OP0090 PRECLINICAL STUDIES OF A NOVEL CATHEPSIN C INHIBITOR IN MPO-ANCA-ASSOCIATED VASCULITIS MODEL

Background

MPO-ANCA-associated vasculitis (MPO-AAV) is a systemic small vessel vasculitis with the production of MPO-ANCA in the serum. This disease develops necrotizing and crescent glomerulonephritis (NCGN) and peritubular capillaritis-mediated interstitial damages in the kidneys, and pulmonary hemorrhage due to capillaritis in the lungs. Recent studies have revealed that neutrophil extracellular traps (NETs) induced by MPO-ANCA are critically involved in its pathogenesis,1 and neutrophil elastase (NE) plays an essential role in the formation of NETs.2 Cathepsin C (CatC) functions as a key enzyme in the activation process of several neutrophil serine proteases (NSPs) such as NE, proteinase 3 and cathepthin G by converting the inactive forms of the NSPs to the active forms by digesting dipeptides at the N-terminus of the enzymes.3

Objectives

Although glucocorticoids and immunosuppressive drugs used as the standard of cares can lead remission in MPO-AAV patients, there are remaining unmet medical needs such as severe side effects, resistance to the treatment and relapse. Therefore, development of new therapeutic strategies is awaited. The aim of this study is to demonstrate the efficacy of MOD06051, a novel CatC inhibitor, against MPO-AAV, using an MPO-AAV rat model established previously.4

Methods

In vitro studies: Cathpsins and NE inhibitory activity was measured using recombinant enzymes and fluorescent substrates. Cellular NE activity in the granulocytes differentiated from the primary human bone marrow-derived hematopietic stem cells under the presence or absence of MOD06051 was determined using fluorescent substrates.

In vivo studies: 4-week-old Wistar Kyoto (WKY) rats were immunized with human MPO according to Little’s protocol.4 The rats were divided into three groups (n=8 in each group), and vehicle (0.5% methylcellulose) or MOD06051 (0.3 or 3 mg/kg bid) was orally administered every day for 42 days. All rats were euthanized at the end of the study for serological and histological evaluations.

Results

In vitro studies: MOD06051 inhibited the enzymatic activity of human recombinant CatC with an IC50 value of 1.5 nM, and no other cathepsins nor NE inhibition was observed at 10 μM. The NE activity in primary human granulocytes was suppressed by MOD06051 with an IC50 value of 18 nM.

In vivo studies: MPO-ANCA was induced in all groups at the same level. The percentage of affected glomeruli including those with NCGN, NET-forming neutrophils in the peripheral blood and glomeruli, and glomerular neutrophil counts were significantly suppressed by MOD06051 treatment in a dose-dependent manner. Furthermore, hematuria score, urinary NGAL (Neutrophil Gelatinase-Associated Lipocalin), tubular erythrocyte cast counts, and pulmonary hemorrhage foci were significantly decreased in the 3 mg/kg of MOD06051 treated group with the similar trends in 0.3 mg/kg group.

Conclusion

MOD06051 showed sepcific inhibition of CatC activity. This compound suppressed the serine proteases activation in primary human neutrophils and NET formation in the MPO-AAV model rats, resulting in amelioration of MPO-ANCA-induced tissue destruction, including NCGN and tubular interstitial damages in the kidneys, and disorder of alveolar septal capillaries in the lungs. MOD06051 appears to be a promising agent for treatment of MPO-AAV patients.

References

[1]Nakazawa D, et al. Nat Rev Rheumatol 15: 91-101, 2019.

[2]Papayannopoulos V, et al. J Cell Biol 191: 677-691, 2010.

[3]Korkmaz B, et al. Pharmacol Ther 190: 202-236, 2018.

[4]Little MA, et al. Am J Pathol 174: 1212-1220, 2009.

Disclosure of Interests

Akihiro Ishizu Grant/research support from: Modulus Discovery, Inc., Mai Taniguchi: None declared, Suishin Arai: None declared, Yuka Nishibata Grant/research support from: Modulus Discovery, Inc., Sakiko Masuda Grant/research support from: Modulus Discovery, Inc., Utano Tomaru: None declared, Takafumi Shimizu Shareholder of: Modulus Discovery, Inc., Employee of: Modulus Discovery, Inc., William Sinko Shareholder of: Modulus Discovery, Inc., Employee of: Modulus Discovery, Inc., Tadashi Nagakura Shareholder of: Modulus Discovery, Inc., Employee of: Modulus Discovery, Inc., Yoh Terada Shareholder of: Modulus Discovery, Inc., Employee of: Modulus Discovery, Inc.

In Vitro and in Vivo Antigen-Induced Release of High-Molecular Weight Neutrophil Chemotactic Activity from Human Nasal Tissue

High molecular weight neutrophil chemotactic activity has been identified in resected human nasal polyps, inferior turbinates, and nasal secretions following antigen challenge. The estimated molecular weight, by gel filtration chromatography, was approximately 600,000. However, a heterogeneity of molecular weight in some patients was recognized. Our results suggest a possible role for high molecular weight-neutrophil chemotactic activity in the pathogenesis of hypersensitivity in the human nasal cavity.

