Name: culturing of human nasal epithelial cells at the air liquid interface
Uploaded: 2013-10-08T17:30:00
Description: Watch this Scientific Journal Video about Culturing of Human Nasal Epithelial Cells at the Air Liquid Interface at JoVE.com

The authors would like to thank Lisa Dailey for the helpful inputs. 
This work was supported by grants from the National Institutes of Health (ES013611 and HL095163), the Flight Attendant Medical Research Institute (FAMRI), and the Environmental Protection Agency (CR83346301) and declares no conflict of interest. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. Although the research described in this article has been funded in part by the U.S. Environmental Protection Agency through cooperative agreement CR83346301 with the Center for Environmental Medicine, Asthma and Lung Biology at the University of North Carolina-Chapel Hill, it has not been subjected to the agency's required peer and policy review and therefore does not necessarily reflect the views of the agency, and no official endorsement should be inferred. Mention of trade names or commercial products does not constitute endorsement or recommendation for use. Loretta M&uuml;ller is supported by the Swiss National Science Foundation with a personal grant.

1. Prepare Plastic Ware: Coat Plate
<ol>
	<li>Add 500 &mu;l PureCol (1:100 diluted with sterile water) to each well of a 12-well plate.</li>
	<li>Incubate at 37 &deg;C in an incubator for 30 min, remove the PureCol and rinse with HBSS right before the cells are added to the plate (see step 3.1 below).</li>
</ol>
2. Obtaining and Pretreating Biopsy of Human NECs
<ol>
	<li>Nasal scrape biopsy
	<ol>
		<li>Obtain superficial ECs lining the nasal turbinates under direct vision through a 9 mm reusab...

