Defining the anatomic location of cells of the innate and adaptive immune system is critical for understanding immune responses to infection. Recently, we published that intravascular staining can distinguish CD8 T cells located in the lung tissue from those confined to capillary vasculature. Remarkably, up to 95% of CD8 T cells isolated from lung were present within capillaries, despite extensive perfusion, and removing these cells from analysis resulted in revised interpretations of lung T cell homing and differentiation. We now show that perfusion results in a disruption of lung architecture and a loss of parenchymal cells of interest. Moreover, we expand our analysis to other leukocyte populations (lymphoid and myeloid) in additional non-lymphoid tissues and in the context of a variety of disease models, including graft versus host disease and infection with influenza or Mycobacterium tuberculosis. We have defined revised methodologies that, if applied, will have a pronounced impact on the interpretation of studies examining numerous leukocyte subsets in many non-lymphoid compartments. We are now utilizing these methods to examine the dynamics of primary and anamnestic responses to, and mechanisms of protection against, respiratory infections.
- Copyright © 2013 by The American Association of Immunologists, Inc.