OBJECTIVETo investigate the biological function of hepatocyte-like cells derived from mesenchymal stem cells that isolated from human umbilical cord UC-MSCs in vitro, and to detect the changes in the immunogenicity of the differentiated hepatocyte-like cells (DHC).

METHODSTransdifferentiation of UC-MSCs into hepatic lineage in vitro was induced in modified two-step induction medium. The expressions of hepatic specific markers were detected by RT-PCR analysis and immunofluorescence staining at different time points after induction. The levels of albumin and urea in the supernatants of cultures were measured by enzyme-linked immunosorbent assay. Furthermore, the immunosuppressive property of DHC was detected by one-way mixed lymphocyte culture.

RESULTSThe mRNA and proteins of alpha fetoprotein (AFP), albumin (ALB),and cytokeratin-19 (CK-19) were expressed in naive UC-MSCs at low levels. DHC highly expressed hepatic markers AFP, ALB, CK-19, and tryptophan 2, 3-dioxygenase 14 and 28 days after hepatic differentiation and were accompanied by an increased production of ALB and urea in supernatant in a time-dependent manner. DHC did not express human leukocyte antigen DR antigen and significantly decreased the lymphocyte proliferation.

CONCLUSIONUC-MSCs are able to differentiate into functional hepatocyte-like cells in vitro, while the immunogenicity of DHC remains low.

Cell Transdifferentiation ; Cells, Cultured ; Hepatocytes ; cytology ; immunology ; Humans ; Mesenchymal Stromal Cells ; cytology ; Umbilical Cord ; cytology

This study was purposed to clarify whether biology function of mesenchymal stem cells (MSCs) is changed by suppressing the development of dendritic cells (DC) derived from hematopoietic stem cells (HSCs). MSCs were cocultured with dendritic cells derived from CD34 positive hematopoietic stem cells (HSCs), and then the expression of cytokines and phenotypes of DCs/MSCs were detected by RT-PCR and flow cytometry respectively. Induced experiments were used to analyze the differentiation ability of MSCs. The results showed that DCs/MSCs were negative for the CD14, CD34, CD45, CD31, CD86, but positive for HLA-ABC, CD29, CD73, though the percentage decreased as MSCs vs DCs/MSCs (93.1% vs 13.44%, 98.3% vs 78.8%, 95.3% vs 75.9%). In addition, the expression of cytokines such as M-CSF, TGF-beta increased in DCs/MSCs. After differentiation induction, DCs/MSCs were deprived of the potential to differentiate into adipocytes, but maintained osteogenesis characteristics. It is concluded that the basic characteristics of MSCs are altered after coculture with DCs, and DCs/MSCs result in lower expression of mesenchymal phenotypes and decrease differentiation ability, but increase the expression of cytokines related to hematopoiesis and immunity.
Antigens, CD34 ; immunology ; Bone Marrow Cells ; cytology ; Cell Differentiation ; Cells, Cultured ; Dendritic Cells ; cytology ; immunology ; Humans ; Mesenchymal Stromal Cells ; cytology

Human leukocyte antigen G (HLA-G), a kind of non-classical major histocompatibility complex class I antigens, can inhibit inflammatory reaction, assist tumor cells to escape from immune surveillance and promote the immunologic tolerance of the graft. HLA-G, expressed and secreted by human amniotic mesenchymal cells (HAMC), suppresses the functions of NK cells, T cells and B cells and modulates the activity of dendritic cells (DC). These findings provide a theoretical basis for illustrating the mechanism of immunosuppression on HAMC. In this article, the recent advances on not only the gene and the molecular structure of HLA-G, but also the possible mechanisms of HLA-G in immunoregulatory function of HAMC, as well as the relation of HLA-G with HAMC, NK, DC, T and B cells are reviewed.
Amnion ; cytology ; HLA-G Antigens ; immunology ; Humans ; Immune Tolerance ; Mesenchymal Stromal Cells ; cytology ; immunology

