Mesenchymal stem cells (MSCs) have been widely studied for their applications in stem cell-based regeneration. During myocardial infarction (MI), infiltrated macrophages have pivotal roles in inflammation, angiogenesis and cardiac remodeling. We hypothesized that MSCs may modulate the immunologic environment to accelerate regeneration. This study was designed to assess the functional relationship between the macrophage phenotype and MSCs. MSCs isolated from bone marrow and bone marrow-derived macrophages (BMDMs) underwent differentiation induced by macrophage colony-stimulating factor. To determine the macrophage phenotype, classical M1 markers and alternative M2 markers were analyzed with or without co-culturing with MSCs in a transwell system. For animal studies, MI was induced by the ligation of the rat coronary artery. MSCs were injected within the infarct myocardium, and we analyzed the phenotype of the infiltrated macrophages by immunostaining. In the MSC-injected myocardium, the macrophages adjacent to the MSCs showed strong expression of arginase-1 (Arg1), an M2 marker. In BMDMs co-cultured with MSCs, the M1 markers such as interleukin-6 (IL-6), IL-1beta, monocyte chemoattractant protein-1 and inducible nitric oxide synthase (iNOS) were significantly reduced. In contrast, the M2 markers such as IL-10, IL-4, CD206 and Arg1 were markedly increased by co-culturing with MSCs. Specifically, the ratio of iNOS to Arg1 in BMDMs was notably downregulated by co-culturing with MSCs. These results suggest that the preferential shift of the macrophage phenotype from M1 to M2 may be related to the immune-modulating characteristics of MSCs that contribute to cardiac repair.
Animals ; Biomarkers/metabolism ; *Cell Differentiation ; Cells, Cultured ; Coculture Techniques ; Culture Media, Conditioned/pharmacology ; Humans ; *Macrophage Activation ; Macrophage Colony-Stimulating Factor/*pharmacology ; Macrophages/drug effects/*immunology/metabolism ; *Mesenchymal Stem Cell Transplantation ; Mesenchymal Stromal Cells/*cytology/drug effects/metabolism ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Myocardial Infarction/surgery ; Rats

This study was aimed to explore the immunoregulatory function and capability supporting the angiogenesis of exosomes secreted by bone marrow mesenchymal stem cells (BMMSC) from healthy persons. Supernatant of BMMSC (P4-P6) was collected for exosome purification. Transmission electron microscopy (TEM) and Western blot were used to identify the quality of isolated exosomes. The amount of exosomes was quantified through bicinchoninic acid (BCA) protein assay. Human peripheral blood mononuclear cells (PBMNC) were isolated from healthy donor and added with isolating exosomes. After co-cultured for 72 h, IFN-γ from the co-culture system was detected by ELISA. The expression of miRNA-associated with immunity were detected by real-time reverse transcription polymerase chain reaction (Real-time RT-PCR). The interactions between exosomes and human umbilical vein endothelial cells (HUVEC) were observed with confocal microscopy. Subconfluent HUVEC were harvested and treated with the indicated concentration of exosomes. Nude mice were injected subcutaneously with exosomes or PBS as control to verify the ability of angiogenesis. The results showed that diameter range of exosomes was range from 40 to 160 nm. The isolated exosomes expressed the CD9. There was approximately linear relation between the secretion of exosomes and cell density. The exosomes suppressed the production of IFN-γ from PBMNC, and contained miRNA associated with immune regulation such as miR301, miR22 and miR-let-7a. Exosomes induced vascular tube formation in vitro and vascularization of Matrigel plugs in vivo. It is concluded that the BMMSC-derived exosomes can regulate immunity and support vascularization.
Adult ; Animals ; Bone Marrow Cells ; cytology ; metabolism ; Cells, Cultured ; Exosomes ; immunology ; metabolism ; Female ; Humans ; Interferon-gamma ; metabolism ; Leukocytes, Mononuclear ; cytology ; Male ; Mesenchymal Stromal Cells ; cytology ; metabolism ; Mice, Nude ; Middle Aged ; Neovascularization, Physiologic

