A Novel Immunomodulatory Mechanism Dependent on Acetylcholine Secreted by Human Bone Marrow-derived Mesenchymal Stem Cells

BACKGROUND AND OBJECTIVES: Mesenchymal stem cells (MSCs) are used to treat autoimmune or inflammatory diseases. Our aim was to determine the immunomodulatory mechanisms elicited by MSCs during inflammation. METHODS AND RESULTS: We cocultured MSCs with peripheral blood mononuclear cells for a mixed lymphocyte reaction or stimulated them by phytohemagglutinin. Morphological changes of MSCs and secretion of acetylcholine (ACh) from MSCs were measured. The effects of an ACh antagonist and ACh agonist on lymphocyte proliferation and proinflammatory-cytokine production were determined. The inflammatory milieu created by immune-cell activation caused MSCs to adopt a neuronlike phenotype and induced them to release ACh. Additionally, nicotinic acetylcholine receptors (nAChRs) were upregulated in activated peripheral blood mononuclear cells. We observed that ACh bound to nAChR on activated immune cells and led to the inhibition of lymphocyte proliferation and of proinflammatory-cytokine production. MSC-mediated immunosuppression through ACh activity was reversed by an ACh antagonist called α-bungarotoxin, and lymphocyte proliferation was inhibited by an ACh agonist, ACh chloride. CONCLUSIONS: Our findings point to a novel immunomodulatory mechanism in which ACh secreted by MSCs under inflammatory conditions might modulate immune cells. This study may provide a novel method for the treatment of autoimmune diseases by means of MSCs.

Two-Round Mixed Lymphocyte Reaction for Evaluation of the Functional Activities of Anti-PD-1 and Immunomodulators

Immune checkpoint inhibitors (ICIs), such as anti-PD-1 and anti-PD-L1 Abs, have shown efficacy for the treatment of various cancers. Although research has actively sought to develop new ICIs and immunomodulators, no efficient in vitro assay system is available to evaluate their functional activities. In the present study, we established a two-round MLR with human PBMCs for evaluation of the T cell-activating capacity of anti-PD-1 and other immunomodulators. We initially performed conventional MLR for this purpose. However, anti-PD-1 blocking Abs could not increase the proliferation of allo-reactive T cells in conventional MLR because PD-L1+ and PD-L2+ cells disappeared gradually during MLR. Therefore, we re-applied the same stimulator PBMCs to the allo-stimulated responder cells as a second-round MLR on day 6 when anti-PD-1 or immunomodulators were also added. In this two-round MLR, the proliferation of allo-reactive T cells was enhanced by anti-PD-1 in a dose-dependent manner or by immunomodulators, such as lenalidomide and galunisertib, a TGF-β receptor-1 inhibitor. Proliferation was further increased by the combination of immunomodulators with anti-PD-1. Here, we established a modified two-round MLR method with human PBMCs for evaluation of the functional activities of anti-PD-1 and immunomodulators.

Extended Culture of Bone Marrow with Granulocyte Macrophage-Colony Stimulating Factor Generates Immunosuppressive Cells

Bone marrow-derived dendritic cells (BM-DCs) are generated from bone marrow (BM) cells cultured with granulocyte macrophage-colony stimulating factor (GM-CSF) for a week. In this study we investigated the effect of duration on the BM culture with GM-CSF. Within several months, the cells in the BM culture gradually expressed homogeneous levels of CD11c and major histocompatibility complex II on surface, and they became unable to stimulate allogeneic naïve T cells in mixed lymphocyte reaction (MLR). In addition, when the BM culture were sustained for 32 wk or longer, the BM cells acquired ability to suppress the proliferation of allogeneic T cells in MLR as well as the response of ovalbumin-specific OT-I transgenic T cells in antigen-dependent manner. We found that, except for programmed death-ligand 1, most cell surface molecules were expressed lower in the BM cells cultured with GM-CSF for the extended duration. These results indicate that BM cells in the extended culture with GM-CSF undergo 2 distinct steps of functional change; first, they lose the immunostimulatory capacity; and next, they gain the immunosuppressive ability.

