Figure 8. Model of impaired innate immunity by inhibition of granulopoiesis in a Clostridium perfringens-infected host.

Infection with C. perfringens diminishes mature neutrophils in bone marrow leading to impairment of replenishment of mature neutrophils in the peripheral circulation, resulting in host innate immune deficiency. The major virulence factor of C. perfringens, α-toxin, plays an important role in this phenomenon by directly blocking neutrophil differentiation. Together, impairment of the innate immune system by the inhibition of granulopoiesis is crucial for the pathogenesis of C. perfringens.