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author:("Lee, Chun gen")
1.  Chitin Regulation of Immune Responses: An Old Molecule With New Roles 
Current opinion in immunology  2008;20(6):684-689.
Chitin, the second most abundant polysaccharide in nature, is commonly found in lower organisms such as fungi, crustaceans and insects, but not in mammals. Although the non-specific anti-viral and anti-tumor activities of chitin/chitin derivatives were described two decades ago, the immunological effects of chitin have been only recently been addressed. Recent studies demonstrated that chitin has complex and size-dependent effects on innate and adaptive immune responses including the ability to recruit and activate innate immune cells and induce cytokine and chemokine production via a variety of cell surface receptors including macrophage mannose receptor, toll-like receptor 2 (TLR-2), and Dectin-1. They also demonstrated adjuvant effects of chitin in allergen-induced Type 1 or Type 2 inflammation and provided insights into the important roles of chitinases and chitinase-like proteins (C/CLP) in pulmonary inflammation. The status of the field and areas of controversy are highlighted.
doi:10.1016/j.coi.2008.10.002
PMCID: PMC2605627  PMID: 18938241
chitin; chitinases; chitinase-like protein; innate and adaptive immunity
2.  Cigarette smoke selectively enhances viral PAMP– and virus-induced pulmonary innate immune and remodeling responses in mice 
The Journal of Clinical Investigation  2008;118(8):2771-2784.
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 exacerbation. Symptomatology and mortality in influenza-infected smokers is also enhanced. To test the hypothesis that these outcomes are caused by CS-induced alterations in innate immunity, we defined the effects of CS on pathogen-associated molecular pattern–induced (PAMP-induced) pulmonary inflammation and remodeling in mice. CS was found to enhance parenchymal and airway inflammation and apoptosis induced by the viral PAMP poly(I:C). CS and poly(I:C) also induced accelerated emphysema and airway fibrosis. The effects of a combination of CS and poly(I:C) were associated with early induction of type I IFN and IL-18, later induction of IL-12/IL-23 p40 and IFN-γ, and the activation of double-stranded RNA-dependent protein kinase (PKR) and eukaryotic initiation factor-2α (eIF2α). Further analysis using mice lacking specific proteins indicated a role for TLR3-dependent and -independent pathways as well as a pathway or pathways that are dependent on mitochondrial antiviral signaling protein (MAVS), IL-18Rα, IFN-γ, and PKR. Importantly, CS enhanced the effects of influenza but not other agonists of innate immunity in a similar fashion. These studies demonstrate that CS selectively augments the airway and alveolar inflammatory and remodeling responses induced in the murine lung by viral PAMPs and viruses.
doi:10.1172/JCI32709
PMCID: PMC2483678  PMID: 18654661

Results 1-2 (2)