Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. C URRENT O PINION Autophagy and role in asthma Soma S.S.K. Jyothula a and N. Tony Eissa b Purpose of review Asthma is a common worldwide respiratory illness with significant morbidity and mortality. The disease is characterized by airway inflammation with involvement of multiple biological pathways. Genetic predisposition and increased susceptibility to severe respiratory viral infections are well known clinical features of asthma. Autophagy is an evolutionarily conserved cellular degradation process with significant impact on immunity and antiviral response. In this review we have described the role of autophagy in immune cell survival, proliferation and function. Autophagy has complex effects on immune response involved in inflammation, specifically Th2 immune response. Common respiratory viruses are associated with increased morbidity and mortality in asthmatic patients. Recent findings We describe recent studies showing the effect of autophagy on replication and immune response to common respiratory viruses. The role of autophagy in asthma has recently been investigated. Two studies have been published describing the association of autophagy with asthma. Genetic polymorphism in specific autophagy genes is associated with asthma and influences gene expression in an experimental in-vivo model. Summary These studies provide us with a window into the possible role of autophagy in asthma and offer new clues to pathogenesis. Modulation of autophagy has the potential to develop into a new therapeutic avenue to treat this common respiratory ailment. Keywords asthma, autophagy, common respiratory viruses, genetic polymorphism INTRODUCTION Asthma is a chronic respiratory illness caused by chronic airway inflammation. In the USA, the pre- valence of asthma was 8.2% (24.6 million persons) in 2009. Prevalence among children (persons aged <18 years) was 9.6%, and among adults was 7.7% [1]. It is a complex disease with multiple known associated triggers and is classified into various clinical phenotypes (allergic asthma, work-related asthma). The biological and pathological pathways involved are myriad with no single process explain- ing the disease process completely. ASTHMA: ROLE OF ADAPTIVE AND INNATE IMMUNITY Airway inflammation is the most accepted paradigm in the pathogenesis of asthma. The role of adaptive immunity in airway inflammation has been studied extensively. The adaptive immune response is anti- gen-dependent and T helper cells (CD4 þ ) play a role in execution. The two major T helper pathways (Th1 and Th2) are characterized by the cytokine profiles (Th1 – IFN-g, TNF-b; Th2 – IL-4, IL-5, IL-10 and IL-13). Th2 immune response is crucial in asthma based on murine models and biological samples from asthmatic patients. Asthma arises from an imbalance between Th1 and Th2 pathways; over- driven Th2 inflammation leads to airway inflam- mation and asthma. Innate immunity is an ancient conserved immune response to infectious agents by recog- nition of pathogen-associated molecular patterns (PAMPs) and acts as the first immune barrier. Unlike the adaptive immune response, it is rapid, antigen processing is not required and memory is not gener- ated. A number of immune and nonimmune cells in a Department of Medicine, The Methodist Hospital/Weill Cornell Medical College and b Baylor College of Medicine, Houston, Texas, USA Correspondence to Soma S.S.K. Jyothula, Department of Medicine, The Methodist Hospital/Weill Cornell Medical College, 6550 Fannin St, SM1001 Houston, TX 77030, USA. Tel: +1 713 441 2104; fax: +1 713 791 5043; e-mail: ssjyothula@tmhs.org Curr Opin Pulm Med 2013, 19:30–35 DOI:10.1097/MCP.0b013e32835b1150 www.co-pulmonarymedicine.com Volume 19  Number 1  January 2013 REVIEW