IgE Levels to Ascaris and House Dust Mite Allergens Are Associated With Increased Histone Acetylation at Key Type-2 Immune Genes.

Background: Epigenetic changes in response to allergen exposure are still not well understood. The aim of this study was to evaluate histone acetylation levels in peripheral blood leukocytes from humans naturally infected by intestinal parasites and perennially exposed to house dust mites (HDM). Methods: Peripheral blood mononuclear cells (PBMCs) were isolated by gradient centrifugation from 20 infected and 21 non-infected individuals living in a rural/village in Colombia. Histone 3 acetylation (H3Ac) and histone 4 acetylation (H4Ac) levels were measured in six immune genes previously associated with helminth immunity by chromatin immunoprecipitation (ChIP)-quantitative PCR. Then we analyzed the association between histone acetylation levels with total parasite egg burden and IgE levels. Results: We found an inverse correlation between H4Ac levels in the IL13 gene and egg worm burden that remained significant after adjustment by age [-0.20 (-0.32 to -0.09), p < 0.0001]. Moreover, we found significant associations between H4Ac levels in IL4 [0.32 (0.05-0.60), p = 0.02] and CHI3L1 [0.29 (0.08-0.51), p = 0.008] with the IgE levels to Ascaris lumbricoides. In addition, the levels of specific IgE antibodies to HDM were associated with H4Ac levels in the gene TNFSF13B encoding the B cell activating factor (BAFF) [0.51 (0.26-0.76), p < 0.001]. All values are presented as beta (95% CI). Conclusion: Histone acetylation levels at key type-2 immune genes in humans were modified by nematode infection and HDM allergens and are associated with the intensity of the IgE response.

Concurrent decreases in the prevalence of wheezing and Ascaris infection among 5-year-old children in rural Bangladesh and their regulatory T cell immunity after the implementation of a national deworming program.

INTRODUCTION: Epidemiological research on the prevalence of asthma and helminthic infections in various countries has led to the hypothesis that helminthic infections protect against asthma by suppressing the host's immune response. This study was conducted to elucidate whether decreased Ascaris infection following a national deworming program was associated with increased recurrent wheezing among rural Bangladeshi children and to test their anti-inflammatory immunity. METHODS: This nested case-control study was conducted from December 2015 to October 2016 in the rural service area of the International Centre for Diarrhoeal Disease Research, Bangladesh. Of the 1800 5-year old children randomly selected for the study, informed consent was obtained from the guardians of 1658 children. Data were collected using a semistructured questionnaire adopted from the International Study of Asthma and Allergies in Childhood and blood samples for the analysis of regulatory T (Treg) cell immune responses and the balance between Th1 and Th2 immunity in Ascaris infections. RESULTS: A total of 145 children were found to have wheezing, yielding a prevalence rate of 8.7%, which was significantly lower than the rate found in 2001 (16.2%, P < .001); Ascaris infection also decreased from 2001 to 2016. The 127 wheezing children who agreed to participate further were compared to 114 randomly selected never-wheezing children. Wheezing had a significant positive association with antibiotic use, history of pneumonia, parents' history of asthma, and Ascaris infection; children with Ascaris infection were twice as likely to have wheezing (adjusted odds ratio = 2.31, P = .053). Flow cytometry found no significant differences in the rates of Th1, Th2, and CD4 + CD25 + CD127low cells by the wheezing group. CONCLUSIONS: Ascaris infection had a positive rather than a negative association with wheezing and the rates of wheezing and Ascaris infections both decreased from 2001 to 2016. These findings undermines the hypothesis that such infections provide protection against asthma.

Modulation of human macrophage activity by Ascaris antigens is dependent on macrophage polarization state.