Tenascin‐C levels in pseudosynovial fluid of loose hip prostheses

OBJECTIVE

Aseptic loosening is one of the most important problems that can occur after total hip arthroplasty (THA). In this study, we analysed levels of large tenascin-C (TN-C) variants and compared them in pseudosynovial fluid from patients with aseptic loosening after THA with those in synovial fluid from patients undergoing primary THA (control).

METHODS

Pseudosynovial fluid samples (n = 24) were obtained by aspiration at the time of revision THA performed due to aseptic loosening. Synovial fluid samples (n = 12) were obtained by aspiration at the time of primary THA. Expression of TN-C splice variants was examined using immunoblotting. TN-C levels were measured using an enzyme-linked immunosorbent assay (ELISA) system that we developed previously.

RESULTS

Western blotting showed the presence of large TN-C variants in pseudosynovial fluid of artificial joints with loosening. TN-C levels were approximately three times higher in pseudosynovial fluid of loose artificial joints (median 151.9 ng/mL) than in synovial fluid controls (median 50.1 ng/mL) (p = 0.035).

CONCLUSION

Levels of TN-C including large variant subunits are elevated in pseudosynovial fluid of loose artificial joints, indicating that TN-C is a useful novel biochemical marker of loose hip prostheses.

Omalizumab is more effective than suplatast tosilate in the treatment of Japanese cedar pollen-induced seasonal allergic rhinitis

BACKGROUND

Seasonal allergic rhinitis (SAR) induced by Japanese cedar pollens is a major problem in Japan. Omalizumab, a humanized monoclonal anti-IgE antibody, improves symptoms associated with SAR, but a comparative study with an anti-allergy drug has not yet been conducted.

OBJECTIVE

To compare the efficacy and safety of omalizumab with suplatast tosilate, a selective T-helper type 2 (Th2) cytokine inhibitor, in patients with Japanese cedar pollen-induced SAR.

METHODS

A randomized, double-blind, double-dummy study was conducted in 308 Japanese patients with a history of moderate-to-severe SAR who showed a CAP-RAST value (> or =2+) specifically to Japanese cedar pollens. Patients were treated for 12 weeks with omalizumab plus placebo of suplatast tosilate or suplatast tosilate plus placebo of omalizumab.

RESULTS

The mean daily nasal symptom medication scores (sum of the daily nasal symptom severity score and daily nasal rescue medication score) were significantly lower in the omalizumab group than in the suplatast tosilate group during three evaluation periods (P<0.001). The omalizumab group also had significantly lower mean daily nasal severity scores, each of the mean daily nasal and ocular symptom severity scores (sneezing, runny nose, stuffy nose, itchy nose, itchy eyes, watery eyes, and red eyes). Omalizumab reduced rescue medication requirements, and the proportion of days with any rescue medication use in the omalizumab group was significantly lower. Serum-free IgE levels markedly decreased in the omalizumab group and it was associated with clinical efficacy. The adverse reaction profiles were similar between the two groups. The overall incidence of injection site reactions was higher in the omalizumab group than in the suplatast tosilate group, but all these events were of mild degree. No anti-omalizumab antibodies were detected.

CONCLUSION

Omalizumab showed significantly greater improvements than suplatast tosilate in the treatment of SAR induced by Japanese cedar pollens.

Human gammadelta T cells modulate the mite allergen-specific T-helper type 2-skewed immunity

BACKGROUND

Gammadelta T cells have been described as one of immune regulators in patients with infection, malignancy, and allergy.

OBJECTIVE

To elucidate the ability of gammadelta T cells as an allergen immunotherapy candidate, the effectiveness of human gammadelta T cells in allergen-specific T-helper type 2 (Th2)-type T cells was evaluated in vitro.

METHODS

House dust mite-specific Th2-type T cell clones, Bacillus Calmette-Guerin (BCG)-specific Th1-type T cell clones, and gammadelta T cell lines were established from the peripheral blood mononuclear cells of two patients with allergic rhinitis. The effectiveness of gammadelta T cells and BCG-specific Th1-type T cell clones in the modulation of allergen-specific Th2 cells in terms of their cytokine productions was evaluated.

RESULTS

In response to cognate antigens, the gammadelta T cell lines demonstrated a proliferation and production of IFN-gamma that exceeded that of BCG-specific Th1-type T cell clones (mean stimulation index: 14.5 vs. 2.8, mean IFN-gamma: 130.5 vs. 10.0 pg/mL). When the gammadelta T cell lines and mite-allergen-specific Th2 clones were co-cultured with each other, only the levels of IL-4 (mean, -87%) decreased, but not the levels of IL-5 and IL-13, with an increasing concentration of gammadelta T cell antigen and IFN-gamma production (mean, +730%).

CONCLUSION

These results demonstrated that gammadelta T cells derived from allergic patients might thus have a partial ability to modulate allergen-specific Th2-skewed immunity.

Improved glucose tolerance via enhanced glucose-dependent insulin secretion in dipeptidyl peptidase IV-deficient Fischer rats

Glucagon-like peptide-1 (GLP-1) is an incretin, which induces glucose-dependent insulin secretion. GLP-1 is rapidly degraded by dipeptidyl peptidase IV (DPPIV) after its release. We investigated whether DPPIV-deficient F344/DuCrj rats show improved glucose tolerance when compared with DPPIV-positive F344/Jcl rats. Oral glucose tolerance test indicated improved glucose tolerance in F344/DuCrj rats, but blood glucose levels of the two strains were almost the same 120 min after the glucose bolus. Valine-pyrrolidide, a DPPIV inhibitor, had no effect on the glucose tolerance of F344/DuCrj rats, but improved that of F344/Jcl rats. Enhanced insulin secretion and high plasma active GLP-1 levels were detected in an intraduodenal glucose tolerance test. Glucose tolerance is improved in DPPIV-deficient F344/DuCrj rats via enhanced insulin release mediated by high active GLP-1 levels. Our results suggest that DPPIV inhibition is a rational strategy to treat diabetic patients by improving glucose tolerance with low risk of hypoglycemia.

