Pulmonary Immune Cell-microbiome Interactions in the Healthy Lung

The overall aim is to to provide a normal material for the composition and spatial heterogeneity of the following in the healthy lung: i) immune cell populations and their activation patterns, ii) the surrounding cytokine-chemokine milieu, including trans-compartmental fluxes of these mediators between the lung and bloodstream, and iii) the lung microbiome. Main hypotheses: * Absolute and relative immune cell counts in bronchoalveolar lavage fluid (BALF) are similar to those previously reported by other methods6,7. * No trans-compartmental flux of cytokines between the lungs and bloodstream is present, but cytokine concentrations (notably IL-6 and IL-8) vary with the immune-cell-microbiome composition. * Immune cell (mainly T cell) activation, differentiation, and gene expression patterns are expected to differ between blood and BALF in a manner that depends on the regional diversity of the pulmonary microbiome.