Gonist on the maturation of LCs, we cultured epidermal cell suspensions from B6 mouse ears for 24 hours with or without the EP3 agonist. The expression levels of co-stimulatory molecules, such as CDEP3 agonist inhibited migration and maturation of BMDCs in vitroPGE2 is known to promote the migration of cutaneous DCs to draining lymph nodes in an EP4-dependent manner during cutaneous inflammatory conditions when the local concentration of PGE2 is high ( 10 M) [10]. Since the binding affinity of EP3 is much higher than that of EP4 [21], we hypothesized that PGE2-EP3 signaling 10457188 may function when the local concentration of PGE2 is low (pM scale), for example, under the steady states or upon innocuous stimuli. Therefore, to validate the physiological significance, we examined the effect of low-dose PGE2 on the chemotactic activity of BMDCs to CCL21, one of the chemokines that induce the homing ofEP3 Signaling Regulates the Cutaneous DC FunctionsFigure 1. Inhibition of migration and maturation of BMDCs by EP3 agonist (AE248). (a) mRNA Expression of the four EP subtypes in BMDCs. (b) Low dose PGE2 attenuated the migration of BMDCs. BMDCs were treated with 0, 1, 10 and 100 pM PGE2 and applied to a transwell. 100 ng/mL CCL21 was administrated to the lower chamber. Migrated BMDCs were SPDB identified as MHC class II+ CD11c+ subset in the lower chamber. The input was calculated as follows: (the number of BMDCs migrated into the lower chamber)/(the number of BMDCs applied into the upper chamber) *100. (c) EP3 agonist attenuated the CCL21-induced migration of BMDCs. BMDCs were treated with 10 M AE248 for 2 days and applied to a transwell. The migration assay was carried out the same way as previously descried. (d) Intracellular cAMP concentration. BMDCs were treated with 0.5 mM IBMX for15min prior to EP3 agonist treatment (30min). (e) The number of total (CD86high MHC class II middle to high) and mature (CD86high MHC class II high ) BMDCs were MedChemExpress BTZ043 counted after EP3 agonist incubation for 2 days (n=6). Each data represents the mean + SD. *p<0.05.doi: 10.1371/journal.pone.0069599.gand CD86, and adhesion molecule CD54 were decreased by the addition of the EP3 agonist (Figure 2c). Taken together, EP3 signaling suppressed the migration and maturation of LCs in vitro.EP3 restricted migration of cutaneous DCs under suboptimal antigen stimulation in vitroTo further test our hypothesis that PGE2-EP3 signaling functions in vivo, we applied different doses of fluorescein-5isothiocyanate (FITC) onto the abdominal skin of mice under the steady state or upon innocuous/mild stimuli. Then we counted the number of FITC+ MHC class II+ cutaneous DCsEP3 Signaling Regulates the Cutaneous DC FunctionsFigure 2. Inhibition of migration and maturation of LCs by EP3 agonist (AE248). (a) Expression of the four EP subtypes in CD11c+ epidermal cell suspensions (Langerhans cells) (Left; mRNA, Right; protein). (b) LCs treated with EP3 agonist for 24 hours were applied to the upper chamber of a transwell. After 3 hours incubation, the numbers of MHC class II + CD11c+ cells in the lower chamber including 100 ng/mL CCL21 were counted. White and black bars indicates the data from B6 and EP3KO mice, respectively (n=3). (c) Expression of maturation markers (CD80, CD86 and CD54) on LCs were analyzed by FACS 24 hours after EP3 agonist treatment (n=3). *p<0.05. MFI, mean fluorescence intensity.doi: 10.1371/journal.pone.0069599.gthat migrated from the skin to the draining lymph nodes after 96 hour.Gonist on the maturation of LCs, we cultured epidermal cell suspensions from B6 mouse ears for 24 hours with or without the EP3 agonist. The expression levels of co-stimulatory molecules, such as CDEP3 agonist inhibited migration and maturation of BMDCs in vitroPGE2 is known to promote the migration of cutaneous DCs to draining lymph nodes in an EP4-dependent manner during cutaneous inflammatory conditions when the local concentration of PGE2 is high ( 10 M) [10]. Since the binding affinity of EP3 is much higher than that of EP4 [21], we hypothesized that PGE2-EP3 signaling 10457188 may function when the local concentration of PGE2 is low (pM scale), for example, under the steady states or upon innocuous stimuli. Therefore, to validate the physiological significance, we examined the effect of low-dose PGE2 on the chemotactic activity of BMDCs to CCL21, one of the chemokines that induce the homing ofEP3 Signaling Regulates the Cutaneous DC FunctionsFigure 1. Inhibition of migration and maturation of BMDCs by EP3 agonist (AE248). (a) mRNA Expression of the four EP subtypes in BMDCs. (b) Low dose PGE2 attenuated the migration of BMDCs. BMDCs were treated with 0, 1, 10 and 100 pM PGE2 and applied to a transwell. 100 ng/mL CCL21 was administrated to the lower chamber. Migrated BMDCs were identified as MHC class II+ CD11c+ subset in the lower chamber. The input was calculated as follows: (the number of BMDCs migrated into the lower chamber)/(the number of BMDCs applied into the upper chamber) *100. (c) EP3 agonist attenuated the CCL21-induced migration of BMDCs. BMDCs were treated with 10 M AE248 for 2 days and applied to a transwell. The migration assay was carried out the same way as previously descried. (d) Intracellular cAMP concentration. BMDCs were treated with 0.5 mM IBMX for15min prior to EP3 agonist treatment (30min). (e) The number of total (CD86high MHC class II middle to high) and mature (CD86high MHC class II high ) BMDCs were counted after EP3 agonist incubation for 2 days (n=6). Each data represents the mean + SD. *p<0.05.doi: 10.1371/journal.pone.0069599.gand CD86, and adhesion molecule CD54 were decreased by the addition of the EP3 agonist (Figure 2c). Taken together, EP3 signaling suppressed the migration and maturation of LCs in vitro.EP3 restricted migration of cutaneous DCs under suboptimal antigen stimulation in vitroTo further test our hypothesis that PGE2-EP3 signaling functions in vivo, we applied different doses of fluorescein-5isothiocyanate (FITC) onto the abdominal skin of mice under the steady state or upon innocuous/mild stimuli. Then we counted the number of FITC+ MHC class II+ cutaneous DCsEP3 Signaling Regulates the Cutaneous DC FunctionsFigure 2. Inhibition of migration and maturation of LCs by EP3 agonist (AE248). (a) Expression of the four EP subtypes in CD11c+ epidermal cell suspensions (Langerhans cells) (Left; mRNA, Right; protein). (b) LCs treated with EP3 agonist for 24 hours were applied to the upper chamber of a transwell. After 3 hours incubation, the numbers of MHC class II + CD11c+ cells in the lower chamber including 100 ng/mL CCL21 were counted. White and black bars indicates the data from B6 and EP3KO mice, respectively (n=3). (c) Expression of maturation markers (CD80, CD86 and CD54) on LCs were analyzed by FACS 24 hours after EP3 agonist treatment (n=3). *p<0.05. MFI, mean fluorescence intensity.doi: 10.1371/journal.pone.0069599.gthat migrated from the skin to the draining lymph nodes after 96 hour.