Eosinophils are required for the induction of bronchial hyperresponsiveness in a Th transfer model of BALB/c background.

BACKGROUND: Helper T (Th) cells are deeply involved in the pathophysiology of bronchial asthma, such as eosinophilic inflammation, bronchial hyperresponsiveness (BHR), airflow limitation and remodeling. It is still unclear whether Th cells contribute to BHR independently of eosinophilic inflammation. The double GATA (dblGATA) site is a high-affinity GATA-binding site in the GATA-1 promoter. dblGATA site-deficient (Delta dblGATA) mice lack eosinophils. METHOD: Ovalbumin (OVA)-reactive Th clones were transferred into Delta dblGATA and wild-type (WT) mice of BALB/c background. The number of eosinophils in the bronchoalveolar lavage fluid (BALF) and bronchial responsiveness to methacholine were examined after OVA challenge. RESULTS: The number of BALF eosinophils was significantly increased in WT mice, but not detectable in Delta dblGATA mice. BHR was also induced in WT mice, but significantly attenuated in Delta dblGATA mice. CONCLUSION: Eosinophils are involved in T-cell-mediated BHR.

Murine Th clones confer late asthmatic response upon antigen challenge.

BACKGROUND: Helper T (Th) cells are deeply involved in the pathophysiology of bronchial asthma, such as eosinophilic inflammation, bronchial hyperresponsiveness and remodeling. However, it is still unclear how Th cells contribute to airflow limitation, another cardinal feature of bronchial asthma. METHOD: Unprimed BALB/c mice were transferred with ovalbumin (OVA)-reactive Th clones. Pulmonary function was monitored using a Buxco BioSystem Plethysmograph before and after OVA challenge. RESULTS: When Th-transferred mice were challenged with OVA, enhanced pause (P(enh)), an indicator of airflow limitation was significantly increased 6 and 24 h after challenge, while no response was observed 30 min after challenge. Neither bovine serum albumin, an irrelevant antigen, challenge on Th-transferred mice nor OVA challenge on Th-non-transferred mice caused airway responses. CONCLUSION: Th cells conferred antigen-induced airflow limitation to unprimed mice.

Evaluation of cysteinyl leukotriene-induced contraction of human cultured bronchial smooth muscle cells.

BACKGROUND: Cysteinyl leukotrienes (cysLTs) are major mediators involved in bronchial asthma, particularly bronchial constriction. However, a contractile response of human bronchial smooth muscle cells (hBSMCs) to cysLTs has not been well characterized at cellular level. METHODS: A contraction assay using collagen gel embedded with cultured hBSMCs was established to analyze contractile responses at cellular level. Contractile responses to several constrictors including cysLTs were evaluated in 6-day cultured gels with varying fetal bovine serum (FBS) concentrations. RESULTS: Removal of FBS from the culture for the designated time periods resulted in increased contractile responses. CysLT-induced contraction of the gel became more pronounced and reproducible. CysLT(1)R expression on the hBSMCs was significantly increased by the removal of FBS. CONCLUSION: Contractile responses of hBSMCs to cysLTs can be evaluated at cellular level for the first time. This experimental system may be useful for the in vitro evaluation and future development of cysLTs antagonists.

[Knowledge of guideline for asthma and a demand at the pharmacy--questionnaire based exploration].

BACKGROUND: To achieve a good control for asthma, cooperation of pharmacists is necessary. It is important to establish the system that the patients easily obtain advice about asthma from pharmacists and to spread the guideline. METHODS: For the first step, we explore the knowledge and usage of asthmatic guideline among pharmacists in the drug stores in this study. The questionnaires were distributed to 465 drug stores in the Seibu, minato-ku and bunnkyo-ku, Tokyo. RESULTS: The knowledge of guideline was 79% but the existence of guideline booklet at the pharmacy was 24%. The major demand at the pharmacy was to distribute pamphlet around 10 pages which contained treatment at the pregnancy and prevention of asthma. DISCUSSION: To spread usage of asthmatic guideline at the pharmacy, newly-devised plan is required.

IL-9 production by peripheral blood mononuclear cells of atopic asthmatics.

BACKGROUND: IL-9 might play a critical role in pathogenesis and development of atopic asthma, but there are few reports on allergen-specific IL-9 production by peripheral blood mononuclear cells (PBMCs) obtained from adult asthmatics. METHODS: PBMCs were obtained from adult atopic asthmatics and incubated with Dermatophagoides farinae(Der f) extract for the designated time periods. The resulting supernatants were assayed for IL-9 by specific sandwich ELISA. RESULTS: IL-9 production was detectable on day 2 and reached maximum on day 6 after stimulation of PBMCs with Der f extract. IL-9 production in response to Der f extract increased in a dose-dependent manner. CD2- or CD4-bearing cell depletion completely abolished IL-9 production by PBMCs, while CD8-bearing cell depletion did not affect it. CONCLUSION: CD4+ lymphocytes are the principal source of IL-9 produced by PBMCs of adult atopic asthmatics.

Effect of formoterol on allergen-induced cytokine synthesis by atopic asthmatics.

BACKGROUND: Effect of formoterol, long-acting beta(2 )agonists, on T cell cytokine synthesis was examined. METHODS: Human peripheral blood mononuclear cells were obtained from atopic asthmatics, and stimulated with Dermatophagoidesfarinae extract. Various concentrations of formoterol were added from the start of some cultures. Cytokine production and cell proliferation were analyzed. RESULTS: Allergen-induced IL-5, IL-13, and IFN-gamma production of PBMC were significantly suppressed by formoterol in a dose-dependent manner, whereas the proliferation response was not suppressed. CONCLUSION: Formoterol downregulates T cell functions of atopic asthmatics in vitro.

