人脐带间充质干细胞向胰岛素分泌细胞分化过程免疫特性的研究

Immunological Characteristics of Mesenchymal Stem Cells Derived from Human Umbilical Cord Wharton's Jelly to the Differentiated Insulin-producing Cells

目的研究人脐带间充质干细胞(huMSCs)向胰岛素分泌细胞(IPCs)分化过程中的免疫学特性,为huMSCs作为胰岛细胞移植治疗1型糖尿病的细胞来源提供依据。方法以流式细胞术检测huMSCs及huMSCs源性IPCs的免疫表型;RT-PCR法检测huMSCs及huMSCs源性IPCs的HLA-A、HLA-DR基因的表达;CCK8法测定细胞增殖率,观察huMSCs及huMSCs源性IPCs对外周血单个核细胞增殖的影响。结果 huMSCs在体外培养条件诱导下,具有向胰岛素分泌细胞分化的潜能;huMSCs及huMSCs源性IPCs均不表达CD80、CD86、CD40、CD40L、HLA-DR,均表达HLA-A;huMSCs能够抑制PHA刺激的外周血单个核细胞的增殖,但huMSCs源性IPCs未见该作用。结论 huMSCs及huMSCs源性IPCs均具有低免疫原性,可作为胰岛细胞移植的细胞来源,huMSCs对免疫反应具有负调节作用,但huMSCs源性IPCs不具有该作用。

Objective To explore the immunologgical characteristics of human umbilical cord wharton＇ s jelly-derived mesenchymal stem cells, huMSCs） during insulin-producing cells （IPCs） differentiation. Methods HuMSCs were isolated, cultured and induced to differentiate into insulin-producing ceils in the con- dition of islet cells grows. The morphology of huMSCs was detected by inversion phase contrast microscope. Immunofluorescence method was used to detect the insulin protein. Fluorescence-activated cell sorting （FACS） was used to detect the expression of immunophenotype in the huMSCs and IPCs differen- tiated from huMSCs. Reverse transcription-polymerase chain reaction （RT-PCR） was used to detect major histocompatibility complex gene HLA-A and HIA-DR in the huMSCs and IPCs differentiated from huMSCs. The proliferation of phytohemagglutinin （PHA） stimulated allogeneic T lymphocytes was measured by CCK8 method. Results HuMSCs were isolated and induced to differentiate into insulin-producing cells under conditions of islet cell growth. Immunofluorescence analysis showed an expression of human insulin in differentiated huMSCs; huMSCs and the IPCs were negative for CD80, CD86, CD40, and CD40L by flow cytometric analysis （FACS）. RT-PCR showed that huMSCs and IPCs were negative for HLA-DR but positive for HLA-A. HuMSCs suppressed proliferation of peripheral blood mononuclear cells （PBMCs） activated by phytohemagglutinin （PHA） while the IPCs had no effect. Conclusion HuMSCs and IPCs differentiated from huMSCs are hypoimmunogenic. HuMSCs are immunomodulatory, while IPCs differentiated from huMSCs are non-immunomodulatory. Thus, huMSCs could be an excellent candidate for islet cell replacement therapy.