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A series of pyridines were synthesized and evaluated as bronchospasmolytic / anti-allergic agents. Several of these compounds were found to: 1) inhibit the release of histamine; 2) antagonize histamine, bradykinin, LTD4 and PAF; 3) suppress the IgE-mediated passive cutaneous anaphylaxis (PCA) reaction. The most interesting substance of this series 2,6-dimethyl-3-nitro-4[(2-(4-diphenylmethyl-1-piperazinyl)ethyl)amino]pyridine 1, (HWA 214), was selected for further pharmacological evaluation. The novel, orally active agent 1 does not have such drawbacks as causing drowsiness or being effective only as a prophylactic drug, and could provide advantages over other non-sedative compounds, such as terfenadine and astemizole, in that it is water soluble and thus can be administered through inhalation or through intravenous application.

Background: Myeloid dendritic cells (DCs) are increased in the airway wall of patients with chronic obstructive pulmonary disease (COPD), and postulated to play a crucial role in COPD. However, DC phenotypes in COPD are poorly understood. Methods: Function-associated surface molecules on bronchoalveolar lavage fluid (BALF) DCs were analyzed using flow cytometry in current smokers with COPD, in former smokers with COPD and in never-smoking controls. Results: Myeloid DCs of current smokers with COPD displayed a significantly increased expression of receptors for antigen recognition such as BDCA-1 or Langerin, as compared with never-smoking controls. In contrast, former smokers with COPD displayed a significantly decreased expression of these receptors, as compared with neversmoking controls. A significantly reduced expression of the maturation marker CD83 on myeloid DCs was found in current smokers with COPD, but not in former smokers with COPD. The chemokine receptor CCR5 on myeloid DCs, which is also important for the uptake and procession of microbial antigens, was strongly reduced in all patients with COPD, independently of the smoking status. Conclusion: COPD is characterized by a strongly reduced CCR5 expression on myeloid DCs in the airway lumen, which might hamper DC interactions with microbial antigens. Further studies are needed to better understand the role of CCR5 in the pathophysiology and microbiology of COPD.