This study was purposed to observe the influence of umbilical cord mesenchymal stem cells (UC-MSC) on the peripheral blood CD4(+)CD25(+)regulatory T cells (Treg), Th17 cells and neutrophils in rats with collagen type II-induced arthritis(CIA), and to explore the regulating effect of UC-MSC transplantation on immunocyte subgroup. The rats wee divided into 3 groups: CIA group (model group), UC-MSC treated group and blank control group. The CIA rats were injected with UC-MSC via tail vein. The percentage of CD4(+)CD25(+) cells in peripheral blood and the expression of NCD11b on neutrophil surface in CIA rates was detected by flow cytometry (FCM), and the serum interleukin-17 (IL-17) was observed by enzyme-linked immunosorbent assay (ELISA). The results showed that the mean fluorescence intensity(MFI) of NCD11b and the level of IL-17 in the model group were significantly higher than those in the blank control group, and the ratio of CD4(+)CD25(+) cells were significantly lower (P < 0.05). The MIF of NCD11b and the level of IL-17 in the UC-MSC treated group were significantly lower than that in the model group (P < 0.05), while the proportion of CD4(+)CD25(+) Treg increased (P < 0.05). Since the fifth week, the above indicators in the UC-MSC group have almostly approached the control group. It is concluded that the UC-MSC can increase peripheral blood Treg proportion in CIA rat, inhibit the secretion of Th17 and the activity of neutrophils, reduce the immune inflammation reaction, decrease the release of proinflammatory factor, and induce immune reconstruction.
Animals ; Arthritis, Experimental ; immunology ; therapy ; Female ; Interleukin-17 ; metabolism ; Mesenchymal Stem Cell Transplantation ; Mesenchymal Stromal Cells ; cytology ; Neutrophils ; immunology ; Rats ; Rats, Sprague-Dawley ; Th17 Cells ; immunology ; Umbilical Cord ; cytology

Mesenchymal stem cells (MSCs) are partially defined by their ability to differentiate into tissues including bone, cartilage and adipose in vitro, but it is their trophic, paracrine and immunomodulatory functions that may have the greatest therapeutic impact in vivo. Unlike pharmaceutical treatments that deliver a single agent at a specific dose, MSCs are site regulated and secrete bioactive factors and signals at variable concentrations in response to local microenvironmental cues. Significant progress has been made in understanding the biochemical and metabolic mechanisms and feedback associated with MSC response. The anti-inflammatory and immunomodulatory capacity of MSC may be paramount in the restoration of localized or systemic conditions for normal healing and tissue regeneration. Allogeneic MSC treatments, categorized as a drug by regulatory agencies, have been widely pursued, but new studies demonstrate the efficacy of autologous MSC therapies, even for individuals affected by a disease state. Safety and regulatory concerns surrounding allogeneic cell preparations make autologous and minimally manipulated cell therapies an attractive option for many regenerative, anti-inflammatory and autoimmune applications.
Animals ; *Cellular Microenvironment ; Humans ; *Mesenchymal Stem Cell Transplantation ; Mesenchymal Stromal Cells/cytology/immunology/*metabolism ; Regenerative Medicine/*methods

