AIMTo amplify mesenchymal stem cells (MSCs) from human bone marrow (HBM) and to induce MSCs differentiated into endothelial cells (ECs) in vitro, which possibility and conditions were to be discussed.

METHODSMSCs were separated by gradient centrifugation on Percoll (density 1.073 g/ml) from HBM, and incubated for purification and amplification in DMEM (low glucose) with 10% fetal bovine serum (FBS). MSCs, which their phenotypic characteristics were analyzed by flow cytometry, were incubated for orientation differentiated into ECs in DMEM (high glucose) with 20% FBS and VEGF (10 ng/ml) for about 14 - 21 days. Afterwards, the cells differentiated were evaluated by immunohistochemistry with Tie-2 monoclonal antibody and by transmission electron microscopy (TEM) for observation Weible-palade corpuscle in the cytoplasm.

RESULTSThe quantity of MSCs was increased from 5.0 - 10(5) in the primary culture to 8.0 x 10(12), or to increase 1.6 x 10(7) times after 15 generations incubated. The purity of MSCs was above 95% and 98% homogeneous at passages 2 and 3, respectively. The typical "cobblestone" of these cells presented from MSCs differentiation culture after 14 - 21 days was observed by light microscopy. More than 90% of the cells were positive stain for Tie-2 related antigen by immunohistochemistry assay. The Weible-palade corpuscle, which form is typical morphology of ECs, was also observed by TEM in the cytoplasm.

CONCLUSIONMSCs from HBM has the capability in differentiation into ECs in vitro, which is possible to provide the seed cells for fabrication of tissue-engineering heart valve.

Adult ; Antibodies, Monoclonal ; Bone Marrow Cells ; cytology ; Cell Differentiation ; Cells, Cultured ; Endothelial Cells ; cytology ; Flow Cytometry ; Humans ; Mesenchymal Stromal Cells ; cytology ; Receptor, TIE-2 ; immunology

The understanding of main mechanisms that determine the ability of immune privilege related to Sertoli cells (SCs) will provide clues for promoting a local tolerogenic environment. In this study, we evaluated the property of humoral and cellular immune response modulation provided by porcine SCs. Porcine SCs were resistant to human antibody and complement-mediated formation of the membrane attack complex (38.41+/-2.77% vs. 55.02+/-5.44%, p=0.027) and cell lysis (42.95+/-1.75% vs. 87.99 +/-2.25%, p<0.001) compared to immortalized aortic endothelial cells, suggesting that porcine SCs are able to escape cellular lysis associated with complement activation by producing one or more immunoprotective factors that may be capable of inhibiting membrane attack complex formation. On the other hand, porcine SCs and their culture supernatant suppressed the up-regulation of CD40 expression (p<0.05) on DCs in the presence of LPS stimulation. These novel findings, as we know, suggest that immune modulatory effects of porcine SCs in the presence of other antigen can be obtained from the first step of antigen presentation. These might open optimistic perspectives for the use of porcine SCs in tolerance induction eliminating the need for chronic immunosuppressive drugs.
Animals ; Antibodies, Heterophile/immunology ; Antibody Formation/*immunology ; Antigens, CD40/immunology ; Aorta/cytology ; Cell Line, Transformed ; Cell Survival/immunology ; Complement Membrane Attack Complex/immunology ; Complement System Proteins/immunology ; Dendritic Cells/cytology/immunology ; Endothelial Cells/cytology/immunology ; Epitopes/immunology ; Humans ; Immune Tolerance/*immunology ; Immunity, Cellular/*immunology ; Male ; Mice ; Mice, Inbred C57BL ; Sertoli Cells/cytology/*immunology ; Swine ; *Tissue Engineering ; Transplantation, Heterologous

OBJECTIVETo investigate whether fetal bone marrow stromal cells have hemangioblastic characteristics.

METHODSHuman fetal bone marrow stromal cells (hfMSCs) were isolated and cultured. Immunophenotypes of hfMSCs were tested by FACS. hfMSCs seeded in the matrigel were induced with vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in vitro. Vascularization and hematopoiesis were detected with immunohistochemistry and electron microscope.

RESULTSThe typical properties of this CD34- stromal cell population were that 99% cells expressed Flk1 (vascular endothelial cell growth factor receptor 2) and tube structure was formed. In the process of induction, hfMSCs could give rise to CD34+ round cells.