Immune Tolerance of Human Dental Pulp-Derived Mesenchymal Stem Cells Mediated by CD4⁺CD25⁺FoxP3⁺ Regulatory T-Cells and Induced by TGF-β1 and IL-10

PURPOSE: Most studies on immune tolerance of mesenchymal stem cells (MSCs) have been performed using MSCs derived from bone marrow, cord blood, or adipose tissue. MSCs also exist in the craniofacial area, specifically in teeth. The purpose of this study was to evaluate the mechanisms of immune tolerance of dental pulp-derived MSC (DP-MSC) in vitro and in vivo. MATERIALS AND METHODS: We isolated DP-MSCs from human dental pulp and co-cultured them with CD4⁺ T-cells. To evaluate the role of cytokines, we blocked TGF-β and IL-10, separately and together, in co-cultured DP-MSCs and CD4⁺ T-cells. We analyzed CD25 and FoxP3 to identify regulatory T-cells (Tregs) by fluorescence-activated cell sorting (FACS) and real-time PCR. We performed alloskin grafts with and without DP-MSC injection in mice. We performed mixed lymphocyte reactions (MLRs) to check immune tolerance. RESULTS: Co-culture of CD4⁺ T-cells with DP-MSCs increased the number of CD4⁺CD25⁺FoxP3⁺ Tregs (p<0.01). TGF-β or/and IL-10 blocking suppressed Treg induction in co-cultured cells (p<0.05). TGF-β1 mRNA levels were higher in co-cultured DP-MSCs and in co-cultured CD4⁺ T-cells than in the respective monocultured cells. However, IL-10 mRNA levels were not different. There was no difference in alloskin graft survival rate and area between the DP-MSC injection group and the non-injection group. Nonetheless, MLR was reduced in the DP-MSC injected group (p<0.05). CONCLUSION: DP-MSCs can modulate immune tolerance by increasing CD4⁺CD25⁺FoxP3⁺ Tregs. TGF-β1 and IL-10 are factors in the immune-tolerance mechanism. Pure DP-MSC therapy may not be an effective treatment for rejection, although it may module immune tolerance in vivo.

Comparative global immune-related gene profiling of somatic cells, human pluripotent stem cells and their derivatives: implication for human lymphocyte proliferation

Human pluripotent stem cells (hPSCs), including embryonic stem cells (ESCs) and induced PSCs (iPSCs), represent potentially unlimited cell sources for clinical applications. Previous studies have suggested that hPSCs may benefit from immune privilege and limited immunogenicity, as reflected by the reduced expression of major histocompatibility complex class-related molecules. Here we investigated the global immune-related gene expression profiles of human ESCs, hiPSCs and somatic cells and identified candidate immune-related genes that may alter their immunogenicity. The expression levels of global immune-related genes were determined by comparing undifferentiated and differentiated stem cells and three types of human somatic cells: dermal papilla cells, ovarian granulosa cells and foreskin fibroblast cells. We identified the differentially expressed genes CD24, GATA3, PROM1, THBS2, LY96, IFIT3, CXCR4, IL1R1, FGFR3, IDO1 and KDR, which overlapped with selected immune-related gene lists. In further analyses, mammalian target of rapamycin complex (mTOR) signaling was investigated in the differentiated stem cells following treatment with rapamycin and lentiviral transduction with specific short-hairpin RNAs. We found that the inhibition of mTOR signal pathways significantly downregulated the immunogenicity of differentiated stem cells. We also tested the immune responses induced in differentiated stem cells by mixed lymphocyte reactions. We found that CD24- and GATA3-deficient differentiated stem cells including neural lineage cells had limited abilities to activate human lymphocytes. By analyzing the transcriptome signature of immune-related genes, we observed a tendency of the hPSCs to differentiate toward an immune cell phenotype. Taken together, these data identify candidate immune-related genes that might constitute valuable targets for clinical applications.

Dendritic Cells Promote the Proliferation of Peripheral Blood CRTH2 Cells (CD4(+)CD294(+)Th2) and Help B Cells to Secrete Immunoglobulin / 中国实验血液学杂志

Objective：To investigate the promotive effect of dendritic cells(DCs) on proliferation of CRTH2 (CD4(+)CD294(+)Th2) cells and the influence of CRTH2 cells on secretion of immunoglobulin from B cells so as to provide a new approach for amplification and sorting of Th2 cells. Methods：DCs were induced from peripheral blood mononuclear cells, then the loaded-BCGV-Ag-DCs were cocultured with T cells, and the mixed lymphocyte reaction(MLR) was performed by CCK8 method. The phenotypes of DCs and CRTH2 cells were detected by flow cytometry. CRTH2 cells sorted by MACS were co-cultured with B cells for 5 days to detect the secretion of immunoglobulin. Results：The subsets and absolute number CRTH2 cells were significantly increased by loaded-BCGV-Ag-DCs. The levels of IgG, IgA and IgE were higher increased in supernatant of CRTH2 and B cell co-culture system than that in control group or that in transwell group(P<0.05). Conclusion：The proliferation of CRTH2 cells can be greatly promoted by loaded-BCGV-Ag-DCs, and the CRTH2 cells can help B cells to secrete IgG, IgA and IgE.

