Abolition of the bactericidal function of polymorphs by ferritin-antiferritin complexes.

In plasma clots the presence of ferritin-antiferritin complexes interferes with the bactericidal powers of polymorphs against Klebsiella pneumoniae and Escherichia coli. Equivalent concentrations of apoferritin-antiferritin complexes, which lack Fe, do not have this effect and it is therefore suggested that the iron-binding capacity of lactoferrin in polymorphs plays an essential role in the bactericidal power of the cell. Similar results were obtained in vivo where ferritin-antiferritin complexes cause a high mortality in otherwise non-lethal infections. Evidence suggests that it is the iron in the ferritin which is responsible for the rapid intracellular bacterial growth and that lactoferrin normally plays an important protective role within the polymorphs.