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

Bone marrow mesenchymal stem cells (BM-MSC) have the characteristics of self-renewal and multipotency. They secrete a variety of cytokines and provided and ideal microenvironment for the division, proliferation and differentiation of hematopoietic stem cells (HSC) through the interaction with other stromal cells. Previous studies indicated that MSC could enhance engrafment and alleviate GVHD in allo-HSC and MSC co-transplantation. This effect on transplantation immunity may associate with escaping MHC compatible HSC from antigen recognition and suppressing activation and proliferation of nonspecific lymphocytes. In this paper, the characteristics of BM-MSC influencing transplantation immunity and its mechanism were reviewed.
Bone Marrow Cells ; cytology ; immunology ; Graft vs Host Disease ; immunology ; prevention & control ; Hematopoietic Stem Cell Transplantation ; Hematopoietic Stem Cells ; cytology ; immunology ; Humans ; Mesenchymal Stem Cell Transplantation ; Mesenchymal Stromal Cells ; cytology ; immunology ; Transplantation Immunology

Objective To investigate the effect of adipose mesenchymal stem cells(AMSCs) on the peripheral blood lymphocyte(PBL) in psoriasis vulgaris(PV) patients and the expression and secretion profiles of related inflammatory cytokines in the PBL.Methods AMSCs from three PV patients were co-cultured with PBL. Peripheral blood regulatory cells(Treg) and T helper cell 17(Th17)ratio was measured by flow cytometry. The anti- and pro-inflammatory cytokines expressed and secreted by PBL were detected by quantitative real-time polymerase chain reaction(qRT-PCR) and enzyme-linked immunosorbent assay(ELISA).Results The Treg/total lymphocyte ratio was significantly higher in the healthy people AMSCs+PBL co-culture group[(3.2±0.5)%;P=0.001],but AMSCs in patients had a tendency to promote the proliferation of Treg cells [(1.3±0.2)%],with no significant difference(P=0.485) when compared with the PBL culture alone group[(1.0±0.1)%]. qRT-PCR showed that the ability of PBL in expressing Treg transcription factor forkhead box p3 and transforming growth factor(TGF)-Β mRNA was significantly lower in psoriasis AMSCs+PBL co-culture group than in the healthy people AMSCs+PBL co-culture group(P=0.00,P=0.03),AMSCs had a tendency to promote the expression of interlukin(IL)-10 in peripheral blood lymphocytes,but there was no significant difference(P=0.09).ELISA showed the PBL in healthy people AMSCs+PBL co-culture group secreted the anti-inflammatory cytokine IL-10[(156.9±41.8) ng/Μl] and TGF-Β[(2774.1 ± 526.4) ng/Μl];in contrast,the abilities of PBL in PV patient AMSCs+PBL co-culture group in secreting the anti-inflammatory cytokines has a downward trend:IL-10[(90.4±28.8) ng/Μl] and TGF-Β[(1597.9±55.7) ng/Μl],although the differences were not statistically significant. After the co-culture,the proportion of Th17 cells in the psoriasis AMSCs+PBL co-culture group[(0.8±0.3)%] showed a decreasing trend when compared with the PBL culture alone group[(1.1±0.1)%],although the results were not statistically significant. Also,the proportion of Th17 cells showed no significant difference between PV patient AMSCs+PBL co-culture group and healthy people AMSCs+PBL co-culture group. Finally,both the psoriasis AMSCs+PBL co-culture group and the healthy people AMSCs+PBL co-culture group showed no obvious inhibitory effect on the expression and secretion of Th17 transcription factor retinoid-related orphan nuclear receptor Γt and pro-inflammatory cytokines IL-17 and IL-23 in PBL,and there was no significant difference between these two groups.Conclusions AMSCs in PV patients have decreased ability in regulating the anti-inflammatory function of peripheral blood Treg lymphocytes. However,they have no effect on the proinflammatory effect of peripheral blood Th17 lymphocytes.
Adipose Tissue ; cytology ; Cytokines ; immunology ; Forkhead Transcription Factors ; immunology ; Humans ; Inflammation ; immunology ; Mesenchymal Stem Cells ; cytology ; Psoriasis ; immunology ; T-Lymphocytes, Regulatory ; immunology ; Th17 Cells ; immunology

There has been an increasing interest in recent years on mesenchymal stem cell (MSC). It is well known that MSCs are capable of self-renewal and differentiating into many cell lineages. MSC can be expended to a large quantity that is required for clinical transplantation. Recent studies show that MSC have potential application in immune diseases due to their unique immunologic characteristics, such as low immunogenicity and immunoregulatory function. But their immunoregulatory mechanism is not yet clear. This review discusses the advances in researches on the mechanism of MSCs' immunoregulatory function and potential clinical application in immune disease and organ transplantation.
Animals ; B-Lymphocytes ; immunology ; Graft vs Host Disease ; immunology ; Humans ; Immune Tolerance ; immunology ; Immunotherapy ; Mesenchymal Stem Cell Transplantation ; methods ; Mesenchymal Stromal Cells ; cytology ; immunology ; T-Lymphocytes ; immunology