Role of glycogen synthase kinase 3β in maturation and function of murine myeloid dendritic cells in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the role of glycogen synthase kinase 3β (GSK-3β) in the maturation and function of murine bone marrow-derived dendritic cells (BMDCs).</p><p><b>METHODS</b>Mature DCs (mDCs) induced by LPS were examined for GSK-3β phosphorylation level with Western blotting before and after LPS exposure. To explore the role of GSK-3β in maturation and function of DCs, we added SB216763, a selective inhibitor of GSK-3β, in the cell culture of immature DCs (iDCs), and examined CD40 and CD86 expressions in the cells by flow cytometry and the expression of IL-6, IL-12 and IL-10 mRNA by real-time PCR; the changes of the immunogenicity of the cells was evaluated by mixed lymphocyte reaction. The expression of GSK-3β and RelB was examined by Western blotting in DC2.4 cells transfected with a lentiviral vector over-expressing murine GSK-3β gene.</p><p><b>RESULTS</b>LPS exposure significantly lowered GSK-3β activity in iDCs as demonstrated by increased Ser9 phosphorylation and reduced Tyr216 phosphorylation. GSK-3β inhibition induced DC maturation by increasing the expression of surface costimulatory molecules CD40 and CD86, lowered the expressions of IL-6 and IL-12 while enhanced the expression of IL-10 in iDCs, and impaired mixed lymphocyte reaction of the cells. In DC2.4 cells, lentivirus-mediated over-expression of GSK-3β obviously down-regulated the expression of RelB.</p><p><b>CONCLUSIONS</b>GSK-3β is a crucial enzyme involved in the differentiation and maintenance of an immature phenotype of DCs. GSK-3β is constitutively active in iDCs to inhibit their spontaneous maturation. DCs become phenotypically mature after inhibition of GSK-3β, which also executes a proinflammatory task in DC activation. The reduction of RelB protein levels as a result of GSK-3β overexpression supports GSK-3β as a new target for inducing tolerogenic DCs.</p>

The immunological characteristics of tonsil mesenchymal stem cells / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the immunological characteristics of human tonsil mesenchymal stem cells (TMSCs).</p><p><b>METHODS</b>Human tonsil tissues were obtained from the children patients with chronic tonsillitis. TMSCs were separated, cultured, and were detected the expression profiles of HLA-I, HLA-II, CD80, CD86 by flow cytometry. The measurement of immunogenicity, the effect on phytohemagglutinin (PHA) induced peripheral blood mononuclear cell (PBMCs) proliferation and mixed lymphocytes reaction (MLR) were performed to identify the immunological characteristics of TMSCs. The co-cultures of TMSCs + PBMCs + PHA and TMSCs + MLR were established, respectively, and the concentration of kynurenine, which is the metabolin of indoleamine 2, 3-dioxygenase, in the culture supernatant were examined. Then we added 1-methyl-L-tryptophan into the co-culture of TMSCs + PBMCs + PHA and TMSCs + MLR, respectively, and tested the proliferation of PBMCs. Each experiment was repeated three times, and there were six samples in each group. Statistical significance was assessed by analysis of variance (ANOVA), and a P value less than 0.05 was considered statistically significant.</p><p><b>RESULTS</b>TMSCs expressed HLA-I, were negative for HLA-II and co-stimulatory molecules CD80 and CD86. The stimulation index in the group of TMSCs + allogeneic PBMCs was 1.38 ± 0.26, whereas the stimulation index in the group of allogeneic PBMCs was 1.22 ± 0.28, and there was no significant difference between the two groups (P > 0.05), indicating that TMSCs could not initiate the proliferation of allogeneic PBMCs. The stimulation indexes in the group of TMSCs + allogeneic PBMCs + PHA were 1.49 ± 0.29 and 1.23 ± 0.22, respectively, whereas the stimulation index in the group of allogeneic PBMCs + PHA was 4.60 ± 0.81, and the difference between the two groups had a statistical significance (P < 0.05) suggesting that TMSCs could inhibit PHA-induced PBMCs proliferation. The stimulation indexes in the group of TMSCs + MLR were 1.29 ± 0.23 and 1.26 ± 0.27, respectively, however, the stimulation index in the group of MLR was 3.04 ± 0.66, and the difference between the two groups had a statistical significance (P < 0.05), demonstrating that TMSCs could suppress MLR-induced PBMCs proliferation. The levels of kynurenine were (26.0 ± 2.3) μmol/L and (23.5 ± 4.5) μmol/L in the culture of TMSCs + PBMCs + PHA and TMSCs + MLR, respectively, thus elevating significantly. After adding of 1-methyl-L-tryptophan, TMSCs-mediated-proliferation suppression of PBMCs restored to normal levels.</p><p><b>CONCLUSION</b>TMSCs possess low immunogenecity and immunosuppressive function, may be used in allogeneic transplantation.</p>