Dietary supplementation with fish oil rich in omega-3 polyunsaturated fatty acids in children with bronchial asthma

Omega-3 polyunsaturated fatty acids have anti-inflammatory effects in vitro, and high dietary levels are associated with a lower incidence of inflammatory diseases. However, only limited effects have been demonstrated in asthma. The effects of dietary supplementation with fish oil for 10 months in 29 children with bronchial asthma was investigated in a randomized controlled fashion. In order to minimize the effects of environmental inhaled allergens and diet, this study was performed in a long-term treatment hospital. Subjects received fish oil capsules containing 84 mg eicosapentaenoic acid (EPA) and 36 mg docosahexaenoic acid (DHA) or control capsules containing 300 mg olive oil. The daily dosages of EPA and DHA were 17.0-26.8 and 7.3-11.5 mg x kg body weight(-1), respectively. Asthma symptom scores decreased and responsiveness to acetylcholine decreased in the fish oil group but not in the control group. In addition, plasma EPA levels increased significantly only in the fish oil group (p<0.0088). No significant side-effects were observed. The present results suggest that dietary supplementation with fish oil rich in the omega-3 polyunsaturated fatty acids eicosapentaenoic acid and docosahexaenoic acid is beneficial for children with bronchial asthma in a strictly controlled environment in terms of inhalant allergens and diet.

Smoking and oxidant stress: assay of isoprostane in human urine by gas chromatography-mass spectrometry

Isoprostane (8-epi-prostaglandin F2alpha) is synthesized non-enzymatically from arachidonate and active oxygen. We examined the relationship of smoking and excretion of isoprostane in urine with gas chromatography-mass spectrometry selected ion monitoring assay and the stable isotope dilution method. Urine isoprostane concentrations were significantly higher in smokers (n=81, 605.24+/-59.01 ng/mg creatinine) than in non-smokers (n=39, 424.07+/-70.37 ng/mg creatinine), but concentrations in ex-smokers (n=21, 487.27+/-98.48 ng/mg creatinine) did not differ significantly from those in the other groups. In smokers, age, the duration of smoking, and the number of cigarettes per day were not correlated with urine isoprostane concentrations. However, urine isoprostane concentrations were negatively correlated with time since quitting in ex-smokers and with age in non-smokers. These results indicate that smoking increases isoprostane concentration in urine and suggest that smoking causes lipid peroxidation by oxidant stress.

Vasorelaxant effect of a phosphodiesterase 3 inhibitor, olprinone, on isolated human radial artery

The radial artery is currently used as a viable arterial conduit for myocardial revascularization. The aims of this study were to identify phosphodiesterase 3 isoenzyme in the human radial artery isolated for coronary artery bypass grafting, and to examine the vasorelaxant effect of a cardiotonic and vasodilating phosphodiesterase 3 inhibitor, 1, 2-dihydro-6-methyl-2-oxo-5-(imidazo[1,2-a]pyridin-6-yl)-3-pyridine carbonitrile hydrochloride monohydrate (olprinone). The phosphodiesterase 3 isoenzyme was separated from the radial artery by DEAE-Sepharose chromatography. Olprinone inhibited the phosphodiesterase 3 activity with an IC(50) value of 1.25 microM. Olprinone relaxed the phenylephrine-induced contractions of endothelium-denuded arterial strips with an EC(50) value of 0. 107+/-0.029 microM (n=5). These findings indicate that the human radial artery possesses phosphodiesterase 3 isoenzyme activity and olprinone causes potent relaxation of the arterial strip in vitro through inhibition of phosphodiesterase 3 isozyme activity.

Attachment-inducing capacities of fish tissue extracts on oncomiracidia of Neobenedenia girellae (Monogenea, Capsalidae)

When oncomiracidia of Neobenedenia girellae (Monogenea, Capsalidae) were incubated in wells with lyophilized extracts of fish skin epithelia on the bottom, some attached to the well bottom with the haptor unfolded and shed the ciliated epidermal cells. Based on these morphological changes in oncomiracidia, we developed a new assay method to examine the attachment-inducing capacities of various fish extracts for oncomiracidia. Attachment-inducing capacities were found only in extracts of fish skin epithelium and not in other fish extracts. No significant difference in capacities was observed among extracts of skin epithelia of 4 fish species. Wheat germ lectin and concanavalin A suppressed capacities in extracts of skin epithelia of Japanese flounder and yellowtail, respectively. Suppressed capacities were recovered by adding sugars that bound specifically to these lectins. These results indicate that some sugar-related chemical substances that exist specifically in fish epithelium induce the attachment of N. girellae oncomiracidia.

