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The pathophysiological characteristics of bronchial asthma consist of chronic inflammation of airways, airway hyperresponsiveness, and bronchoconstriction. Studies have shown that T helper type 2 (Th2) cytokines produced by both T cells and mast cells in the airway contribute substantially to the initiation of inflammation in both experimental and human bronchial asthma. GATA-3 is a transcription factor essential to the production of Tb2 cytokines by T lymphocytes. To clarify the role of GATA-3-expressing T cells in the pathophysiology of bronchial asthma, we utilized transgenic (Tg) mice carrying the GATA-3 gene and the ovalbumin (OVA)-specific T cell receptor gene (GATA-3-Tg/OVA-Tg). Mice were intranasally administrated OVA without systemic immunization. Airway responses were analyzed with noninvasive and invasive whole body plethysmographs. GATA-3-Tg/OVA-Tg mice exhibited significantly higher IL-13 and IL-4 protein expression in the airway. Although there were no differences in the types of infiltrating cells between GATA-3-Tg/OVA-Tg and GATA-3-non-Tg/OVA-Tg mice and no significant increase in IgE level in either group compared with nontreated mice, the response after ACh inhalation was significantly elevated in GATA-3-Tg/ OVA-Tg on the seventh day of intranasal treatment with OVA. This hyperresponsiveness was inhibited by 5-1ipoxygenase inhibitor and IL-13 neutralization, suggesting that airway responses were induced through IL-13 and leukotriene pathway. In conclusion, airway hyper-responsiveness, a characteristic of bronchial asthma, is regulated at the level of GATA-3 transcription by T lymphocytes in vivo. T helper type 2 cytokines; transgenic mice: allergic inflammation

Four lipopolysaccharide (LPS)-core- specific human monoclonal antibodies (mAbs) were used in the analysis of the core region of Pseudomonas aeruginosa LPS to characterize its homogeneity. The four monoclonal antibodies (FK-2E7, MH-4H7, OM-1D6 and NM-3G8) expressed variable reactivities when tested with 180 P. aeruginosa strains. The results suggest that the antigenic heterogeneity of the LPS core is related with the O-polysaccharide-based serotype. Agglutination and flow cytometry demonstrated anin vivo protective activity closely related to in vitro binding activity to whole cells.