Effect of SAHA on Maturation of Dendritic Cells and Its Mechanism / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the effect of SAHA on the maturation of human dendritic cells (DC) and to explore its underlying mechanism.</p><p><b>METHODS</b>Peripheral blood mononuclear cells (PBMNC) were isolated from human peripheral blood and cultured in RPMI 1640 medium with 100 ng/ml rhGM-CSF and 500 U/ml rhIL-4. In the LPS induced maturation process, dendritic cells treated with or without SAHA were used as test group, and dendritic cells treated without LPS or SAHA were used as control group. DC was observed under inverted microscope. Flow cytometer was used to detect the surface antigen molecules expressed by DC. The mixed lymphocyte culture (MLC) was used to observe the allogeneic lymphocyte stimulation. The NF-κB signaling pathway was detected by electrophoretic mobility shift assay (EMSA).</p><p><b>RESULTS</b>The SAHA could effectively suppress the maturation of DC induced by LPS, the DC treated with SAHA+LPS had immature morphological characteristics; the expression of CD80, CD83 and HLA-DR in SAHA+LPS group and control group were significantly down-regulated as compared with single LPS group (P<0.01); the ability of DC to stimulate the proliferation of allogeneic T lymphocytes in SAHA+LPS group and control group was significantly weaker than that in single LPS group (P<0.01); EMSA results showed that NF-κB activity decreased after SAHA and LPS treatment and was significantly lower than that of single LPS group.</p><p><b>CONCLUSION</b>SAHA can effectively suppress DC maturation induced by LPS and also weaken the ability to stimulate allogeneic T lymphocyte. NF-κB signaling pathway is involved in regulating DC maturation.</p>

Corticotropin-releasing Factor Changes the Phenotype and Function of Dendritic Cells in Mouse Mesenteric Lymph Nodes

BACKGROUND/AIMS: Dendritic cells (DCs) are a significant contributor to the pathology of numerous chronic inflammatory autoimmune disorders; however, the effects of Corticotropin-releasing factor (CRF) on intestinal DCs are poorly understood. In this study, we investigated the role of CRF in alterations of intestinal dendritic cell phenotype and function. METHODS: Mouse mesenteric lymph node dendritic cells (MLNDCs) were obtained using magnetic bead sorting. Surface expression of CRF receptor type 1 (CRF-R1) and CRF-R2 was determined by double-labeling immunofluorescence and quantitative polymerase chain reaction (qPCR) and MLNDCs were subsequently exposed to CRF in the presence or absence of CRF-R1 and CRF-R2 antagonists. Expression of surface molecules (MHC-I and MHC-II) and co-stimulatory molecules (CD80 and CD86) was determined by flow cytometric and western blot analyses, and the T cell stimulatory capacity of MLNDCs was evaluated by mixed lymphocyte reaction. RESULTS: Immunofluorescent staining and quatitative polymerase chain reaction indicated that both the CRF receptors (CRF-R1 and CRF-2) are expressed on the surface of MLNDCs. Exposure to CRF increased the expression of MHC-II on MLNDCs as well as their capacity to stimulate T cell proliferation. MLNDCs treated with CRF-R1 antagonist exhibited a phenotype characterized by a less activated state and reduced surface expression of MHC-II, and consequently showed reduced capacity to stimulate T cells. In contrast, treatment of MLNDCs with CRF-R2 antagonist yielded an opposite result. CONCLUSIONS: CRF can alter the phenotype and function of intestinal DCs through direct action on CRF-R1 and CRF-R2, and activation of the CRF-R1 and CRF-R2 pathways yields opposing outcomes.

