The deficiency of G[alpha]q leads to enhanced T-cell survival

We have previously reported that Gαq , the α subunit of the Gq protein, had important roles in dendritic cell migration, B-cell survival and autoimmunity. In this study, we showed that the deficiency of Gαq led to enhanced T-cell survival. Cultured Gnaq-/- T cells exhibited survival advantages both in medium alone and in the presence of anti-CD3 stimulation. Gnaq-/- T cells still exhibited a survival advantage when they were cultured in the presence of interleukin (IL)-2 or IL-7. Gnaq-/- T cells were more resistant to activation-induced cell death (AICD) in vitro. The survival advantage of Gnaq-/- T cells was further confirmed by transferring T cells into syngeneic hosts in vivo. Gαq deficiency might promote T-cell survival by upregulated Bcl-xL expression and downregulated Fas and FasL expressions. Furthermore, upon T-cell receptor (TCR) ligation, Akt activity was increased in Gnaq-/- T cells in comparison with wild-type (WT) T cells. The survival advantage of Gnaq-/- T cells was significantly attenuated after adding Akt inhibitor. Taken together, our data demonstrated a negative role of Gαq in regulating T-cell survival.