<ol>
	<li>Swamy, M., Jamora, C., Havran, W., Hayday, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epithelial+decision+makers:+in+search+of+the+'epimmunome.">Epithelial decision makers: in search of the 'epimmunome.</a> Nat. Immunol. 11, 656-665 (2010).</li><li>Vareille, M., Kieninger, E., Edwards, M. R., Regamey, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+airway+epithelium:+soldier+in+the+fight+against+respiratory+viruses.">The airway epithelium: soldier in the fight against respiratory viruses.</a> Clin. Microbiol Rev. 24, 210-229 (2011).</li><li>Muller, L., Jaspers, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epithelial+cells,+the+"switchboard"+of+respiratory+immune+defense+responses:+Effects+of+air+pollutants.">Epithelial cells, the "switchboard" of respiratory immune defense responses: Effects of air pollutants.</a> Swiss Med. Wkly. , (2012).</li><li>Sanders, C. J., Doherty, P. C., Thomas, P. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Respiratory+epithelial+cells+in+innate+immunity+to+influenza+virus+infection.">Respiratory epithelial cells in innate immunity to influenza virus infection.</a> Cell Tissue Res. 343, 13-21 (2011).</li><li>Robertson, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Role+of+chemokines+in+the+biology+of+natural+killer+cells.">Role of chemokines in the biology of natural killer cells.</a> J. Leukoc. Biol. 71, 173-183 (2002).</li><li>Adachi, M., Matsukura, S., Tokunaga, H., Kokubu, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Expression+of+cytokines+on+human+bronchial+epithelial+cells+induced+by+influenza+virus.">Expression of cytokines on human bronchial epithelial cells induced by influenza virus.</a> A. Int. Arch. Allergy Immunol. 113, 307-311 (1997).</li><li>Borchers, M. T., Harris, N. L., Wesselkamper, S. C., Vitucci, M., Cosman, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=NKG2D+ligands+are+expressed+on+stressed+human+airway+epithelial+cells.">NKG2D ligands are expressed on stressed human airway epithelial cells.</a> Am. J. Physiol. Lung Cell Mol. Physiol. 291, L222-L231 (2006).</li><li>Groh, V., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Costimulation+of+CD8alphabeta+T+cells+by+NKG2D+via+engagement+by+MIC+induced+on+virus-infected+cells.">Costimulation of CD8alphabeta T cells by NKG2D via engagement by MIC induced on virus-infected cells.</a> Nat. Immunol. 2, 255-260 (2001).</li><li>Obeidy, P., Sharland, A. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=NKG2D+and+its+ligands.">NKG2D and its ligands.</a> Int J. Biochem. Cell Biol. 41, 2364-2367 (2009).</li><li>Horvath, K. M., Brighton, L. E., Zhang, W., Carson, J. L., Jaspers, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epithelial+Cells+From+Smokers+Modify+Dendritic+Cell+Responses+in+the+Context+of+Influenza+Infection+1.">Epithelial Cells From Smokers Modify Dendritic Cell Responses in the Context of Influenza Infection 1.</a> Am. J. Resp. Cell. , (2010).</li><li>Muller, L., Brighton, L. E., Jaspers, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ozone+exposed+epithelial+cells+modify+co-cultured+natural+killer+cells.">Ozone exposed epithelial cells modify co-cultured natural killer cells.</a> AJP Lung. , (2013).</li><li>Turi, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oxidative+stress+activates+anion+exchange+protein+2+and+AP-1+in+airway+epithelial+cells.">Oxidative stress activates anion exchange protein 2 and AP-1 in airway epithelial cells.</a> Am. J. Physiol. Lung Cell Mol. Physiol. 283, 791-798 (2002).</li><li>Zimmermann, G. S., Neurohr, C., Villena-Hermoza, H., Hatz, R., Behr, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anti-inflammatory+effects+of+antibacterials+on+human+Bronchial+epithelial+cells.">Anti-inflammatory effects of antibacterials on human Bronchial epithelial cells.</a> Respir. Res. 10, 89 (2009).</li><li>Lopez-Souza, N., Avila, P. C., Widdicombe, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polarized+cultures+of+human+airway+epithelium+from+nasal+scrapings+and+bronchial+brushings.">Polarized cultures of human airway epithelium from nasal scrapings and bronchial brushings.</a> In Vitro Cell Dev. Biol. Anim. 39 (2003), 266-269 (2003).</li><li>Gray, T. E., Guzman, K., Davis, C. W., Abdullah, L. H., Nettesheim, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mucociliary+differentiation+of+serially+passaged+normal+human+tracheobronchial+epithelial+cells.">Mucociliary differentiation of serially passaged normal human tracheobronchial epithelial cells.</a> Am. J. Respir. Cell Mo.l Biol. 14, 104-112 (1996).</li><li>Adler, K. B., Schwarz, J. E., Whitcutt, M. J., Wu, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+New+Chamber+System+for+Maintaining+Differentiated+Guinea-Pig+Respiratory+Epithelial-Cells+between+Air+and+Liquid-Phases.">A New Chamber System for Maintaining Differentiated Guinea-Pig Respiratory Epithelial-Cells between Air and Liquid-Phases.