Mesenchymal stem cells (MSCs) can inhibit T cell proliferation, the effects of MSCs on various T cell subsets have showed different immune regulatory reactions, and their mechanisms mainly include cell-cell contact and mediation by cytokines secreted from MSCs. Encouragingly, recent studies have showed that the effects of MSCs on T-cell response to pathogens is not significant, but can obviously suppress T cell response to allogeneic antigens. In addition, MSCs can regulate the proliferation, survival, antibody secretion and differentiation of B cells, inhibit the production, proliferation, migration and antigen-presentation of DCs, and modulate the differentiation and maturation of DCs, and regulate the proliferation, cell toxicity and cytokine secretion of NK cells. In this review, the research advances on immunomodulatory effects of MSCs on various immune cells including T-lymphocytes, B-lymphocytes, NK cells and DCs are summarized with emphasis on the immunoregulatory effects of MSCs on T-lymphocytes.
B-Lymphocytes ; immunology ; Dendritic Cells ; immunology ; Humans ; Killer Cells, Natural ; immunology ; Mesenchymal Stromal Cells ; cytology ; immunology ; T-Lymphocytes ; immunology

This study was purposed to explore the immunoregulatory effects of human bone marrow mesenchymal stem cells (MSCs) on active T lymphocytes in vitro and the new strategy to prevent graft-versus-host disease (GVHD) in allogeneic hematopoietic stem cell transplantation (allo-HSCT). Mononuclear cells from human peripheral blood cells were isolated and cultured in the presence of phytohemagglutinin (PHA) (final concentration was 10 microg/ml) for different times. The ability of T lymphocyte proliferation and activation was measured by (3)H-Thyramine incorporation. The expressions of CD3(+)CD4(+), CD3(+)CD8(+), CD4(+)CD25(+) and CD4(+)CD152(+) on T cells were detected by FCM after coculture for 72 hours. Experiment was divided into 4 groups: A group as control (no added MSCs), B group (actived T cells + 2 x 10(4) MSCs), C group (actived T cells + 4 x 10(4) MSCs), D group (actived T cells + 8 x 10(4) MSCs). The results showed that the ability of T lymphocyte proliferation in the same PHA concentration increased with prolonging of time. ability of T lymphocyte proliferation was strongest when culturing for 48 hours (p < 0.01); the expressions of CD44, CD105, CD29 and FIK1 of MSCs were positive, expressions of CD33, CD34, CD45 and HLA-DR were negative. MSCs inhibited T lymphocyte proliferation and the inhibitory effect depended on the amount of MSCs. CD3(+)CD8(+), CD4(+)CD25(+) and CD4(+)CD152(+) T cells cocultured with MSCs increased obviously and CD3(+)CD4(+) expression significantly decreased, as compared with control group (p < 0.01). It is concluded that the MSCs inhibit T lymphocyte proliferation induced by mitogen (PHA), and perform their immunosuppressive function by up-regulation of CD3(+)CD8(+), CD4(+)CD25(+) and CD4(+)CD152(+) expressions and down-regulation of CD3(+)CD4(+) expression.
Bone Marrow Cells ; cytology ; Cell Separation ; Cells, Cultured ; Humans ; Lymphocyte Activation ; immunology ; Mesenchymal Stromal Cells ; cytology ; immunology ; T-Lymphocytes ; immunology

In an attempt to study the immunoregulatory effect of osteoblasts derived from mesenchymal stem cells (MSC), MSC was induced to differentiate into osteoblasts for one week. The growth pattern and the phenotype were evaluated by MTT and flow cytometry respectively. The immunoregulatory effect was tested by the inhibitory effect on T cell proliferation. The result showed that during the differentiation cells grew fast and there was no significant change in the phenotypes but keeping CD73, CD105, CD44, CD29 positive and CD34, CD45, HLA-DR, CD86 negative. Osteocyte derived from MSC also showed immunosuppressive effect on T cell proliferation in adose-dependent manner. It is concluded that osteoblasts derived from MSC also harbored immunoregulatory effect.
Bone Marrow Cells ; cytology ; immunology ; Cell Differentiation ; immunology ; Cell Lineage ; Cell Proliferation ; Cells, Cultured ; Humans ; Mesenchymal Stromal Cells ; cytology ; immunology ; Osteoblasts ; cytology ; immunology ; T-Lymphocytes ; cytology ; immunology

Mesenchymal stem cells (MSCs) are non-hematopoietic stem cells possessing multi-differentiation potential, and were widely used in stem cell transplantation, tissue engineering, organ transplantation and immunotherapy, etc. However, the distribution and differentiation of MSCs after reinfusion directly influence their application. In this paper the "homing" characteristics, mechanisms and significance of MSCs were reviewed.
Cell Movement ; Humans ; Mesenchymal Stem Cell Transplantation ; Mesenchymal Stromal Cells ; cytology ; immunology

