Figure 1.
Development of reduced allergic airway responses in sensitized and challenged LTA4H−/− mice (ovalbumin [OVA]/OVA). (A) Lung resistance (RL) was determined in response to increasing concentrations of inhaled methacholine as described in Materials and Methods (n = 12 in each group). Open triangles, LTA4H+/+ PBS/OVA; open squares, LTA4H−/− PBS/OVA; solid triangles, LTA4H+/+ OVA/OVA; solid squares, LTA4H−/− OVA/OVA. (B) Eosinophil numbers in bronchoalveolar lavage (BAL) fluid. Horizontally striped bar, LTA4H+/+ PBS/OVA; open bar, LTA4H−/− PBS/OVA; hatched bar, LTA4H+/+ OVA/OVA; solid bar, LTA4H−/− OVA/OVA. (C) Numbers of CD3+, CD4+, and CD8+ T cells in the lung and BAL fluid after sensitization and challenge. Numbers of cells in the lung and BAL were determined as described in Materials and Methods. Open bars, LTA4H+/+ OVA/OVA; solid bars, LTA4H−/− OVA/OVA. (D) Cytokine levels in BAL fluid. IL-4, IL-5, IL-13, and IFN-γ levels in BAL fluid were measured in supernatants by enzyme-linked immunosorbent assay (ELISA). Horizontally striped bars, LTA4H+/+ PBS/OVA; open bars, LTA4H−/− PBS/OVA; hatched bars, LTA4H+/+ OVA/OVA; solid bars, LTA4H−/− OVA/OVA. (E) IL-4, IL-5, and IL-13 production in lung cells from LTA4H−/− mice after sensitization and challenge. Cytokine levels in culture supernatants of cultured lung mononuclear cells (MNC), in the presence or absence of OVA (100 μg/ml), were determined by ELISA. Open bars, LTA4H+/+ OVA/OVA; solid bars, LTA4H−/− OVA/OVA.*P < 0.05 and **P < 0.01 between LTA4H−/− mice (LTA4H−/− OVA/OVA) and LTA4H-sufficient mice (LTA4H+/+ OVA/OVA).