</a> Biotechniques. 5, 462 (1987).</li><li>Whitcutt, M. J., Adler, K. B., Wu, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+biphasic+chamber+system+for+maintaining+polarity+of+differentiation+of+cultured+respiratory+tract+epithelial+cells.">A biphasic chamber system for maintaining polarity of differentiation of cultured respiratory tract epithelial cells.</a> In Vitro Cell. Dev. Biol. 24, 420-428 (1988).</li><li>Jaspers, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reduced+expression+of+IRF7+in+nasal+epithelial+cells+from+smokers+after+infection+with+influenza.">Reduced expression of IRF7 in nasal epithelial cells from smokers after infection with influenza.</a> Am. J. Respir. Cell Mol. Biol. 43, 368-375 (2010).</li><li>Muller, L., Brighton, L. E., Jaspers, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ozone+exposed+epithelial+cells+modify+cocultured+natural+killer+cells.">Ozone exposed epithelial cells modify cocultured natural killer cells.</a> Am. J. Physiol. Lung Cell Mol. Physiol. 304, 332-341 (2013).</li><li>Ochs, M., Weibel, E. R., Fishmanetal, A. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Fishman's Pulmoary Diseases and Disorders. 4, 23-69 (2008).</li><li>Kesic, M. J., Meyer, M., Bauer, R., Jaspers, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Exposure+to+Ozone+Modulates+Human+Airway+Protease/Antiprotease+Balance+Contributing+to+Increased+Influenza+A+Infection.">Exposure to Ozone Modulates Human Airway Protease/Antiprotease Balance Contributing to Increased Influenza A Infection.</a> PLoS ONE. 7, e35108 (2012).</li><li>Jaspers, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diesel+exhaust+enhances+influenza+virus+infections+in+respiratory+epithelial+cells.">Diesel exhaust enhances influenza virus infections in respiratory epithelial cells.</a> Toxicol. Sci. 85, 990-1002 (2005).</li><li>Jaspers, I., Flescher, E., Chen, L. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ozone-induced+IL-8+expression+and+transcription+factor+binding+in+respiratory+epithelial+cells.">Ozone-induced IL-8 expression and transcription factor binding in respiratory epithelial cells.</a> Am. J. Physiol. 272, L504-L511 (1997).</li><li>Blume, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Barrier+responses+of+human+bronchial+epithelial+cells+to+grass+pollen+exposure.">Barrier responses of human bronchial epithelial cells to grass pollen exposure.</a> Eur. Respir. J. , (2012).</li><li>Bauer, R. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influenza+enhances+caspase-1+in+bronchial+epithelial+cells+from+asthmatic+volunteers+and+is+associated+with+pathogenesis.">Influenza enhances caspase-1 in bronchial epithelial cells from asthmatic volunteers and is associated with pathogenesis.</a> J. Allergy Clin. Immunol. 130, 958-967 (2012).</li><li>Ostrowski, L. E., Stewart, D., Hazucha, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interferon+gamma+stimulates+accumulation+of+gas+phase+nitric+oxide+in+differentiated+cultures+of+normal+and+cystic+fibrosis+airway+epithelial+cells.">Interferon gamma stimulates accumulation of gas phase nitric oxide in differentiated cultures of normal and cystic fibrosis airway epithelial cells.</a> Lung. 190, 563-571 (2012).</li><li>Jardim, M. J., Fry, R. C., Jaspers, I., Dailey, L., Diaz-Sanchez, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Disruption+of+microRNA+expression+in+human+airway+cells+by+diesel+exhaust+particles+is+linked+to+tumorigenesis-associated+pathways.">Disruption of microRNA expression in human airway cells by diesel exhaust particles is linked to tumorigenesis-associated pathways.</a> Environ. Health Perspect. 117, 1745-1751 (2009).</li><li>Horvath, K. M., Brighton, L. E., Herbst, M., Noah, T. L., Jaspers, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Live+Attenuated+Influenza+Virus+(LAIV)+induces+different+mucosal+T+cell+function+in+nonsmokers+and+smokers.">Live Attenuated Influenza Virus (LAIV) induces different mucosal T cell function in nonsmokers and smokers.</a> Clin. Immunol. 142, 232-236 (2012).</li><li>Horvath, K. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nasal+lavage+natural+killer+cell+function+is+suppressed+in+smokers+after+live+attenuated+influenza+virus.">Nasal lavage natural killer cell function is suppressed in smokers after live attenuated influenza virus.</a> Respir. Res. 12, 102 (2011).</li><li>Noah, T. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tobacco+smoke+exposure+and+altered+nasal+responses+to+live+attenuated+influenza+virus.">Tobacco smoke exposure and altered nasal responses to live attenuated influenza virus.</a> Environ. Health Perspect. 119, 78-83 (2011).</li></ol>

