Part 1: Lymphocytes as Orchestrators of Airway Inflammation. T-Lymphocytes in Allergic Asthma. Immune Regulation By T Cells Secreting Different Cytokines. T Cell Subtypes in Allergy. Hyposensitisation of Allergic Immune Responses and T Cell Anergy. New Prospects for Immunotherapy in Asthma. Part 2: Eosinophils in Asthma. Possible Role of IL-5 Ligand-Receptor System in Eosinophilia. The IL-5 Receptor on Human Eosinophils. The Mobilization and Activation of Eosinophils. Eosinophil Derived Pro-Inflammatory Mediators. Mechanisms of Immediate Hypersensitivity and Hyperresponsiveness: Mediators, Antagonists and Role of Interleukins. The Role of Cytokines in Eosinophilia and Modulatory Effects of Glucocorticoids. Immunopharmacology of the Eosinophil in Asthma. Matrix Components of Airways and Their Deposition in Asthma. Part 3: Monocyte and Macrophage Function in Asthma. Role of Monocytes-Macrophages in Bronchial Asthma. Mast Cells and Their Role in Inflammation. Part 4: New Perspectives in Asthma. Novel Therapeutic Approaches in Asthma. Anti-Inflammatory Effects of Novel Selective Cyclic Nucleotide Phosphodiesterase Inhibitors. Concluding Remarks. Possibilities for Future Therapies.