• Manisha Singh, Seung-Hyo Lee, Paul Porter, Chuang Xu, Ayako Ohno, Robert L Atmar, Stephen B Greenberg, Venkata Bandi, Jim Gern, Svetlana Amineva, Alex Aminev, Tim Skern, Pamela Smithwick, Sarah Perusich, Nadia Barrow, Luz Roberts, David B Corry, and Farrah Kheradmand.
• Department of Medicine, Division of Pulmonary and Critical Care, Baylor College of Medicine, Houston, Tex., USA.
• J. Allergy Clin. Immunol. 2010 Jun 1;125(6):1369-1378.e2.

BackgroundTobacco-related lung diseases, including chronic obstructive pulmonary disease (COPD), are major causes of lung-related disability and death worldwide. Acute exacerbation of COPD (AE-COPD) is commonly associated with upper and lower respiratory tract viral infections and can result in respiratory failure in those with advanced lung disease.ObjectiveWe sought to determine the mechanism underlying COPD exacerbation and host response to pathogen-derived factors.MethodsOver a 24-month period, we assessed the viral causes for upper and lower respiratory tract infections in patients with COPD (n = 155) and control subjects (n = 103). We collected nasal and bronchoalveolar lavage fluid and peripheral blood under baseline and exacerbated conditions. We determined the effect of human rhinovirus (HRV) proteinases on T-cell activation in human subjects and mice.ResultsHRVs are isolated from nasal and lung fluid from subjects with AE-COPD. Bronchoalveolar lavage fluid and CD4 T cells from patients with COPD exhibited a T(H)1 and T(H)2 cell cytokine phenotype during acute infection. HRV-encoded proteinase 2A activated monocyte-derived dendritic cells in vitro and induced strong T(H)1 and T(H)2 immune responses from CD4 T cells. Intranasal administration of recombinant rhinovirus proteinase 2A in mice resulted in an increase in airway hyperreactivity, lung inflammation, and IL-4 and IFN-gamma production from CD4 T cells.ConclusionOur findings suggest that patients with severe COPD show T(H)1- and T(H)2-biased responses during AE-COPD. HRV-encoded proteinase 2A, like other microbial proteinases, could provide a T(H)1- and T(H)2-biasing adjuvant factor during upper and lower respiratory tract infection in patients with severe COPD. Alteration of the immune response to secreted viral proteinases might contribute to worsening of dyspnea and respiratory failure in patients with COPD.Copyright (c) 2010 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

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