Measurement of allergens associated with dust mite allergy. I. Development of sensitive radioimmunoassays for the two groups of Dermatophagoides mite allergens, Der I and Der II

Sensitive radioimmunoassays were developed to measure the two groups of major allergens (Der I and Der II) of Dermatophagoides pteronyssinus and Dermatophagoides farinae, in which radiolabeled protein A served as a general tracer. Glass rods covalently coupled with F(ab')2 fragments of rabbit antiserum IgG were incubated first with mite or house dust extracts, and then with affinity-purified rabbit antibodies. The bound allergen-antibody complex was detected with a 125I-labeled protein A. The two Der I allergens, Der p I and Der f I, were measured separately with the use of immunoabsorbed rabbit antibodies directed against species-specific determinants, while the two Der II allergens, Der p II and Der f II, were measured as 'Der II' with the use of antibodies directed against common determinants on both allergens. Each assay demonstrated consistently parallel dilution curves with mite and house dust extracts. The mean intraassay and interassay coefficient of variation for each assay ranged from 4.3 to 7.7% and from 3.6 to 9.0%, respectively. The Der p I and Der f I assays were shown to be highly species-specific so that the ratio of Der p I: Der f I would provide a good index of the distribution of the two mite species in a dust sample. The concentrations of the Der I and Der II allergens in different types of mite extract and dust samples from houses were compared using these assays.(ABSTRACT TRUNCATED AT 250 WORDS)

[Measurement of IgE, IgG1 and IgG4 antibodies against mite Sephadex fractions and purified allergens by means of enzyme-linked immunosorbent assay]

Mite antigens (Dermatophagoides farinae) were fractionated by a Sephadex G-200 column and their reactivities with IgE, IgG1 and IgG4 antibodies were investigated with enzyme-linked immunosorbent assay (ELISA). High IgE antibody values were observed in fractions with low molecular weight (allergenic part), while high IgG1 and IgG4 antibody values were observed in fractions with high molecular weight. High IgG4 antibody values to crude mite extract and fractions with high molecular weight were detected in individuals who had received immunotherapy. However, IgG4 antibodies directed to allergenic part were found in only one out of 12 sera tested. IgG4-ELISA using DF1 (major allergen of Dermatophagoides farinae) as antigen was also performed. In the group treated with mite, significant IgG4 antibody levels were detected in only one out of 13 sera tested. In the group treated with house dust, significant IgG4 antibodies were detected in only one out of 12 sera tested. Patients who showed high IgG4 antibody responses to crude mite extract and to high molecular weight did not show responses to allergenic part and DF1. The only case who showed positive IgG4 responses to allergenic part also reacted with DF1. Those results suggest that IgG1 and IgG4 antibody values in ELISA using crude mite extract as antigen do not reflect major allergen-specific antibody values. The importance of the use of partially purified antigens in measuring major allergen-specific IgG4 antibodies was also suggested.

Comparative analysis of physicochemical and immunochemical properties of the two major allergens from Dermatophagoides pteronyssinus and the corresponding allergens from Dermatophagoides farinae

Two major allergens, DP1 (Der p I) and DP2 (Der p II), were isolated from the whole culture extract of Dermatophagoides pteronyssinus, and the physicochemical and immunochemical properties of these allergens were compared with those of the corresponding allergens from Dermatophagoides farinae, DF1 (Der fI) and DF2 (Der fII). On sodium dodecyl sulfate-polyacrylamide gel electrophoresis, polyacrylamide gel isoelectric focusing and amino acid analysis, both DP1 and DP2 were demonstrated to have close physicochemical similarity with DF1 and DF2, respectively. On immunodiffusion with the use of rabbit antisera, the two Der I allergens showed the reaction of typical partial identity, while the two Der II allergens showed the reaction of almost complete identity. Radioallergosorbent test (RAST) and RAST absorption experiments with the use of sera from mite-allergic patients showed that human IgE antibody response to the Der I allergens was directed against both cross-reactive and species-specific determinants. In contrast, IgE antibodies to the Der II allergens were demonstrated to react almost completely to cross-reactive determinants.

