Chun Geun Lee

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Interleukin (IL)-13 is a key mediator of tissue fibrosis caused by T helper cell type 2 inflammation. We hypothesized that the fibrogenic effects of IL-13 are mediated by transforming growth factor (TGF)-beta. To test this hypothesis we compared the regulation of TGF-beta in lungs from wild-type mice and CC10-IL-13 mice in which IL-13 overexpression causes(More)
Exaggerated levels of VEGF (vascular endothelial growth factor) are present in persons with asthma, but the role(s) of VEGF in normal and asthmatic lungs has not been defined. We generated lung-targeted VEGF165 transgenic mice and evaluated the role of VEGF in T-helper type 2 cell (TH2)-mediated inflammation. In these mice, VEGF induced, through(More)
Chitin is a ubiquitous polysaccharide in fungi, insects, and parasites. We hypothesized that chitin is a size-dependent regulator of innate immunity. To test this hypothesis, we characterized the effects of chitins of different sizes on murine bronchoalveolar or peritoneal macrophages. In these studies, large chitin fragments were inert, while both(More)
BACKGROUND The evolutionarily conserved 18-glycosyl-hydrolase family contains true chitinases and chitinase-like proteins that lack enzymatic activity. Acidic mammalian chitinase has recently been associated with animal models of asthma. The related chitinase-like protein, YKL-40 (also called human cartilage glycoprotein 39 [HCgp-39] and chitinase 3-like(More)
Viral infections have more severe consequences in patients who have been exposed to cigarette smoke (CS) than in those not exposed to CS. For example, in chronic obstructive pulmonary disease (COPD), viruses cause more severe disease exacerbation, heightened inflammation, and accelerated loss of lung function compared with other causes of disease(More)
The 18 glycosyl hydrolase family of chitinases is an ancient gene family that is widely expressed from prokaryotes to eukaryotes. In mammals, despite the absence of endogenous chitin, a number of chitinases and chitinase-like proteins (C/CLPs) have been identified. However, their roles have only recently begun to be elucidated. Acidic mammalian chitinase(More)
Research interest in bronchopulmonary dysplasia (BPD) has steadily increased, and numerous potential mediators have been implicated in the development of the disease. Among such mediators is transforming growth factor (TGF)-beta. Unfortunately, commonly utilized murine transgenic models are not optimal to investigate the effects of TGF-beta specifically(More)
Asthma is a disease whose ability to cause episodic symptomatology has been appreciated since antiquity. Although the fine points of the definition can be debated, it is reasonable to think of asthma as a pulmonary disorder characterized by the generalized reversible obstruction of airflow and to define reversibility as a greater than 12% increase in the(More)
Chitin is the second most abundant biopolymer in nature, where it protects crustaceans, parasites, fungi, and other pathogens from the adverse effects of their environments, hosts, or both. Because chitin does not exist in mammals, it had been assumed that the chitinases that degrade it are also restricted to lower life forms. However, chitinases and(More)
Chitin is a ubiquitous polysaccharide in fungi, insects, and parasites. To test the hypothesis that chitin is an important immune modulator, we characterized the ability of chitin fragments to regulate murine macrophage cytokine production in vitro and induce acute inflammation in vivo. In this study, we show that chitin is a size-dependent stimulator of(More)