Late Allergic Response Research Articles

The immediate and late allergic response to segmental bronchopulmonary provocation in asthma.

The response to antigen is an important factor in the development of airway inflammation. Segmental bronchoprovocation (SBP) with antigen and subsequent bronchoalveolar lavage (BAL) have provided valuable insight into the mechanisms of allergic inflammation. To determine the features of allergic airway response in asthma, 19 subjects with mild asthma underwent antigen SBP in a dose-dependent manner. The amount of antigen used in SBP was 0 (saline), and 1, 5, or 20% of the antigen dose required to drop the FEV1 by 20% (APD20). BAL was done at 5 min and 48 h after SBP. BAL histamine levels increased modestly 5 min after antigen SBP. At 48 h, there was a marked increase in eosinophils and IL-5 concentration even in airway segments where the release of histamine was small. Moreover, eosinophils correlated with IL-5 levels at 48 h (r = 0.63; p < 0.001), but not with BAL histamine concentrations at 5 min. GM-CSF levels did not increase after antigen SBP and did not correlate with eosinophils. These observations indicate that asthmatic subjects can develop a dose-dependent response to antigen SBP that is characterized by a modest increase in histamine immediately after antigen exposure, and marked eosinophilia, which appears proportionately greater than the histamine response and relatively greater than what is seen in allergic nonasthmatic subjects. This feature might be important to the eventual development of airway inflammation in asthma.

Adoptively transferred late allergic airway responses are associated with Th2-type cytokines in the rat.

Late allergic airway responses can be transferred by CD4+ T cells in the rat. To investigate the role of T-cell cytokines in these responses, we examined the expression of mRNA for Th2 (interleukin [IL]-4 and IL-5) and Th1 (IL-2 and interferon gamma [INF-gamma])-type cytokines in Brown Norway rats that were administered either antigen-primed W3/25(CD4)+ or OX8(CD8)+ T cells. Donors were actively sensitized by subcutaneous injection of ovalbumin (OVA) in the neck and T cells were obtained from the cervical lymph nodes by immunomagnetic cell sorting for administration to unsensitized rats. Control rats received bovine serum albumin (BSA)-primed CD4+ and CD8+ T cells. Two days later, recipient rats were challenged with aerosolized OVA, and bronchoalveolar lavage (BAL) was performed 8 h after challenge. BAL cells expressing mRNA for IL-2, IL-4, IL-5, and INF-gamma were analyzed using the technique of in situ hybridization. Recipients of OVA-primed CD4+ T cells had an increase in the fraction of BAL cells expressing mRNA for IL-4 and IL-5 compared with BSA-primed CD4+ or OVA-primed CD8+ cells (P < 0.001). Recipients of CD8+ T cells had an increase in INF-gamma mRNA expression after OVA challenge compared with recipients of BSA-primed-CD8+ or OVA-primed CD4+ T cells (P < 0.001). In conclusion, T-cell-dependent allergen-induced late responses are associated with the expression of mRNA for IL-4 and IL-5, indicating Th2 cell activation. Furthermore, the increased expression of INF-gamma in allergen challenge recipients of antigen-primed CD8+ T cells suggests that CD8+ T cells may be important in modulating allergic responses.

Late allergic airway response to segmental bronchopulmonary provocation in allergic subjects is related to peripheral blood basophil histamine release

Background: Basophil histamine release has been found to correlate with the presence and severity of allergic disease. However, it remains to be established whether airway response to antigen is related to basophil involvement and its release of histamine. Objective: The purpose of this study was to investigate whether the intensity of airway response to an inhaled antigen challenge in allergic subjects is related to IgE-dependent peripheral blood basophil histamine release. Methods: The response to segmental bronchoprovocation with antigen was examined in 34 subjects with allergic rhinitis. Bronchoalveolar lavage samples were obtained 5 minutes (immediate response) and 48 hours (late response) after allergen challenge. Peripheral blood maximal basophil histamine release (MBHR) in response to in vitro antigen stimulation was determined in each subject before segmental bronchoprovocation. Results: Bronchoalveolar lavage samples obtained during immediate response showed an increase in histamine, whereas the late response was noted for a marked enhancement in airway cells, particularly eosinophils. Interestingly, a significant correlation ( r = 0.73, p < 0.0001, Spearman Rank test) was noted between MBHR and intensity of bronchoalveolar lavage eosinophilia at 48 hours. Furthermore, subjects with high (≥20%) MBHR had significantly higher total cells and eosinophils in bronchoalveolar lavage fluid 48 hours after antigen segmental bronchoprovocation when compared with subjects with low (<20%) MBHR. Conclusion: Our data suggest that the intensity of airway eosinophilia in response to antigen challenge is correlated with the magnitude of basophil mediator release in allergic subjects. (J Allergy Clin Immunol 1997;99:87-93.)

