Airway epithelium

The pharynx, larynx, trachea and bronchi are lined with pseudostratified, ciliated columnar epithelium that contain at least eight cell types, including mucous secretory goblet and Clara cells, which produce a protective mucus layer of 5-10 jum thickness (see Table 9.2). Subepithelial secretory glands, present in the bronchial submucosa, also contribute to the mucus blanket [9]. Through coordinated ciliary movement a propulsive wave is created, which continuously moves the mucus layer up towards the larynx. Consequently, the mucosal surface of trachea and bronchi is constantly swept to remove inhaled materials. As the bronchi divide into bronchioli, the ciliated columnar respiratory epithelium is much thinner and changes to a simpler non-ciliated cuboidal epithelium. The epithelium in the terminal and respiratory bronchioles consists of ciliated, cuboidal cells and a small number of Clara cells. However, Clara cells become the most predominant type in the most distal part of the respiratory bronchioles [10]. 

Site Generation Diameter [mm] Epithelial cell type Thickness [pm] 

Conducting airways Trachea 0 20-18 Pseudostrati fled cell Ciliated cell Columnar cell Goblet cell Serous cell Mucous cell 20-40 

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The importance of respiratory heat and water losses is not confined to the respiratory structures. Inspiration of cold, hot, or dry air poses the potential threats of thermal injury or desiccation to the airway epithelium" - T8,69 g challenge to whole-body thermoregulation. 

Submucosa Layer of tissue beneath the airway epithelium. 

Matrosovich M, Klenk H-D (2003) Natural and synthetic sialic acid-containing inhibitors of influenza virus receptor binding. Rev Med Virol 13 85-97 Matrosovich MN, Matrosovich TY, Gray T, Roberts NA, Klenk H-D (2004) Neuraminidase is important for the initiation of influenza virus infection in human airway epithelium. J Virol 78 12665-12667... 

ILLEK B and FISCHER H (1998) Flavonoids stimulate Cl conductance of hmnan airway epithelium in vitro and in vivo. Am. /Physiol. 275 (5 Ptl) L902-L910. 

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First clinical human gene therapy trials with polyplexes were performed using cancer vaccines based on autologous patient tumor cells. These were modified ex vivo with interleukin-2 pDNA. To obtain high level transfection rates of patient s primary tumor cells, Tf-PLL/pDNA polyplexes linked with inactivated endosomolytic adenovirus particles were applied [221]. Polymer-based in vivo human gene transfer studies were performed with PEGylated PLL polyplexes, delivering CFTR pDNA to the airway epithelium of cystic fibrosis patients [222],... 

Ferkol T, Perales JC, Eckman E, Kaetzel CS, Hanson RW, Davis PB (1995) Gene transfer into the airway epithelium of animals by targeting the polymeric immunoglobulin receptor 200. J Clin Invest 95 493-502... 

Hastie, A.T., et al., HSP27 elevated in mild allergic inflammation protects airway epithelium from H2S04 effects, Am. J. Physiol. 273, 2 Pt 1, L401, 1997. 

Baeza-Squiban, A., Bonvallot, V., Boland, S. and Marano, F. (1999). Airborne particles evoke an inflammatory response in human airway epithelium. Activation of transcription factors, Cell Biol. Toxicol., 15, 375-380. 

J. L. Lemoine, R. Farley, and L. Huang. Mechanism of efficient transfection on the nasal airway epithelium by hypotonic shock. Gene Ther 12 1275-1282 (2005). 

In vitro models based on CF airway epithelium have been used widely in order to better understand the CF pathophysiology, to have a tool to study alterations in airway permeability and to assess the efficiency of gene vectors. Utilising approaches similar to those for cultivation of cells from healthy tissues, several protocols have been developed to culture airway epithelial cells harvested from CF patients [83, 84], The development of immortalised cell lines with a CF phenotype has been a significant benefit for investigators in... 

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Boers JE, Ambergen AW, Thunnissen FB (1999) Number and proliferation of Clara cells in normal human airway epithelium. Am J Respir Crit Care Med 159(5 Pt 1) 1585—1591. 

Jain B, Rubinstein I, Robbins RA, Sisson JH (1995) TNF-alpha and IL-1 beta upregulate nitric oxide-dependent ciliary motility in bovine airway epithelium. Am J Physiol 268(6 Pt 1) L911-L917. 

Ehrhardt C, Collnot EM, Baldes C, Becker U, Laue M, Kim KJ, Lehr CM (2006) Towards an in vitro model of cystic fibrosis small airway epithelium Characterisation of the human bronchial epithelial cell line CFBE41o-. Cell Tissue Res 323(3) 405-415. 

Bahadduri PM, D Souza VM, Pinsonneault JK, Sadee W, Bao S, Knoell DL, Swaan PW (2005) Functional characterization of the peptide transporter PEPT2 in primary cultures of human upper airway epithelium. Am J Respir Cell Mol Biol 32(4)319-325. 

Hubbs, A. F., Battelli, L. A., Goldsmith, W. T., Porter, D. W., Frazer, D., Friend, S., Schwegler-Berry, D., Mercer, R. R., Reynolds, J. S., Grote, A., Castranova, V., Kullman, G., et al. (2002). Necrosis of nasal and airway epithelium in rats inhaling vapors of artificial butter flavoring. Toxicol. Appl. Pharmacol. 185, 128-135. 

Values for the average vapor-transfer coefficient from the gas phase to the airway epithelium can also be estimated from heat-transfer data in straight, curved, or bifurcating cylindrical tubes by using the analogy between heat transfer and mass transfer. Such an approach has been used by Yeh to predict the diffusional deposition of small particles in the conducting airways. 

The airway effects of released acetylcholine are mediated via activation of three distinct muscarinic receptor subtypes Mj, in parasympathetic ganglia, mucous glands and alveolar walls autoinhibitory M2, in parasympathetic nerve terminals and M3, in airway smooth muscle, mucus glands, and airway epithelium. 

Perricone, M.A., Morris, J.E., Pavelka, K., et al. (2001). Aerosol and lobar administration of a recombinant adenovirus to individuals with cystic fibrosis. II. Transfection efficiency in airway epithelium. Hum. Gene Ther., 12(11), 1383-1394. 

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Pickles RJ. 2004. Physical and biological barriers to viral vector-mediated delivery of genes to the airway epithelium. Proc Am Thorac Soc. 1 302-308. 

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