Parasitic worms (helminths) are known to actively modulate host immune responses and inflammation. The aim of this study was to investigate if adult body fluid (ABF) from the helminth Ascaris suum has immunomodulatory effects on different subtypes of human monocyte-derived macrophages (Mɸ) in vitro. Mɸs were exposed to A. suum ABF at different stages of their differentiation and/or polarization. Mɸ were first differentiated from monocytes into either uncommitted (M-), classically activated (M(GM-CSF)) or alternatively activated (M(M-CSF)) phenotypes and then stimulated with lipopolysaccharide (LPS). ABF strongly suppressed LPS-induced TNF-α, IL-6 and IL-10 secretion in M(GM-CSF)s, however in M(M-CSF)s only TNF-α was suppressed, with these cells secreting high levels of IL-10 which was not affected by ABF treatment. To determine if ABF modulated the differentiation of previously uncommitted Mɸ to either type 1 or type 2 Mɸ, monocytes were differentiated with human serum into (M-)s and then polarized by IFN-γ/LPS or IL-4 treatment in the presence of ABF. Under these conditions, ABF did not modulate cytokine secretion but did reduce CD80 expression in IFNγ/LPS-polarized cells but not IL-4-polarized cells. Finally, we demonstrate that when monocytes are differentiated into M(GMCSF)s in the presence of ABF, subsequent inflammatory responses are markedly suppressed. Our data suggest that ABF inhibits cytokine secretion and co-stimulatory molecule expression in classically activated Mɸ but not in alternatively activated Mɸ, indicating selective action of ABF depending on Mɸ subtype. Moreover, ABF appears to exert stronger activity when acting upon Mɸ that have already been polarized to the type 1 phenotype, rather than influencing the polarization process per se.

Effects of geohelminth infection and age on the associations between allergen-specific IgE, skin test reactivity and wheeze: a case-control study.

BACKGROUND: Most childhood asthma in poor populations in Latin America is not associated with aeroallergen sensitization, an observation that could be explained by the attenuation of atopy by chronic helminth infections or effects of age. OBJECTIVE: To explore the effects of geohelminth infections and age on atopy, wheeze, and the association between atopy and wheeze. METHODS: A case-control study was done in 376 subjects (149 cases and 227 controls) aged 7-19 years living in rural communities in Ecuador. Wheeze cases, identified from a large cross-sectional survey, had recent wheeze and controls were a random sample of those without wheeze. Atopy was measured by the presence of allergen-specific IgE (asIgE) and skin prick test (SPT) responses to house dust mite and cockroach. Geohelminth infections were measured in stools and anti-Ascaris IgE in plasma. RESULTS: The fraction of recent wheeze attributable to anti-Ascaris IgE was 45.9%, while those for SPT and asIgE were 10.0% and 10.5% respectively. The association between atopy and wheeze was greater in adolescents than children. Although Anti-Ascaris IgE was strongly associated with wheeze (adj. OR 2.24 (95% CI 1.33-3.78, P = 0.003) and with asIgE (adj. OR 5.34, 95% CI 2.49-11.45, P < 0.001), the association with wheeze was independent of asIgE. There was some evidence that the association between atopy and wheeze was greater in uninfected subjects compared with those with active geohelminth infections. CONCLUSIONS AND CLINICAL RELEVANCE: Atopy to house dust mite and cockroach explained few wheeze cases in our study population, while the presence of anti-Ascaris IgE was an important risk factor. Our data provided only limited evidence that active geohelminth infections attenuated the association between atopy and wheeze in endemic areas or that age modified this association. The role of allergic sensitization to Ascaris in the development of wheeze, independent of atopy, requires further investigation.

Differences in both prevalence and titre of specific immunoglobulin E among children with asthma in affluent and poor communities within a large town in Ghana.

BACKGROUND: Reports from several African countries have noted an increasing prevalence of asthma in areas of extensive urbanization. OBJECTIVE: To investigate the relevance of allergen-specific sensitization and body mass index (BMI) to asthma/wheezing and exercise-induced bronchospasm (EIB) among children from affluent and poorer communities within a large town in Ghana. METHODS: Children with physician-diagnosed asthma and/or current wheezing aged 9-16 years (n=99; cases) from three schools with differing socio-economic backgrounds [urban affluent (UA), urban poor (UP) or suburban/rural (SR)] were recruited from a cross-sectional study (n=1848) in Kumasi, Ghana, and matched according to age, sex and area of residence with non-asthmatic/non-wheezy controls. We assayed sera for IgE antibodies to mite, cat, dog, cockroach, Ascaris and galactose-α-1,3-galactose. RESULTS: Children from the UA school had the lowest total serum IgE. However, cases from the UA school had a higher prevalence and mean titre of sIgE to mite (71.4%, 21.2 IU/mL) when compared with controls (14.3%, 0.8 IU/mL) or cases from UP (30%, 0.8 IU/mL) and SR community (47.8%, 1.6 IU/mL). While similar findings were observed with EIB in the whole population, among cases there was no difference in IgE antibody prevalence or titre between children with or without EIB. BMI was higher among UA children with and without asthma; in UP and SR communities, children with EIB (n=14) had a significantly higher BMI compared with children with asthma/wheezing without EIB (n=38) (18.2 vs. 16.4, respectively, P<0.01). CONCLUSIONS AND CLINICAL RELEVANCE: In the relatively affluent school, asthma/wheezing and EIB were associated with high titre IgE antibodies to mite, decreased total IgE, and increased BMI. This contrasted with children in the urban poor school and suggests that changes relevant to a Western model of childhood asthma can occur within a short geographical distance within a large city in Africa.