Simultaneous assay of prostaglandins and thromboxane in the cerebrospinal fluid by gas chromatography-mass spectrometry-selected ion monitoring

A method of simultaneous analysis of prostaglandins (PGs) and thromboxane (TX) B2 in cerebrospinal fluid (CSF) with GC-MS-SIM was established. Deuterated PGs and TXB2 were used as internal standards: tetra-deuterated PGE2 (d4-PGE2) for PGE2, PGE1 and PGD2; d5-PGF2alpha for PGF2alpha and 9alpha,11beta-PGF2 and 8-epi PGF2alpha; d4-TXB2 for TXB2; and d4-6-keto PGF1alpha for 6-keto PGF1alpha. The PGs and TXB2 were derivatized to the methyl ester of the methoxim dimethyisopropylsilyl (DMiPSi) ether form or the methyl ester of the DMiPSi ether form with simultaneous preparation. Samples were extracted with octadecyl silica gel and purified in two steps with silisic acid gel chromatography between derivatization steps. The calibration curve of each PG and TXB2 was linear from 10 pg to 10 ng with the isotope dilution method. The levels of the seven types of PG and of TXB2 were assayed simultaneously in the cerebrospinal fluid (CSF) from patients with aseptic meningitis. The CSF pattern of the PG and TXB2 concentrations in mumps meningitis differed from those in other types of aseptic meningitis and in disease controls.

Eicosapentaenoic acid inhibits prostaglandin D2 generation by inhibiting cyclo-oxygenase-2 in cultured human mast cells

BACKGROUND

Eicosapentaenoic acid (EPA) is catalysed by cyclo-oxygenase (COX), as is arachidonic acid, and is a competitive inhibitor of arachidonate metabolism.

OBJECTIVES

We examined the effect of EPA on prostaglandin (PG) D2 generation in the cultured human mast cells with IgE-anti-IgE challenge incubation.

METHODS

Cultured human mast cells were incubated with EPA (1 micromol/L) for 20 h, then challenged with anti-IgE incubation after treatment with IgE. At the same time, COX inhibitors were tested to identify COX-1 and COX-2 activity. PGD2 synthetic activity was also assayed in a cell-free homogenate of cultured mast cells with COX inhibitors and EPA. Histamine in the culture medium and in cells was assayed with the HPLC-fluorescent method. PGD2 and PGD3 were assayed with gas chromatography-mass spectrometry and the stable isotope dilution method.

RESULTS

Although EPA incubation did not affect histamine release by cultured human mast cells in response to IgE-anti-IgE challenge incubation, it did decrease PGD2 generation by inhibiting the COX-2 pathway. In contrast, in the cell-free homogenate of cultured human mast cells, EPA inhibited both COX-1 and COX-2 activities.

CONCLUSION

Pre-incubation with EPA primarily affects the COX-2 pathway in cultured human mast cells and reduces PGD2 generation in response to IgE-anti-IgE challenge incubation. These findings suggest that COX-1 and COX-2 have different substrate flow systems in mast cells. They also suggest that endogenous EPA diet supplementation would reduce PGD2 production and could serve as an anti-inflammatory substrate in human mast cells.

GC/MS analysis of urinary excretion of 9alpha,11beta-PGF2 in acute and exercise-induced asthma in children

BACKGROUND

9Alpha,11beta-prostaglandin (PG) F2 is an initial metabolite of PGD2 which has a potent bronchoconstrictive activity.

OBJECTIVES

We measured the urinary levels of 9alpha,11beta-PGF2 in asthmatic children to investigate its role in not only acute asthmatic attack in a time course study but also in exercise-induced asthma (EIA).

METHODS

In the acute asthma study, 30 asthmatic children were examined. Urine samples were collected on the first, third, and sixth days. Urinary levels of 9alpha,11beta-PGF2 were measured with gas chromatography mass spectrometry using the electron impact method. In the exercise challenge study, 14 children with EIA and 14 children without EIA were studied. Urine samples were collected before exercise challenge, and at 1 h, and 5 h after exercise challenge. Urinary levels of 9alpha,11beta-PGF2 were measured.

RESULTS

Elevated urinary levels of 9alpha,11beta-PGF2, which were observed on the first day when treatment was started in the hospital, were gradually decreased on the third day (P < 0.05), and on the sixth day (P < 0.01). A significant correlation between urinary levels of 9alpha,11beta-PGF2 and symptom scores (P < 0.005) was observed on the first day. In EIA, there was a significant increase in urinary levels of 9alpha,11beta-PGF2 at 1 h (P < 0.01) and at 5 h (P < 0.01) after exercise challenge, but not in the children without EIA.

CONCLUSION

9Alpha,11beta-PGF2 may be involved in the pathogenesis of acute and exercise-induced asthma in children.

