This study was aimed to investigate the effect of human umbilical vein endothelial cells (HUVEC) on dendritic cell (DC) development. First, HUVEC were isolated from human umbilical cord by collagenase digestion, and then the morphology, immunophenotypes and functions were identified. Furthermore, the HUVEC were cocultured with CD14(+) monocytes under the cytokine condition for detecting the influence of HUVEC on differentiation of CD14(+) cells to DC. The phenotype of dendritic cells derived from CD14(+) cells was analyzed by flow cytometry, the immunoregulatory function of DC was tested by mixed lymphocyte reaction (MLR). The change of IL-6 and VEGF as well as EPK and p38 signal pathway were analyzed by neutral antibody experiment and Western blot. The results showed that HUVEC isolated from human umbilical cord were characterized by spindle-shaped morphology, homogenous immunophenotypes (vWF(+)CD31(+)CD73(+)CD45(-)HLA-DR(-)CD86(-)CD34(low)), Dil-Ac-LDL incorporation ability and forming capillary-like structures. Following stimulation with granulocyte-macrophage colony-stimulating factor (GM-CSF) plus interleukin-4 (IL-4), HUVEC cocultures could inhibit the initial differentiation of CD14(+) monocyte to DC. Interestingly, IL-6 and VEGF enhanced the suppression effect of HUVEC on generation of DC via activation of the ERK or p38 mitogen activated protein kinase pathway. It is concluded that HUVEC are involved in DC development and can suppress the differentiation of monocyte to DC.
Cell Differentiation ; Coculture Techniques ; Dendritic Cells ; cytology ; Human Umbilical Vein Endothelial Cells ; cytology ; Humans ; Monocytes ; cytology

Dendritic cells (DCs) are professional antigen presenting cells of the immune system. They can be generated in vitro from peripheral blood monocytes supplemented with GM-CSF, IL-4 and TNF alpha. During induction, DCs will increase in size and acquire multiple cytoplasmic projections when compared to their precursor cells such as monocytes or haematopoietic stem cells which are usually round or spherical. Morphology of DCs can be visualized by conventional light microscopy after staining or phase-contrast inverted microscopy or confocal laser scanning microscopy. In this report, we described the morphological appearances of DCs captured using the above-mentioned techniques. We found that confocal laser scanning microscopy yielded DCs images with greater details but the operating cost for such a technique is high. On the other hand, the images obtained through light microscopy after appropriate staining or phase contrast microscopy were acceptable for identification purpose. Besides, these equipments are readily available in most laboratories and the cost of operation is affordable. Nevertheless, morphological identification is just one of the methods to characterise DCs. Other methods such as phenotypic expression markers and mixed leukocyte reactions are additional tools used in the characterisation of DCs.
Dendritic Cells/*cytology ; Microscopy, Confocal ; Microscopy, Phase-Contrast

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

AIMTo provide experimental basis for clinical use of cryopreserved dendritic cells (DCs) by investigating the biological properties of cryopreserved DCs derived from cord blood.

METHODSThe biological discrepancies between unfrozen DCs (UFDC) derived from unfrozen cord blood (UFCB) and DCs from cryopreserved cord blood (CPCB) or cryopreserved DCs (CPDCs) were explored by morphological observation and immunophenotype analysis. Moreover, the stimulating index (SI) in mixed lymphocyte culture and cytotoxic eliminating rate (ER) were measured by MTT.

RESULTSThe TBR of CPCB and CPDCs were 95.8% and 88.7% respectively. Compared to UFCB, CPCB differentiated toward DCs in a delayed and decreased mode, displayed lower expression of CD1a, CD83 and HLA-DR, and had reduced SI and ER. Similarly, the CPDCs became adherent DCs later and grew less in number than UFDCs. After culture, the expression of CD1a, CD83 and HLA-DR as well as SI and ER were lower in CPDCs than those in UFDCs.

CONCLUSIONThough the biological properties of CPCB and CPDCs were injured after cryopreservation, they still had relatively complete basic function. Their recoveries rate were > 85%.

Cell Proliferation ; Cells, Cultured ; Cryopreservation ; Dendritic Cells ; cytology ; Fetal Blood ; cytology ; Humans

To investigate the effect of mycobacterium phlei F.U.36 suspended liquor (Utilin"s", U) on the culture and proliferation of dendritic cells (DCs) derived from human umbilical cord blood in vitro, the mononuclear cells (MNCs) were isolated from human umbilical cord blood and cultured with RPMI 1640 in the control group. Test groups consisted of Utilin"s" group (only Utilin"s"), GTI group (GM-CSF, TNF-alpha, IL-4) and GTIU group (GM-CSF, TNF-alpha, IL-4 and Utilin"s"). MNCs in all test groups were cultured with RPMI-1640. The growth of DCs was observed by the light microscopy, the phenotypes of DCs were determined by flow cytometry on the 10th day of culture, and some harvest cells were stained with Wright-Giemsa, then observed and photographed under the oil immersion objective. The results showed that the test groups all displayed some number of typical DCs; both CD1a positive cell rate and HLA-DR positive cell rate of the Utilin"s" group were higher than those of the control; HLA-DR positive cell rate of GTIU group increased most significantly and much higher than that of the GTI group. It is concluded that mycobacterium phlei F.U.36 not only promotes the proliferation of DCs derived from human umbilical cord blood in vitro, but also co-operates with rhGM-CSF, rhTNF-alpha and rhIL-4 in promoting the maturity of DCs.
Cell Proliferation ; Cells, Cultured ; Dendritic Cells ; cytology ; Fetal Blood ; cytology ; Humans ; Mycobacterium phlei ; physiology