Measurement of allergens associated with dust mite allergy. II. Concentrations of airborne mite allergens (Der I and Der II) in the house

Assays of mite allergens (Der p I, Der f I and Der II) in the air of houses became feasible with the use of a low-noise air sampler and a sensitive radioimmunoassay described previously. The levels of the airborne allergens Der I (Der p I + Der f I) and Der II in the living room of 10 houses during usual domestic life were very low, 29.5 and 6.3 pg/m3, respectively, with a Der I: Der II ratio of 4.7:1. At the time of bedmaking, they greatly increased, about 1,000-fold, to 30,900 and 12,600 pg/m3, respectively, with a Der I: Der II ratio of 2.5:1. The amounts of Der I and Der II in the floor dust of the living room were 2,040 and 2,690 ng/g of fine dust, respectively, with a Der I: Der II ratio of 0.8:1. Der I seemed more prone to become airborne than Der II.

Isocratic determination of arachidonic acid 5-lipoxygenase products in human neutrophils by high-performance liquid chromatography

A high-performance liquid chromatographic method was developed to determine arachidonic 5-lipoxygenase products in calcium ionophore-stimulated neutrophils. This procedure allows the simultaneous measurement of leukotriene B4 (LTB4) and its omega-oxidation products without using a gradient elution system. 20-Carboxy-LTB4, 20-hydroxy-LTB4, 6-trans-LTB4, 12-epi-6-trans-LTB4, LTB4 and 5s,12s-dihydroxyeicosatetraenoic acid can be separated and quantitated by reversed-phase chromatography using isocratic elution. The generation and degradation of 5-lipoxygenase products by human neutrophils following stimulation with calcium ionophore have been examined by this method.

Immunopharmacological studies on TBX, a new antiallergic drug (1). Inhibitory effects on passive cutaneous anaphylaxis in rats and guinea pigs

The effects of 9-methyl-3-(1H-tetrazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one potassium salt (TBX), a new antiallergic drug, on passive cutaneous anaphylaxis (PCA) mediated by homologous IgE or IgG antibody were investigated in rats and guinea pigs. TBX (i.v. and p.o.) clearly inhibited IgE- and IgGa-mediated homologous PCAs in rats, without showing any inhibition of the skin reactions caused by histamine, serotonin and bradykinin in contrast to the inhibition of prostaglandin E1-induced skin reaction. Neither adrenalectomy nor propranolol treatment modified TBX's inhibition of the former PCA. With regard to tachyphylaxis to TBX, it was demonstrable in IgE-mediated homologous PCA in rats when they were pretreated with TBX (0.5 mg/kg, i.v.), followed 60 min later by a second dose of the drug (0.05 mg/kg, i.v.). There was no cross-tachyphylaxis between disodium cromoglycate (DSCG) and TBX. Homologous PCA caused by guinea pig IgE was also inhibited in a dose-dependent fashion by i.v. and p.o. administrations of TBX, although higher doses of TBX were needed to inhibit guinea pig PCA than the rat one. Interestingly, TBX showed more potent inhibition of both rat and guinea pig homologous PCAs than DSCG or tranilast. The results obtained indicate that TBX is an orally effective antiallergic agent displaying no antagonistic actions on the chemical mediators released.

Immunopharmacological studies on TBX, a new antiallergic drug (2). Inhibitory effects on histamine release from peritoneal mast cells and lung fragments of rats

The ability of 9-methyl-3-(1H-tetrazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one potassium salt (TBX) to inhibit histamine release from both peritoneal exudate cells (PEC) containing mast cells and lung fragments of rats was investigated in vitro. Low concentrations of TBX dose-dependently inhibited IgE-mediated histamine release from PEC of passively sensitized animals; its IC50 was 5.1 x 10(-9) g/ml. When TBX was added simultaneously with the antigen challenge, the highest inhibition was obtained. In contrast, extension of preincubation time with the agent resulted in a marked decrease in the inhibition of histamine release. The potent inhibition of histamine release by TBX was observed equally in glucose-free as well as complete Tyrode's solution, whereas TBX reduced its inhibitory action in Ca2+-free or D2O-supplemented medium. In addition, TBX inhibited compound 48/80- but not calcium ionophore A23187-induced histamine release from normal PEC. With regard to the intracellular cyclic AMP level in normal PEC, it was significantly enhanced by a high concentration of TBX (10(-3) g/ml). TBX also inhibited antigen-induced histamine release from lung fragments of actively immunized animals. Interestingly, TBX displayed non-competitive inhibition of cyclic AMP-dependent phosphodiesterase derived from lung homogenates; its K1 value was 8.70 x 10(-4) M.

