m-50367 and Asthma

We previously reported an orally active anti-allergic agent, M50367, modulated Th1/Th2 balance to down-regulate Th2 response in a murine model of atopic asthma. In this study, we examined the effect of M50354, the active metabolite of M50367, on the differentiation of naïve Th cells into Th1/Th2 cells. M50354 at 3 microM decreased the generation of Th2 cells by 0.2-fold and increased that of Th1 cells by 1.6-fold from naïve Th cells primed with antigenic peptide and antigen-presenting cells. Its effect was also seen when naïve Th cells were primed with anti-T cell receptor and anti-CD28 agonistic antibodies instead of antigen and antigen-presenting cells. M50354 decreased early endogenous IL-4 production in the nai;ve Th cell priming culture without affecting interferon-gamma production and proliferation. In contrast, M50354 had no effect on interferon-gamma and IL-4 production from mature Th1 and Th2 cells. These results suggest that M50354 directly acts on naïve Th cells to suppress their differentiation into Th2 cells.

Topics: Administration, Oral; Animals; Anti-Allergic Agents; Antibodies; Antigen-Presenting Cells; Antigens; Asthma; Benzimidazoles; Cell Differentiation; Cell Division; Dose-Response Relationship, Drug; Interferon-gamma; Interleukin-4; Mice; Mice, Inbred BALB C; Mice, Transgenic; Reaction Time; Th1 Cells; Th2 Cells

We have found a novel anti-allergic agent, M50367, which suppresses IgE biosynthesis and eosinophil accumulation in vivo. In this study, we evaluated the ability of M50367 to modulate Th1/Th2 balance in Th2-background BALB/c mice and to inhibit airway hyperresponsiveness in a murine model of atopic asthma. Oral M50367 at 3-30 mg/kg/day exhibited 51 to 73% reduction of IL-4/IL-5 production and 2- to 5-fold augmentation of IFN-gamma production by Ag-stimulated cultured splenocytes of the mice sensitized with DNP-Ascaris. These alterations in Th1/Th2 cytokine production were accompanied by 55-85% suppression of plasma IgE level. Oral M50367 at a dose of 10 mg/kg/day significantly inhibited Ig-independent peritoneal eosinophilia by 54%, which was induced by repeated i.p. injections of Ascaris suum extract. To develop airway hyperresponsiveness caused by allergic airway inflammation, BALB/c mice were sensitized with i.p. OVA injections, followed three times by OVA inhalation. Oral M50367 significantly inhibited the increase in airway reactivity to acetylcholine, together with the elevation of plasma IgE level and pulmonary eosinophilia, which were observed in vehicle-treated mice 1 day after the last inhalation. Moreover, M50367 treatment reduced IL-4 and IL-5 production and tended to enhance IFN-gamma production, not only by cultured splenocytes, but also in bronchoalveolar lavage fluid. These results suggest that M50367 has a modulating ability of Th1/Th2 balance to down-regulate Th2 response in the circulating system as well as at the sites of inflammation, and may be beneficial for the treatment of allergic disorders such as atopic asthma.

Topics: Adjuvants, Immunologic; Administration, Oral; Animals; Anti-Allergic Agents; Antibody Specificity; Antigens, Helminth; Ascaris suum; Asthma; Benzimidazoles; Bronchial Hyperreactivity; Dinitrobenzenes; Disease Models, Animal; Eosinophilia; Hypersensitivity, Immediate; Immunoglobulin E; Immunoglobulins; Male; Mice; Mice, Inbred BALB C; Peritoneal Lavage; Spleen; Th1 Cells; Th2 Cells