Advanced Imaging of Lung Homing Human Lymphocytes in an Experimental In Vivo Model of Allergic Inflammation Based on Light-sheet Microscopy

Our technique allows the precise imaging of lung-accumulated human immune cells in in vivo inflammatory conditions providing exciting insights into the process of T cell lung homing. This protocol supports translational research on T cell lung homing and may thereby help in the identification of new targets for an optimized therapy of inflammatory or allergic pulmonary diseases. In particular, the ability to consider the influence of disease-specific immune cell properties, pulmonary tissue organization, and inflammatory milieu on T cell lung homing makes this method highly advantageous.

Overall, our technique is of high value for immunological research in the field of chronic inflammatory lung diseases, which are often driven by an overwhelming tissue accumulation of activated immune cells. After confirming a lack of response to toe pinch in an at least 16-gram, six-week-old, anesthetized C57 black 6J mouse, use a micropipet to slowly deliver 10 microliters of freshly prepared papain solution into one nostril of the mouse once a day for three consecutive days. The day after the last papain administration, layer 10 milliliters of Ficoll medium under human peripheral blood from a healthy volunteer pre-diluted at a one to two ratio in PBS for density gradient separation by centrifugation.