Human Hepatocytes and Differentiated Adult-Derived Human Liver Stem/Progenitor Cells Display In Vitro Immunosuppressive Properties Mediated, at Least in Part, through the Nonclassical HLA Class I Molecule HLA-G

Figure 3

Analysis of HLA-G protein expression by human liver cells. (a) The membrane and intracytoplasmic expression of HLA-G by hepatocytes (Hep), undifferentiated ADHLSCs (ADHLSCs), and differentiated ADHLSCs (ADHLSCs diff) was evaluated by flow cytometry using PE-anti-HLA-G1/-G5 IgG1 (clone MEM-G9, which recognizes both membrane-bound HLA-G1 and soluble HLA-G5/-G6 isoforms). Gates were placed based on the corresponding isotype. Results in percent of positive cells are expressed as . The images shown are representative of at least 3 independent experiments. (b) The expression of HLA-G by human liver cells was determined by immunofluorescence. Cells were stained with specific antibodies (clone 4H84 or 5A6 which recognize all HLA-G isoforms or HLA-G5 and HLA-G6 isoforms, respectively) or the corresponding isotype control antibodies followed by Alexa Fluor 488-conjugated secondary antibodies (green). The samples were then counterstained with DAPI in order to visualize the nuclei (blue). Picture magnification is 400x. (c) The presence of soluble HLA-G in the culture supernatants of hepatocytes and undifferentiated and differentiated ADHLSCs was evaluated using a Luminex assay. Results are expressed as pg/ml/100 000 cells/24 hours.

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