Respiratory ECs provide not only a physical barrier to protect the human body from exogenous stimuli20, but also act as a switchboard to initiate and regulate respiratory immune defense responses1-3 via secretion of soluble mediators or direct receptor-ligand cell-cell interactions. In order to further study the role of ECs in the immune response, to examine potential differences among ECs from diseased populations, or to study the effects of exogenous stressors on ECs, it is important to recapitula...

Goal of the technique
Epithelial cells (ECs) in the airways are among the first sites to be directly exposed to inhaled environmental stressors, such as pathogens, allergens or air pollutants. ECs are more than a structural barrier: They act as a switchboard to initiate and regulate the respiratory immune response1-3 via the release of soluble mediators4-6 and the expression of ligands/receptors on their surfac 7-9. While immortalized cell lines can be used as models to study respiratory ECs in vitro, they fail to differentiate into heterogeneous cell populations composed of polarized ciliated and mucus producing cells, similar to what is observed in vivo. To recapitulate important characteristics of the respiratory epithelium observed in vivo, primary airway ECs can be used. Therefore, our goal was to optimize our method utilizing nasal ECs (NECs) obtained from human volunteers. The NECs are expanded and cultured in vitro, yielding a cell culture model of differentiated NECs which mimics many of the features of the nasal epithelium seen in vivo.
Rationale
The use of in vitro models with human primary ECs mimicking in vivo situation - as described in this study - gives unique possibilities to study disease specific differences of ECs, physiological parameters associated with the airway epithelium, or the interactions between ECs and other cell types, such as dendritic cell 10, natural killer cells11 or macrophages. Several existing methods utilize bronchial ECs, which can be obtained invasively via brush biopsies during bronchoscopies, or from otherwise discarded lung tissue12-17. In addition, commercial sources to obtain fully differentiated human airway epithelial cell cultures exist (EpiAirway model from MatTek, Ashland, MA , Clonetics from Lonza, Basel, Switzerland, MucilAir from Epithelix Sars, Geneva Switzerland), where investigators can choose from different donors. However, because of the limited pool of commercially available epithelial cells, limited or prescribed set of parameters, the cost associated with commercially obtaining primary human airway ECs, and the limited access to discarded lung tissue or freshly obtained human bronchial biopsy tissue, prohibit many investigators from conducting studies in fully differentiated human airway ECs. Therefore, we set out to develop a technique that will 1) utilize non-invasively obtained human NECs, 2) provide a protocol yielding cultures of differentiated human airway epithelium, and 3) be reproducible in most lab settings with an existing tissue culture infrastructure.
Advantages over Existing Techniques/Models
Obtaining fresh NECs, as compared to bronchial or small airway ECs, is much less invasive, individuals can be biopsied multiple times with no significant side effects, and superficial nasal scrape biopsies can be conducted in diseased populations which would otherwise not qualify for research-related bronchoscopies. Noninvasive superficial scrape biopsies to obtain NECs allow the investigator to set donor specification a priori, including age, gender, disease status, etc. in accordance with the research objective to be accomplished. Thus, when designing research studies investigators are not limited by clinically available tissues/epithelial specimen, purchase expensive differentiated cell culture models from commercial vendors, or design invasive bronchoscopy studies. In addition, the ease to obtain NECs increases the ability to conduct experiments in cells from different donors, which enhances statistical validation of observed findings. Lastly, the nose is one of the first sites to be exposed to any kind of air-borne stressors. Thus, generating organotypic in vitro culture systems mimicking the nasal epithelium are useful for studying inhalation of viral particles, pollutants, allergen, or gases, which can be easily achieved by using this cell culture system.