IgE cross-reactivity between Ascaris and domestic mite allergens: the role of tropomyosin and the nematode polyprotein ABA-1.

BACKGROUND: Analysis of cross-reactivity between the nematode Ascaris ssp. and dust mites, two important allergen sources in the tropics, will contribute in understanding their influence on asthma and atopy. The objective of this study was to investigate immunoglobulin E (IgE) cross-reactivity between Ascaris and two domestic mites in the tropics. METHODS: Sera from 24 asthmatic patients were used in ELISA and immunoblotting IgE-binding inhibition assays using Ascaris, Blomia tropicalis and Dermatophagoides pteronyssinus extracts and the recombinants Blo t 10, ABA-1 and Blo t 13 as competitors. Identification of Ascaris allergens was confirmed by mass spectrometry (LC-MS/MS). RESULTS: We detected at least 12 human IgE-binding components in Ascaris extract. Blomia tropicalis and D. pteronyssinus inhibited 83.3% and 79% of IgE-binding to Ascaris, while Ascaris inhibited 58.3% and 79.3% to B. tropicalis and D. pteronyssinus respectively. Mite tropomyosin inhibited 85% of IgE-binding to Ascaris. Affinity-purified human IgE to rBlo t 10 identified an allergen of 40 kDa in Ascaris extract, further confirmed as tropomyosin by LC-MS/MS. We found no evidence of IgE cross-reactivity between rABA-1 and any allergen component in mite extracts, including rBlo t 13. CONCLUSIONS: There is cross-reactivity between Ascaris and mites, determined by several allergens including tropomyosin and glutathione-S-transferase. In addition to its potential impact on asthma pathogenesis, Ascaris infection and mite allergy diagnosis relying on the determination of specific IgE could be affected by this cross-reactivity. ABA-1 has no cross-reactive counterpart in mite extracts, suggesting its usefulness as a more specific marker of Ascaris infection.

Anisakis simplex as a risk factor for relapsing acute urticaria: a case-control study.

BACKGROUND: IgE-mediated hypersensitivity reactions to Anisakis simplex have been described after ingestion of fish, suggesting that sensitisation to this parasite may induce acute urticaria and anaphylaxis. Anisakis simplex allergens are highly resistant to heat and freezing, and sensitisation may occur even in populations with low consumption of raw/undercooked fish. This study aimed to quantify the association between sensitisation to A. simplex and relapsing acute urticaria. METHODS: This is the first case-control study on this topic. Cases (n = 200) were patients with a clinical diagnosis of relapsing acute urticaria, consecutively approached at the immunoallergology unit of Porto's largest paediatric hospital. Controls (n = 200) were consecutively selected at the surgery department of the same hospital, from subjects undergoing programmed orthopaedic, maxillofacial or general surgical procedures. Specific IgE measurements (Anisakis and Ascaris) were taken, and skin-prick tests (A simplex, common aeroallergens, fish, and Ascaris) were done. RESULTS: Sensitisation to A simplex (OR 3.86, 95% CI 2.04% to 7.29%), Ascaris (OR 3.37, 95% CI 1.89% to 6.02%), fish (OR 4.62, 95% CI 1.85% to 11.52%), and at least one aeroallergen (OR 4.59, 95% CI 2.99% to 7.05%) were associated with increased risk of acute urticaria. Regarding the sensitisation to A simplex, the aeroallergen sensitisation-adjusted OR was 2.61 (95% CI 1.33% to 5.12%) for the whole sample, and 2.72 (95% CI 0.99% to 7.47%) for those not sensitised to Ascaris or fish. CONCLUSION: Sensitisation to A simplex increases the risk of relapsing acute urticaria in subjects not sensitised to Ascaris or fish, and this is independent of aeroallergen sensitisation.