CONCLUSIONSWe have demonstrated that fetal bone marrow stroma-derived Flk1+ CD34- cells could differentiate into vascular endothelial cells and hematopoietic cells, indicating that fetal bone marrow stroma-derived Flk1+ CD34- cells have hemangioblastic characteristics.

Antigens, CD34 ; immunology ; Bone Marrow Cells ; cytology ; immunology ; metabolism ; Cell Differentiation ; Cells, Cultured ; Fetus ; Fibroblast Growth Factor 2 ; metabolism ; Hematopoiesis ; Hematopoietic Stem Cells ; cytology ; immunology ; metabolism ; Humans ; Immunophenotyping ; Stromal Cells ; cytology ; immunology ; metabolism ; Vascular Endothelial Growth Factor Receptor-2 ; physiology

This study was purposed to investigate the immunoregulatory effect of endothelial cells derived from mesenchymal stem cells (MSC). The human MSC was induced to differentiate into endothelial cells for one week. The phenotypes were evaluated by flow cytometry, the cell morphologic feature was observed by invert phase-contrast microscope and analysis of capillary formation was performed by using the in vitro angiogenesis kit. The immunoregulatory effect was detected by lymphocyte transformation test. The result indicated that during the differentiation cells grew fast and there was no significant change in the phenotypes, i.e. CD73, CD105, HLA-ABC were positive and CD34, CD80, CD86, HLA-DR, CD31 were negative. Immunofluorescence analysis showed typical expression of the von Willebrand factor. Differentiated MSCs formed capillary-like structure. Endothelial cells derived from MSC also revealed immunosuppressive effect on T cell proliferation in a dose-dependent manner. It is concluded that endothelial cells derived from MSC also harbor immunoregulatory effect on T lymphocytes.
5'-Nucleotidase ; metabolism ; Cell Differentiation ; physiology ; Cells, Cultured ; Child ; Endothelial Cells ; cytology ; immunology ; Humans ; Mesenchymal Stromal Cells ; cytology ; metabolism ; T-Lymphocytes ; immunology ; von Willebrand Factor ; metabolism

OBJECTIVETo investigate the prevalence of anti-endothelial cell antibodies (AECAs) in the sera of connective tissue diseases (CTD) patients with pulmonary arterial hypertension (PAH) and its correlation with clinical manifestations.

METHODSAECAs in sera of 39 CTD patients with PAH, 22 CTD patients without PAH, and 10 healthy donors as controls were detected with Western blotting. The prevalence of different AECAs in different groups was compared and its correlation with clinical manifestations was also investigated.

RESULTSThe prevalence of AECAs was 82.1% in CTD patients with PAH, 72.7% in CTD patients without PAH, and 20.0% in healthy donors. Anti-22 kD AECA was only detected in CTD patients with PAH (15.4%). Anti-75 kD AECA was more frequently detected in CTD patients with PAH than in those without PAH (51.3% vs. 22.7%, P < 0.05). In CTD patients with PAH, anti-75 kD AECA was more frequently detected in those with Raynaud's phenomenon or with positive anti-RNP antibody.

CONCLUSIONAECAs could be frequently detected in CTD patients with or without PAH, while anti-22 kD and anti-75 kD AECA might be specific in CTD patients with PAH.

Adult ; Autoantibodies ; blood ; immunology ; Cell Line ; Connective Tissue Diseases ; blood ; immunology ; pathology ; physiopathology ; Endothelial Cells ; cytology ; immunology ; Female ; Humans ; Hypertension, Pulmonary ; blood ; immunology ; pathology ; physiopathology ; Middle Aged

OBJECTIVETo study the isolation, culture and identification of CD133+ endothelial progenitor cells (EPCs) from human umbilical cord blood in vitro.

METHODSEPC separation was performed with density gradient centrifugation and MACS separation. Purity of EPCs was determined by flow cytometry. EPC was cultured with EBM-2 to study the cultivate features of EPC. Uptake test of Dil-LDL and FITC-Lectin and immunohistochemistry were performed.

