Research Article Differential Mucin Expression by Respiratory Syncytial Virus and Human Metapneumovirus Infection in Human Epithelial Cells Ma. Del Rocío Baños-Lara, 1 Boyang Piao, 1 and Antonieta Guerrero-Plata 1,2 1 Department of Pathobiological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA 2 Center for Experimental Infectious Disease Research, Louisiana State University, Baton Rouge, LA 70803, USA Correspondence should be addressed to Antonieta Guerrero-Plata; aguerrp@lsu.edu Received 23 December 2014; Accepted 8 April 2015 Academic Editor: Julio Galvez Copyright © 2015 Ma. Del Roc´ ıo Ba˜ nos-Lara et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Mucins (MUC) constitute an important component of the infammatory and innate immune response. However, the expression of these molecules by respiratory viral infections is still largely unknown. Respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) are two close-related paramyxoviruses that can cause severe low respiratory tract disease in infants and young children worldwide. Currently, there is not vaccine available for neither virus. In this work, we explored the diferential expression of MUC by RSV and hMPV in human epithelial cells. Our data indicate that the MUC expression by RSV and hMPV difers signifcantly, as we observed a stronger induction of MUC8, MUC15, MUC20, MUC21, and MUC22 by RSV infection while the expression of MUC1, MUC2, and MUC5B was dominated by the infection with hMPV. Tese results may contribute to the diferent immune response induced by these two respiratory viruses. 1. Introduction Te mucosal surface of the respiratory tract is protected by a layer of mucus [1], a viscoelastic, gel-like substance that covers the epithelial surface of various mammalian tissues, including the respiratory tract. Te main functions of mucus include protecting the epithelial surface from injury, by facilitating removal of materials that enter the lung and in the pathogene- sis of many lung diseases, particularly those involving chronic infammation of the airways or susceptibility to infection. Te viscous and elastic properties of mucus gel are generally attributable to the physical properties and structural features of mucin (MUC). MUC are high molecular mass, highly glycosylated macromolecules that are the major components of mucus secretions [2]. To date, 22 MUC proteins have been described in human; according to their subcellular local- ization they are classifed in two groups: membrane-bound MUC, which have a transmembrane domain that anchors them to the cell membrane. Te members in this group are MUC1, MUC3A/B, MUC4, MUC11, MUC12, MUC13, MUC15, MUC16, MUC17, MUC18, MUC20, MUC21, and MUC22 and secreted mucins: MUC2, MUC5AC, MUC5B, MUC6, MUC7, MUC8, and MUC19. MUC9 is both located in the cell surface and secreted as well. Except for MUC6, MUC7, and MUC17, all the mucins abovementioned are expressed in the airways [3–5]. High production of mucus is a characteristic in infammatory lung diseases such as bronchial asthma, chronic obstructive pulmonary disease, bronchiectasis, and cystic fbrosis [5]. Moreover, overexpres- sion of MUC has been reported in several malignancies like breast, gastric, colorectal, pancreatic, lung, small bowel, and ovarian cancers [6, 7]. Respiratory syncytial virus (RSV) is a negative sense single stranded RNA virus member of the Paramyxoviridae Hindawi Publishing Corporation Mediators of Inflammation Volume 2015, Article ID 347292, 7 pages http://dx.doi.org/10.1155/2015/347292