» Articles » PMID: 27096000

Inhibition of Gαs/cAMP Signaling Decreases TCR-Stimulated IL-2 Transcription in CD4(+) T Helper Cells

Overview
Journal J Mol Signal
Publisher Ubiquity Press
Date 2016 Apr 21
PMID 27096000
Citations 4
Authors
Affiliations
Soon will be listed here.
Abstract

Background: The role of cAMP in regulating T cell activation and function has been controversial. cAMP is generally known as an immunosuppressant, but it is also required for generating optimal immune responses. As the effect of cAMP is likely to depend on its cellular context, the current study investigated whether the mechanism of activation of Gαs and adenylyl cyclase influences their effect on T cell receptor (TCR)-stimulated interleukin-2 (IL-2) mRNA levels.

Methods: The effect of blocking Gs-coupled receptor (GsPCR)-mediated Gs activation on TCR-stimulated IL-2 mRNA levels in CD4(+) T cells was compared with that of knocking down Gαs expression or inhibiting adenylyl cyclase activity. The effect of knocking down Gαs expression on TCR-stimulated cAMP accumulation was compared with that of blocking GsPCR signaling.

Results: ZM-241385, an antagonist to the Gs-coupled A2A adenosine receptor (A2AR), enhanced TCR-stimulated IL-2 mRNA levels in primary human CD4(+) T helper cells and in Jurkat T cells. A dominant negative Gαs construct, GαsDN3, also enhanced TCR-stimulated IL-2 mRNA levels. Similar to GsPCR antagonists, GαsDN3 blocked GsPCR-dependent activation of both Gαs and Gβγ. In contrast, Gαs siRNA and 2',5'-dideoxyadenosine (ddA), an adenylyl cyclase inhibitor, decreased TCR-stimulated IL-2 mRNA levels. Gαs siRNA, but not GαsDN3, decreased TCR-stimulated cAMP synthesis. Potentiation of IL-2 mRNA levels by ZM-241385 required at least two days of TCR stimulation, and addition of ddA after three days of TCR stimulation enhanced IL-2 mRNA levels.

Conclusions: GsPCRs play an inhibitory role in the regulation of TCR-stimulated IL-2 mRNA levels whereas Gαs and cAMP can play a stimulatory one. Additionally, TCR-dependent activation of Gαs does not appear to involve GsPCRs. These results suggest that the context of Gαs/cAMP activation and the stage of T cell activation and differentiation determine the effect on TCR-stimulated IL-2 mRNA levels.

Citing Articles

CD73, a significant protein in liver diseases.

Shi H, Dai H, Sun Q, Wang S, Chen Y Front Med (Lausanne). 2023; 10:1147782.

PMID: 37122331 PMC: 10130655. DOI: 10.3389/fmed.2023.1147782.


Soluble adenylyl cyclase contributes to imiquimod-mediated inflammation and is a potential therapeutic target in psoriasis.

You J, Reilly M, Eljalby M, Bareja R, Yusupova M, Vyas N Exp Dermatol. 2023; 32(7):1051-1062.

PMID: 37039485 PMC: 10523866. DOI: 10.1111/exd.14811.


Purinergic signalling in liver diseases: Pathological functions and therapeutic opportunities.

Wang P, Jia J, Zhang D JHEP Rep. 2020; 2(6):100165.

PMID: 33103092 PMC: 7575885. DOI: 10.1016/j.jhepr.2020.100165.


The GS Protein-coupled A2a Adenosine Receptor Controls T Cell Help in the Germinal Center.

Abbott R, Silva M, Labuda J, Thayer M, Cain D, Philbrook P J Biol Chem. 2016; 292(4):1211-1217.

PMID: 27974461 PMC: 5270467. DOI: 10.1074/jbc.C116.764043.

References
1.
Boomer J, Green J . An enigmatic tail of CD28 signaling. Cold Spring Harb Perspect Biol. 2010; 2(8):a002436. PMC: 2908766. DOI: 10.1101/cshperspect.a002436. View

2.
Koh W, Yang K, Kaminski N . Cyclic AMP is an essential factor in immune responses. Biochem Biophys Res Commun. 1995; 206(2):703-9. DOI: 10.1006/bbrc.1995.1099. View

3.
Vang T, Torgersen K, Sundvold V, Saxena M, Levy F, Skalhegg B . Activation of the COOH-terminal Src kinase (Csk) by cAMP-dependent protein kinase inhibits signaling through the T cell receptor. J Exp Med. 2001; 193(4):497-507. PMC: 2195911. DOI: 10.1084/jem.193.4.497. View

4.
Lee E, Taussig R, GILMAN A . The G226A mutant of Gs alpha highlights the requirement for dissociation of G protein subunits. J Biol Chem. 1992; 267(2):1212-8. View

5.
Grishina G, Berlot C . Identification of common and distinct residues involved in the interaction of alphai2 and alphas with adenylyl cyclase. J Biol Chem. 1997; 272(33):20619-26. DOI: 10.1074/jbc.272.33.20619. View