[Antiallergic effects of mequitazine. 2. In vivo experiments]

Antiallergic effects of mequitazine were investigated in vivo and compared with those of ketotifen and disodium cromoglycate (DSCG). The results obtained were as follows: 1) Mequitazine in doses of 2 and 5 mg/kg given, p.o., 1 hr prior to antigen challenge inhibited dose-dependently the 48-hr passive cutaneous anaphylaxis in rats. Five mg/kg of mequitazine showed almost the same extent of inhibitory activity as that of 1 mg/kg of ketotifen. An i.v. administration of 1 mg/kg DSCG 1 min before antigen challenge also showed a marked inhibition. 2) The experimental asthma induced by challenge with an i.v. injection of antigen in passively sensitized guinea pigs was fairly inhibited by the pretreatment with 5 mg/kg of mequitazine administered p.o., although 2 mg/kg of this drug showed only a slight inhibition. 3) The experimental asthma induced by aerosolized antigen was also fairly inhibited by the pretreatment with 5 mg/kg of mequitazine given p.o.

[Antiallergic effects of mequitazine. 1. In vitro experiments]

The antiallergic effects of 10-(3-quinuclidinylmethyl)phenothiazine (mequitazine) were investigated in vitro. The results obtained were as follows: 1) In the isolated trachea and lung parenchyma of guinea pigs, mequitazine showed a fairly potent antagonistic action against contractions induced by both histamine (Hi) and acetylcholine (ACh). Mequitazine was much less potent in antihistaminic action and slightly more potent in anticholinergic action than ketotifen. The contractions of the preparation by leukotriene (LT) D4 were antagonized by mequitazine, although the potency was moderate, showing an IC50 value of 2.3 x 10(-5) g/ml in the trachea and 5.1 x 10(-5)g/ml in the lung parenchyma. Mequitazine had no effect on the contraction of the trachea by PGF2 alpha, but inhibited that of the lung parenchyma with pA2 = 7.0. 2) Mequitazine (10(-6) g/ml) slightly inhibited the Schultz-Dale reaction of the isolated guinea pig trachea, while ketotifen at the same concentration did not show any effect. 3) The contraction of the isolated guinea pig trachea by Ca2+ influx was slightly inhibited by mequitazine (10(-5) g/ml). 4) Mequitazine competitively inhibited the cyclic AMP-dependent phosphodiesterase activity from the rat lung with a potency of 10 times and 5 times more than those of ketotifen and theophylline, respectively. 5) Mequitazine (10(-6) to 10(-5) M) suppressed both the anaphylactic and phospholipase A2-induced histamine release from the peritoneal cells of rats. 6) Mequitazine (10(-5) g/ml) also inhibited the anaphylactic and Ca ionophore-induced histamine release from the leukocytes of the atopic patients and normal subjects. 7) The anaphylactic releases of histamine, LTB4 and peptide LT from the human lung fragments were dose-dependently inhibited by mequitazine (10(-7) approximately 10(-5) g/ml).

Immunopharmacological actions of the new antiallergic drug butyl 3'-(1H-tetrazol-5-yl)oxanilate. 5th communication: effects on immunological reactions in mice and humans

The effects of butyl 3'-(1H-tetrazol-5-yl)oxanilate (WP-833), a new antiallergic drug, on immunological reactions in mice and humans were studied in view of possible side effects. Hemagglutinin formation in mice immunized with sheep red blood cells was not suppressed by WP-833 administered i.p. or p.o. for 3 days either before or after immunization. In addition, the same treatments with WP-833 showed no suppression of hapten-specific immunoglobulin E (IgE) or immunoglobulin G (IgG) antibody formation in mice immunized with dinitrophenyl-conjugated ovalbumin mixed with alum. The proliferation of human peripheral blood lymphocytes induced by concanavalin A, phytohemagglutinin-P, pokeweed mitogen, protein A or Cowan I was not suppressed by WP-833. Nitroblue tetrazolium reduction test, phagocytosis and chemotaxis in human neutrophils were not inhibited by WP-833.

