Phosphoantigens and butyrophilin 3A1 induce similar intracellular activation signaling in human TCRVγ9+ γδ T lymphocytes

Human gamma delta cells expressing TCRV gamma 9 are T lymphocytes with great potential for cancer immunotherapy and unconventional pattern of antigen specificity. These HLA-unrestricted lymphocytes are specifically reactive to non-peptide metabolites (phosphoantigens) and to the butyrophilin 3A (BTN3A/CD277) protein. Whether recognition of such highly different structures trigger the same activation signaling pathway remains unclear, however. Here we combined fluorescent cell barcoding and phosphoflow analysis of TCRV gamma 9(+) T lymphocytes to compare simultaneously the level of several signaling phosphoproteins after activation by phosphoantigen (BrHPP) or by anti-BTN3A (monoclonal antibody 20.1). This approach shows that the same pathways involving ZAP70, PLC gamma 2, Akt, NF kappa B p65, MAPK p38 and Erk1, were induced by either of these stimuli. These data strongly suggest the TCRV gamma 9(+) T lymphocytes detect phosphoantigens and butyrophilin A3 by the same recognition process.(C) 2014 Published by Elsevier B.V.