This study was aimed to investigate the immunomodulatory ability of human umbilical cord mesenchymal stem cells (UB-MSC) along with prolonging of culture time and increasing of passages in vitro. Mesenchymal stem cells (MSC) were isolated from human umbilical cord and cultured in vitro. The morphological changes and nucleocytoplasmic ratio of MSC were observed using Giemsa staining. MSC of the 5th passage were selected as control group, and MSC of the 13th passage were taken as senile group. The degree of cell senescence was detected by aging cells in situ test kit. Cell Counting Kit-WST-8 was used to determine the proliferation of lymphocytes in mixed lymphocytes coculture system with different passages of MSC. The expression of immunomodulation-related genes was detected by RT-PCR. The results showed that the length-breadth ratio of MSC increased and nucleocytoplasmic ratio decreased along with the increasing of passages. The senium degree of cells of the 13th passage was higher than that of the 5th passage cells. The capacity of suppressing lymphocyte proliferation of the 13th passage MSC was enhanced, compared with the 5th passage. Moreover, the expression of immunosuppression-related genes of senile MSC increased and the expression of most anti-inflammation associated genes declined as compared with young MSC by RT-PCR. It is concluded that the degree of MSC senescence gradually develops with increasing of culture passage, but the immunosuppressive ability of MSC strengthens with continuous culture.
Cell Differentiation ; Cell Proliferation ; Cells, Cultured ; Cellular Senescence ; Humans ; Lymphocytes ; cytology ; immunology ; Mesenchymal Stromal Cells ; cytology ; immunology ; Umbilical Cord ; cytology

The main aim of this study was to investigate the biological activities and immune modulation changes of chorionic villi mesenchymal stem cells (CV-MSC) after long term culture. The morphology of the CV-MSC of passage 3 and passage 9 were observed by microscopy, and their phenotypes were detected by flow cytometry. CV-MSC of passage 3 and 9 were co-cultured with PHA-stimulated PBMNC, and IFN-γ concentration in culture medium was detected by ELISA. The mRNA expression of COX-2, HGF and HLA-G in CV-MSC were detected by real-time PCR. The results showed that after long term culture, the CV-MSC kept the MSC morphology and most of the phenotypes including CD31, CD34, CD44, CD45, CD62L, CD73, CD90, CD105, CD117, CD151, CD235a, CD271 and HLA-DR, while the CD49d was significantly up-regulated. Immune modulation ability of CV-MSC was reduced and the mRNA expression of COX-2 and HGF was down regulated after long term culture, but the expression of HLA-G did not found to be obvious change. It is concluded that the long term in vitro expansion changes the expression of CD49d and reduces immune modulation of CV-MSC.
Cells, Cultured ; Chorionic Villi ; immunology ; Female ; Humans ; Integrin alpha4 ; metabolism ; Mesenchymal Stromal Cells ; cytology ; immunology ; Monocytes ; cytology ; Placenta ; cytology ; Pregnancy

OBJECTIVETo compare the adipose-derived mesenchymal stem cells (ADMSCs) isolated from the greater omentums and subcutaneous adipose tissues of rats for their characteristics in cell morphology, growth kinetics and immunophenotypes.

METHODSADMSCs were isolated from the greater omentums and inguinal fat pads of 6 SD rats and cultured in vitro. The morphologies of the ADMSCs were observed using phase-contrast microscopy, and their growth curves were generated and the doubling times determined. The phenotypic marker profiles including CD11b, CD29, CD45, CD49d, CD90 and CD106 of the ADMSCs in the fourth passage were determined using flow cytometry.

RESULTSThe ADMSCs harvested from the greater omentums and inguinal fat pads showed almost identical morphologies. The growth curves and the mean doubling time of the ADMSCs from the two different sources showed no obvious difference. With similar positivity rates for CD11b, CD29, CD106 and CD90, the two ADMSCs exhibited different expression rates of CD45 and CD49d.

CONCLUSIONSThe immunophenotypic characteristics of the ADMSCs from the greater omentums and subcutaneous adipose tissues are not totally identical.

Adipose Tissue ; cytology ; immunology ; Animals ; Cells, Cultured ; Immunophenotyping ; Mesenchymal Stromal Cells ; cytology ; immunology ; Omentum ; cytology ; immunology ; Rats ; Rats, Sprague-Dawley ; Subcutaneous Fat ; cytology ; immunology