Late allergic airway response to segmental bronchopulmonary provocation in allergic subjects is related to peripheral blood basophil histamine release

Late allergic airway response to segmental bronchopulmonary provocation in allergic subjects is related to peripheral blood basophil histamine release

Dysfunctional muscarinic M 2 autoreceptors in vagally induced bronchoconstriction of conscious guinea pigs after the early allergic reaction

We studied the function of autoinhibitory muscarinic M 2 receptors on vagal nerve endings in the airways of conscious, unrestrained, ovalbumin-sensitized guinea pigs after the early and late allergic reaction. For this purpose, the effects of the selective muscarinic M 2 receptor antagonist gallamine were examined on unilateral vagus nerve stimulation-induced bronchoconstriction, which was determined as an increase in basal respiration amplitude, measured as changes in pleural pressure. Under control conditions, i.e., before antigen challenge, a significant increase in the pleural pressure was found after inhalation of 0.1 mM and, even more pronounced, 1.0 mM gallamine, at medium stimulation frequencies (2–16 Hz), leading to a leftward shift of the frequency-response curve. After inhalation of 10 mM of gallamine, a complete reversal of the left-shift was observed and the frequency-response curve was depressed. However, 6 h after challenge with ovalbumin (i.e., after the early allergic reaction) no increase in nerve stimulation-induced bronchoconstriction by gallamine was found; a decrease in this bronchoconstriction was again observed with the highest concentration. At this moment, bronchial responsiveness to histamine was enhanced 4.5-fold compared to control, i.e., prior to antigen provocation. Both after the late allergic response (24 h after challenge; 1.6-fold histamine hyperresponsiveness) and 4 days after allergen challenge (normal histamine responsiveness) the gallamine-induced potentiation of the bronchoconstriction was restored, similar to the responses under control conditions. The results clearly demonstrate that prejunctional muscarinic M 2 receptors control bronchoconstriction in conscious, unrestrained guinea pigs in vivo. Furthermore, these autoinhibitory receptors appear to be completely dysfunctional after the early allergic phase, but their function is largely restored after the late phase. The results indicate that dysfunction of autoinhibitory muscarinic M 2 receptors might contribute to the strongly enhanced responsiveness to histamine after the early allergic response.

Role of tumor necrosis factor and granulocyte-macrophage colony-stimulating factor in the late allergic response in human nasal mucosa

Cytokines play an integral role in the allergic response of the nasal mucosa. The ideal model for analysis of this interaction has yet to be perfected. We present a model for such evaluation and present results of experiments on the release of several cytokines. Freshly harvested human nasal turbinate mucosa was placed on a Gelfoam (Upjohn Co., Kalamazoo, Mich.) raft in a liquid medium to simulate the in situ environment. The allergic response was initiated by exposing the nasal mucosa to various combinations and amounts of human immunoglobulin E and antihuman immunoglobulin E antibody. The supernatants were collected and analyzed by enzyme-linked immunosorbent assay techniques for various cytokines. Histopathologic evaluation of the mucosa was performed throughout the exposure period, confirming normal cellular and tissue architecture and viability. This model was used to monitor the release of interleukin-3, granulocyte-macrophage colony-stimulating factor, tumor necrosis factor-α, and soluble tumor necrosis factor receptors after exposure to immunoglobulin E and immunoglobulin E antibody. Interleukin-3 did not show significant increases during the experiment testing period of 48 hours. Tumor necrosis factor-α and soluble tumor necrosis factor receptors demonstrated time-dependent increases in concentration after immunoglobulin E stimulation. Granulocyte-macrophage colony-stimulating factor showed the greatest time-dependent increases. Their impact on the understanding of the allergic response will be discussed. (Otolaryngol Head Neck Surg 1996;114:418-23.)