Wheeze, allergic sensitization and geohelminth infection in Butajira, Ethiopia.

BACKGROUND: The effect of geohelminth infection on wheeze and allergen sensitization is inconsistent across different epidemiological studies. OBJECTIVE: To investigate the association between self-reported wheeze, self-reported asthma, allergic sensitization and geohelminth infection in urban and rural areas of Butajira, southern Ethiopia. METHODS: Questionnaire data on wheeze, asthma and a range of confounding variables was gathered in a cross-sectional study of 7649 people aged 5 years or more from the Butajira Rural Health Project database. Allergic skin sensitization to Dermatophagoides pteronyssinus and cockroach was measured, and a stool sample collected for qualitative and quantitative geohelminth analysis. RESULTS: Wheeze was weakly associated with allergic sensitization to D. pteronyssinus and cockroach (odds ratios (OR) 1.21, 95% confidence interval (CI) 0.98-1.51, and 1.27, 95% CI 1.00-1.62, respectively). Self-reported asthma was related to sensitization to D. pteronyssinus only (OR 4.09, 95% CI 2.86-5.84). Geohelminths were present in 33.8% of participants, and the median egg load in infested individuals was 6 eggs/g. Overall, presence of any geohelminths was associated with a diminished risk of cockroach sensitization (adjusted OR 0.82, 95% CI 0.68-0.99) but there were no significant protective effects of any geohelminth infection against wheeze or asthma. CONCLUSION: In a developing country community with relatively low geohelminth prevalence and intensity, we found weak association between allergic sensitization and wheeze, but no evidence of a protective effect of geohelminths against wheeze or asthma.

T helper cell type 2 responsiveness predicts future susceptibility to gastrointestinal nematodes in humans.

Some humans are persistently more susceptible to gastrointestinal nematodes than others. Here, for the first time, susceptibility to reinfection has been linked to host cytokine responses. Ascaris lumbricoides and Trichuris trichiura abundance was assessed immediately before and 8-9 months after deworming in a Cameroonian population (starting n=191). Profiles of whole-blood cytokine responses to parasite antigens (for interleukin [IL]-5, IL-13, IL-10, IL-12p40, tumor necrosis factor- alpha , and interferon- gamma), assayed before treatment, were significantly related both to an overall measure of host susceptibility and to susceptibility to reinfection. Significant effects were primarily due to a negative association between IL-13 and IL-5 responses and infection. Persistently susceptible individuals were, therefore, characterized by a weak T helper cell type 2 response. The apparent plasticity of age-specific cytokine response-worm abundance relationships between different populations is also discussed.

Overexpression of interleukin-4 in lungs of mice impairs elimination of Histoplasma capsulatum.

Protection against the pathogenic fungus Histoplasma capsulatum requires Th1 cytokines. Since interleukin-4 (IL-4) can inhibit both Th1 cytokine production and activity, we examined the effects of overproduction of IL-4 in the lung on the course of pulmonary histoplasmosis. IL-4 lung transgenic mice manifested a higher fungal burden in their lungs, but not spleens, compared to wild-type infected controls. Despite the higher burden, the transgenic animals were ultimately capable of controlling infection. The adverse effects of IL-4 on H. capsulatum elimination were not observed during the early phase of infection (days 1 to 3) but were maximal at day 7 postinfection, prior to the induction of cell-mediated immunity. Analysis of total body and lung cytokine levels revealed that gamma interferon and tumor necrosis factor alpha production were not inhibited in the presence of excess IL-4. Our results with transgenic mice were supported by additional in vivo studies in which allergen induction of pulmonary IL-4 was associated with delayed clearance of H. capsulatum yeast and increased fungal burden. These findings demonstrate that excess production of endogenous IL-4 modulates protective immunity to H. capsulatum by delaying clearance of the organism but does not prevent the generation of a Th1 response that ultimately controls infection.

