Integrin activation enables rapid detection of functional V delta 1(+) and V delta 2(+) gamma delta T cells

Conformational change of the beta 2 integrin lymphocyte function-associated antigen 1 (LFA-1) is an early marker of T cell activation. A protocol using the mAb clone m24 recognizing the active, extended high-affinity conformation has been previously described for the assessment of functional CD4(+) and CD8(+) T cells in response to MHC-peptide stimulation. We investigated the applicability of the m24 mAb to detect the activation of gamma delta T cells in response to different soluble and immobilized stimuli. m24 mAb staining was associated with the expression of cytokines and was detectable as early as 10 min after stimulation, but with different kinetics depending on the nature of the stimulus. Hence, we conclude that this assay is suitable for the detection of functional gamma delta T cells and allows the assessment of activation more rapidly than alternative methods such as cytokine detection. Intracellular staining, protein trafficking inhibitors, or prior knowledge of the stimulating moiety recognized are no longer required for monitoring gamma delta T cell activation.