Immunopharmacological actions of the new antiallergic drug butyl 3'-(1H-tetrazol-5-yl)oxanilate. 3rd communication: inhibitory effects on histamine release from lung fragments, Schultz-Dale reaction in isolated tracheal muscle and experimental asthma in guinea pigs

The inhibitory effects of butyl 3'-(1H-tetrazol-5-yl) oxanilate (WP-833), a new antiallergic drug, on histamine release from lung fragments, Schultz-Dale (SD) reaction in isolated tracheal muscle and experimental asthma were investigated in guinea pigs passively sensitized with homologous immunoglobulin E (IgE) serum. WP-833 dose-dependently inhibited antigen-induced histamine release from lung fragments. In addition, synergism as to inhibition of histamine release was observed with a combination of WP-833 and isoprenaline but not with that of WP-833 and theophylline. WP-833 also inhibited antigen-mediated SD reaction of isolated tracheal muscle without showing antagonistic actions upon histamine- and leukotriene D4-induced contraction of normal tracheal muscle. Experimental asthma was clearly inhibited in a dose-dependent fashion by oral administration of WP-833.

Effect of deuterium oxide on leukotriene C4 generation in immunologically stimulated human leukocytes

Addition of deuterium oxide (D2O), 6-36%, resulted in a dose-dependent increase in allergen- or anti-IgE-induced leukotriene C4 (LTC4) generation from human basophils. In the presence of 36% D2O, the enhancement was 260 +/- 135% for allergen stimulation and 480 +/- 152% for anti-IgE stimulation as compared with the control incubated in normal buffer. The increasing effect of D2O on LTC4 generation from basophils was completely reversed by washing the cells before incubation with allergen. Vinblastine as well as colchicine, at a concentration of 100 microM, counteracted the effect of D2O. The enhanced release of histamine and LTC4 from basophils challenged with allergen was suppressed by Dimaprit, a histamine H2 receptor agonist, at a concentration required to inhibit the release by 50% of 5 X 10(-5) M for histamine and 10(-5) M for LTC4. These observations suggest that microtubules may be involved in LTC4 generation from immunologically stimulated basophils.

Immunopharmacological actions of the new antiallergic drug butyl 3'-(1H-tetrazol-5-yl)oxanilate. 1st communication: effects on type I to type IV allergic reactions in animal models

The effects of butyl 3'-(1H-tetrazol-5-yl)oxanilate (WP-833), a new antiallergic drug, on type I to type IV allergic reactions were investigated by employing various animal models. WP-833 (i.v. and p.o.) dose-dependently inhibited homologous or heterologous passive cutaneous anaphylaxis (PCA) mediated by rat or mouse immunoglobulin E (IgE) in rats. Homologous PCA caused by guinea pig IgE was also inhibited by WP-833. In addition, WP-833 had inhibitory actions upon homologous PCA induced by rat or guinea pig IgG. However, WP-833 showed no inhibition of rat skin reactions caused by histamine, serotonin and bradykinin, contrasting with the inhibition of prostaglandin E1-induced skin reaction. Furthermore, both adrenalectomy and propranolol treatment exerted no influences on the inhibition of IgE-mediated homologous PCA in rats by WP-833. In contrast to above findings demonstrating that WP-833 clearly inhibited type I allergic reaction, systemic Forssman shock in guinea pigs and reversed cutaneous anaphylaxis in rats (type II), passive Arthus reaction in rats (type III), and contact dermatitis and tuberculin reaction in mice (type IV) were unaffected by WP-833 even in higher doses than in those capable of completely inhibiting type I allergic reaction.

Immunopharmacological actions of the new antiallergic drug butyl 3'-(1H-tetrazol-5-yl)oxanilate. 4th communication: effects on histamine release from human leukocytes and from human and monkey lung fragments

The effects of butyl 3'-(1H-tetrazol-5-yl)oxanilate (WP-833), a new antiallergic drug, on histamine release from human leukocytes and from human and monkey lung fragments were investigated. WP-833 showed no inhibition of antigen, anti-immunoglobulin E (IgE)- and calcium ionophore A23187-induced histamine release from leukocytes of atopic patients allergic to house dust mite. In addition, no influences of WP-833 on the levels of cyclic adenosine monophosphate and guanosine monophosphate in leukocytes from healthy subjects were observed. However, antigen- or anti-IgE-mediated histamine release from human and monkey lung fragments passively sensitized in vitro with human serum IgE sensitive to mite antigen was clearly inhibited by WP-833. Interestingly, prolonged pretreatment of lung fragments with WP-833 resulted in a decay in inhibition of anaphylactic histamine release. Spontaneous histamine release from human leukocytes and monkey lung fragments were not inhibited by WP-833.

