Pulmonary cryptococcosis induces chitinase in the rat.
BACKGROUND
We previously demonstrated that chronic pulmonary infection with Cryptococcus neoformans results in enhanced allergic inflammation and airway hyperreactivity in a rat model. Because the cell wall of C. neoformans consists of chitin, and since acidic mammalian chitinase (AMCase) has recently been implicated as a novel mediator of asthma, we sought to determine whether such infection induces chitinase activity and expression of AMCase in the rat.


METHODS
We utilized a previously-established model of chronic C. neoformans pulmonary infection in the rat to analyze the activity, expression and localization of AMCase.


RESULTS
Our studies indicate that intratracheal inoculation of C. neoformans induces chitinase activity within the lung and bronchoalveolar lavage fluid of infected rats. Chitinase activity is also elicited by pulmonary infection with other fungi (e.g. C. albicans), but not by the inoculation of dead organisms. Enhanced chitinase activity reflects increased AMCase expression by airway epithelial cells and alveolar macrophages. Systemic cryptococcosis is not associated with increased pulmonary chitinase activity or AMCase expression.


CONCLUSIONS
Our findings indicate a possible link between respiratory fungal infections, including C. neoformans, and asthma through the induction of AMCase.
Vicencio
Alfin G
AG
Department of Pediatrics, Division of Respiratory and Sleep Medicine, Albert Einstein College of Medicine and Children's Hospital at Montefiore, Bronx, USA. dvicenci@montefiore.org
Narain
Swati
S
Du
Zhongfang
Z
Zeng
Wang Yong
WY
Ritch
James
J
Casadevall
Arturo
A
Goldman
David L
DL
D000818:Animals; D015153:Blotting, Western; D001992:Bronchoalveolar Lavage Fluid; D002688:Chitinases / Q000378:metabolism*; D003453:Cryptococcosis / Q000201:enzymology* / Q000382:microbiology*; D003455:Cryptococcus neoformans / Q000276:immunology; D004195:Disease Models, Animal; D008172:Lung Diseases, Fungal / Q000201:enzymology* / Q000382:microbiology*; D008297:Male; D051381:Rats; D011916:Rats, Inbred F344
D002688:Chitinases