Catalytic and structural importance of Gly-454, Tyr-455, and Leu-456 in the carboxy-terminal region of Escherichia coli F1-ATPase alpha subunit

Monoclonal antibody alpha110 recognizes Leu-456 in the alpha subunit of the Escherichia coli F1-ATPase. Binding of this antibody to the alpha subunit or mutation of this residue to Pro caused enhancement of the ATPase activity, suggesting that this residue is involved in the catalytic mechanism of this molecule (H. Kanazawa et al. (1995) Arch. Biochem. Biophys. 317, 348-356). Leu-456 together with Gly-454 and Tyr-455 are the only residues in the carboxy-terminal 75 amino acids conserved among various species, suggesting that these three residues play important roles in catalysis by the ATPase. Here, we introduced site-directed mutations into these residues. Not only L456P but also G454L, Y455K, Y455L, and L456N mutations caused enhancement of the ATPase activity. Surprisingly, Y455V, L456H, and L456S caused assembly defects of F1 subunits on the membrane. Reconstitution of the alpha betagamma complex from the wild-type beta and gamma subunits with the mutant alpha subunit (L4gamma6P) exhibited enhanced ATPase activity. Addition of delta or epsilon fused to glutathione S-transferase which are functionally similar to the delta and epsilon subunits, respectively, to the reconstituted F1-ATPase did not cause significant enhancement of its activity. Decreased interaction between alpha and beta subunits with the L456P mutation was detected by the yeast two-hybrid system. According to the deduced three-dimensional structure of the bovine a subunit, Leu-456, Gly-454, and Tyr-455 are included in a small alpha helix. These results suggest that this alpha helix affects interaction of the alpha subunit with the beta subunit but not with delta or epsilon, which may be important for the catalytic mechanism and F1 assembly.

IgE-anti-IgE-induced prostaglandin D2 release from cultured human mast cells

To elucidate the characterization of cultured human mast cells, the generation of prostaglandin D2 (PGD2) upon stimulation with IgE-anti IgE challenge was determined by using gas chromatography/mass spectrometry/selected ion monitoring (GC/MS/SIM) assay. Mononuclear cells obtained from human umbilical cord blood were cultured in the presence of Steel Factor, IL-6, and PGE2. After 8 weeks of culture, approximately 90 to 95% of cultured cells became tryptase-positive and included basophilic granules. At 12 weeks of culture, cells were harvested and incubated with 1 microgram/ml of human IgE for 1 hr and then challenged with 10 micrograms/ml of anti-IgE. The level of PGD2 release into the supernatant was measured by GC/MS/SIM with the stable isotope dilution method. Cyclooxygenase inhibitors affected the PGD2 release from the cell by IgE-anti IgE challenge incubation. Indomethacin inhibited 98% of PGD2 release. Acetylsalicylic acid (aspirin) and NS-398 (potent COX-2 inhibitor) also inhibited PGD2 release by 85 and 45% respectively.

Major Dermatophagoides mite allergen, Der 1, in soft toys

BACKGROUND

Allergen avoidance is recommended when treating atopic asthma.

OBJECTIVES

Soft toys are often kept in close proximity to children and may serve as a source of exposure. Due to the potential danger from the mite allergen content of these toys, Der 1 from toys was measured.

METHODS

We quantified the level of Der 1 (Der p 1 + Der f 1) in both 30 new and 174 old soft toys (weight 216 +/- 2.5 g, height 26.5 +/- 3.4 cm), as well as in washed and in vacuumed soft toys. Dust was collected using an electric vacuum cleaner. Der 1 was measured by monoclonal antibody-based enzyme-linked immunosorbent assay (MoAb-ELISA).

RESULTS

In brand new toys Der 1 was 0.1 microgram/g of dust, and in toys used for 1 year, 9.0; 2 year, 22.2; 3 year, 18.9; and more than 4 year, 22.7 micrograms/g of dust. Der 1 in new toys was measured every 4 months for 1 year. Der 1 rapidly increased 10- to 20-fold in the first 4 months, but there was no clear seasonal change. In toys washed using a chemical detergent or cleaned using a vacuum cleaner, there was a stastistically significant (P < 0.001) decrease in Der 1 in the washed group, but not in the vacuumed group.

CONCLUSION

These results confirm that mite allergens accumulate rapidly in toys to form a potentially important source of allergens and that washing toys with a chemical detergent is effective in the reduction of allergens.

Reconstitution of the F1-ATPase activity from purified alpha, beta, gamma and delta or epsilon subunits with glutathione S-transferase fused at their amino termini

Systems for overexpression and purification of active alpha, beta and gamma subunits of Escherichia coli H(+)-ATPase were established. The alpha and beta subunits recovered as soluble form were purified by hydroxyapatite column chromatography. Since the gamma subunit was overexpressed as the insoluble form, this subunit was purified by polyacrylamide gel-electrophoresis containing sodium dodecyl sulfate. By subsequent denaturation of this subunit with guanidine hydrochloride and renaturation, the active gamma subunit for reconstitution of the F1-ATPase activity with the purified alpha and beta subunit was obtained. The delta and epsilon subunits which were fused to the carboxy terminus of glutathione S-transferase (GST) were overproduced and purified by affinity chromatography. These fused proteins (delta-GST and epsilon-GST) were incubated with the purified alpha, beta and gamma subunits and applied to affinity chromatography. The alpha beta gamma delta-GST and alpha beta gamma epsilon-GST complex were eluted specifically by addition of glutathione and exhibited high and low ATPase activity, respectively, with a subunit stoichiometry similar to that in the native F1-ATPase, indicating that active complexes could be reconstituted with the fused proteins. These results suggested that the amino-terminal ends of the delta and epsilon subunits are not involved in formation of the active complex. The fused epsilon-GST bound the gamma subunit strongly, and the alpha subunit weakly. The delta-GST bound the gamma subunit significantly, and the alpha and beta subunits very weakly.