Anaphylactic shock to oysters and white fish with generalized urticaria to prawns and white fish.

Because seafood consumption is moderate-to-high in Spain, allergic reactions to seafood such as fish, crustacea and mollusc are fairly frequent. The clinical features of these reactions depend on the implicated species and whether the reaction is provoked by ingestion, handling or vapor inhalation. Because different species have common antigenic structures, cross-sensitization is frequent, especially between crustaceans and molluscs. Contamination of fish by nematodes (Anisakis) may produce severe reactions. We report the case of a female patient with no personal or family history of allergy who experienced two episodes of anaphylactic shock: the first occurred immediately after eating oysters and the second after ingestion of white fish. The patient also developed generalized urticaria provoked by crustacean (prawns) and white fish. The results of skin prick tests were negative for fish, shellfish, crustacean and oysters while in vitro tests were positive for oyster, prawns, Anisakis, Ascaris and Echinococcus, although stool samples and gastric endoscopy were negative.

In vitro responses to antigen stimulation: comparison between human lung parenchyma resected from asthmatic patients and non-asthmatic patients.

BACKGROUND: The airway of asthmatic patients is hyperresponsive to various stimuli in vivo. There are, however, only a few reports that compared the in vivo responsiveness of asthmatic patients and non-asthmatic subjects to those of lung parenchyma in vitro. OBJECTIVES: To compare the contractile response, release of various chemical mediators, and responsiveness to drugs in samples of lung parenchyma excised from asthma patients with those of non-asthmatic subjects. METHODS: Human lung parenchymal strips were subjected to passive sensitization with sera of 5+ RAST titer to mites. The strip was suspended in a magnus bath containing a buffer solution. Parenchymal contraction was induced by PGF2 alpha. After washing, the baseline concentrations of thromboxane B2 (TXB2), leukotriene (LT), and histamine were measured in each bath and then contraction was induced by the addition of a mite antigen. The concentrations of TXB2, LT, and histamine were measured after contraction. The inhibitory effects of TXA2 synthetase inhibitor (DP-1904) and TXA2 receptor antagonist (AA-2414) were also evaluated in both tissue samples. RESULTS: There were no significant differences between lung parenchymal tissues of asthmatic and non-asthmatic patients with regard to PGF2 alpha-induced contraction, antigen-induced contraction, release of chemical mediators, and the response to drugs. CONCLUSION: Unlike the response in vivo, there are no differences in the response to stimuli in vitro between lung parenchymal tissues of asthmatic and non-asthmatic patients.

Role of CD86 (B7-2) in triggering of antigen-specific IgE antibody response by lipopolysaccharide.

The role of CD86 in triggering of ascaris extract-specific IgE antibody response by lipopolysaccharide was studied. The simultaneous administration of anti-CD86 antibody with ascaris extract and lipopolysaccharide prevented the production of IgE antibody response to ascaris extract. CD86+ cells were detected in peritoneal cavities and spleens of mice injected intraperitoneally with lipopolysaccharide. CD86+ cells appeared in peritoneal cavities and spleens eight hours after lipopolysaccharide injection, and they were detectable for a week. CD86+ cells in peritoneal cavities and spleens were mainly surface Ig-positive B-cells and some Ig-negative cells. It was suggested that lipopolysaccharide induced the expression of CD86 mainly on B-cells, and that CD86+ cells induced by lipopolysaccharide injection might play an important role as antigen-presenting cells on triggering of ascaris extract-specific IgE antibody response by lipopolysaccharide.

ASABF, a novel cysteine-rich antibacterial peptide isolated from the nematode Ascaris suum. Purification, primary structure, and molecular cloning of cDNA.

Previously, we reported antibacterial activity in the body fluid of the nematode Ascaris suum (Kato, Y. (1995) Zool. Sci. 12, 225-230). The antibacterial activity is due to a heat-stable and trypsin-sensitive molecule that was designated as ASABF (A. suum antibacterial factor). In the present study, the purification, determination of primary structure, and cDNA cloning of ASABF were carried out. The mature peptide of ASABF is a basic peptide consisting of 71 residues and containing four intramolecular disulfide bridges. The amino acid sequence of a precursor for ASABF, deduced from a cDNA clone, indicates that flanking peptides both at the N terminus and at the C terminus are eliminated by processing. ASABF exhibits potent antibacterial activity particularly against Gram-positive bacteria. ASABF has several features that resemble those of insect/arthropod defensins, whereas the statistical significance of the similarity is not observed on comparison of amino acid sequences. A search of data bases revealed ASABF homologues in Caenorhabditis elegans.