Isolation, amplification and identification of human natural CD4⁺CD25⁺ regulatory T cells in vitro / 中南大学学报(医学版)

OBJECTIVE@#To establish a method for in vitro expansion of human natural CD4⁺CD25⁺ T regulatory cell (Treg) cells for clinical study and immunotherapy.@*METHODS@#Human natural CD4⁺CD25⁺ Treg were isolated from peripheral blood monocyte cells (PBMCs) by magnetic activated cell sorting (MACS) and expanded by CD3/CD28 expansion beads, IL-2 and rapamycin. The number and the viability of the freshly isolated and expanded Treg were detemined by trypan blue staining. The phenotype and the purity of the freshly isolated and expanded Treg were analyzed by FACS. Treg suppression activity was assessed by mixed lymphocyte reaction (MLR) assay.@*RESULTS@#Human natural Treg were expanded up to 2 000 folds after 3 weeks in culture, and the activity was more than 97%. The expanded Treg retained Treg phenotype as shown by their freshly isolated counterparts, and the purity of CD4⁺CD25⁺FoxP3⁺ Treg was (94.22 ± 2.12)%. The expanded Treg demonstrated a similar potent suppression of both proliferating auto- and allo- CD4⁺CD25⁻ effector T cells in vitro in a cell number-dependent manner.@*CONCLUSION@#An in vitro expansion of human natural Treg was established to obtain large numbers of human Treg with highly suppressive phenotype and function, thereby providing a solution to the availability of sufficient human natural Treg in clinical study and immunotherapy.

Expression of costimulatory molecule CD86 in HL-60 cells induced by MG132 and its effect on allogeneic mixed lymphocyte reaction / 中国实验血液学杂志

This study was aimed to elucidate the expression of costimulatory molecule CD80 and CD86 in HL-60 cells induced by proteasome inhibitor MG132 and its effect on allogeneic mixed lymphocyte reaction. Acute myelocytic leukemia cell line HL-60 and chronic myelocytic leukemia cell line K562 were cultured. The viability of the cells was measured by flow cytometry. Proteasome inhibitor MG132 at the concentrations of 2 or 3 µmol/L was used to stimulate the HL-60 cell cultured for 24 h and 48 h respectively, and the Annexin V/7-AAD staining and flow cytomotry were used to detect the apoptosis of the HL-60 cells. HL-60 and K562 cells were treated with 1 µmol/L MG132 for 24 h and 48 h respectively, then CD80 and CD86 antibodies were added, finally the expression of CD80 and CD86 was analysed by flow cytomery. The mRNA expression of CD86 in the HL-60 cells treated with 1 µmol/L MG132 was detected by RT-PCR. HL-60 and K562 cells were treated by 1 µmol/L MG132 and then underwent irradiation of 75 Gy (60)Co to kill the cells with their antigenicity preserved. Peripheral blood mononuclear cells (PBMNCs) of healthy volunteers, as reactive cells, were isolated and inoculated into the (60)Co irradiated HL-60 cells of different concentrations, as stimulating cells, CCK-8 was added and then the A value of absorbance was measured at the wave length of 450 nm in an enzyme labeling instrument. The results showed that the cell viability of the HL-60 cells treated with 1 µmol/L MG132 for 24 h an d 48 h was 92.95% and 85.87% respectively. The apoptotic rates of the HL-60 cells treated with MG132 increased in dose-and time-dependent manner. High-concentration of MG132 directly killed HL-60 cells. Before MG132 treatment K562 cells did not express CD86, but the CD86 expression of the HL-60 cells was up-regulated time-dependently after MG132 treatment (P < 0.01). The mRNA expression of CD86 in the HL-60 treated with MG132 was up-regulated time-dependently (P < 0.01). CCK-8 test showed that the proliferation level of PBMNC gradually increased along with the concentration of HL-60 cells treated with MG132 and reached its peak when the concentration of the HL-60 cells was 1×10(5) (P < 0.01). No remarkable proliferation of PBMNC was observed in the K562 groups no matter if the HL-60 cells had been treated with MG132. It is concluded that the high concentration of MG132 can directly kill HL-60 cells, low-concentration of MG132 can induce the expression of costimulatory molecule CD86 in HL-60 cells, also can improve the proliferation of PBMNC.

Effect of glycolytic inhibitor 3-BrPA on the proliferation and apoptosis of mouse splenic lymphocytes in mixed lymphocytes culture / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the effect of glycolytic inhibitor 3-Bromopyruvate (3-BrPA) on the proliferation and apoptosis of mouse spleen lymphocytes and explore its mechanism.</p><p><b>METHODS</b>An one-way mixed lymphocyte culture (MLC) system was established, including BALB/c mouse spleen cells (H-2d) as stimulator and C57BL/6 mouse spleen cells (H-2b) as responder. With treatment of 3-BrPA at different concentrations (0-200 μmol/L), lymphocyte proliferation capacity was detected by the CCK-8 method, the expression of CD3, CD4, and CD8 by flow cytometry, and the concentrations of cytokine interleukin (IL)-4 and interferon (IFN)-γ in the supernatant by ELISA.</p><p><b>RESULTS</b>At a middle or high dose (over 20 μmol/L), 3-BrPA displayed a dose-dependent inhibitory effect on lymphocyte proliferation in the MLC system. The 50% inhibitory concentration (IC50) were 48.6, 41.2, and 41.9 μmol/L after 24, 36, and 48 h culture, respectively. With treatment of 50 μmol/L 3-BrPA, the IFN-γ level [(164.25 ± 20.14) ng/L] was significantly lower, compared with control [(277.61 ± 18.46) ng/L]. The IL-4 level [(31.06 ± 6.06) ng/L] was significantly higher, compared with control [(28.64 ± 3.97) ng/L]. Consequently, the IFN-γ/IL-4 ratio decreased significantly.</p><p><b>CONCLUSION</b>These results indicate that 3-BrPA had a significant inhibitory effect on the proliferation of mouse spleen lymphocytes cultured in MLC system, accompanied with the Th2-biased secretion of cytokines.</p>

