuclear stimulation of nuclear factor kappa B (NF kappa B), a transcription factor involved in the expression of inflammatory cytokine genes. Several other transcription factors including NF-IL-6, AP-1, AP-2, GR, CREB, Oct-1, and Sp-1 are not affected by IL-10. This selective inhibition by IL-10 of NF kappa B activation occurs rapidly and in a dose-dependent manner and correlates well with IL-10's cytokine synthesis inhibitory activity in terms of both kinetics and dose responsiveness. Furthermore, compounds such as tosylphenylalanyl chloromethyl ketone and pyrrolidinedithiocarbamate that are known to selectively inhibit NF kappa B activation block cytokine gene transcription in LPS-stimulated monocytes. Taken together, these results suggest that inhibition of NF kappa B activation may be an important mechanism for IL-10 suppression of cytokine gene transcription in human monocytes. IL-4, another cytokine that inhibits cytokine mRNA accumulation in monocytes, shows little inhibitory effect on LPS-induced NF kappa B activation. Further examination reveals that, unlike IL-10, IL-4 enhances mRNA degradation and does not suppress cytokine gene transcription. These data indicate that IL-10 and IL-4 inhibit cytokine production by different mechanisms.

Mast cells are important effector cells in IgE-mediated acute allergic reactions. Mast cells also produce cytokines such as interleukin (IL)-3, IL-4, IL-5, tumor necrosis factor (TNF), and granulocyte-macrophage colony-stimulating factor (GM-CSF) that regulate the function of eosinophils and the development of a late-phase inflammatory response to antigen challenge. To evaluate the role of mast cells on the development of IgE-mediated allergic pulmonary eosinophilia in vivo, we compared the eosinophil infiltration into lungs of mast cell deficient mice (WBB6F1/J-W/Wv) with their congenic normal littermates (W/W+). Mice were sensitized with alum-precipitated ovalbumin and challenged with aerosolized ovalbumin on day 12 after sensitization. Bronchoalveolar lavage (BAL) fluid, lung tissue biopsies, and blood samples were collected after ovalbumin challenge. Eosinophil numbers in the BAL and lung tissue, lung eosinophil peroxidase (EPO) activity and serum levels of IgE and IgG1 were measured. In sensitized W/W+ mice, there were increased numbers of eosinophils in the BAL fluid and lung tissue, and EPO levels were increased after ovalbumin challenge. Ovalbumin challenge of sensitized mast-cell-deficient mice produced fewer numbers of eosinophils in the BAL fluid and lungs, and EPO levels were also reduced compared with their challenged congenic littermates. On the other hand, levels of serum IgE and IgG1 were not different between W/Wv mice and their congenic littermates.(ABSTRACT TRUNCATED AT 250 WORDS)

Interleukin-5 (IL-5) is a cytokine that preferentially effects the development and function of eosinophils, and is considered important in the pathophysiology of allergic inflammation. In this study, we evaluated the ability of recombinant human IL-5 (rHu IL-5) to promote tissue eosinophilia and the importance of this eosinophilia to pathological alterations in vascular function. Repetitive subcutaneous administration for 18 days of rHu IL-5 resulted in a 7-fold increase in the number of eosinophils found in the ipsilateral hamster cheek pouch membrane. The contralateral cheek pouch membrane and peritoneum of these animals showed lesser but significant elevations in the number of eosinophils. In contrast, denatured rHu IL-5 did not elevate eosinophils in these tissues. Through the use of intravital microscopy and fluorometric analysis, rHu IL-5 treated hamster cheek pouch membranes were evaluated for alterations in microvascular permeability, using plasma clearance of FITC-dextran 150 as an index. Despite promoting a prominent tissue eosinophilia, the repetitive subcutaneous injections of rHu IL-5 did not alter the clearance of FITC-dextran 150. Topical application of rHu IL-5 to the cheek pouch, also, had no effect on the clearance of FITC-dextran 150. Immunofluorescence observations using an antibody to the granule protein, eosinophil peroxidase, indicated that the recruited cells had not degranulated. Our results support the importance of IL-5 in the recruitment of tissue eosinophils, but further stimulation is probably required to cause degranulation of these cells and the ensuing tissue damage.