<table border="1">
 <tbody>
 <tr>
 <td>Name of the reagent</td>
 <td>Company</td>
 <td>Catalogue number</td>
 <td>Comments (optional)</td>
 </tr>
 <tr>
 <td>Nasal speculum</td>
 <td>Welch Allyn</td>
 <td>Model 22009</td>
 <td>9 mm, reusable polyproylene</td>
 </tr>
 <tr>
 <td>Operating otoscope</td>
 <td>Welch Allyn</td>
 <td>Model 21700</td>
 <td></td>
 </tr>
 <tr>
 <td>Rhino probe cell cuvette</td>
 <td>Arlington Scientific</td>
 <td>SY-96-092</td>
 <td>bend the head of the cuvette a little more</td>
 </tr>
 <tr>
 <td>12-well culture plates</td>
 <td>Corning</td>
 <td>3512</td>
 <td></td>
 </tr>
 <tr>
 <td>Transwell membrane cell culture inserts</td>
 <td>Corning</td>
 <td>3460</td>
 <td></td>
 </tr>
 <tr>
 <td>Tissue culture flask </td>
 <td>Corning</td>
 <td>430639 and 430641</td>
 <td>T25 and T75 vented flask</td>
 </tr>
 <tr>
 <td>RPMI 1640 media (with L-Glutamine)</td>
 <td>Gibco</td>
 <td>11875</td>
 <td></td>
 </tr>
 <tr>
 <td>Bronchial/Tracheal Epithelial Cell Growth Medium</td>
 <td>Cell applications</td>
 <td>511-500</td>
 <td></td>
 </tr>
 <tr>
 <td>BEGM Bronchial Epithelial Cell Growth Medium</td>
 <td>Lonza</td>
 <td>CC-3170</td>
 <td>This comes as a kit of one bottle of medium and vials with supplements.</td>
 </tr>
 <tr>
 <td>Sodium Bicarbonate 7.5% solution</td>
 <td>Gibco</td>
 <td>25080</td>
 <td>Use as it is.</td>
 </tr>
 <tr>
 <td>NuSerum</td>
 <td>BD Biosciences</td>
 <td>355104</td>
 <td>Use as it is.</td>
 </tr>
 <tr>
 <td>BAMBANKER freezing media</td>
 <td>BAMBANKER</td>
 <td>302-14681</td>
 <td>Use as it is.</td>
 </tr>
 <tr>
 <td>CoolCell </td>
 <td>Biocision</td>
 <td>HTBCS-136</td>
 <td>(CryoPrep alcohol-free cell freezing container)</td>
 </tr>
 <tr>
 <td>PureCol</td>
 <td>AdvancedBioMatrix</td>
 <td>5005-B</td>
 <td>dilute 1:100 with sterile water (should be roughly 0.03 mg/ml)use 500 &mu;l/well of a 12-well plate</td>
 </tr>
 <tr>
 <td>HBSS with Ca2 and Mg2+</td>
 <td>Gibco</td>
 <td>14025</td>
 <td></td>
 </tr>
 <tr>
 <td>DNAse 1</td>
 <td>Sigma</td>
 <td>DN25</td>
 <td>Dissolve at 1.5 mg/ml, which is a 100x solution, add 10 &mu;l to each ml of media</td>
 </tr>
 <tr>
 <td>Trypsin, 0.25%, 1x, with phenol red</td>
 <td>Gibco</td>
 <td>25200-056</td>
 <td>Use at it is</td>
 </tr>
 <tr>
 <td>Soy Bean Trypsin Inhibitor (SBTI)</td>
 <td>Sigma</td>
 <td>T6522</td>
 <td>Use dissolved in HBSS at a concentration of 1 mg/ml</td>
 </tr>
 <tr>
 <td>Retinoic acid</td>
 <td>Sigma</td>
 <td>R7632</td>
 <td>Make it up 100 &mu;M stock solution (see below), dilute to 10 &mu;M with absolute alcohol, take 5 &mu;l of this and add it to 1 ml BEGM media (our working solution). 
 