A preliminary study on the biological characteristics and function of tolerogenic dendritic cells induced by tacrolimus / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the biological characteristics and the immuno-suppression function of tolerogenic dendritic cells (tDC) induced by tacrolimus.</p><p><b>METHODS</b>Human monocytes derived from peripheral blood were cultured in the cGMP-compliant CellGro DC medium supplemented with GM-CSF and IL-4 to obtain dendritic cells (DCs), and 0.1 μmol/L immunosuppressive drug tacrolimus was added to the culture medium at the third and fifth day to obtain tDCs. The molecular markers of them and the livability were assayed by flow cytometry. Then the tolerance functionality of tDCs induced by many agents and these tDCs modulated allogeneic CD4 T cells was determined via CFSE proliferation assay. And the research also analyzed the biological characters and immunosuppression function of tDCs induced by tacrolimus after storing.</p><p><b>RESULTS</b>tDCs induced by tacrolimus exhibit a typical tolerogenic phenotype, whose level of costimulatory molecules CD80, CD83, CD86 and HLA-DR is (2.95 ± 1.32)%, (2.33 ± 1.60)%, (90.02 ± 7.42)% and (91.80 ± 6.18)%, respectively. It's survival rate was (85.2 ± 4.72)%. And immunosuppressive drugs didn't influence the differentiation of tDCs from monocytes. tDCs induced by immunosuppressive drugs dexamethasone, cyclosporin A and tacrolimus had lower immunogenic than control DCs as CD4+ T proliferation rate of tDCs induced by tacrolimus is 0.42% and could not primed allogeneic CD4+ T cells proliferation. Functional analyses showed that tDCs induced by tacrolimus can more effectively suppressed mature DC-induced T cell proliferation than other tDCs, whose inhibition rate can reach (67.01 ± 19.73)%. Importantly, tDCs induced by tacrolimus had phenotypical and functional stability after storing.</p><p><b>CONCLUSION</b>tDCs induced by tacrolimus with tolerance functionality are a promising cellular therapeutic for immunomodulation.</p>

Bacterial strains isolated from Jeotgal (salted seafood) induce maturation and cytokine production in mouse bone marrow-derived dendritic cells / 대한수의학회지

Jeotgal (salted seafood) has been one of major fermented foods in Korea for long time. Although there are many studies about Jeotgal in various aspects of food, its immunological importance on hosts has not been elucidated yet. In this study, we investigated if several bacteria isolated from Jeotgal may modulate the function of dendritic cells (DCs), powerful antigen-presenting cells equipped with special immunological capabilities. 4 Jeotgal bacteria were selected as representatives and used for experiments. To treat viable DCs, those bacteria were killed at 60degrees C for 30 min. The viability of DCs treated with Jeotgal bacteria was verified and two isolates significantly induced high production of interleukin-12, a representative cell-mediated cytokine of DCs. Surface activation and maturation markers (MHC class II, CD40, CD86) of DCs were analyzed by flow cytometer. In addition, the treated DCs showed significantly high lymphocyte stimulatory capability compared to control DCs based on allogeneic mixed lymphocyte reactions. These observations suggest that Jeotgal isolates can function as immunostimulating bacteria in hosts, like Lactobacillus. Taken together, these experimental evidences may broaden the use of Jeotgal isolates in immunological fields in addition to as a fermented food.

