SignificanceStudying the functions of G-protein-coupled muscarinic receptors, which are protein tyrosine kinase independent, might inspire new cancer therapies by bypassing classical TCR signaling pathways. Stimulating heterologously expressed muscarinic receptors (M1 and the synthetic hM3Dq) induced calcium responses and phosphorylation of ERK in preactivated T cells if PLCβ1 was coexpressed. Unexpectedly, whereas stimulation of hM3Dq that couples to PLCβ1 induced high IFN-γ, CD69, and CD25 expression, surprisingly, it did not induce high IL-2 expression. Stimulation of hM3Dq reduced IL-2 mRNA stability which correlated with an effect on the IL-2 mRNA stability. The selective effect on IL-2 mRNA may be attributable to reduced pAKT downstream pathway function, suggesting that the pAKT pathway is critical for IL-2 production.