 All-trans Retinol has a coefficient of extinction of 52,480 in ethanol at 325 nm. Dissolve 25 mg in 50 ml absolute ethanol. Serial dilutions need to be made, dilute 50 ml of stock in 450 ml absolute ethanol, take 50 ml of this, dilute in 450 ml absolute ethanol, take 50 ml of this, dilute in 450 ml absolute ethanol, and again take 50 ml of this, dilute in 450 ml absolute Ethanol, take 100 ml of this and dilute in 900 ml absolute ethanol and read in the spectrophotometer at 325 nm, this number is then multiplied by its' dilution factor, then divided by the extinction coefficient of 52,480, this will give a number in mM. Make a 100 mM stock (store at -20 &deg;C) and from this stock a 10 mM aliquot is made, the daily retinoic acid needed would be 5 ml of this 10 mM aliquot in 995 ml ALI media.
 Example: 325nm reading is 1.15. 1.15 x 10,000 (dilution factor) / 52,480 = 0.219 = 219 mM, make a 100 mM stock from this, in absolute ethanol.</td>
 </tr>
 <tr>
 <td>DMEM high glucose (1x), liquid, with L-glutamine and sodium pyruvate</td>
 <td>Gibco</td>
 <td>11995</td>
 <td></td>
 </tr>
 <tr>
 <td>Bovine Pituitary Extract</td>
 <td>Gibco</td>
 <td>13028-014</td>
 <td>Used for BEGM ALI media.</td>
 </tr>
 <tr>
 <td>Nystatin</td>
 <td>Sigma</td>
 <td>N4014-50 mg</td>
 <td>Make up a solution of 3.3 mg/ml.</td>
 </tr>
 <tr>
 <td>Bovine Serum Albumin</td>
 <td>Fisher Scientific</td>
 <td>BP1600-100</td>
 <td>Make up a solution of 10 mg/ml solution in milliQ water.</td>
 </tr>
 <tr>
 <td>PneumaCult-ALI media</td>
 <td>StemCell</td>
 <td>5001</td>
 <td>This comes as a kit of one bottle of medium and vials with supplements. For details see below.</td>
 </tr>
 <tr>
 <td>Hydrocortisone </td>
 <td>StemCell</td>
 <td>7904</td>
 <td>Dissolve 2.4 mg hydrocortisone in 1 ml ddH2O (used to make the 200x Hydrocortisone stock solution)</td>
 </tr>
 <tr>
 <td>Heparin Sodium Salt in PBS (2 mg/ml)</td>
 <td>StemCell</td>
 <td>7980</td>
 <td>Use at it is. </td>
 </tr>
 <tr>
 <td>Filter flasks (500 ml)</td>
 <td>Corning</td>
 <td>431097</td>
 <td>0.22 &mu;m pore size</td>
 </tr>
 <tr>
 <td>Filter tubes (50 ml)</td>
 <td>Millipore</td>
 <td>SCGP00525</td>
 <td>Steriflip, 0.22 &mu;m pore size</td>
 </tr>
 <tr>
 <td>Pipette tips - ART Barrier Tips</td>
 <td>Molecular Bioproducts</td>
 <td>2139RI, 2069RI, 2179RI</td>
 <td></td>
 </tr>
 <tr>
 <td>Conical tubes, sterile, 15 ml and 50 ml</td>
 <td></td>
 <td></td>
 <td></td>
 </tr>
 <tr>
 <td>ddH2O, absolute ethanol, ice</td>
 <td></td>
 <td></td>
 <td></td>
 </tr>
 <tr>
 <td>CO2 incubator</td>
 <td></td>
 <td></td>
 <td></td>
 </tr>
 <tr>
 <td>refrigerated centrifuge</td>
 <td></td>
 <td></td>
 <td></td>
 </tr>
 <tr>
 <td>biological safety cabinet</td>
 <td></td>
 <td></td>
 <td></td>
 </tr>
 <tr>
 <td>pipettes (p2, p200, p1000), 9 in glass pipettes</td>
 <td></td>
 <td></td>
 <td></td>
 </tr>
 <tr>
 <td>gloves</td>
 <td></td>
 <td></td>
 <td></td>
 </tr>
 <tr>
 <td>lab coat with tight cuffs</td>
 <td></td>
 <td></td>
 <td></td>
 </tr>
 <tr>
 <td></td>
 <td></td>
 <td></td>
 <td>
 <table border="1">
 <tbody>
 <tr>
 <td>Media and solutions used:</td>
 <td>Recipe</td>
 <td>Used for</td>
 </tr>
 <tr>
 <td colspan="3">General remark: always warm the media to room temperature</td>
 </tr>
 <tr>
 <td rowspan="2">BEGM media</td>
 <td><ul><li> 500 ml BEGM Cell Application media with one aliquot of retinoic acid</li></ul> </td>
