The normal function of the immune system in a clinical context

The normal response of the human immune system is a highly integrated process in which signals generated though early recognition by the innate immune system will have significant impact of the subsequent adaptive response. This integration ensures that the effector mechanisms triggered are effectively targeted towards the infectious agent in question, whether, for example, a virus or bacteria. Here the different components of the immune system are discussed and the way these components interact to define the final response is considered. Although a thorough review of immune dysfunction and clinical immunology is beyond the scope of this review and will be considered elsewhere within this series, certain clinical example will be used in order to illustrate particular points.