|
||
By

From * Ciba-Geigy Ltd., Asthma and Allergy Research Department, Pharmaceutical Division,
CH-4002 Basel, Switzerland; The recruitment of eosinophils into the airways after allergen exposure is dependent on interleukin (IL) 5 secreted from antigen-specific CD4+ T cells of the T helper cell (Th) 2 subset.
However, while it is established that costimulation through CD28 is required for TCR-mediated activation and IL-2 production, the importance of this mechanism for the induction of a
Th2 immune response is less clear. In the present study, we administered the fusion protein CTLA-4 immunoglobulin (Ig) into the lungs before allergen provocation to determine
whether CD28/CTLA-4 ligands are required for allergen-induced eosinophil accumulation
and the production of Th2 cytokines. Administration of CTLA-4 Ig inhibited the recruitment
of eosinophils into the lungs by 75% and suppressed IgE in the bronchoalveolar lavage fluid.
CTLA-4 Ig also inhibited the production of IL-4, IL-5, and IL-10 by 70-80% and enhanced
interferon-
R&D Dept. Kissei Pharmaceutical Co. Ltd., Matsumoto, 399, Japan; § Basel Institute for Immunology, CH-4005 Basel, Switzerland
production from CD3-T cell receptor-activated lung Thy1.2+ cells. Allergen
exposure upregulated expression of B7-2, but not B7-1, on B cells from the lung within 24 h.
Moreover, airway administration of an anti-B7-2 monoclonal antibody (mAb) inhibited eosinophil infiltration, IgE production, and Th2 cytokine secretion comparable in magnitude to that
observed with CTLA-4 Ig. Treatment with an anti-B7-1 mAb had a small, but significant effect on eosinophil accumulation, although was less effective in inhibiting Th2 cytokine production. The anti-B7-2, but not anti-B7-1, mAb also inhibited antigen-induced airway hyperresponsiveness in vivo. In all of the parameters assessed, the combination of both the anti-B7-1
and anti-B7-2 mAb was no more effective than anti-B7-2 mAb treatment alone. We propose that strategies aimed at inhibition of CD28 interactions with B7-2 molecules may represent a
novel therapeutic target for the treatment of lung mucosal allergic inflammation.
This article has been cited by other articles:
| TABLE OF CONTENTS |
|