 <td>(mix them half-half and filter )</td>
 </tr>
 <tr>
 <td><ul><li> 500 ml BEGM Lonza media with one aliquot of single quot supplements </li></ul></td>
 <td><ul><li> digestion of the biopsy</li></ul> </td>
 </tr>
 <tr>
 <td rowspan="3">BEGM+ media</td>
 <td><ul><li> 50 ml BEGM media </li></ul></td>
 <td><ul><li> maintaining cells on plastic in the plates (passage0) </li></ul></td>
 </tr>
 <tr>
 <td><ul><li> 10 &mu;l retinoic acid (working solution)</li></ul> </td>
 <td><ul><li> seeding cells in the flask (passage1; partially)</li></ul> </td>
 </tr>
 <tr>
 <td></td>
 <td><ul><li> maintain the cells in the flask </li></ul></td>
 </tr>
 <tr>
 <td rowspan="3">BEGM++ media</td>
 <td><ul><li> 50 ml Lonza's BEGM media with supplements</li></ul> </td>
 <td><ul><li> seeding fresh cells in 12-well plate on plastic</li></ul> </td>
 </tr>
 <tr>
 <td><ul><li> 1 ml Sodium BiCarb</li></ul> </td>
 <td><ul><li> maintaining cells in the plates on plastic (passage0; only partially)</li></ul> </td>
 </tr>
 <tr>
 <td><ul><li> 2.5 ml NuSerum</li></ul> </td>
 <td><ul><li> seeding cells in the flask (passage1; partially)</li></ul> </td>
 </tr>
 <tr>
 <td rowspan="5">BEGM ALI media</td>
 <td><ul><li> 250 ml DMEM-H </li></ul></td>
 <td rowspan="5"><ul><li> Maintaining cells on the transwell before they go ALI</li></ul> </td>
 </tr>
 <tr>
 <td><ul><li> 250 ml BEGM including supplements</li></ul> </td>
 </tr>
 <tr>
 <td><ul><li> 2 ml Bovine Pituitary Extract (12.5 mg/ml solution)</li></ul> </td>
 </tr>
 <tr>
 <td><ul><li> 1 ml Nystatin (3.3 mg/ml solution)</li></ul> </td>
 </tr>
 <tr>
 <td><ul><li> 75 &mu;l BSA (10 mg/ml solution)</li></ul> </td>
 </tr>
 <tr>
 <td rowspan="5">200X Hydrocortisone Stock Solution (96 &mu;l/ml solution)</td>
 <td><ul><li> 200 &mu;l dissolved hydrocortisone</li></ul> </td>
 <td rowspan="5"><ul><li> As a supplement to the PneumaCult-ALI Complete Base Medium for the last day in the flask and when cells are on inserts</li></ul> </td>
 </tr>
 <tr>
 <td><ul><li> 4250 &mu;l dissolved sodium chloride </li></ul></td>
 </tr>
 <tr>
 <td><ul><li> 540 &mu;l ddH2O</li></ul> </td>
 </tr>
 <tr>
 <td><ul><li> 10 &mu;l absolute ethanol</li></ul> </td>
 </tr>
 <tr>
 <td>Filter solution through 0.22 &mu;m filter, aliquot solution and store at -20 &deg;C, avoid additional freeze/thaw cycles</td>
 </tr>
 <tr>
 <td rowspan="3">PneumaCult-ALI Complete Base Media</td>
 <td><ul><li> 450 ml PneumaCult-ALI Basal Medium</li></ul> </td>
 <td><ul><li> Base medium for all three PneumaCult-ALI media </li></ul></td>
 </tr>
 <tr>
 <td><ul><li> 50 ml PneumaCult 10x Supplement </li></ul></td>
 <td><ul><li> The PneumaCult media is light sensitive, thus always keep it in the dark</li></ul> </td>
 </tr>
 <tr>
 <td>(this is stable for 2 weeks at 2-8 &deg;C or for up to 6 months at -20 &deg;C)</td>
 <td></td>
 </tr>
 <tr>
 <td rowspan="4">PneumaCult-ALI Maintenance Medium</td>
 <td>Per 1 ml of PneumaCult-ALI Complete Base Medium add:</td>
 <td rowspan="4">ALI culture on inserts</td>
 </tr>
 <tr>
 <td><ul><li> 10 &mu;l PneumaCult 100x Maintenance Supplement </li></ul></td>
 </tr>
 <tr>
 <td><ul><li> 2 &mu;l Heparin (of a 2 mg/ml stock solution) </li></ul></td>
 </tr>
 <tr>
 <td><ul><li> 5 &mu;l Hydrocortisone (of a 96 &mu;l/ml stock solution) </li></ul></td>
 </tr>
 </tbody>
</table>
 </td>
 </tr>
 </tbody>
</table>

