Programming of Distinct Chemokine-Dependent and -Independent Search Strategies for Th1 and Th2 Cells Optimizes Function at Inflamed Sites.

T-helper (Th) cell differentiation drives specialized gene programs that dictate effector T cell function at sites of infection. Here, we have shown Th cell differentiation also imposes discrete motility gene programs that shape Th1 and Th2 cell navigation of the inflamed dermis. Th1 cells scanned a smaller tissue area in a G protein-coupled receptor (GPCR) and chemokine-dependent fashion, while Th2 cells scanned a larger tissue area independent of GPCR signals. Differential chemokine reliance for interstitial migration was linked to STAT6 transcription-factor-dependent programming of integrin αβ expression: Th2 cell differentiation led to high αβ expression relative to Th1 cells. Th1 and Th2 cell modes of motility could be switched simply by manipulating the amount of αβ on the cell surface. Deviating motility modes from those established during differentiation impaired effector function. Thus, programmed expression of αβ tunes effector T cell reliance on environmental cues for optimal exploration of inflamed tissues.