Immune and hemopoiesis are one of basic project of experimental hematology. Immune function is a essential activity of white blood cells. It was puzzled for the diversity and complexity of immune response. Polarized immune response of immune cells was discovered 30 years ago, which facilitates the study on differentiation of lymphocyte. Recently recognition on multifunctional polarized immune response of lymphocyte and monocyte/macrophage would promote to elucidate the regulatory network of immune cells, diversity and complexity of immune response as well as the study on hemopoiesis. In this paper the approach of multifunctional polarized immune response of lymphocyte, monocyte/macrophage and dendritic cells were reviewed, and their role, especially in cytokine storm and tumor pro-inflammation condition were discussed.
Cell Differentiation ; Cytokines ; immunology ; Cytotoxicity, Immunologic ; Dendritic Cells ; cytology ; immunology ; Humans ; Monocytes ; cytology ; immunology

OBJECTIVETo observe the effect of mesenchymal stem cells derived from umbilical cord (UC-MSCs) on natural killer (NK) cells-mediated cytotoxicity against dendritic cells (DCs) and explore the mechanism.

METHODSMSCs were isolated from human umbilical cord by collagen digestion and cultured in vitro. NK cells were separated from healthy human peripheral blood by magnetic bead sorting. Mononuclear cells from healthy human peripheral blood were cultured in the presence of granulocyte and macrophage colony stimulating factor (GM-CSF) and interleukin-4 (IL-4) to obtain the immature DCs. The DCs were then co-cultured with UC-MSCs in the presence of tumor necrosis factor α (TNFα) for 2 days, and the expressions of CD11c and CD86 on DCs and IL-12 level in the culture medium was detected using flow cytometry and ELISA, respectively. The cytotoxicity of NK cells against DCs was analyzed by LDH-releasing assay, and the expressions of ligands for killer activator receptor (MICA/B and ULBP1-3) on the DCs were detected with flow cytometry.

RESULTSCompared with the cytokine-induced DCs, the DCs induced by co-culture with UC-MSCs showed an identical CD11c expression but lowered CD86 expression and IL-12 secretion. The natural killer cells produced a stronger cytotoxicity against UC-MSCs-induced DCs than against cytokine-induced DCs. The UC-MSCs-induced DCs also showed increased expressions of MICA and MICB on the surface.

CONCLUSIONUC-MSCs can enhance NK cells-mediated cytotoxicity against DCs possibly by inhibiting DC maturation and up-regulating the ligands for killer activator receptor on the surface of the DCs.

Cells, Cultured ; Cytotoxicity, Immunologic ; immunology ; Dendritic Cells ; cytology ; immunology ; Humans ; Killer Cells, Natural ; cytology ; Mesenchymal Stromal Cells ; cytology ; Umbilical Cord ; cytology

This study was aimed to investigate the specific anti-leukemia cell effect of cytotoxic T lymphocytes (CTLs) induced by HL-60 or K562 cell-sensitized dendritic cells (DCs) from umbilical cord blood. 12 units of human umbilical cord blood (UCB) were collected and the mononuclear cells (MNCs) were isolated from UCB, then cultured with granulocyte monocyte colony- stimulating factor (GM-CSF), interleukin 3 (IL-3), recombinant human stem cell factor (SCF) and EPO for 3 - 4 weeks. Flow cytometry was used to determine the number of DCs and cell surface antigens before and after culture with monoclonal antibodies including CD83, CD1a, CD11c and CDw123. HL-60 and K562 were frozen-thawed, and released their tumor antigen peptides (TAP). The CTLs were produced by sensitizing T lymphocytes with DC-loaded HL-60 and K562 cell antigens. The test of (3)H-TdR incorporation was used to detect the immunostimulation activity of DCs. MTT assay was applied to evaluate specific cytotoxicity of CTL on leukaemia cells. The results indicated that the MNCs of UCBs cultured with GM-CSF, IL-3, EPO and SCF were shown to differentiate into CD1a(+) CD11c(+) CD83(+) CDw123(+) DCs. Numbers of DCs from UCBs remarkably increased in 2 - 4 weeks and then decreased. After culture with cytokines DCs increased (10.6 - 28.2) x 10(5)/ml in actual numbers. The CTL induced by DC pulsed with HL-60, K562 frozen-thawed lysates were effective to kill HL-60 and K562. Cytotoxicity of CTL to HL60 and K562 were (42.04 +/- 8.46)% and (31.25 +/- 11.07)% respectively. It is concluded that the MNCs of UCBs cultured with cytokines of GM-CSF, SCF, EPO and IL-3 can differentiate into CD1a(+), CD83(+), CD11c(+) and CDw123(+) DCs. The CTL induced by DCs pulsed with HL-60, K562 frozen-thawed lysates can effectively kill HL-60 and K562. These DCs as antigen presenting cells play an important role in cancer immunotherapy.
Dendritic Cells ; cytology ; immunology ; Fetal Blood ; cytology ; immunology ; HL-60 Cells ; Humans ; K562 Cells ; T-Lymphocytes, Cytotoxic ; immunology