Role of Tumor Necrosis Factor and Granulocyte‐Macrophage Colony‐Stimulating Factor in the Late Allergic Response in Human Nasal Mucosa

Cytokines play an integral role in the allergic response of the nasal mucosa. The ideal model for analysis of this interaction has yet to be perfected. We present a model for such evaluation and present results of experiments on the release of several cytokines. Freshly harvested human nasal turbinate mucosa was placed on a Gelfoam (Upjohn Co., Kalamazoo, Mich.) raft in a liquid medium to simulate the in situ environment. The allergic response was initiated by exposing the nasal mucosa to various combinations and amounts of human immunoglobulin E and antihuman immunoglobulin E antibody. The supernatants were collected and analyzed by enzyme‐linked immunosorbent assay techniques for various cytokines. Histopathologic evaluation of the mucosa was performed throughout the exposure period, confirming normal cellular and tissue architecture and viability. This model was used to monitor the release of interleukin‐3, granulocyte‐macrophage colony‐stimulating factor, tumor necrosis factor‐α, and soluble tumor necrosis factor receptors after exposure to immunoglobulin E and immunoglobulin E antibody. Interleukin‐3 did not show significant increases during the experiment testing period of 48 hours. Tumor necrosis factor‐α and soluble tumor necrosis factor receptors demonstrated time‐dependent increases in concentration after immunoglobulin E stimulation. Granulocyte‐macrophage colony‐stimulating factor showed the greatest time‐dependent increases. Their impact on the understanding of the allergic response will be discussed.

Mechanisms of allergic bronchoconstriction in the rat.

A number of animal models of allergic bronchoconstriction have been developed in order to better understand the mechanisms of airway narrowing induced by inhalation of allergen and the underlying immunobiology of the reaction to allergen. The Brown Norway (BN) rat has been extensively characterized and appears to be among the best models thus far described, showing high levels of specific immunoglobulin E (IgE) on active sensitization (9,15), early and late allergic responses in high prevalence (4), airway eosinophili and cholinergic hyperresponsiveness after inhalations of allergen (5,10). Further to the striking similarity of the responses of the BN rat to human allergic subjects, there are several practical advantages of the BN rat, namely, its highly inbred nature which reduces inter-animal variability, commercial availability and its size which is such that it is large enough for reliable measurements of pulmonary function, but small enough to offer the advantages associated with the study of small animals. Although we have a reasonable understanding of some of the characteristics of the BN that make it responsive to allergen, the ultimate genetic basis for its atopic nature has yet to be evaluated.

The Effect of Cetirizine on Nasal Allergic Response

The effect of cetirizine on both early and late nasal allergic response was assessed in 15 ragweed sensitive patients. All patients were challenged before treatment and after 7 days of cetirizine 10 mg qd. Clinical assessments and measurements of mediators were performed at baseline, after positive challenge, 1 and 2 hours later, and repeated 7 and 8 hours later. There was a significant change (P &lt; 0.0001) in the early response threshold to ragweed challenges after cetirizine. There were early phase elevations of prostaglandin D2, leukotriene C4, and eosinophil cationic protein both pre and post-treatment. Late phase changes were difficult to detect, but a statistically significant rise of both prostaglandin D2 and histamine was diminished after cetirizine treatment. Cetirizine clinically inhibited the early response to nasal allergen challenge, but early mediators were not affected. An effect on the late phase could not be clearly demonstrated.

Induction of nitric oxide synthase in a model of allergic occupational asthma.