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

The aim of this study was to investigate the effects of interferon (IFN)-γ on biological characteristics and immunomodulatory property of human umbilical cord-derived mesenchymal stem cells (hUC-MSC). hUC-MSC were treated with IFN-γ 10 ng/ml (IFN-γ group) or without IFN-γ (control group). The phenotype of hUC-MSC was detected by flow cytometry. The proliferation status was detected by CCK-8 method, and its differentiation ability was assessed by oil red O and von Kossa staining. The production of PGE-2 was measured by ELISA, and the mRNA expression levels of COX-2, IDO-1 and IDO-2 in hUC-MSC were detected by real-time quantitative PCR. Furthermore, the proliferation of human peripheral blood mononuclear cells (hPBMNC) was evaluated after co-culture with hUC-MSC, IFN-γ pretreatment or not. The results showed that after IFN-γ stimulation, the expression of SSEA-4 on hUC-MSC decreased significantly [(8.15 ± 2.94) vs (16.42 ± 8.5), P < 0.05], and the expression of CD54 increased [(96.64 ± 3.29) vs (84.12 ± 10.73), P = 0.051]. The immunomodulatory property of hUC-MSC on the proliferation of hPBMNC was enhanced (P < 0.05). All the above mentioned effects were IFN-γ concentration-dependent. When hUC-MSC were stimulated by IFN-γ for 24 h, the production of PGE-2 secreted by hUC-MSC decreased significantly (P < 0.01). The mRNA expression level of COX-2 also decreased though the difference did not reach to statistically significant level. Compared with control group, IDO-1 expression level in IFN-γ group increased significantly (P < 0.01), and the mRNA expression level of IDO-2 remained unchanged. It is concluded that IFN-γ can influence the phenotype of hUC-MSC and enhance the immunomodulatory property of hUC-MSC.
Cells, Cultured ; Cyclooxygenase 2 ; metabolism ; Flow Cytometry ; Humans ; Indoleamine-Pyrrole 2,3,-Dioxygenase ; metabolism ; Interferon-gamma ; pharmacology ; Mesenchymal Stromal Cells ; cytology ; drug effects ; immunology ; Umbilical Cord ; cytology

Mesenchymal stem cells (MSC) are characterized by their potent immuno-regulatory activity, however our previous data have shown that MSC have no therapeutic effects on collagen-induced arthritis (CIA). To further clarify the complexity, the effects of tumor necrosis factor-alpha (TNF-α) on the in vitro and in vivo immunoregulatory activity of MSC were investigated in this study, as TNF-α is recognized as the key factor in the development of rheumatoid arthritis. The nuclear translocation of the inflammation-associated factor NF-κB was observed after human umbilical cord MSC were treated with TNF-α and the cell proliferation status was assessed by MTT test. The inhibitory effects of MSC or TNF-α-treated MSC on the mixed lymphocyte reaction, in which Wistar rat spleen mononuclear cells were served as the responders and the splenocytes from SD rat spleens as the stimulators, were also determined by the MTT test. Further, the therapeutic potentials of MSC or TNF-α-treated MSC were observed in a Wistar rat CIA model. The results showed that NF-κB translocated into the nuclei promptly after TNF-α treatment, though TNF-α had little effect on the MSC proliferation. MSC, whether pre-stimulated by TNF-α or not and when different doses were tested, exhibited obviously inhibitory effects on the proliferation of the lymphocytes (P < 0.001 for all groups tested), while MSC-treated by TNF-α displayed more potent suppression especially when low-density were used. Unexpectedly, the infiltration of inflammatory cells into the involved knees was aggravated by cell treatment and the pathological scores were significantly higher than those of controls (P < 0.05). It is concluded that the TNF-α exhibits different effects on immune regulation activity of MSC, and its underlying mechanism needs to further investigate.
Animals ; Arthritis, Experimental ; metabolism ; pathology ; Cell Proliferation ; drug effects ; Cells, Cultured ; Humans ; Male ; Mesenchymal Stromal Cells ; cytology ; drug effects ; immunology ; NF-kappa B ; metabolism ; Rats ; Rats, Sprague-Dawley ; Rats, Wistar ; Tumor Necrosis Factor-alpha ; pharmacology

BACKGROUNDOverwhelming evidences on chronic myeloid leukemia (CML) indicate that patients harbor quiescent CML stem cells that are responsible for blast crisis. While the hematopoietic stem cell (HSC) origin of CML was first suggested over 30 years ago, recently CML-initiating cells beyond HSCs are also being investigated.