1 The GABA-B receptor agonists baclofen and 3-aminopropylphosphinic acid (3-APPi) have antitussive activity in the cat and guinea pig. The purpose of this study was to investigate the sites of action of these GABA-B receptor agonists to inhibit the cough reflex. 2 Single intracerebroventricular (i.e.v.) cannulas were placed in the lateral ventricles of anaesthetized guinea pigs. Approximately 1 week later, the animals were exposed to aerosols of capsaicin (0.3 μm) to elicit coughing. Coughs were detected with a microphone and counted. 3 Cough was produced in anaesthetized cats by mechanical stimulation of the intrathoracic trachea and was recorded from electromyograms of respiratory muscle activity. Cannulas were placed for intravenous (i.v.) or, in separate groups of animals, intravertebral arterial (i.a.) administration of baclofen, 3-APPi, the centrally active antitussive drug codeine or the peripherally active antitussive drug BW443c. Dose-response relationships for i.v. and i.a. administration of each drug were generated to determine a ratio of i.v. ED50 to i.a. ED50, known as the effective dose ratio (EDR). The EDR will be 20 or greater for a centrally acting drug. 4 In the guinea pig, baclofen (3 mg kg−1, s.c.) and 3-APPi (10 mg kg−1, s.c.) inhibited capsaicin-induced cough by 50% and 35% respectively. The antitussive activity of baclofen was completely blocked by i.e.v. administration of the GABA-B receptor antagonist CGP 35348 (10 μg). Conversely, the antitussive effect of 3-APPi was unaffected by i.e.v. CGP 35348. However, systemic administration of CGP 35348 (30 mg kg−1, s.c.) completely blocked the antitussive activity of 3-APPi (10 mg kg−1, s.c). In separate experiments baclofen alone (1 μg, i.c.v.) inhibited capsaicin-induced cough by 78%. 3-APPi (10 and 100 μg, i.c.v.) had no effect on capsaicin-induced cough in the guinea pig. 5 In the cat, potencies (ED50) of the standards and GABA-B agonists by the i.v. route were: codeine (0.34 mg kg−1), BW443C (0.17 mg kg−1), baclofen (0.63 mg kg−1) and 3-APPi (2.3 mg kg−1). Potencies of these drugs by the i.a. route were: codeine, 0.013 mg kg−1; BW443C, 0.06 mg kg−1; baclofen, 0.016 mg kg−1; and 3-APPi, 0.87 mg kg−1. The EDRs for each drug were: codeine, 26; BW443C, 3; baclofen, 39; and 3-APPi, 3. 6 We conclude that in both the cat and guinea pig baclofen inhibits cough by a central site of action, while 3-APPi inhibits cough by a peripheral site of action.

In highly purified human polymorphonuclear leukocyte (PMN) preparations containing less than 0.1% contaminating monocytes, significant amounts of interleukin-8 (IL-8) and small amounts of IL-1 alpha, IL-1 beta, and tumor necrosis factor-alpha (TNF-alpha) were produced by lipopolysaccharide (LPS) stimulation. Contrary to published reports, IL- 6 production could not be detected. IL-10 inhibited the production of IL-1 alpha, IL-1 beta, IL-8, and TNF-alpha in LPS-stimulated PMNs, as it did in human blood mononuclear cell (MNC) preparations enriched in monocytes. Subsequent investigation of cytokine synthesis inhibitory effect of IL-10 on PMNs was focused on IL-8. IL-10 inhibited IL-8 synthesis in a dose-dependent manner and, in this regard, it was more potent than IL-4 and transforming growth factor-beta 1 (TGF-B1). In both MNCs and PMNs, degradation of LPS-induced IL-8 mRNA was enhanced by IL-10. Furthermore, as determined by nuclear run-on assays, IL-10 inhibited LPS-induced transcription of IL-8 gene in MNCs. However, in PMNs, run-on assays could not reliably detect IL-8 gene transcription. These results provide the first evidence that the human peripheral neutrophil is a target for inhibition of cytokine synthesis by IL-10, and that IL-10 acts by affecting both gene transcription and mRNA stability.

Pulmonary inflammation with eosinophil (EOs) infiltration is a prominent feature of allergic respiratory diseases such as asthma. In order to study the cellular response during the disease development, an animal model of IgE-mediated pulmonary inflammation with characteristic eosinophilia is needed. We developed a method for inducing severe pulmonary eosinophilia in the mouse and also studied the numbers of EOs in blood and bone marrow and the response to corticosteroid treatment. Animals were sensitized with alum-precipitated ovalbumin (OVA) and challenged with aerosolized OVA 12 days later when serum IgE levels were significantly elevated. Four to eight hours after challenge there were moderate increases in the number of EOs in the bone marrow and peripheral blood, but only a few EOs were observed in the lung tissue and in bronchoalveolar lavage (BAL) fluid. Twenty-four hours after challenge, there was a marked reduction of EOs in bone marrow, while the number of EOs peaked in the perivascular and peribronchial regions of the lung. Forty-eight hours after challenge, the highest number of EOs was found in the BAL fluid, making up80% of all cells in that compartment. The high levels of EOs in the lung tissue and BAL fluid lasted for 2-3 days and was followed by a more moderate but persistent eosinophilia for another 10 days. Nonsensitized animals showed no significant changes in the number of EOs in BAL fluid, lungs, blood or bone marrow. Histopathological evaluation also revealed epithelial damage, excessive mucus in the lumen and edema in the submucosa of the airways.(ABSTRACT TRUNCATED AT 250 WORDS)