IntroductionLittle is known about how neonatal airway epithelial cell phenotype impacts on respiratory disease in later life. This study aimed to establish a methodology to culture and characterise neonatal nasal epithelial cells sampled from healthy, non-sedated infants within 48 hours of delivery.MethodsNasal epithelial cells were sampled by brushing both nostrils with an interdental brush, grown to confluence and sub-cultured. Cultured cells were characterised morphologically by light and electron microscopy and by immunocytochemistry. As an exemplar pro-inflammatory chemokine, IL-8 concentrations were measured in supernatants from unstimulated monolayers and after exposure to IL-1β/TNF-α or house dust mite extract.ResultsPrimary cultures were successfully established in 135 (91%) of 149 neonatal samples seeded, with 79% (n  =  117) successfully cultured to passage 3. The epithelial lineage of the cells was confirmed by morphological analysis and immunostaining. Constitutive IL-8 secretion was observed and was upregulated by IL-1β/TNF-α or house dust mite extract in a dose dependent manner.ConclusionWe describe a safe, minimally invasive method of culturing nasal epithelial cells from neonates suitable for functional cell analysis offering an opportunity to study “naïve” cells that may prove useful in elucidating the role of the epithelium in the early origins of asthma and/or allergic rhinitis.

Results AEC mediator release was greater following TNF-a/IL-1b, HDM or LPS stimulation compared to constitutive release. Increased maternal dietary vitamin D was associated with significant increases in IL-10 release by AEC after stimulation with TNF-a/IL-1b (P = 0.024) or HDM (P = 0.049). Maternal plasma a-tocopherol at 10-12 weeks gestation was positively associated with MIP1a (Spearman's rho 0.242, P = 0.009) and IL-3 (q 0.189, P = 0.043) responses after TNF-a/IL-1b stimulation and negatively associated with TNF (q -0.404, P = 0.011) and MIP1b (q -0.322, P = 0.046) responses after LPS stimulation. Discussion Neonatal AECs respond to pro-inflammatory and allergenic stimuli in vitro demonstrating their potential to function as components of the innate immune response. Our findings suggest that associations exist between maternal micronutrient intake during early pregnancy and aspects of stimulated neonatal airway epithelial cell secretory function that may in turn impact on the development of asthma and/or allergic rhinitis in later life.

Montelukast treatment for asthma symptoms reversibly suppresses nasal AEC release of pro-inflammatory mediators (i.e. IL-8 and RANTES) but only in those cells cultured from subjects with concomitant allergic rhinitis.