Does caesalpinia bonducella ameliorate genotoxicity? An in vitro study in human lymphocyte culture and in vivo study in albino mice

Most of the world's populations residing in developing countries depend on alternative medicine and use of plant ingredients. The plant Caesalpinia bonducella belongs to the family of Caesalpiniaceae and it is commonly known as Natakaranja in Hindi. It contains bonducin and two phytosterols namely sitosterol and hepatsane. The twigs and young leaves of C. bonducella are rationally used for curing tumors, inflammation and liver disorders. In our present work alcoholic extracts of this ayurvedic plant were tested for their antimutagenic and anticarcinogenic properties. The aim of the study is to investigate the antimutagenic and antigenotoxic potential of alcoholic extracts of C. bonducella against methyl methane sulfonate [MMS] induced genotoxicity. In this experiment we have used in vitro method i.e., human lymphocyte culture and in vivo method in bone marrow cells of albino mice, while the parameters studied included chromosomal aberrations [CA], sister chromatid exchanges [SCEs] and cell growth kinetics [RI] both in the presence as well as in the absence of exogenous metabolic activation system for in vitro studies whereas total aberrant cells and the frequencies of aberrations were used for in vivo methods. Alcoholic extracts of C. bonducella significantly reduce chromosomal aberration from 42.75%, 44.25%, and 51.75% levels [at 24, 48, and 72 h due to methyl methane sulfonate [MMS]] to 28.50%, 30.25%, and 35.10%, respectively similarly sister chromatid exchanges were reduced from 7.70 +/- 1.50 to 5.20 +/- 1.50 at 48 h of treatment and replication index was enhanced in vitro for each concentration and duration of treatment and their ameliorating potential was dose and duration dependent. Similarly these extracts significantly reduced the number of aberrant cells and frequency of aberrations per cell in in vivo

In vitro amplification of CD4(+) CD25(+) regulatory T cells and identification of amplified T cell immunosuppressive function / 中国实验血液学杂志

This study was purposed to compare the effect of 3 different cell components for expanding CD4(+) CD25(+) Treg in vitro, and identify their immunosuppressive function. CD4(+) T cells, CD4(+) CD25(-)T cells and CD4(+) CD25(+)T cells were isolated from mouse splenocytes by MACS and then expanded in vitro. Phenotype of the T cell lines and expression of the FOXP3 was determined by flow cytometry. The inhibitory effect of expanded CD4(+) CD25(+) T cells on CD4(+) CD25(-)T cells was tested by MLR method. The results showed that the Treg cells from all the three groups were expanded significantly after culture for 2 weeks. In the CD4(+) T cells group, the proliferation rate was (77.8 ± 5.32) folds with a percentage of Treg cells increasing from (6.61 ± 1.00)% to (15.33 ± 1.31)%. The proliferation rate in the CD4(+) CD25(-) T cells group was (95.20 ± 7.67) folds, with the percentage of CD4(+) CD25(+) T cells raising from (0.37 ± 0.13)% to (9.84 ± 0.98)%. The proliferation rate in the CD4(+) CD25(+) T cells group was (41.20 ± 6.92) folds, the proportion of Treg cells decreased from (86.75 ± 1.25)% to (85.32 ± 1.62)%, and the expression of Foxp3 decreased from (76.92 ± 1.72)% to (75.33 ± 2.11)% during the culture, there were not significant differences in the cell purity and the expression of Foxp3, compared with pre-amplification. The inhibitory test showed that the expanded CD4(+) CD25(+) T cells could inhibit the proliferation of CD4(+) CD25(-) T cells in vitro in a cell dose-dependent manner. It is concluded that the amplification of CD4(+) CD25(+) Treg cells is successful in vitro, especially in the CD4(+) CD25(+) T cells group, the cell purity and Foxp3 gene is not obviously changes after amplification.

Functional Characteristics of C-terminal Lysine to Cysteine Mutant Form of CTLA-4Ig

CTLA-4Ig is regarded as an inhibitory agent of the T cell proliferation via blocking the costimulatory signal which is essential for full T cell activation. To improve applicability, we developed the CTLA-4Ig-CTKC in which the c-terminal lysine had been replaced by cysteine through single amino acid change. The single amino acid mutation of c-terminus of CTLA-4Ig was performed by PCR and was checked by in vitro transcription and translation. DNA construct of mutant form was transfected to Chinese hamster ovary (CHO) cells by electroporation. The purified proteins were confirmed by Western blot and B7-1 binding assay for their binding ability. The suppressive capacity of CTLA-4Ig-CTKC was evaluated by the mixed lymphocyte reaction (MLR) and in the allogeneic pancreatic islet transplantation model. CTLA-4Ig-CTKC maintained binding ability to B7-1 molecule and effectively inhibits T cell proliferation in MLR. In the murine allogeneic pancreatic islet transplantation, short-term treatment of CTLA-4Ig-CTKC prolonged the graft survival over 100 days. CTLA-4Ig-CTKC effectively inhibits immune response both in MLR and in allogeneic islet transplantation model, indicating that single amino acid mutation does not affect the inhibitory function of CTLA-4Ig. CTLA-4Ig-CTKC can be used in vehicle-mediated drug delivery system such as liposome conjugation.

