title: Impact of sex and ozone exposure on the course of pneumonia in wild type and SP-A (-/-) mice.
abstract: Female mice exhibited higher survival rate than males after pneumonia, with a reversal of this pattern following ozone exposure. Surfactant protein A (SP-A) plays an important role in innate immunity and SP-A (-/-) mice were more susceptible to pneumonia than wild type mice. Here, we investigated underlying mechanisms of the differential susceptibility of mice to pneumonia. Wild type and SP-A (-/-) C57BL/6J male and female mice were exposed to ozone or filtered air (FA) and then infected intratracheally with Klebsiella pneumoniae. Blood, spleen, and lung were analyzed for bacterial counts, lung and spleen weights, and sex hormone and cortisol levels were measured in plasma within two days post-infection. We found: 1) in the absence of ozone-induced oxidative stress, males had higher level of bacterial dissemination compared to females; ozone exposure decreased pulmonary clearance in both sexes and ozone-exposed females were more affected than males; 2) ozone exposure increased lung weight, but decreased spleen weight in both sexes, and in both cases ozone-exposed females were affected the most; 3) plasma cortisol levels in infected mice changed: ozone-exposed>FA-exposed, females>males, and infected>non-infected; 4) no major sex hormone differences were observed in the studied conditions; 5) differences between wild type and SP-A (-/-) mice were observed in some of the studied conditions. We concluded that reduced pulmonary clearance, compromised spleen response to infection, and increased cortisol levels in ozone-exposed females, and the higher level of lung bacterial dissemination in FA-exposed males, contribute to the previously observed survival outcomes.
authors.affiliation: Center for Host defense, Inflammation, and Lung Disease (CHILD) Research, Department of Pediatrics, The Pennsylvania State University College of Medicine, 500 University Drive, Hershey H085, PA 17033, USA.
authors.forename: Anatoly N
authors.initials: AN
authors.lastname: Mikerov
authors.forename: Sanmei
authors.initials: S
authors.lastname: Hu
authors.forename: Faryal
authors.initials: F
authors.lastname: Durrani
authors.forename: Xiaozhuang
authors.initials: X
authors.lastname: Gan
authors.forename: Guirong
authors.initials: G
authors.lastname: Wang
authors.forename: Todd M
authors.initials: TM
authors.lastname: Umstead
authors.forename: David S
authors.initials: DS
authors.lastname: Phelps
authors.forename: Joanna
authors.initials: J
authors.lastname: Floros
mesh_terms: D000393:Air Pollutants / Q000633:toxicity*; D000818:Animals; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007710:Klebsiella Infections / Q000276:immunology* / Q000382:microbiology / Q000503:physiopathology; D007711:Klebsiella pneumoniae / Q000502:physiology; D008168:Lung / Q000254:growth & development / Q000276:immunology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009929:Organ Size / Q000187:drug effects; D010126:Ozone / Q000633:toxicity*; D011014:Pneumonia / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D037662:Pulmonary Surfactant-Associated Protein A / Q000172:deficiency* / Q000235:genetics / Q000276:immunology; D012737:Sex Factors; D013154:Spleen / Q000254:growth & development / Q000276:immunology
chemical_list: D000393:Air Pollutants; D037662:Pulmonary Surfactant-Associated Protein A; D010126:Ozone