Lysolipids such as lysophosphatidylcholine (LPC), sphingosylphosphorylcholine (SPC), galactosyl-sphingosine (psychosine) have been matched as ligands for OGRI-subfamily G-protein-coupled receptors (GPCR), consisted of OGRl, GPR4, G2A, and TDAG8. Recently, those members of GPCRs have been reported as proton-sensing GPCRs. We used Jurkat T cells, which express four members of OGRI subfamily GPCRs endogenously to investigate effects of proton on lysolipid-induced several cellular events. We found no significant effect of proton on the lysolipid-induced Ca2+ increase and ROS production in Jurkat T cells. Further investigation is necessary to clarify the relationship of lysolipid and proton on the OGRI-subfamily GPCRs.