The role of CD28-B7 costimulation in allergen-induced cytokine release by bronchial mucosa from patients with moderately severe asthma

JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY

卷:108

Article

Lordan, JL ; Davies, DE ; Wilson, SJ ; Dent, G ; Corkhill, A ; Jaffar, Z ; Roberts, K ; Djukanovic, R ; Holgate, ST

关键词: asthma;    costimulation;    CTLA-4;    CD28;    T cell;    allergen;    explant;    inflammation;    IL;   

DOI  :  10.1067/mai.2001.119740

来源: Elsevier

【 摘 要 】

Background: T cells play an important role in airway inflammation in asthma through the release of T(H)2 cytokines. Optimal T-cell activation by antigen-presenting cells requires costimulatory signaling, such as the interaction of CD80, CD86, or both with CD28. In patients with mild allergic asthma, the fusion protein cytotoxic T-lymphocyte antigen 4Ig (CTLA-4Ig), which inhibits CD28-mediated signaling, blocks the release of IL-5 and IL-13 from bronchial explant cultures exposed to the allergen Dermatophagoides pteronyssinus. Objectives: To assess costimulation in more severe forms of atopic asthma, we have compared the ability of CTLA-4Ig to block allergen-induced cytokine responses of bronchial explants and PBMCs from patients with moderately severe asthma. Methods: Bronchial explants and PBMCs were cultured in vitro, and cytokine expression was measured by means of quantitative RT-PCR and ELISA. Results: Constitutive mRNA transcripts for IL-5, IL-13, and GM-CSF were detected in the tissue explants, but only IL-5 mRNA increased significantly with allergen stimulation. Consistent with increased transcription, allergen-stimulated IL-5 protein release into explant supernatants, but this was not blocked by CTLA-4Ig. Allergen did not induce GM-CSF release, and IL-13 protein could not be detected in the explant supernatants under any condition. In contrast, allergen enhanced production of IL-5 and IL-13 by PBMC cultures from the same subjects, and this was inhibited effectively by CTLA-4Ig. Conclusions: These data suggest that IL-5 production in the airways of subjects with moderately severe asthma is largely independent of CD28-mediated costimulation. The different requirements for CD28-mediated costimulation in PBMC cultures and bronchial tissue cultures emphasizes the importance of the tissue microenvironment in pulmonary inflammatory responses in severe asthma.

【 授权许可】

Free