FIG 3.

Upregulation of CTLA-4 expression via treatment with PGE₂ or an EP4 agonist. (a and b) First, PBMCs of cattle not infected with M. avium subsp. paratuberculosis were cultured with PGE₂ or the EP4 agonist, and dimethyl sulfoxide (DMSO) was used as a vehicle control. Subsequently, CTLA-4 expression in CD4⁺ T cells (a) and CD8⁺ T cells (b) was measured by using flow cytometry (n = 10; P values were obtained using Mann-Whitney U tests). (c and d) CD3⁺ cells were sorted from the PBMCs of cattle not infected with M. avium subsp. paratuberculosis cattle and cultured with PGE₂ (c) or the EP4 agonist (d), and DMSO was used as a vehicle control. The gene expression of CTLA-4 was quantitated using qPCR (n = 8; P values were obtained using Steel-Dwass tests).