Effects of Human Adipose-Tissue Derived Stem Cell Infusion on the Immunological Consequences in Skin Allograft Mice / 대한이식학회지

BACKGROUND: Many in vitro experiments have demonstrated the immunosuppressive properties of mesenchymal stem cells (MSCs). However, such properties have not yet been fully established in an in vivo setting. The purpose of this study was to determine immunosuppressive and anti-inflammatory properties of MSCs in a preclinical animal model in order to pave the way for replacement of conventional immunosuppressive therapy. METHODS: Male C57BL/6 mice and male BALB/c mice were chosen as skin graft donors and recipients, respectively. After performance of full-thickness skin transplantation on the back of mice, adipose tissue derived stem cells (1.0x10(6)/0.1 mL) stained with 4, 6-diamidino-2-phenylindole were transplanted into adipose tissue derived stem cell (ASC)-infused mice and phosphate buffered saline (PBS; 0.1 mL) was infused into PBS-infused mice. Immunological properties and graft survival were accessed and compared. RESULTS: The serum levels of proinflammatory interleukin (IL)-6 showed a decrease in ASC-infused mice compared to PBS-infused mice (P<0.005). In addition, interferon-lambda, IL-10, and tumor necrosis factor-alpha mRNA levels in the skin graft showed a decrease in ASC-infused mice, although without statistical significance. In ASC-infused mice, donor specific hyporesponsiveness was identified in a mixed lymphocyte reaction assay at 30 days after transplantation. In addition, ASC-infusion resulted in markedly prolonged skin allograft survival compared with PBS-infusion (P<0.001). CONCLUSIONS: Administration of ASC not only induced anti-inflammation and immunosuppression, but also resulted in prolonged graft survival, suggestive of their potent immunosuppressive properties. Therefore, conduct of further and more exquisite studies will be required in order to determine the role of MSC in the solid organ transplantation field in order to avoid adverse effects and toxicities caused by chemical immunosuppressive regimens.

Carboxymethylpachymaran enhances immunologic function of dendritic cells cultured in two kinds of hepatoma carcinoma cell line's supernatant via nuclear factor κ B/Rel pathway / 中国结合医学杂志

<p><b>OBJECTIVE</b>To study the immunologic function of dendritic cells (DCs) cultured in two kinds of hepatoma cell line's supernatant and the enhancing effects of carboxymethylpachymaran (CMP) on DCs.</p><p><b>METHODS</b>DCs were harvested after stimulation by granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin (IL)-4 from umbilical cord blood using density-gradient centrifugation method. Cultured supernatant of two hepatoma cell lines (HepG2 and HepG2.2.15) were collected for condition medium (CM) according to a volume ratio of supernatant to incomplete RPMI-1640 medium, which was 3:1. CMP was dissolved in incomplete RPMI-1640 medium. Experimental groups were divided according to the culture medium, either CM or with CMP in it. DCs subsets CD83, CD86, CD1a, and d-related human leukocyte antigens (HLA-DR) were analyzed by flow cytometry. The proliferation ability of allogeneic T cells in mixed lymphocyte reaction (MLR) stimulated by DCs was examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) analysis. IL-12p70, interferon-γ (IFN-γ), and nuclear factor κB (NF-κB) were detected by enzyme-linked immunosorbent assay analysis.</p><p><b>RESULTS</b>The proliferation of lymphocytes and secreting level of IL-12 and expression of phenotype of DCs cultured in two kinds of CM were lower than those of normal group (P <0.01). Compared with the normal group, groups treated with CMP showed a higher expression level of DCs subsets, lymphocyte reproductive activity, as well as IL-12 and IFN-γ secretion levels. Groups treated with CMP also demonstrated higher levels of DCs phenotype expression and IL-12 and IFN-γ secretion in supernatant of MLR and higher lymphocyte reproductive activity compared with CM group (P <0.05). Compared with the normal group, the expression level of NF-κB in DCs nuclear was higher in CMP groups but lower in two CM groups (P <0.05). After CMP was added, the NF-κB expression levels of two CM groups were increased compared with levels before CMP was added (P <0.05). However, there was no significant difference between the two CM groups (P >0.05).</p><p><b>CONCLUSIONS</b>Two kinds of hepatoma cell line's supernatant can inhibit the immunologic function of DCs. This suppressive effect may be related to the inhibition of NF-κB/Rel pathway. CMP may up-regulate the DCs function by activating the NF-κB/Rel pathway.</p>