The effects of a cysteinyl leukotriene antagonist (ONO-1078) on antigen-induced responses in allergic sheep.

The cysteinyl leukotrienes (LTC4/D4/E4) are putative mediators of asthma. In this study we used sheep allergic to Ascaris suum antigen to examine the effects of a novel orally active cysteinyl LT antagonist, ONO-1078, on antigen-induced early and late responses, airway inflammation, post challenge (24 h) airway hyperresponsiveness (AHR) and mucociliary clearance. Airway responses to antigen were determined by measuring specific lung resistance (SRL) before and for 8 h after challenge, bronchoalveolar lavage (BAL) was used to estimate airway inflammation, and airway responsiveness was measured by determining the carbachol dose that increased SRL by 400% (PC400). We also used a radiographic technique to measure the antigen-induced change in tracheal mucus velocity (TMV), a marker of mucociliary clearance. In two trials separated by at least 21 days, sheep were treated once with ONO-1078 (30 mg/kg, p.o.) and once with placebo (0.5% methylcellulose), 2 h before and 4 h after antigen challenge. Treatment with ONO-1078 (n = 7) provided 40% protection (p < 0.10) against the peak early increase in SRL, resulted in a more rapid reversal of the early response, and provided 96% protection against the peak late (6-8 h) increase in SRL. ONO-1078 also inhibited the AHR 24 h after challenge. In the drug trial, PC400 was unchanged as compared to pre-challenge, whereas in the placebo trial, PC400 was decreased 1.4-fold (p < 0.05). Treatment however, did not affect BAL cell numbers or differential.(ABSTRACT TRUNCATED AT 250 WORDS)

Hepatic lesions caused by excretory and secretory products of Ascaris lumbricoides in golden hamster.

OBJECTIVE: To ascertain the role of excretory and secretory (ES) products of Ascaris lumbricoides in liver damage. METHODS: The ES products of A lumbricoides were collected in vitro and their SDS-PAGE analysis was done. Feeding and subcutaneous injection of ES products were done in hamsters. Estimation of serum proteins, alkaline phosphatase and alanine aminotransferase and histology of liver were carried out. Control animal experiments were done concurrently. RESULTS: The ES products of A lumbricoides contained several proteins ranging in molecular weight from 14 to 205 Kd. Prolonged feeding of ES products caused elevation of ALT and amyloid deposition in the liver, whereas short term feeding or subcutaneous challenge caused focal cell necrosis and granuloma formation in the liver. CONCLUSION: ES products of A lumbricoides can produce liver damage.

Mechanism of action of MY-1250, an active metabolite of Repirinast, in inhibiting histamine release from rat mast cells.

1. When MY-1250 (3.6 x 10(-5) M) was added to mast cells, it caused a rapid increase in adenosine 3':5'-cyclic monophosphate (cyclic AMP) and decrease in adenosine 5'-triphosphate (ATP), both of which recovered to their original levels within 2 min. The accumulation of cyclic AMP was maximal at 20 s after challenge with MY-1250. The minimum level of ATP was observed at 20 s after addition of MY-1250. 2. The initial rise in [Ca2+]i and the histamine release induced by DNP-AS antigen (40 micrograms ml-1) was most strongly inhibited at 20 s after incubation of the mast cells with MY-1250. 3. MY-1250 strongly and dose-dependently inhibited the histamine release from rat mast cells induced by antigen. Moreover, MY-125 strongly inhibited calcium ion mobilization from the intracellular Ca(2+)-store. 4. These results suggested that the inhibitory mechanism of MY-1250 on the initial rise in [Ca2+]i and histamine release induced by antigen was due to the inhibition of ATP-dependent Ca(2+)-release from the intracellular Ca(2+)-stores.

Mechanism of allergic cross-reactions--III. cDNA cloning and variable-region sequence analysis of two IgE antibodies specific for trinitrophenyl.

