Distribution and leukocyte contacts of γδ T cells in the lung

Pulmonary γδ T cells protect the lung and its functions, but little is known about their distribution in this organ and their relationship to other pulmonary cells. We now show that γδ and αβ T cells are distributed differently in the normal mouse lung. The γδ T cells have a bias for nonalveolar locations, with the exception of the airway mucosa. Subsets of γδ T cells exhibit further variation in their tissue localization, γδ and αβ T cells frequently contact other leukocytes, but they favor different cell-types. The γδ T cells show an intrinsic preference for F4/80⁺ and major histocompatibility complex class II⁺ leukocytes. Leukocytes expressing these markers include macrophages and dendritic cells, known to function as sentinels of airways and lung tissues. The continuous interaction of γδ T cells with these sentinels likely is related to their protective role.