Determination of 9 alpha, 11 beta-prostaglandin F2 in human urine and plasma by gas chromatography-mass spectrometry

Sensitive and specific assay methods for 9 alpha, 11 beta-prostaglandin F2 (9 alpha, 11 beta-PGF2) by gas chromatography-mass spectrometry with electron impact ionization are described. The mass spectrometric assay for 9 alpha, 11 beta-PGF2 was based on the use of the methyl ester-dimethylisopropylsilyl ether derivative, and pentadeuterated PGF2 alpha as a convenient internal standard. The calibration graph for 9 alpha, 11 beta-PGF2 was linear from 5 pg to 100 ng for both the standard and spiked biological samples. The limit of detection was 50 pg/ml for urine and 25 pg/ml for plasma (signal-to-noise ratio = 2.3). The method was applied to the determination of 9 alpha, 11 beta-PGF2 in urine and plasma samples from patients with bronchial asthma.

[Clinical significance of IgG4 antibody determination in children against egg white, milk, soybean and Dermatophagoides farinae]

The measurement of IgE and IgG4 antibodies against egg white, milk, soybean and Dermatophagoides farinae was performed by FAST (fluorescence allergosorbent test) using 21 serum samples obtained from non-allergic children and 160 serum samples from atopic children with bronchial asthma and/or atopic dermatitis. Their antibody levels were evaluated for any association with disease severity and for clinical significance in establishing diagnosis. It was found that children with bronchial asthma showed lower levels of IgE antibodies against egg white, milk and soybean and higher levels of IgE antibodies against Dermatophagoides farinae compared with those of children with atopic dermatitis, while both groups showed higher levels of egg white and milk-specific IgG4 antibodies compared with non-allergic children. These IgE and IgG4 antibody levels revealed a tendency to correlate with disease severity in patients with atopic dermatitis, while this was not observed in patients with bronchial asthma. The contribution percentages of IgG4 antibody determination, together with IgE antibody determination, in retrieving causal allergens were 71% for egg white, 70% for milk and 48% for soybean allergy, implying their diagnostic value in establishing clinical diagnosis.

[The effect of sustained-release theophylline granules in the inhibition of exercise-induced asthma]

We studied the protective effect of sustained-release theophylline granules on early or late response in exercise-induced asthma (EIA) in 16 patients ranging in age from 7 to 18 years. A standardized exercise test was examined 2 hours after administration of theophylline granules on one day and after no medication on another day. On both days, the lung functions and the serum theophylline and cortisol concentrations of the patients were examined before exercise and over a period of 8 hours after exercise. On days without medication, early response was seen in 16 patients and late response in 6. On days with medication, the theophylline granules inhibited early response in 13 of the 16 patients and late response in 5 of the 6 patients. This suggests that theophylline preparation is a useful drug for inhibiting the dual responses of EIA.

Drug effects on antigen-induced release of high molecular weight-neutrophil chemotactic activity and histamine in nasal secretion from children with allergic rhinitis

Five children with allergic rhinitis sensitive to house dust mite as documented by skin test, radioallergosorbent test, score and nasal provocation were studied. Patients were subjected to nasal challenge with 3.125, 6.25, 12.5, and 25 protein nitrogen micrograms per disc of house dust mite antigens and nasal secretions were collected by the filter paper method. Neutrophil chemotactic activity (NCA) and histamine content of the nasal secretions were measured. NCA and histamine were released in a dose- and time-dependent manner, and no significant correlation between NCA and histamine was revealed in each subject. Pretreatment with 5.2 mg of nasal disodium cromoglycate or 0.5 micrograms of nasal adrenaline 5 minutes before provocation totally inhibited mediator release upon nasal challenge with 12.5 micrograms of house dust mite. A dose of 100 micrograms of nasal beclomethasone dipropionate 5 minutes before challenge neither inhibited clinical symptoms nor mediator release; 100 micrograms x 3 times per day of nasal beclomethasone dipropionate for 3 days, however, significantly inhibited clinical symptoms and release of both NCA (p less than 0.05) and histamine (p less than 0.05). NCA eluted as a single peak with an estimated molecular weight of 600,000. These results suggest that high molecular weight-NCA may be involved in the pathogenesis of allergic rhinitis.

The effect of platelet-activating factor on IgE binding to, and IgE-dependent biological properties of, human eosinophils

This study investigated the effect of platelet-activating factor (PAF), leukotriene B4 (LTB4) histamine and formyl-methionyl-leucyl-phenylalanine (FMLP) on immunoglobulin E (IgE) binding and IgE-dependent cytotoxicity of human normal density eosinophils. The binding of a native myeloma IgE to normal human eosinophils was measured by flow cytometry using a fluorescein-conjugated polyclonal anti-IgE antibody. Preincubation with PAF (optimal at 10(-7)M), but not lyso-PAF or FMLP, gave dose-dependent increases in IgE binding. PAF and LTB4 gave significant increases in IgE binding after 5 min preincubation (P less than 0.05); the effect was further enhanced at 30 min (P less than 0.01). This was further confirmed using the rosette assay where PAF and LTB4, but not lyso-PAF or FMLP, gave dose- and time-dependent increases in IgE eosinophil rosettes. Eosinophil cytotoxicity for schistosomula of Schistosoma mansoni, incubated with immune serum, was also significantly enhanced (P less than 0.01) by PAF in a dose-dependent fashion (optimal at 10(-8) M). Schistosomula coated with FPLC-purified IgE fractions were susceptible to killing by normal density eosinophils, and this was enhanced with PAF (10(-8)M), LTB4 (10(-7)M) and histamine (10(-5)M) but not with FMLP (10(-7)M) or lyso-PAF. IgE-dependent cytotoxicity was confirmed by the removal of contaminating IgG from IgE-rich fractions, and by the abolishment of IgE-dependent cytotoxicity after IgE adsorption. These results suggest that PAF (and to a lesser extent LTB4 and histamine) increase IgE binding, IgE-dependent adherence and cytotoxicity of normal human eosinophils. Although IgE receptors have not been identified, the data support current concepts that certain biological properties of eosinophils may be IgE associated.

