Anti-inflammatory drug development: Broad or specific chemokine receptor antagonists?

Chemokines and chemokine receptors form a complex and diverse system known to be relevant for leukocyte activation and trafficking. There has been significant interest in the development of anti-inflammatory drugs that antagonize the function of chemokines or their receptors. However, the translation of results from animal models to human disease has not been simple, and drug development in the field has failed in many instances, leading to the question of whether targeting several chemokines may be more useful than targeting a single chemokine or receptor. This question has no simple answer. The complexity of the chemokine system may result in functional redundancy, which is not absolute. However, this complexity is likely important for the physiology of the immune system. The success of future development of therapies targeting chemokines and their receptors requires a complete understanding of the diversity and complexity of the system in human chronic inflammatory diseases and infection.