OBJECTIVETo study the effect of emodin on the differentiation, maturation and function of human dendritic cells (DC) in vitro.

METHODSCells isolated from human peripheral blood mononuclear cells (PBMCs) were induced to dendritic cells (DC) with recombinant interleukin-4 and recombinant granulocyte-macrophage colony stimulating factor (GM-CSF). Lipopolysaccharide (LPS) and different concentrations of emodin were added respectively in the cultured cells on the 5th and the 7th to obtain mature or immature DCs. The phenotype of DCs ( HLA-DR, CD80, CD86, CD83, CD14, CD11c) and the secretion of interleukin-12 (IL-12) were analyzed by flow cytometry, and the immune-stimulating function of DCs was evaluated by co-culture of DCs and self-T-lymphocytes.

RESULTSThe expression rate of CD80 and CD83 in the emodin group were 13.4% +/- 6.6% and 9.3% +/- 2.2% respectively; which were significantly lower than those in the control group (39.3% +/- 8.6% and 30.7% +/- 5.6%), respectively (P<0.05). IL-12 secretion of DCs was lower (1700.44 +/- 1000.21 microg/L vs 4500.60 +/- 1200.6 microg/L) but IL-10 secretion was higher (350.6 +/- 150.2 microg/L vs 230.7 +/- 90.1 microg/L) in the emodin group than in the control group (P<0.05). Mixed lymphocyte culture (MLR) examination showed that emodin could significantly inhibit the stimulation of DCs on self-T-lymphocyte proliferation.

CONCLUSIONEmodin could evidently suppress the maturation and immune stimulating function of DCs during their in vitro conversion process.

Cell Differentiation ; drug effects ; Cells, Cultured ; Dendritic Cells ; cytology ; drug effects ; Emodin ; pharmacology ; Humans

OBJECTIVETo investigate the biological properties of immature dendritic cells( imDC) derived from cord blood before and after cryopreservation, so as to provide a method for preservation of imDC.

METHODSImmature dendritic cells were generated from human cord blood (CB) monocytes and cultured with rhGM-CSF and rhIL-4, and 10% DMSO was added into culture medium as cryopreservation reagent. After freezing in - 80 degrees C refrigerator, the cells were finally cryopreserved in - 196 degrees C liquid nitrogen, and then thawed with 40 'C water, and they were finally named frozen-thawed imDC. The morphology of imDC were observed with light microscope, and TBR were calculated. Cellular surface markers for DC maturation were determined with flow cytometry, and the ability of the cells to stimulate proliferation of non-sensitized T lymphocyte was determined with allogeneic mixed lymphocyte reaction.

RESULTSMonocyte (MNC) from cord blood could differentiate into DC after GM-CSF and rhIL-4 induction. Under light microscope, the cells showed irregular morphology, with branch-like prominence on the cell surface. Similar changes were also observed with scan electron microscope. The cryopreserved imDC were resistant to trypan blue staining, and TBR was (86. 8 +/- 1. 3) % . There was no obvious difference in the cell morphology between cryopreserved and fresh imDCs. The expression of cell surface markers and maturation markers in imDCs before cryopreservation were as follows: CDla(62 +/-8)% , CD14 (18 +/- 7)% , HLA-DR (67 +/- 5)% , CD80 (13+/-7)%, CD 86 (12+/- 5) % . Though the expression of CD80, CD86 and CD83 of cryopreserved imDC increased to (15 +/-5)% , (17 +/-5)% and (7.4 +/-3. 3)% , respectively( P <0.05), they still possessed the phenotype of imDC. There exhibited no obvious difference in cmp value between fresh imDC[ (463 +/- 104) min(-1) ] and cryopreserved imDC[ (512 +/-78 )min(-1) ] , ( P > 0. 05 ). The cpm in control group was (488 +/- 197 ) min'. The stimulation index in all groups was lower than 2, and both fresh imDC and cryopreserved imDC could not stimulate the proliferation of non-sensitized T lymphocyte.

CONCLUSIONThe cryopreserved imDC exhibits immature characteristic in cell phenotypes, function and good cell activity, indicating that the method of cryopreservation of imDC is feasible.

Cell Differentiation ; Cell Separation ; Cryopreservation ; methods ; Dendritic Cells ; cytology ; Fetal Blood ; cytology ; Flow Cytometry ; Humans ; Monocytes ; cytology