Abstract
Background: Chronic obstructive pulmonary disease (COPD) is associated with chronic airway inflammation and structural remodelling, in particular of the epithelium, which is impaired in its capacity to transport immunoglobulin (Ig) A. Although peribronchial lymphoid follicles have been described in severe COPD, it remains unknown whether B-cell conditioning (e.g. for IgA production) is altered in this disease.
Objectives: In this study, we report on preliminary data using a model of coculture of B cells with human primary bronchial epithelium (re)differentiated in vitro in air-liquid interface.
Methods: IgA synthesis was studied in CD19+ B cells (purified by immunomagnetic sorting from healthy blood donors) following co-culture for 13 days with a bronchial epithelium. B cells were also assessed by flow cytometry for cell activation and survival (annexinV/propidium iodine staining).
Results: In two independent experiments, we observed that Ig production was upregulated in B cells cocultured with the bronchial epithelium, as compared to B cells cultured alone (2.2 fold increase in IgG, and modest 1.4 fold increase in IgA), whereas IgM was decreased (0.8 fold). In contrast to expression of CD69, CD80 and CD86 which did not change, B-cell survival also increased (55.3% vs 20.8% for B cells alone) following epithelial coculture.
Conclusion: These preliminary data using this model of coculture, which should reveal useful to investigate crosstalks between the epithelium and B cells with respect to COPD, confirm that the airway epithelium provides B cells with signals promoting both survival and Ig synthesis.
- © 2011 ERS