CLA inhibits CD68 and increases MR expression in HPBMC-derived macrophages. (a) Freshly isolated HBPMCs were cultured for four days in the presence or absence of M-CSF and treated with c-9,t-11-CLA, t-10,c-12-CLA, CLA blend (80:20 c-9,t-11:t-10,c-12), OA, LA or TROG for a further 48 hrs. At day 6, macrophage were fixed and stained. Immunofluorescence analysis of unstimulated macrophage shows that both CLA isomers and their blend increase MR expression but do not affect CD68 expression. (b) Differentiation of HBPMCs in the presence of 100 ng/ml M-CSF showed that c-9,t-11-CLA and CLA blend inhibits CD68 expression and increases MR expression. Epifluorescent microscope images (63× magnification) are representative of three independent experiments. Blue indicates DAPI (nuclei), green indicates CD68 (macrophage marker), cyan indicates MR and red indicates phalloidin (cytoplasmic) staining. (c) Spectrophotometry quantification of CD68 and MR fluorescent signal confirms the regulation of CD68 and MR by c-9,t-11-CLA and the atheroprotective blend. Statistical analysis of three independent experiments is expressed mean % as fluorescence ± SEM vs vehicle where *p < 0.05; **p < 0.01 and ***p < 0.001.