Butyrophilin 3A1 engages the CDR2δ loop of the Vγ9Vδ2+ T cell receptor.
It is shown that intracellular pAg accumulation can modulate binding of Vγ9Vδ2+ TCR in a BTN3A1-dependent manner, indicating the important role of TCR binding to BTN3A1 in pAg recognition.