The cellular immune response to Bordetella pertussis in two children with whooping cough

There is increasing evidence that the cellular immune response to Bordetella pertussis plays an important role in the immune protection. Particularly in animal models, Bordetella pertussis-specific T-cells have been shown to confer immunity. In this case report, we therefore investigated the cellular immune response to whole cell Bordetella pertussis bacteria, to the pertussis antigens filamentous hemagglutinin and pertussis toxoid defined by lymphoproliferation and cytokine secretion. Two children with whooping cough were compared to three individuals vaccinated against whooping cough with a whole cell pertussis vaccine. In contrast to the vaccinated controls, the cellular immune response to Bordetella pertussis in children with whooping cough was characterized by a strong proliferation of T cells to whole pertussis bacteria as well as to filamentous hemagglutinin and pertussis toxoid. This response was defined by a marked Th-1 type T cell response with IFN-gamma secretion to all Bordetella pertussis antigens. However, in the control individuals IFN-gamma was secreted only to whole cell Bordetella pertussis bacteria and filamentous hemagglutinin but not to pertussis toxoid. A Th-2 type cytokine response could not be detected in any condition. Our observations suggest that in the immune defense of a natural Bordetella pertussis infection, the Th-1 specific T cell response to filamentous hemagglutinin and particularly to pertussis toxoid may play a major role.