Inhalation of allergens and pathogens elicits multiple changes in a variety of immune cell
types in the lung. Flow cytometry is a powerful technique for quantitative analysis of cell
surface proteins on immune cells, but it provides no information on the localization and
migration patterns of these cells within the lung. Similarly, chemotaxis assays can be
performed to study the potential of cells to respond to chemotactic factors in vitro, but these
assays do not reproduce the complex environment of the intact lung. In contrast to these …