Regulation of Human IgE Production by Peripheral Blood Mononuclear Cells from Atopic Patients in Mice with Severe Combined Immunodeficiency.

Human peripheral blood mononuclear cells (PBMC) were transferred (i.p.) to severe combined immunodeficient (SCID) mice. PBMC from atopic donors developed both IgE and IgG synthesis, while only IgG synthesis was developed by normal human PBMC. IgE synthesis by atopic PBMC was detected from 2 weeks after transfer and reached a maximum in 3-4 weeks and declined thereafter, while serum human IgG concentrations increased steadily at least for 8 weeks. Specific IgG antibodies (anti-house dust mite) were detected in the sera of SCID mice transferred with atopic PBMC, but were not boosted by the stimulation with mite antigen injected (i.e.) with aluminum hydroxide gel. Neither IgE nor IgG synthesis was detected in the sera of the nude mice transferred with atopic PBMC. Removal of CD4 + cells from the atopic PBMC resulted in the depletion of both IgE and IgG synthesis in SCID mice. Depletion of CD8+ cells from the atopic PBMC changed the pattern of IgE synthesis from transient to persistent, but little affected IgG synthesis in SCID mice.

Anti-Dermatophagoides farinae Groups I and II IgE Antibodies in Atopic Patients.

Sera from 23 mite-sensitive bronchial asthma patients without atopic dermatitis and from 19 atopic dermatitis patients without bronchial asthma were examined for anti-Der f I and anti-Der f II IgE antibody contents. Anti-Der f I IgE antibody was predominant over anti-Der f II IgE antibody in atopic dermatitis patients, while the inverse was the case in bronchial asthma patients.

An asthma patient with steroid-resistant decrease in peak expiratory flow after the Great East Japan earthquake showing spontaneous recovery after 1 month.

People living in Japan were affected in various ways after the Great East Japan earthquake of March 11, 2011. A 52-year-old female asthma patient not directly affected by the disaster experienced a decrease in peak expiratory flow (PEF) immediately after the earthquake. Despite increasing the inhaled and oral corticosteroid doses, her PEF did not recover. One month later, her PEF level abruptly returned to normal with minimal medications, which were previously ineffective, and the asthma-related symptoms vanished. The stabilization of her state of mind and actual social state seemed to be a part of the reason for the patient's recovery.

Genetic factors in the treatment of bronchial asthma.

Owing to the recent vast progress in analytical tools and procedures to elucidate the relationship between genes and diseases, many candidate genes leading to the development of bronchial asthma have been reported. However, the quantitative phenotypes of asthma, such as decrease in forced expiratory volume in the first second, serum hyper-IgE, bronchial hyperresponsiveness and blood hyper-eosinophilia, do not represent this disease completely. On the other hand, eosinophilic inflammation of the bronchial mucosa represents accurately the feature of bronchial asthma, although accurate quantification of its status is difficult. While the production of interleukin (IL)-5 in peripheral CD4(+) T cells probably correlates with eosinophilic inflammation of the airway, the effectiveness of anti-IL-5 antibody for the treatment of bronchial asthma is controversial. Since intervention with asthma-causing gene products may not be sufficient for the treatment of this disease, identification of therapy-responsive genes should become more important in the near future.

Th2-cell-mediated chemokine synthesis is involved in allergic airway inflammation in mice.

Eosinophilic inflammation in the bronchial mucosa has been recognized as a prominent pathological feature of bronchial asthma. Th2 cells have been implicated in the local infiltration and activation of eosinophils. The migration of eosinophils as well as Th2 cells is controlled by chemokines, suggesting a crucial role of chemokines in the pathogenesis of bronchial asthma. To elucidate the mechanism by which Th2 cells induce eosinophilic inflammation, a Th2-cell-dependent murine model of asthma was employed in this study. Along with the infiltration of eosinophils and antigen-specific Th2 cells, CC chemokine receptor-3-active eotaxin, monocyte chemoattractant protein (MCP)-3 and RANTES, as well as CC chemokine receptor-3-inactive MCP-1 were produced in the lungs of Th2-cell-transferred mice after antigen provocation in vivo. On the other hand, differentiated antigen-specific Th2 cells produced MCP-3 and RANTES but not eotaxin or MCP-1 upon stimulation in vitro. Chemokines synthesized by Th2 cells and other cell types are involved in the development of eosinophilic inflammation in bronchial asthma.

IL-2-induced IL-13 production by allergen-specific human helper T cell clones.

BACKGROUND: Interleukin (IL)-5 and IL-13 are important cytokines in allergic diseases such as asthma and atopic dermatitis. We have reported that the production of IL-5 and IL-13 by mite-responsive T helper cells (Th) is controlled under similar signal requirements, but precise mechanisms are not yet well characterized. METHODS: Allergen-specific Th clones were established from peripheral blood lymphocytes of atopic asthmatics, and cytokine synthesis in response to various stimuli was determined by specific ELISAs. IL-13 gene expression was enumerated by quantitative real-time PCR. RESULTS: IL-13 production was clearly induced by IL-2. IL-13 mRNA expression was also induced. CONCLUSION: The IL-2 signal by itself causes IL-13 synthesis independent of T cell receptor stimulation.