Table 2.

Summary of the virulence functions of protease IV.

Type of Host	Host Studied	Effect on Host	References
Plant	Arabidopsis (thale cress, a cabbage)	Disruption of normal homeostatis and induction of a defensive host response	[77]
Insect	Tenebrio molitor (mealworms) or Galleria mellonella (wax moth)	Bacteremia protected by PIV-mediated killing of defensive cells. Also, destruction of apolipophorin III to reduce phagocytosis of bacteria	[75,76,78,79]
Mammals	Rabbit corneal infection	Destruction of host defensive proteins and possibly collagens and induction of inflammation	[38,39,40,41,42,64,81,83,84]
	Rodent respiratory tract	Wild-type P. aeruginosa in agar beads had more colony forming units that a mutant deficient in PIV.	[45]
	Rodent respiratory tract	Destruction of host defense proteins (surfactants A, D, and B) that opsonize the bacteria. Also, enhance bacteria (CFU) in lung more than PIV-lacking mutant	[50]
	Mouse lung	PIV enhanced pneumococcal lung infection and bacteremia by destroying IL-22 in the lung.	[80]
	Human lung	Destroy IL-22 in human lung fluids including sputum of patients with Pseudomonas pneumonia	[51]