Best fit values for parameters of the homotropic two-state model, HOTSM, based on IPP-proliferation of γδ T cells.

Values for equilibrium association constants As and Am and the cooperative binding constant c were extracted by fitting the HOTSM relation [25] to bell-shaped dose-response curves of IPP activation-inhibition of γδ T cell proliferation from this study and data in the literature [34], Fig. 4A. As our experiments indicated almost no response in the absence of ligands IPP and EtOH, parameter L was kept at zero symbolizing no spontaneous activity. Values for our proliferative response of T cells - most likely as memory CD45RA-CD27+ cells - to IPP in a concentration range from 3×10−3 to 3×102 µM are within a factor of 10 to the data set for memory cells in Dieli et al's 2003 study, columns 2 and 1.