METHODSWe have previously isolated fetal liver kinase-1-positive (Flk1(+)) cells carrying the BCR/ABL fusion gene from the bone marrow of Ph(+) patients with hemangioblast property. In this study, we isolated CML patient-derived Flk1(+)CD31(-)CD34(-) mesenchymal stem cells (MSCs) and detected their biological characteristics and immunological regulation using fluorescence in situ hybridization (FISH) analysis, fluorescence activated cell sorting (FACS), enzyme-linked immunoadsorbent assay, mixed lymphocyte reaction assays; then we compared these characters with those of the healthy donors.

RESULTSCML patient-derived Flk1(+)CD31(-)CD34(-) MSCs had normal morphology, phenotype and karyotype while appeared impaired in immuno-modulatory function. The capacity of patient Flk1(+)CD31(-)CD34(-) MSCs to inhibit T lymphocyte activation and proliferation was impaired in vitro.

CONCLUSIONSCML patient-derived MSCs have impaired immuno-modulatory functions, suggesting that the dysregulation of hematopoiesis and immune response may originate from MSCs rather than hematopoietic stem cells (HSCs). MSCs might be a potential target for developing efficacious treatment for CML.

Adolescent ; Adult ; Antigens, CD34 ; genetics ; metabolism ; Apoptosis ; drug effects ; Blotting, Western ; Cell Cycle ; drug effects ; Cells, Cultured ; Enzyme-Linked Immunosorbent Assay ; Female ; Flow Cytometry ; Fusion Proteins, bcr-abl ; genetics ; metabolism ; Humans ; Immunomodulation ; In Situ Hybridization, Fluorescence ; Karyotype ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; enzymology ; immunology ; metabolism ; Male ; Matrix Metalloproteinase 9 ; genetics ; metabolism ; Mesenchymal Stromal Cells ; cytology ; immunology ; Middle Aged ; Platelet Endothelial Cell Adhesion Molecule-1 ; genetics ; metabolism ; T-Lymphocytes ; Vascular Endothelial Growth Factor Receptor-2 ; genetics ; metabolism ; Young Adult

OBJECTIVETo study the immunomodulatory effects and mechanisms of mesenchymal stem cells (MSC) derived from the bone marrow in acute leukemia patients in vitro.

METHODSBone marrow mononuclear cells from acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) were obtained and cultured in low serum medium. The immunophenotypes were assessed by FACS and immunol histochemistry. The levels of cytokines were evaluated by enzyme linked immunosorbant assay (ELISA). T-cell suppression ability was evaluated by Transwell chamber assay. Moreover, the immunoregulatory ability of AML- and ALL-derived MSC was detected by mixed lymphocyte culture assay.

RESULTSALL-derived MSC showed a typical fibroblast-like morphology. They were positive for CD29, CD44 and CD105, the positive rate were 98.81%, 99.25% and 90.52%, respectively, while negative for CD31, CD45 and CD34. Moreover, ALL- and AML-derived MSC didn't express HLA-DR and co-stirnulatory molecules (CD40, CD80 and CD86). ALL and AML derived MSC could secret several cytokines, such as TGF-β1 (567.58 ± 52.64 and 357.15 ± 33.52), HGF (647.27 ± 102.54 and 219.67 ± 62.37), IL-6 (59.67 ± 15.69 and 54.35 ± 12.31) and IL-11 (102.58 ± 23.54 and 78.21 ± 9.67), the level of secretion of TGF-β1 and HGF were higher in ALL bone marrow derived MSC than that of in AML bone marrow derived MSC. ALL and AML derived MSC significantly suppressed T lymphocyte proliferation in a dose-dependent manner, the counts per minute (CPM) were (3.58 ± 0.54) × 10(4), (2.87 ± 0.33) × 10(4), (1.78 ± 0.51) × 10(4) and (1.15 ± 0.15) × 10(4) for AML derived MSC, and CPM were (1.96 ± 0.31) × 10(4), (1.57 ± 0.28) × 10(4), (0.91 ± 0.41) × 10(4) and (0.22 ± 0.11) × 10(4) for ALL derived MSC when MSC were 0.5 × 10(4), 1 × 10(4), 2 × 10(4) and 5 × 10(4). In addition, the CPM was (4.01 ± 0.72) × 10(4) in control group. The immunosuppressive ability was different between MSCs derived from AML and ALL. The immunosuppressive effect of ALL derived MSC could be reversed by anti-TGF-β1 and anti-HGF antibody.

