Figure 1. Detection of MHC proteins by flow cytometry and immunofluorescence staining of MHC class II (MHC-II) in combination with the neural stem cell marker, SOX2, and the microglial markers CD11b.

(A) HLA-A, -B, -C (MHC-class I) and HLA-DR, -DP, -DQ (MHC-class II) assessed by flow cytometry in UC-MSCs (FCS), UC-MSCs (CP), ADSCs and hNSCs (light grey curves: negative controls; dark grey curves: labelled cells). These are representative histograms of ≥3 cell isolates. Data are percentages represented as mean ± SEM. Abbreviations: ADSC, adipose-derived stem cells; CP, cord plasma; FCS, fetal calf serum; HLA, human leukocyte antigens; NSC, neural stem cells; UCMSC, umbilical cord mesenchymal stem cell. (B) MHC-II staining in hNSCs from 3 brains at different stages of development. Cs: Carnegie stage. Nuclei are counterstained with Hoechst dye (blue). Note that subsets of hNSCs are positive at all stages. (C) hNSCs (Cs23) double-labelled for SOX2 and MHC-II. All nuclei are SOX2-positive, and some cells display also cytoplasmic SOX2 staining; a subset of SOX2-positive cells expresses MHC-II protein. (D) hNSCs and astrocytes stained for MHC-II; positive cells are observed in hNSCs but not in astrocyte cultures. (E) hNSCs stained for MHC-II and CD11b; no CD11b-positive cells are observed.