Exercise-induced anaphylaxis: improvement after removal of amalgam in dental caries

We present a case of exercise-induced anaphylaxis with improvement following the removal of dental amalgam. Although her symptoms were unresponsive to various kinds of therapy until removal of the amalgam, her symptoms related to exercise improved remarkably after the removal. The increase in plasma histamine levels for exercise provocation test also improved. This suggests that sensitivity to metals might cause exercise-induced asthma in some patients.

Interleukin 4 induces CD4+/CD8- to CD8+/CD4- transformation of human neonatal T cells by way of a double positive intermediate

We have determined that IL-4 induces the generation of CD4+/CD8+ T cells in cultures of neonatal lymphocytes. Sorting, positive, and negative selection experiments indicate that these cells arise from a subpopulation of CD4+/CD8- cells present in the neonate but not in the adult. We have further determined that these IL-4 generated "double positive" cells further differentiate to express only the CD8 marker. Our findings suggest an undescribed and dramatic role for IL-4 in T cell differentiation.

Chemical mediators in hypersensitivity reactions

The study of chemical mediators is essential in clarifying the mechanism of hypersensitivity reactions. Recent advances in this field have been made particularly with the arachidonic acid metabolites, several of which strongly contract smooth muscle, attract granulocytes to inflammatory foci and lead to increased vascular permeability. These functions play a crucial role in allergic reactions. Furthermore these mediators might work to modulate the intracellular network which mediates the complicated inflammatory process of hypersensitivity reactions.

Treatment of status asthmaticus--hormone changes before and after aminophylline i.v. drip therapy

The treatment of status asthmaticus is one of the most important factors in controlling the patient with asthma attacks. We have studied hormone changes in status asthmaticus and considered what is the best treatment in the asthma attack condition in children. Antidiuretic hormone (ADH), renin activity, and aldosterone activity are elevated in severe asthma attack conditions, and these high levels are correlated with high levels in Wood's clinical score. It is theoretical that patients with dehydration and respiratory failure show such elevation in hormones, and it is well known that under such conditions beta 2-stimulant enhances renin production. From our study, it is concluded that beta 2-stimulant subcutaneous injection must be considered in status asthmaticus. In children, aminophylline i.v. drip therapy may be one of the best treatments in status asthmaticus.

Human cord blood lymphocytes do not simultaneously express CD4 and CD8 cell surface markers

Several authors have reported finding significant numbers of immature T lymphocytes of the CD4/CD8 'double positive' phenotype in human cord blood. We have studied over 30 cord blood samples using directly conjugated reagents and have failed to detect such cells in any of the samples. Differences in staining methodologies that may account for this discrepancy are discussed.

Determination of 3 beta-hydroxylated bile acids in human serum and liver tissue

3 beta, 7 alpha-Dihydroxy-5 beta-cholanoic acid (3 beta, 7 alpha-diOH) was detected in serum of 3 patients with intrahepatic cholestasis. 3 beta, 7 beta-dihydroxy-5 beta-cholanoic acid (3 beta, 7 beta-diOH) appeared in serum of those patients after treatment with ursodeoxycholic acid (UDC). These bile acids were also detected in only unconjugated fractions of serum of another 7 patients with chronic liver diseases, but not in liver tissue of them. The liver does not seem to from these bile acids itself because they were absent in liver tissue.

Effects of human recombinant interleukin 5 and 3 on the differentiation of cord blood-derived eosinophils and basophils

When mononuclear cells from umbilical-cord blood were cultured for 3 weeks, low concentrations of interleukin 3 supported the preferential growth of basophils, with eosinophils comprising a smaller proportion. These basophils contained 0.15-0.3 microgram histamine per 10(6) cells, and released histamine by the IgE-dependent and -independent stimuli. Interleukin 5 increased the number and proportion of eosinophils in a dose-dependent manner without affecting the proliferation of other cell types in the interleukin 3-supplemented cultures. These cultured eosinophils could be activated by platelet-activating factor.

High molecular weight-neutrophil chemotactic activity in nasal allergy

HMW-NCA is involved in the pathogenesis of nasal hypersensitivity reactions in humans. We, however, have little evidence about the role of neutrophils which migrate to the site of allergic reactions by HMW-NCA and other chemotactic mediators. This role of neutrophils in nasal hypersensitivity still remains to be clarified.

Antidiuretic hormone in acute asthma in children: effects of medication on serum levels and clinical course

This study of seventeen patients presenting to the emergency room with acute severe asthma determined levels of antidiuretic hormone in serum as well as serum electrolytes and arterial blood gases serially. There was a progressive increase in plasma ADH concentration with severe asthma and ADH levels were substantially higher in those patients with PaCO2's higher than 45 Torr. Patients treated with intravenous aminophylline had a fall in ADH levels while those treated with injectable epinephrine showed an elevation of these levels. As the asthma improved, ADH levels decreased in all patients. In this series of children, sick for not more than 24 hours, serum sodium levels were normal. However, children who have been ill for longer periods than this or who are on prolonged intravenous fluid therapy need close monitoring of serum electrolyte concentrations.

