DMAPP, also known as Dimethylallyl pyrophosphate, is an isoprenoid precursor found in all life forms. It serves as an isomer of isopentenyl pyrophosphate (IPP).
Synthetic and natural alkyl phosphates, also known as phosphoantigens, stimulate the proliferation of γδ-T lymphocytes. Isopentenyl pyrophosphate, and related derivatives including (E)-hydroxy-dimethyl-allyl pyrophosphate ((E)-HDMAPP), are particularly effective activators of γδ-T cells. (E)-C-HDMAPP is the pyrophosphonate form of (E)-HDMAPP. The pyrophosphonate moiety in (E)-C-HDMAPP is much less susceptible to chemical or enzymatic hydrolysis than its pyrophosphate counterpart. As a result, (E)-C-HDMAPP is much more stable in solution and in vascular circulation. (E)-C-HDMAPP possesses comparable activity to (E)-HDMAPP, which is the most potent of the isoprenoid phosphoantigens. (E)-C-HDMAPP stimulates the synthesis of tumor necrosis factor (TNF-α) by γδ-T lymphocytes with an IC50 value of 0.91 nM. (E)-C-HDMAPP also significantly increases the number of circulating γδ-T cells in vivo, in cynomolgus monkeys.