As a first step toward defining the molecular interactions between ligands and the IgE antigen-combining site, we report here the cDNA cloning and variable (V) region nucleic acid sequences of the heavy (H) and light (L) chains of 2 monoclonal mouse IgE antibodies to trinitrophenyl (ATCC-TIB142 = IGELa2 and ATCC-TIB141 = IGELb4). In all instances, full-length cDNA clones were obtained to facilitate future expression studies. The H chains were encoded by VH genes from the VH3660 and J558 gene families in context with DQ52 and DSP2.2 diversity (D) mini genes, and JH3 and JH4 joining (J) gene segments, respectively. Vk8/Jk2 and Vk1/Jk5 rearrangements encoded the respective L chain V-regions. Both antibodies exhibited considerable conservation of complementarity determining region (CDR) sequences, which will facilitate template-based computer modeling of the three-dimensional structures of complexes formed between various ligands and these antibodies. From sequence comparison between the dinitrophenyl (DNP)-binding myeloma protein MOPC-315 and these IgE antibodies likely candidates for hapten-contact residues within the binding sites of IGELa2 and IGELb4 have been suggested.

The onset and recovery from airway hyperresponsiveness: relationship with inflammatory cell infiltrates and release of cytotoxic granule proteins.

Previous studies from our laboratory have demonstrated a temporal relationship between eosinophil influx into the airways and the onset of airway hyperresponsiveness to inhaled methacholine. The purpose of the present study was to extend this observation by evaluating changes in airway cellular composition and measuring the levels of granulocyte-derived mediators recovered in BAL fluid during the onset and recovery from antigen-induced airway hyperresponsiveness. Airway cellular composition, airway responsiveness to inhaled methacholine and the levels of BAL fluid EPO and MPO were monitored over a 32 day study in eight adult male Ascaris suum sensitive cynomolgus monkeys. Repeated Ascaris suum inhalation (nine challenges during days 0-21) resulted in a selective, sustained airway eosinophilia that was temporally related with the onset and maintenance of airway hyperresponsiveness (r = 0.67, P less than 0.001). The level of BAL eosinophil-derived EPO was increased and remained elevated concurrent with the increase in airway eosinophils and airway responsiveness. During the recovery phase (days 22-32) the actual number of eosinophils remained elevated, while BAL EPO levels were significantly decreased. The recovery phase was also associated with a transient increase in the number of BAL neutrophils and MPO concentration. We conclude that the number and state of activation of airway eosinophils directly correlate with the onset and maintenance of airway hyperresponsiveness. Recovery from airway hyperresponsiveness is associated with a decrease in eosinophil activation and a transient increase in the number of activated neutrophils.

Dysfunction of nonadrenergic noncholinergic inhibitory system after antigen inhalation in actively sensitized cat airways.

We have investigated whether proteases released during antigen inhalation cause dysfunction of the nonadrenergic noncholinergic inhibitory nervous system (NANCIS). Frequency-response (F-R) studies of NANCIS were performed before and after Ascaris antigen (ASC) inhalation using actively sensitized cats. NANC dilatatory effects were obtained by stimulating bilateral cervical vagi under cholinergic and beta-adrenergic blockade and serotonin-induced bronchoconstriction, and assessed by maximal percent relaxation (rmax) and the frequency causing 50% of maximal relaxation (EF50). ASC inhalation caused a transient increase in pulmonary resistance in all animals. One hour after ASC inhalation, pulmonary resistance returned to the baseline value, but ASC inhalation significantly attenuated NANC inhibitory activities: rmax decreased from 82.2 +/- 4.7 (mean +/- SE) to 64.3 +/- 11.2% (p less than 0.05), and the geometric mean of EF50 increased from 1.7 to 4.3 Hz (p less than 0.05). Dilatatory effects of infused VIP, a possible neurotransmitter of NANCIS, was also attenuated after ASC inhalation. Pretreatment with leupeptin (3 mg/kg) abolished ASC-induced impairment of NANC inhibitory activities. By contrast, dilatatory effects of adrenergic nerve stimulation were not affected by ASC inhalation. These results suggest that NANC inhibitory activities can be impaired after ASC inhalation, and that this impairment of NANCIS may be due to effects of proteases released during allergic reaction.