CONCLUSIONALL-derived MSC show immunoregulatory effect in vitro and this effect is achieved through cytokines. But MSCs derived from AML display abnormal changes in T-cell suppression ability.

Bone Marrow ; immunology ; Bone Marrow Cells ; cytology ; Cell Proliferation ; drug effects ; Cytokines ; pharmacology ; Humans ; Immunophenotyping ; Interleukin-11 ; metabolism ; Interleukin-6 ; metabolism ; Leukemia, Myeloid, Acute ; immunology ; Mesenchymal Stromal Cells ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; immunology ; Transforming Growth Factor beta1 ; metabolism

This study was purposed to explore the effect of bone marrow derived mesenchymal stem cells (MSCs) on the expression of CD69 on cytokine-induced killer (CIK)/natural killer (NK) cells derived from cord blood and on the quantity ratio of CD4+CD25+ T regulatory cells in CIK/NK cell culture system using Transwell non-contact cell culture system. The experiments were divided into two groups: Transwell non-contact culture and mixture culture. The ratio of MSC to CIK/ NK cells was 1:20, 1:50 and 1:100. In mixture culture groups, MSC and CIK/NK cells were co-cultured by together contact as the same ratio of Transwell non-contact culture groups. The expression of CD69 on CIK/NK cells, as well as the quantity ratio of CD4+CD25+ T regulatory cells in CIK/NK cell culture were evaluated by flow cytometry. The results showed that the expression of CD69 on CIK/NK cells in experimental groups were significantly lower than that in control group (p<0.001). As to Transwell groups, CD69 expression on the CIK/NK cells at 1:20 ratio of MSC and CIK/NK was significantly lower than that at 1:50 and 1:100 ratio. There were no differences in the expression of CD69 on CIK cells in mixture groups with various MSC ratios, whereas the expression of CD69 on NK cells at 1:20 ratio was significantly lower than that at 1:50 and 1:100. The quantity ratio of CD4+CD25+ cells in CIK/NK cell culture system of experimental groups with MSC co-culture was significantly higher than that in control. As to Transwell groups, the ratio of CD4+CD25+ cells in CIK/NK cell culture system at 1:20 and 1:50 was significantly higher than that at 1:100. The quantity ratio of CD4+CD25+ cells in CIK/NK cell culture system showed significant differences in various mixture groups. As to 1:20 ratio the amount of CD4+CD25+ cells in CIK/NK cell culture system of mixture groups was significantly higher than that in Transwell groups, while there were no differences of the quantity ratio of CD4+CD25+ cells in CIK/NK cell culture at 1:50 and 1:100. It is concluded that either by non-contact Transwell or mixed co-culture, the MSC can suppress the activation of allogeneic CB-CIK/NK cells, which maybe relate to up-regulating the ratio of CD4+CD25+ T regulatory cells in CIK/NK cell culture system in dose-dependent manner.
Antigens, CD ; metabolism ; Antigens, Differentiation, T-Lymphocyte ; metabolism ; Cell Culture Techniques ; Cells, Cultured ; Cytokine-Induced Killer Cells ; immunology ; metabolism ; Fetal Blood ; cytology ; immunology ; Humans ; Lectins, C-Type ; metabolism ; Mesenchymal Stromal Cells ; cytology ; T-Lymphocytes, Regulatory ; cytology ; metabolism