We have studied the induction of nitric oxide during late allergic responses, using a guinea pig model of trimellitic anhydride (TMA)-induced airway allergy. TMA is a low molecular weight chemical which can cause occupational asthma. The activity of nitric oxide synthase (NOS) was investigated by the detection of 3H-labeled citrulline formation from 3H-labeled arginine. In sensitized animals, challenge with TMA conjugated to guinea pigs albumin (TMA-GPSA) increased the activity of Ca(2+)-independent NOS (inducible NOS; iNOS) in lung and bronchial tissues at 15-17 h after challenge compared to nonsensitized animals. The induction of iNOS activity was associated with an associated with an increased level of nitrite, an end metabolite of the l-arginine-NO pathway, in bronchoalveolar lavage fluid. In contrast to iNOS, the activity of Ca(2+)-dependent NOS (constitutive NOS; cNOS) was not affected by the allergen challenge. These results demonstrate that iNOS in bronchial tissue is induced late after allergen challenge in sensitized guinea pig.

Association between late allergic bronchoconstriction in the rat and allergen-stimulated lymphocyte proliferation in vitro.

T lymphocytes are potentially of importance in determining the inflammatory response in the airways after allergen challenge. We hypothesized that the proliferative response of lymphocytes on exposure to allergen in vitro would be associated with the magnitude of the airway response in vivo after inhalational challenge. We studied Brown Norway rats that were actively sensitized with ovalbumin (OA) in aluminum hydroxide gel using Bordetella pertussis as an adjuvant. Two weeks later, blood mononuclear cells were isolated, and their proliferative response to culture with OA was measured with 3H-thymidine incorporation. Subsequently, the animals were anesthetized and challenged with aerosolized OA. Early allergic response (ER) and late (LR) allergic response were determined from the changes in pulmonary resistance (RL). Both significant ER and LR were observed in sensitized and challenged animals. The LR (measured as the area under the curve of RL against time) had a median value of 15.2 and ranged from 0.1 to 81.1 units. Lymphocyte proliferation occurred on exposure to OA (34,336 +/- 7,447 cpm) but less than after the mitogen Concanavalin A (250,685 +/- 76,676 cpm). The stimulation index (OA-stimulated 3H-thymidine incorporation standardized for baseline incorporation) was positively correlated with the magnitude of the late response. Interleukin-2 was significantly increased in the supernatant of cultured mononuclear cells exposed to OA, confirming T-cell activation. We conclude that the capacity of sensitized peripheral blood lymphocytes to respond to allergens may determine the magnitude of late airway responses.

A common cold virus, rhinovirus 16, potentiates airway inflammation after segmental antigen bronchoprovocation in allergic subjects.

Many patients with asthma have increased wheezing with colds. We hypothesized that rhinovirus colds might increase asthma by augmenting airway allergic responses (histamine release and eosinophil influx) after antigen challenge. Seven allergic rhinitis patients and five normal volunteers were infected with rhinovirus type 16 (RV16) and evaluated by segmental bronchoprovocation and bronchoalveolar lavage. Segmental challenge with saline and antigen was performed 1 mo before infection, during the acute infection, and 1 mo after infection. Lavage was performed immediately and 48 h after antigen challenge. Data were analyzed by two-way analysis of variance, and a P value of < or = 0.05 was considered to be significant. All volunteers inoculated with RV16 developed an acute respiratory infection. BAL fluid obtained from allergic rhinitis subjects during the acute viral infection, and 1 mo after infection, showed the following significant RV16-associated changes after antigen challenge: (a) an enhanced release of histamine immediately after local antigen challenge; (b) persistent histamine leak 48 h afterwards; and (c) a greater recruitment of eosinophils to the airway 48 h after challenge. These changes were not seen in non-allergic volunteers infected with RV16 and challenged with antigen, nor in allergic volunteers repetitively challenged with antigen but not infected with RV16, nor in RV16 infected allergic volunteers sham challenged with saline. We conclude that rhinovirus upper respiratory infection significantly augments immediate and late allergic responses in the airways of allergic individuals after local antigen challenge. These data suggest that one mechanism of increased asthma during a cold is an accentuation of allergic responses in the airway which may then contribute to bronchial inflammation.

Virus-induced airway obstruction and parasympathetic hyperresponsiveness in adult rats.

