Sorted mDC were 70–80% pure, with 5–20% monocytes and less than 1% pDC Selleckchem Hydroxychloroquine contamination. Probe-based quantitative PCRs were designed using the human Universal Probe Library design center (Roche Applied Science, Penzberg, Germany). Real-time quantitative PCRs (qPCRs) were performed on the CFX96™ real-time PCR detection system (Biorad, Herts, UK) using iTaq Supermix with Rox (Biorad) and the following primer (Invitrogen/Life Technologies, Paisley, UK) and probe (human Exiqon probe library; Roche, Woerden, the Netherlands) combinations: IL-12p40 5′-CCACATTCCTACTTCTCCCTGA-3′ and 5′-ACCGTGGCTGAGGTCTTGT-3′ with
TCCAGGTC fluorescent probe, TNF-α 5′-AAGCCTGTAGCCCATGTTGT-3′ and 5′-GCTGGTTATCTGTCAGCTCCA-3′, with CCAGGAGG fluorescent probe and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) 5′-CAACGAATTTGGCTACAGCA-3′ and 5′-GTGGTCCGGGGGTCTTAC-3′ with CCACCACC fluorescent probe. IL-12p40 and TNF-α mRNA expression levels were standardized to reference gene GAPDH mRNA expression levels using the Pfafll method [31]. The non-parametric Mann–Whitney U-test was used to determine the statistical NVP-BKM120 cell line significance of cell numbers and TLR-induced cytokine expression in rhesus macaque versus human DC subsets and monocytes. As published
previously [16, 24], pDC and mDC subsets can be distinguished in peripheral blood of rhesus macaques on the basis of CD11c versus CD123 expression in HLA-DR-positive cells, which are negative for lineage markers CD3, CD8, CD16, CD20 and CD14 (Fig. 1). However, comparison of the dot-plots
shown in Fig. 1 (right graphs) reveals a striking difference in the percentage of pDC relative to mDC in the lineage–, HLA-DR+ cells in human versus rhesus macaque blood. As shown in Fig. 2, analysis of a larger cohort showed that the absolute number of pDC was significantly lower in rhesus macaques (3020 ± 1357 cells/ml) than in humans (10 495 ± 4353 cells/ml), while there was no difference in the number of mDC (20 811 ± 14 361 versus 17 178 ± 5671 cells/ml) or monocytes (324 000 ± 161 000 versus 217 000 ± 107 000 cells/ml). In order to evaluate the function of MTMR9 peripheral blood DC subsets in rhesus macaques without interference of cell isolation procedures, a whole blood stimulation assay was used, analogous to the previously described assay for human blood DC [29]. In brief, heparin blood was diluted 1:5 in RPMI-1640 medium with 0·1% bovine serum albumin (BSA), heparin and β-mercaptoethanol. Samples were exposed for 8 h to different TLR ligands and the cells were then stained and analysed by flow cytometry for the induction of maturation markers and cytokine expression. This procedure has the advantage that it allows detection of the response of different DC subsets simultaneously in one tube. Time–course experiments showed optimal induction of cytokine expression after 5–8 h incubation with all selected TLR-7/8 (CL097), TLR-9 (CpG-C) and TLR-4 (LPS) ligands (Fig. 3).