['To engineer a stable HLA-G molecule and evaluate its immunomodulatory properties in transgenic human dermal fibroblasts (HDFs).', "A mutated HLA-G1 (mHLA-G1) molecule was generated by modifying the endoplasmic reticulum retrieval motif and 3'-untranslated region miRNA-binding sites of HLA-G1. Immunomodulatory properties of transgenic HDF-mHLA-G1 were evaluated in vitro.", 'Stable mHLA-G1 expressing HDF cells were successfully generated and flow cytometry analysis revealed that mHLA-G1 efficiently localized to the cell surface. Natural killer cell-mediated cytolysis of HDF-mHLA-G1/green fluorescent protein (GFP) was reduced by 73% compared with HDF-GDP. HDF-mHLA-G1/GFP decreased phytohemagglutinin-activated peripheral blood mononuclear cell proliferation by 30% versus HDF-GFP.'] Does heterologous expression of mutated HLA-G1 reduce alloreactivity of human dermal fibroblasts?