culturing of human nasal epithelial cells at the air liquid interface

In vitro models using human primary epithelial cells are essential in understanding key functions of the respiratory epithelium in the context of microbial infections or inhaled agents. Direct comparisons of cells obtained from diseased populations allow us to characterize different phenotypes and dissect the underlying mechanisms mediating changes in epithelial cell function. Culturing epithelial cells from the human tracheobronchial region has been well documented, but is limited by the availability of human lung tissue or invasiveness associated with obtaining the bronchial brushes biopsies. Nasal epithelial cells are obtained through much less invasive superficial nasal scrape biopsies and subjects can be biopsied multiple times with no significant side effects. Additionally, the nose is the entry point to the respiratory system and therefore one of the first sites to be exposed to any kind of air-borne stressor, such as microbial agents, pollutants, or allergens. 
Briefly, nasal epithelial cells obtained from human volunteers are expanded on coated tissue culture plates, and then transferred onto cell culture inserts. Upon reaching confluency, cells continue to be cultured at the air-liquid interface (ALI), for several weeks, which creates more physiologically relevant conditions. The ALI culture condition uses defined media leading to a differentiated epithelium that exhibits morphological and functional characteristics similar to the human nasal epithelium, with both ciliated and mucus producing cells. Tissue culture inserts with differentiated nasal epithelial cells can be manipulated in a variety of ways depending on the research questions (treatment with pharmacological agents, transduction with lentiviral vectors, exposure to gases, or infection with microbial agents) and analyzed for numerous different endpoints ranging from cellular and molecular pathways, functional changes, morphology, etc. 
In vitro models of differentiated human nasal epithelial cells will enable investigators to address novel and important research questions by using organotypic experimental models that largely mimic the nasal epithelium in vivo.

NECs cultured following the here described protocol re-differentiate into a heterogeneous layer of ECs composed of ciliated and non-ciliated cells, representing the in vivo situation (Figure 1). Some of the differentiated NECs are mucus producing (cells staining in blue using AB/PAS, Figure 1B). Even though the here presented protocol is optimized, differentiation can vary with regards to the distribution of the overall cell populations (i.e. different ratios of ciliate...

Watch this Scientific Journal Video about Culturing of Human Nasal Epithelial Cells at the Air Liquid Interface at JoVE.com

Culturing of Human Nasal Epithelial Cells at the Air Liquid Interface

Nasal epithelial cells, obtained through superficial scrape biopsy of human volunteers, are expanded and transferred onto tissue culture inserts. Upon reaching confluency, cells are grown at air liquid interface, yielding cultures of ciliated and non-ciliated cells. Differentiated nasal epithelial cell cultures provide viable experimental models for studying the respiratory mucosa.

In vitro models using human primary  epithelial cells are essential in understanding key functions of the respiratory  epithelium in the context of ...

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