Y. Aratani et al., Differential host susceptibility to pulmonary infections with bacteria andfungi in mice deficient in myeloperoxidase, J INFEC DIS, 182(4), 2000, pp. 1276-1279
Myeloperoxidase (MPO), which is located within neutrophils capable of produ
cing hypochlorous acid, is active in vitro against bacteria and fungi. Howe
ver, MPO-deficient persons are usually healthy. To define the in vivo contr
ibution of MPO to early host defense against pulmonary infections, MPO-defi
cient and control mice were intranasally infected with various fungi and ba
cteria, and the number of residual microorganisms in lungs was compared 48
h later. MPO-deficient mice showed severely reduced cytotoxicity to Candida
albicans, Candida tropicalis, Trichosporon asahii, and Pseudomonas aerugin
osa. However, the mutant mice showed a slight but significantly delayed cle
arance of Aspergillus fumigatus and klebsiella pneumoniae and had comparabl
e levels of resistance to the wild type against Candida glabrata, Cryptococ
cus neoformans, Staphylococcus aureus, and Streptococcus pneumoniae. These
results suggest that the MPO-dependent oxidative system is important for ho
st defense against fungi and bacteria, although the effect varies by pathog
en species.