Sex differences in the impact of ozone on survival and alveolar macrophage function of mice after Klebsiella pneumoniae infection.
BACKGROUND
Sex differences have been described in a number of pulmonary diseases. However, the impact of ozone exposure followed by pneumonia infection on sex-related survival and macrophage function have not been reported. The purpose of this study was to determine whether ozone exposure differentially affects: 1) survival of male and female mice infected with Klebsiella pneumoniae, and 2) the phagocytic ability of macrophages from these mice.


METHODS
Male and female C57BL/6 mice were exposed to O3 or to filtered air (FA) (control) and then infected intratracheally with K. pneumoniae bacteria. Survival was monitored over a 14-day period, and the ability of alveolar macrophages to phagocytize the pathogen in vivo was investigated after 1 h.


RESULTS
1) Both male and female mice exposed to O3 are significantly more susceptible to K. pneumoniae infection than mice treated with FA; 2) although females appeared to be more resistant to K. pneumoniae than males, O3 exposure significantly increased the susceptibility of females to K. pneumoniae infection to a greater degree than males; 3) alveolar macrophages from O3-exposed male and female mice have impaired phagocytic ability compared to macrophages from FA-exposed mice; and 4) the O3-dependent reduction in phagocytic ability is greater in female mice.


CONCLUSIONS
O3 exposure reduces the ability of mice to survive K. pneumoniae infection and the reduced phagocytic ability of alveolar macrophages may be one of the contributing factors. Both events are significantly more pronounced in female mice following exposure to the environmental pollutant, ozone.
Mikerov
Anatoly N
AN
The Penn State Center for Host defense, Inflammation, and Lung Disease (CHILD) Research, Department of Pediatrics, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA. anm3@psu.edu
Gan
Xiaozhuang
X
Umstead
Todd M
TM
Miller
Laura
L
Chinchilli
Vernon M
VM
Phelps
David S
DS
Floros
Joanna
J
D000818:Animals; D005260:Female; D007710:Klebsiella Infections / Q000139:chemically induced* / Q000473:pathology / Q000503:physiopathology*; D007711:Klebsiella pneumoniae; D008264:Macrophages / Q000187:drug effects*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010126:Ozone / Q000633:toxicity*; D018410:Pneumonia, Bacterial / Q000188:drug therapy / Q000473:pathology / Q000503:physiopathology*; D011650:Pulmonary Alveoli / Q000187:drug effects / Q000503:physiopathology*; D012737:Sex Factors; D016019:Survival Analysis; D015996:Survival Rate
D010126:Ozone