Figure 4. ADRB2 signaling suppresses mouse CD8⁺ T-cell cytokine secretion independent of acetylcholine or cAMP.

(A) Splenocytes from OT-I mice were isolated and incubated 23 hours with the OVA peptide SIINFEKL and NE with increasing concentrations of an α7 nicotinic receptor antagonist (methyllycaconitine) or a β2 adrenergic receptor antagonist (ICI-118,551). TNF-α in the supernatants was measured. (B) Splenocytes from Cl4 mice were incubated overnight with the HA peptide IYSTVASSL and in the presence or absence of albuterol or increasing concentrations of the cAMP stimulator forskolin. IFN-γ and TNF-α were measured. (C) Splenocytes from Cl4 mice were incubated with HA peptide in the presence or absence of NE, and with increasing concentrations of an adenylyl cyclase inhibitor (2’5’-dideoxyadenosine;) or a β2 adrenergic receptor antagonist (ICI-118,551). (D) CD8⁺ T cells from Balb/cJ mice were isolated and stimulated with anti-CD3 and anti-CD28 Abs (3 µg/mL each) for 24 hours in the presence or absence of NE and increasing concentrations of a soluble adenylyl cyclase inhibitor (KH7) or a β2 adrenergic receptor antagonist (ICI-118,551). Data are presented as mean +/− SEM of triplicate determinations and are representative of (A and D) a single experiment with pooled data from 3 mice measured separately, (B and C) 2 experiments with pooled data from 3 mice measured separately in each experiment. *p<0.05, **p<0.01, ***p<0.001, and ****p<0.0001 compared to 0µM NE, No Albuterol, or Ctrl, 2-way (A, C and D) or 1-way (B) ANOVA with Bonferroni post-test.