Figure 1.

Human umbilical cord‐derived mesenchymal stem cells (hUC‐MSCs) promote interleukin (IL)−17 release by human peripheral blood mononuclear cells (hPBMCs)/CD4⁺ T cells. (a) hPBMCs (1 × 10⁵) were stimulated with 10 μg/ml phytohaemagglutinin (PHA), with or without different numbers of hUC‐MSCs. (MSCs1: 5 × 10³; MSCs2: 1 × 10⁴; MSCs3: 2 × 10⁴; MSCs4: 5 × 10^4; MSCs5: 1 × 10⁵). The data are expressed as the mean ± standard error of the mean (s.e.m.) from three different experiments, each performed in triplicate. *P < 0·05, **P < 0·01. (b) PHA‐activated‐hPBMCs from 10 donors were co‐cultured with one source of hUC‐MSCs from eight donors were co‐cultured with one source of PHA‐activated hPBMCs. IL‐17 concentrations in each culture were measured by enzyme‐linked immunosorbent assay (ELISA) and the data represent the mean of single experiments, each performed in triplicate. (c) IL‐17 secretion is shown from CD4⁺ T cells stimulated in the presence or absence of hUC‐MSCs for different days. (d) Quantitative reverse transcription–polymerase chain reaction (qRT–PCR) analysis of RAR‐related orphan receptor C (RORC) transcripts in anti‐CD3/CD28 Dynabeads‐stimulated CD4⁺ T cells in the presence or absence of hUC‐MSCs for different days. The data are expressed as the mean ± s.e.m. from three different experiments, each performed in triplicate. *P < 0·05, **P < 0·01. (e) Flow cytometry analysis of percentages of T helper type 17 (Th17) cells in the presence or absence of hUC‐MSCs for 3 days of culture. All data were excluded from the autofluorescence and were analysed based on four repeat experiments. **P < 0·01.