Immunopharmacological actions of the new antiallergic drug butyl 3'-(1H-tetrazol-5-yl)oxanilate. 2nd communication: inhibitory effects on histamine release from rat mast cells and lung fragments

The effects of butyl 3'-(1H-tetrazol-5-yl)oxanilate (WP-833), a new antiallergic drug, on its ability to inhibit histamine release from both peritoneal mast cells and lung fragments of rats were investigated. WP-833 inhibited in a dose-dependent fashion immunoglobulin E (IgE)-mediated histamine release from mast cells. Such potent inhibition was observed in glucose-free as well as complete Tyrode's solution but neither in Ca2+-free nor D2O-supplemented Tyrode's solution. In addition, WP-833 significantly increased intracellular cyclic adenosine monophosphate (AMP) levels in purified mast cells. On the other hand, WP-833 inhibited compound 48/80-but not calcium ionophore A23187-induced histamine release from normal mast cells. Also both IgE- and IgG-mediated histamine release from lung fragments were inhibited by WP-833. WP-833 showed non-competitive inhibition of cyclic AMP-dependent phosphodiesterase derived from lung preparations.

Augmentation of leukotriene C4 production by gamma interferon in leukocytes challenged with an allergen

Leukocytes from mite-sensitive asthmatic patients were challenged with an allergen and the supernatant assayed for histamine, immunoreactive leukotriene C4 (i-LTC4), and gamma-interferon (gamma-IFN). In addition, the concentration of gamma-IFN in the plasma of patients with bronchial asthma was assayed. Significantly higher concentrations (p less than 0.01) of gamma-IFN were detected in patients' plasma (0.27 +/- 0.32 U/ml, n = 61) than in that of healthy controls (0.04 +/- 0.06 U/ml, n = 19). The leukocytes produced 7.3 +/- 6.7 ng of i-LTC4/10(6) basophils (n = 32), and histamine release was 41.1 +/- 37.1% of total histamine. There was a significant correlation (p less than 0.01) between the capacity of leukocytes to release i-LTC4 and gamma-IFN. The capacity of leukocytes to release histamine and to produce gamma-IFN was not significantly correlated (r = 0.263). About twice as much i-LTC4 was generated from leukocytes pretreated for 24 h with 0.1-1.0 U/ml of recombinant human gamma-IFN, but histamine release was not changed. Another type of IFN, alpha-IFN, did not alter the capacity of leukocytes to release histamine as well as gamma-IFN upon preincubation for 24 h at 1-1,000 U/ml. Pretreatment with 1-10 U/ml of beta-IFN slightly enhanced the capacity upon challenge with 10 ng/ml of mite allergen. The enhancing effect of gamma-IFN on i-LTC4 generation was decreased by treatment with H-7, a nonspecific inhibitor of protein kinase C activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of butyl 3-(1H-tetrazol-5-Yl) oxanilate (MTB) on immunological or non-immunological histamine and SRS(-A) release from guinea-pig, monkey and human lung tissue

We investigated the influence of butyl 3-(1H-tetrazol-5-yl) oxanilate (MTB) on the release of histamine and slow reacting substance of anaphylaxis (SRS-A) in vitro. MTB dose-dependently inhibited the release of not only histamine but also SRS-A from passively sensitized guinea-pig lung, while disodium cromoglycate (DSCG) hardly affected either release. MTB also resulted in a dose-dependent inhibition of the release of these mediators from the passively sensitized cynomolgus and rhesus monkey and that from human lung at concentrations similar to those inhibiting the release in the guinea-pig. Relatively lower inhibitory activities on the releases of both mediators from the cynomolgus monkey and human lung, but no effects on those from the rhesus monkey were observed with DSCG. MTB dose-dependently inhibited only SRS release from guinea-pig lung induced by phospholipase A2, although the compound did not show any inhibitory activity on the release of those from the calcium ionophore (A23187)-stimulated one. On the other hand, the release of SRS, but not that of histamine from the lung stimulated with A23187 as well as phospholipase A2 was inhibited by N-(3,4-dimethoxycinnamoyl)-anthranilic acid (tranilast, N-5'). From these results, MTB was a potent inhibitor of the anaphylactic release of the mediators, particularly SRS-A. It was suggested that the inhibitory mechanism of MTB is different from those of DSCG and N-5'.