Proinflammatory Roles of T-Cell Receptor (TCR) γδ and TCR αβ Lymphocytes in a Murine Model of Asthma

The role of lymphocytes bearing αβ or γδ T-cell receptors (TCRs) was assessed during the acute allergic response in a mouse model of asthma. The inflammatory immune response to ovalbumin (OVA) was characterized in wild-type C57BL/6J mice and congenic TCRβ−/− and TCRδ−/− mice by evaluation of airway eosinophilia, histopathology, serum immunoglobulin (Ig)E levels, and in vivo airway responsiveness to methacholine. OVA-challenged wild-type mice demonstrated marked pulmonary inflammation, evidenced by airway eosinophilia (68 ± 7 × 104 cells), peribronchial lympho-plasmocytic infiltration, and elevated serum IgE (4.9 ± 0.6 μg/ml). These responses were markedly attenuated in TCRδ−/− animals (5.0 ± 1.0 × 104 eosinophils and 1.6 ± 0.3 μg/ml IgE) and were completely absent in TCRβ−/− mice (< 1 × 103 eosinophils and 0.38 ± 0.21 μg/ml IgE). Similar results were observed in mice treated with anti-TCRγδ or anti-TCRαβ monoclonal antibodies. Airway responsiveness to aerosolized methacholine was also reduced in challenge...