HMB-PP is an essential metabolite in most pathogenic bacteria including Mycobacterium tuberculosis as well as in malaria parasites, but is absent from the human host.[3]
HMB-PP is the physiological activator ("phosphoantigen") for human Vγ9/Vδ2 T cells, the major γδ T cell population in peripheral blood. With a bioactivity of 0.1 nM it is 10,000-10,000,000 times more potent than any other natural compound, such as IPP or alkyl amines. HMB-PP functions in this capacity by binding the B30.2 domain of BTN3A1.[4]
References
^Rohmer, M; Rohmer, Michel (1999). "The discovery of a mevalonate-independent pathway for isoprenoid biosynthesis in bacteria, algae and higher plants". Natural Product Reports. 16 (5): 565–74. doi:10.1039/a709175c. PMID10584331.
^Fox, DT; Poulter, CD (2002). "Synthesis of (E)-4-hydroxydimethylallyl diphosphate. An intermediate in the methyl erythritol phosphate branch of the isoprenoid pathway". The Journal of Organic Chemistry. 67 (14): 5009–10. doi:10.1021/jo0258453. PMID12098326.