Viral respiratory infections in humans have been associated with exacerbations of late allergic responses and asthma, as well as with airway abnormalities that persist after resolution of the acute infection. We hypothesized that augmented parasympathetic contractile mechanisms may contribute to postviral airway dysfunction. We studied airway physiology in anesthetized rats at 1 to 8 wk after inoculation with Parainfluenza 1 virus or vehicle. The virus groups had airway obstruction (abnormal lung mechanics, gas exchange and residual volume), and increased sensitivity to intravenous methacholine at 1 to 4 wk, although methacholine hypersensitivity was minimal in vagotomized rats; these abnormalities were absent at 7 to 8 wk after inoculation. Airway responses to vagal parasympathetic nerve stimulation were enhanced markedly at 1 to 4 wk, and significantly at 7 to 8 wk, after viral inoculation. Dysfunction of M2 muscarinic autoreceptors during acute viral infection was indicated by a significant attenuation of gallamine-induced augmentation of airway parasympathetic responses; in contrast, gallamine-augmentation of parasympathetic responses at 2 to 8 wk after viral inoculation was not different from noninfected control animals. We conclude that respiratory virus infection in rats produces airway dysfunction that remains for weeks after resolution of the acute infection, and that is caused in part by parasympathetic hyperresponsiveness, associated both with M2 autoreceptor malfunction and with M2-independent mechanism(s).

Bronchial provocation with cat allergen: correlation between the individual IgE-CRIE pattern and the occurrence of a late allergic reaction.

Twenty-one mild asthmatic patients allergic to cat dander underwent a bronchial provocation test (BPT) with a cat extract. An early allergic response (EAR) was observed in all 21 patients and a late allergic response (LAR) in 8/21 patients. In the EAR, the patients with subsequent LAR had a greater fall in FEV1. Their baseline FEV1, and total dose of inhaled allergen were not significantly different from patients who did not develop a LAR, but their serum specific IgE level was higher. Crossed immunoelectrophoresis (CIE) of the same cat extract showed that it contained eight different proteins. An IgE-CRIE was obtained from all 21 patients, using radiolabelled anti-IgE and autoradiography. Radiolabelled standards allowed a semiquantitative scoring of the radiostaining. The CRIE pattern of the eight patients with LAR showed a higher score of radiostaining and a greater number of proteins bound to IgE. The two major allergen cat albumin and Fel dI bound equally to IgE of patients with and without LAR whereas another protein (antigen No. 7) bound to IgE of 100% of patients with LAR but of only 38% of patients without LAR. These data suggest that the pattern of the IgE response to specific proteins of a cat extract may be related to the occurrence of LAR after BPT with this allergen.

Allergen-induced airway responses in rats pretreated with Sephadex.

Even though the eosinophil is potentially an important contributor to airway narrowing during the late allergic airway response, direct evidence of its participation is lacking. Therefore, we examined the effects of eosinophilia induced by Sephadex on the magnitude of the late airway response of sensitized rats following allergen challenge. Brown Norway rats were actively sensitized to ovalbumin (OA). At the same time and 14 days later, a test group was administered Sephadex G200 (0.5 mg intravenously). The animals were challenged with an aerosol of OA and pulmonary resistance (RL) was measured over 6 h. The early response to OA reached a peak more rapidly and the magnitude of the late response, measured as the area under the curve of RL against time, was significantly greater in the Sephadex-treated group (48.3; geometric mean) compared to the control animals (18.9; p < 0.02). The percentage of eosinophils was increased in the bronchoalveolar lavage of Sephadex-treated animals (4%) compared to the controls (0.9%; p < 0.02) following OA challenge. These results demonstrate that Sephadex induces eosinophilia in Brown Norway rats and is associated with an increase in the late allergic airway response. This is consistent with the hypothesis that the eosinophil is an important determinant of the late response.

The Role of Eosinophils in the Pathophysiology of Asthmaa

From current information, a number of conclusions can be drawn. Antigen activation of the allergic reaction in the airways is associated with an immediate rise in mast cell derived mediators, including histamine and tryptase. Associated with antigen activation of the allergic reaction is recruitment of eosinophils to the airways. This can best be seen in the airway lavage 48 hours after challenge with antigen. An increased presence of eosinophils suggests that they are an important contributor to the late allergic reaction and may be one of the major constituents in the development of bronchial inflammation. Although many factors participate in the late allergic inflammatory response, eosinophil-derived proteins are known to cause airway injury. Regulation of eosinophils in this process is not clearly established; however, our findings of increased IL-5 in relationship to the presence of eosinophils and their granular proteins suggests that this cytokine may be an important modulator of eosinophil function and activation following allergen challenge. However, much remains unknown in understanding bronchial inflammation and the eosinophil's role in the process. In conclusion, the eosinophil is a major cellular participant in late phase allergic airway disease. Its presence and known functions suggest that the eosinophil is a significant cellular factor in the development of allergic airways disease in asthma. Further advances in this area will follow continued studies, particularly those which involve biopsy and correlation with airway physiology.