Release of high-molecular-weight neutrophil chemotactic activity from resected human nasal turbinate after antigen challenge

Eleven patients with allergic rhinitis were studied. All subjects were sensitive to house dust mite documented by skin test, RAST score, and nasal provocation test. The patients needed lower turbinectomy because of chronic hypertrophic rhinitis. Tissues of the lower turbinate were obtained at the time of surgery, fragmented, and subsequently challenged with house dust mite in vitro. Diffusates were collected for measurement of neutrophil chemotactic activity (NCA) and histamine. NCA and histamine were released in a dose-dependent manner, and the time course of release of these mediators was identical. Release of NCA and histamine correlated significantly (p less than 0.001). The prior administration of the antiallergic drugs, disodium cromoglycate or tranilast, significantly blocked the release of NCA and histamine from antigen-challenged tissues. NCA released from nasal tissues eluted as a single peak with estimated molecular size of between 669 kd and 440 kd in three subjects and as two or three peaks in two patients. These results provide evidence that NCA might be involved in the pathogenesis of allergic rhinitis.

Flow-cytometric analysis of increased IgE uptake by normal eosinophils following activation with PAF-acether and other inflammatory mediators

Using flow-cytometric analysis and a fluorescein-conjugated anti-IgE antibody, we have investigated whether normal-density human eosinophils will bind greater amounts of native IgE following activation with platelet-activating factor (PAF), leukotriene B4 (LTB4) and histamine. Incubation with PAF resulted in a large dose- and time-dependent increase in IgE binding, optimal at 10(-7) M and 30 min, respectively. LTB4 and histamine gave lower but significant increases in IgE binding. Enhanced binding of IgE by activated normal-density eosinophils is probably a consequence of enhanced Fc epsilon RII receptor expression, suggesting a functional role for this receptor in allergic inflammation.

Release of high molecular weight-neutrophil chemotactic activity from human tissues, cells and secretion

Release of high molecular weight-neutrophil chemotactic activity from human tissues, cells and secretion was studied in vivo and in vitro. Lung, nasal turbinate, nasal polyps, skin of neurofibromatosis, basophils from chronic myeloid leukemia and cultured basophilic cells from cord blood released this mediator following calcium ionophore, antigen, anti-IgE or homogenization in vitro. Its release was also demonstrated in human nasal secretions from patients with allergic rhinitis following antigen challenge. Regarding mononuclear cells no release of this mediator was observed from normal donors or asthmatic patients having no active attack upon challenge with calcium ionophore, phytohemagglutinin or antigen. Homogenized duodenum released high molecular weight-neutrophil chemotactic activity but less activity in comparison with other tissues or cells mentioned above.

Studies on steroids. CCXXXVIII. Determination of bile acids in liver tissue by gas chromatography-mass spectrometry with negative ion chemical ionization detection

A method for the determination of bile acids in 2-10 mg of human liver tissue by gas chromatography (GC) in combination with negative ion chemical ionization (NICI) mass spectrometry is described. Unconjugated, glycine- and taurine-conjugated bile acids labelled with 18O and 2H were used as internal standards. The preparation of these compounds was attained by the exchange reaction of the carbonyl group with H218O, followed by metal hydride reduction. Bile acids in solubilized liver tissue were extracted with a Sep-Pak C18 cartridge, separated into the unconjugated, glycine- and taurine-conjugated fractions by ion-exchange chromatography on piperidinohydroxypropyl-Sephadex LH-20 and then derivatized to the pentafluorobenzyl ester-dimethylethylsilyl ethers. Subsequent resolution of each fraction into lithocholate, deoxycholate, chenodeoxycholate, ursodeoxycholate and cholate was attained by GC on a cross-linked 5% phenylmethyl silicone fused-silica capillary column where bile acids were monitored with a characteristic carboxylate anion [M - 181]-in the NICI mode using isobutane as a reagent gas. The newly developed method was applied to the quantitation of bile acids in liver tissue with satisfactory sensitivity and reliability.

Drug effects on exercise-induced late asthmatic responses

Disodium cromoglycate, prednisolone, beclomethasone and salbutamol were administered prior to the cycle ergometer exercise task separately to different groups of children with exercise-induced dual asthmatic reaction. Pre-treatment with disodium cromoglycate of ten asthmatics totally inhibited the dual reaction. Prednisolone treatment of eleven asthmatics and beclomethasone treatment of five asthmatics did not inhibit the early response but only the late response. Salbutamol treatment of ten asthmatics mainly inhibited the early phase reaction. Changes in neutrophil chemotactic activity correlated with airflow limitation in the disodium cromoglycate and prednisolone study, however, there were some discrepancies between the changes in FEV1 and neutrophil chemotactic activity in the beclomethasone and salbutamol studies. These findings suggest that exercise-induced dual asthmatic reaction are modified by disodium cromoglycate, prednisolone, beclomethasone or salbutamol in a mechanism which may be different in each drug and that there are similarities in the inflammatory responses in antigen- and exercise-induced dual asthmatic responses.