Functional expression of the P2Y₁₄ receptor in murine T‐lymphocytes

Abstract

1 Quantitative reverse transcriptase polymerase chain reaction (RT-PCR) analysis has previously shown that the P2Y 14 receptor is expressed in peripheral immune cells including lymphocytes. Although in transfected cells the P2Y 14 receptor couples to pertussis toxin-sensitive G i/o protein, the functional coupling of endogenously expressed P2Y 14 receptors to the inhibition of adenylyl cyclase activity has not been reported. Therefore, the primary aim of this study was to determine whether the P2Y 14 receptor is functionally expressed in murine spleen-derived T-and B-lymphocyte-enriched populations.2 RT-PCR analysis detected the expression of P2Y 14 receptor mRNA in whole spleen and isolated T-and B-lymphocytes. 3 In T cells, UDP-glucose (EC 50 ¼ 335 nM) induced a small but significant inhibition (circa 20%) of forskolin-stimulated cAMP accumulation, suggesting functional coupling of endogenously expressed P2Y 14 receptors to the inhibition of adenylyl cyclase activity. In contrast, the other putative P2Y 14 receptor agonists UDP-galactose, UDP-glucuronic acid and UDP-N-acetylglucosamine had no significant effect alone but behaved as partial agonists by blocking UDP-glucose responses. In B cells, UDP-glucose (100 mM) had no significant effect on forskolin-stimulated cAMP accumulation. 4 Treatment of T cells with pertussis toxin (G i/o blocker) abolished the inhibitory effects of UDPglucose on forskolin-stimulated cAMP accumulation. 5 T-cell proliferation in response to anti-CD3 monoclonal antibody (1 mg ml À1 ) was significantly inhibited by UDP-glucose (59% inhibition; p[IC 50 ] ¼ 5.970.3), UDP-N-acetylglucosamine (37%; 6.170.3), UDP-galactose (56%; 8.270.2) and UDP-glucuronic acid (49%; 6.370.2). Interleukin-2-(5 ng ml À1 ) induced T-cell proliferation was also significantly inhibited by all four agonists. 6 In summary, we have shown that the P2Y 14 receptor appears to be functionally expressed in murine spleen-derived T-lymphocytes. These observations suggest that UDP-glucose and related sugar nucleotides presumably via the P2Y 14 receptor may play an important role in modulating immune function.

The inflammatory effects of UDP-glucose in N9 microglia are not mediated by P2Y14 receptor activation

“…Whereas both UDPG and UDP-gal are agonists of P2Y14 receptors [1,14], in human neutrophils [12] and in murine T-lymphocytes [10] UDP-gal does not mimic the effects of UDPG. Coincidentally, the source of UDPG used in the above studies was also microbialderived.…”

“…Its newly identified presence in microglia [5] suggests that P2Y14 may have a role in modulating microglial responses in the CNS. Uracil-containing sugar nucleotides, such as uridine 5' diphosphoglucose (UDPG) and UDP-galactose (UDP-gal), are selective agonists for the P2Y14 receptor [1], which couples intracellularly to the inhibition of adenylyl cyclase via Gi/o [1,8,10,11] in many cell types. Adenylyl cyclase catalyzes the formation of cyclic AMP, enabling protein kinase A (PKA) to phosphorylate and activate the transcription factor cAMP response element binding protein (CREB), among many others.…”

Purinergic signaling in inflammatory cells: P2 receptor expression, functional effects, and modulation of inflammatory responses

“…In contrast to the study by Lee et al, Wang et al found similar expression levels between P2X1 and P2X7 [153]. Moore et al furthermore showed expression of P2Y 14 in peripheral immune cells including lymphocytes [39], which was in a further study reported to be predominantly expressed in T lymphocytes rather than in B lymphocytes [154].…”

“…The only P2Y receptor for which functional data are available in lymphocytes is P2Y 14 ; in T cells UDP, glucose induces significant inhibition of forskolin-stimulated cAMP accumulation via P2Y 14 receptors [154].…”

Selective Induction of P2Y14 Receptor by RANKL Promotes Osteoclast Formation

“…Moreover, deficiency of P2Y14 by RNA interference resulted in defective osteoclast formation. Study of P2Y14 has so far demonstrated the functional expression of this receptor in several cell types such as human lung epithelial cells (Muller et al, 2005), neutrophils (Scrivens and Dickenson, 2006), dendritic cells (Skelton et al, 2003), murine spleenderived T-lymphocytes (Scrivens and Dickenson, 2005), and bone-marrow derived hematopoietic cells with stem cell characteristics (Lee et al, 2003). The presently-described RANKLinduced expression of P2Y14 in osteoclast precursors constitutes the first report of a role for P2Y14 in osteoclast biology.…”