Fig. 6: PGE2 via EP4 controls post-resolution T cells populations and phenotype.

A Osmotic pumps loaded with either the pan COX inhibitor naproxen or the EP4 antagonist MF498 were implanted into mice once inflammation resolved (day 4) and their effects of blocking the biological action of post-resolution PGE2 was established 6 weeks later as determined by measuring (B) late effector T cell numbers and (C) their effector function as well as (D) early effector T cells and their expression of (E, F) the α-integrin, CD103. as a marker of T cell residence potential. Linking PGE2 with this post-resolution T cell phenotype, T cells were incubated PGE2 and its direct effect on (G) CD103 expression or with other cytokines expressed during post-resolution that are known to affect lymphocyte function, (H) namely TGFβ, were examined for their collective effects on intracellular (I) IL-17 and (J) IFNγ. Data were analysed by one-way analysis of variance (ANOVA) and Tukey’s multiple comparisons test. A p value of <0.05 was taken as the threshold of significance with graphical representation as; p < 0.05 = *, p < 0.01 = ** and p < 0.001 = *** and presented as mean ± SEM (n = 3–6 mice/group).