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

This study was aimed to investigate if human heart harbored a population of primitive undifferentiated cells with the characteristics of MPC. Cells were isolated from human fetal heart and were cultured under conditions appropriate for bone marrow-derived MPCs. Their morphology, phenotypes and functions were tested by methods developed for MPC from other sources. The results showed that morphologically, cells were spindle shaped and resembled fibroblasts. In their undifferentiated state, cells were CD73, CD105, CD29, CD44, HLA-ABC, CD166 positive and CD45, CD34, CD86, HLA-DR negative. When cultured in adipogenic, osteogenic or chondrogenic media, cells differentiated into adipocytes, osteocytes and chondrocytes respectively. They could be extensively expanded in vitro and exhibited very low immunogenicity as evaluated by T cell proliferation assays. It is concluded that cells isolated from fetal heart possess similarity to their adult and fetal bone marrow counterparts in morphologic, immunophenotypic, and functional characteristics.
Bone Marrow Cells ; cytology ; Cell Adhesion ; Cell Differentiation ; Cells, Cultured ; Fetal Heart ; cytology ; Fetus ; Humans ; Mesenchymal Stromal Cells ; cytology ; immunology ; Multipotent Stem Cells ; physiology

OBJECTIVETo observe the influence of guinea pig mesenchymal stem cells (MSCs) culture in vitro on the immunological status in heterogeneous recipient, and to evaluate the immunomodulation of MSCs to the immune rejection of liver xenotransplantation.

METHODSThe mononuclear cell fraction obtained by centrifugation over Percoll was cultured in vitro. Cell surface epitopes were analyzed by flow cytometry technique, and MSCs were incubated at the addition of adipocyte induction media, and stained in Oil Red O. The immunoglobulin and complement in rat recipient serum were assayed after infusion of donor MSCs. Thirty guinea pigs and thirty Wistar rats were randomly divided into three groups. All rat recipients undertook cyclophosphamide (CTX) infusion. Group A was MSCs infusion group, group B was saline infusion group and group C was dexamethasone (DXM) infusion group. Orthotopic guinea pig to rat liver transplantation model was established. The survival time and the immunopathology of graft were observed.

RESULTSAccording to flow cytometry assay, MSCs were positive for CD44 and CD29, while negative for CD34 and CD45. Lipid droplets were found in the MSCs cytoplasm after being incubated in adipogenic inducation media. The concentrations of IgG, IgM, C3 at all time point after MSCs infusion were significantly decreased than before (P < 0.05), while the concentrations of IgA and C4 did not changed. The survival time of group A (431 +/- 27 min) was obviously longer than group B (148 +/- 16 min) and group C (141 +/- 22 min) (P < 0.01). The intense hyperacute rejection rapidly occurred of group B and C after blood re-perfusion. The severe immunopathological injury could be observed at the grafts of group B and C. However, the hyperacute rejection of group A occurred slightly.

CONCLUSIONSMSCs can be identified by virtue of cell morphology, membrane phenotype and differential potential. MSC may play a role in the immunosuppression in hyperacute rejection in the liver xenotransplantation.

Animals ; Graft Rejection ; prevention & control ; Guinea Pigs ; Liver Transplantation ; immunology ; Male ; Mesenchymal Stem Cell Transplantation ; Mesenchymal Stromal Cells ; cytology ; immunology ; Rats ; Rats, Wistar ; Transplantation, Heterologous

Mesenchymal stem cells have two main properties: self renewal and the ability to differentiate multiple lineage. Because MSCs exhibit low immunogenicity and demonstrate significant suppressive activity in cell cultures containing alloreactive T cells, they play an important role in transplantation immunology, but the exact mechanism remains unknown. This article focuses on the immunoregulatory feature of MSCs to immunoeffector cells, such as T cells, B cells, and NK cells. The role of MSC in transplantation immunoregulation, regulatory mechanism of MSC in cellular immunity (direct contact of cells with cells, apoptosis and immunoregulation of MSC on lymphocytes), immunoregulation of MSC on DC and NK cells were reviewed.
Animals ; Cell Communication ; Cell Proliferation ; Cells, Cultured ; Coculture Techniques ; Humans ; Killer Cells, Natural ; cytology ; immunology ; Mesenchymal Stem Cell Transplantation ; Mesenchymal Stromal Cells ; cytology ; physiology ; Signal Transduction ; T-Lymphocytes ; cytology ; immunology

This study was aimed to find a better method to isolate and enrich mesenchymal stem cells (MSCs)from bone marrow between CD271 (low affinity nerve growth factor receptor, LNGFR) and CD133 used for immunomagnetic positive selections through comparison of characteristics of MSCs isolated by these two agents. CD271+ and CD133+ cells were isolated from bone marrow and their colony forming unit-fibroblast (CFU-F) efficiency and proliferative capacity were assessed. Cell surface phenotype, adipogenic and osteogenic inductions were also assayed on the cells (after passage 3) isolated by both methods. The results showed that the purities of immunomagnetically selected CD271+ and CD133+ cells were (89.50+/-0.98)% and (88.03+/-3.06)% respectively. The CFU-F median frequency of CD271+ cells was 3 times as high as that of CD133+ cells, no CFU-F was observed in CD271- cells, while a few CFU-F was found in the CD133- cells. Phenotype of cells (after passage 3) isolated by the two methods was same, that is CD34-, CD14-, CD45-, CD90+, CD29+, CD44+, CD105+, CD73+. CD271+ cells possessed faster proliferation and stronger osteogenic and adipogenic differentiation potential than that of CD133+ cells. It is concluded that as compared with CD133 positive selection, CD271 positive selection is a better method for isolating and enriching mesenchymal stem cells from bone marrow.
AC133 Antigen ; Antigens, CD ; immunology ; metabolism ; Bone Marrow Cells ; cytology ; Glycoproteins ; immunology ; metabolism ; Humans ; Immunomagnetic Separation ; methods ; Mesenchymal Stromal Cells ; cytology ; Nerve Tissue Proteins ; immunology ; metabolism ; Peptides ; immunology ; metabolism ; Receptors, Nerve Growth Factor ; immunology ; metabolism ; Stem Cells

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