114 Dexamethasone reduces baseline methacholine responsiveness and prevents late allergic response in rats

114 Dexamethasone reduces baseline methacholine responsiveness and prevents late allergic response in rats

Late pulmonary allergic responses in actively but not passively IgE-sensitized rats

Previous studies suggested that although rats that were passively sensitized [monoclonal murine immunoglobulin E (IgE)] would respond to pulmonary antigen challenge with an immediate increase in resistance, they exhibited no late increases in resistance, unlike late changes in rats actively sensitized to preferentially produce IgE antibody. We hypothesized that passively sensitized rats also would not develop antigen-induced pulmonary inflammation. In a blinded protocol we compared immediate responses and pulmonary resistance and inflammation at 8, 19 and 24 h after challenge with placebo antigen, with dinitrophenol-bovine serum albumin (DNP-BSA) to elicit a passively sensitized response, or with ovalbumin (OA) to elicit an actively sensitized response. Despite similar immediate responses to OA and DNP-BSA, only the rats challenged with OA had marked inflammatory changes and a significant incidence of late elevations in resistance. Inflammation scores and lung resistance were significantly correlated only in the OA group. We also observed that anesthesia with fentanyl/droperidol significantly attenuated the immediate but not the late responses to antigen challenge, compared with rats anesthetized with ketamine. We conclude that IgE-mediated immediate responses to pulmonary antigen challenge are insufficient, and may be unnecessary, to initiate antigen-induced late inflammatory changes.

Asthma and mast cell activation

Many agents are capable of mast cell activation (MCA). In the lung, exposure to allergens induces IgE-mediated mast cell degranulation. By this process, chemical mediators are released and attract inflammatory cells that infiltrate the airway wall. This immune response is a potent stimulus for the pathologic changes seen in asthma (e.g., bronchospasm, mucosal edema, airway hyperreactivity, and mucus secretion). One neglected component of the asthmatic response is vascular permeability—the hallmark of mast cell degranulation. Like muscle contraction, vascular permeability occurs rapidly in response to an antigen challenge and is prevented by classic antiasthmatic therapy. Studies with antidromic nerve stimulation have indicated a relationship between MCA and the histamine-induced release of the sensory neuropeptide substance P, which causes vasodilation. Mediators released during the immediate hypersensitivity reaction may attract neutrophils and other chemotactic factors involved in the late allergic response, which includes a recrudescence of MCA caused by the release of histamine-releasing factors. Understanding these pathophysiologic events in asthma will be useful in formulating therapy.

Effect of Glucocorticosteroid Treatment on Ovalbumin-Induced IgE-Mediated Immediate and Late Allergic Response in Guinea Pig

The effect of glucocorticosteroid (GCS) treatment on ovalbumine-induced IgE-mediated immediate and late allergic response was studied in sensitized guinea pigs. The results show that the GCS budesonide (BUD) inhibits the allergen-induced IgE-mediated immediate and late bronchial obstruction. The effect on the early reaction is correlated to the inhibition of leukotrienes and histamine release. The importance of mediator release inhibition for the antianaphylactic effect of GCS is discussed. In examining the effect on the late reaction, it was found that BUD had to be present during the early reaction but did not inhibit the early reaction. Furthermore, the effect on the late reaction was correlated to the inhibition of vascular leakage but not to the infiltration of inflammatory cells as examined in bronchoalveolar lavage. The results indicate that some triggering factors important for the development of the late reaction are released during the early reaction. Inhibition of the release of that factor or the activation of inflammatory cells by that factor might be the mechanism behind the antiinflammatory activities of GCS.