RESULTSAccording to flow cytometry, (1.13 +/- 0.10)% of mono-nuclear cells were CD133+ and the purities of CD133+ EPCs were (91.45 +/- 1.04)% on average. CD133+ EPCs became adherent, spindle-shaped and formed cluster during culture. Uptake test of Dil-LDL and FITC-Lectin were positive. (95.83 +/- 1.72)% of CD133+ cells were found positive in both uptake tests. The positive rates of immunostaining of cell markers CD34 and factor VIII were (95.83 +/- 2.23)% and (95.92 +/- 1.43)% after cultured for one week, which showed no significant differences between CD133+ EPCs and human umbilical vein endothelial cells. Capillary structures were formed by CD133+ EPCs after cultured for 4 and 7 d in vitro.

CONCLUSIONSHigh purity of CD133+ EPCs can be obtained by MACS separation. CD133+ EPCs can differentiate into mature endothelial cells with the effects of stimulating factors.

AC133 Antigen ; Antigens, CD ; analysis ; blood ; Cell Culture Techniques ; Cell Differentiation ; Cells, Cultured ; Endothelial Cells ; cytology ; immunology ; Fetal Blood ; cytology ; immunology ; Flow Cytometry ; Glycoproteins ; analysis ; blood ; Humans ; Immunomagnetic Separation ; Peptides ; analysis ; blood ; Stem Cells ; cytology ; immunology

OBJECTIVETo explore the role of CD44 in monocyte adhesion to human brain microvascular endothelial cells (HBMECs) and monocyte migration across an in vitro model of blood-brain barrier (BBB) infected by Cryptococcus neoformans (Cn).

METHODSAn in vitro blood-brain barrier model was constructed using a transwell chamber covered with a HBMEC monolayer. The wild-type strain of Cn B4500FO2, TYCC645#32 strain with CPS1 gene deletion and PCIP strain with CPS1 complementation were chosen to infect the monolayer HBMECs. THP-1 cells were added to the upper chamber of transwell, and the relative migration rate was determined by counting the number of the cells entering the lower chambers. The inhibitory effects of anti-CD44 monoclonal antibody and the CD44 inhibitor bikunin were examined on THP-1 binding to and migration across HBMECs.

RESULTSCn infection of the HBMECs caused markedly enhanced THP-1 cell adhesion and migration across the monolyers (P<0.01) dependent on Cn concentration and exposure time. Addition of anti-CD44 monoclonal antibody and bikunin significantly lowered THP-1 adhesion and migration rates in the BBB model with Cn-infected HBMECs (P<0.01) with a dose dependence of the antibody (within 0-1 µg) and inhibitor (within 0-20 nmol/L). Both THP-1 adhesion rate and migration rate were lowered in the BBB model infected with CPS1 gene-deleted Cn but increased in the model infected with the complemented strain compared with those in the wild-type strain-infected model.

CONCLUSIONIn the in vitro BBB model, CD44 expressed on HBMECs may play an essential role in monocyte adhesion to and migration across the BBB. The capsular hyaluronic acid may mediate Cn-induced monocyte adhesion and migration.

Blood-Brain Barrier ; immunology ; microbiology ; Brain ; cytology ; microbiology ; Cell Line ; Cryptococcosis ; immunology ; Cryptococcus neoformans ; Endothelial Cells ; microbiology ; Humans ; Hyaluronan Receptors ; metabolism ; Monocytes ; cytology

OBJECTIVETo investigate the immune-functional epitopes and inflammation-inducing effects of the major outer envelope proteins of Leptospira interrogans.

METHODSNi-NTA affinity chromatography was established to extract the target recombinant proteins rOmpL1/1 and OmpL1/2, LipL32/1 and rLipL32/2, LipL41/1 and rLipL41/2 expressed by the different genotypes. By using Signal P-NN software in Signal P3.0 prediction server, EMBOSS software in propred MHC class-II binding peptide prediction-ProPred prediction server, the possible signal peptides, MHC-II binding peptides and lymphocyte B epitopes were analyzed. The IL-1, IL-8 and TNF-alpha secretion in human umbilical vein endothelial cell line EVC-304 induced by target recombinant proteins were measured by ELISA.

RESULTSUnder the inducement of IPTG, the constructed prokaryotic systems efficiently expressed rOmpL1/1 and rOmpL1/2, rLipL32/1 and rLipL32/2, and rLipL41/1 and rLipL41/2 with outputs of 30% and 15%, 40% and 35%, and 15% and 10% of the total bacterial proteins, respectively. Each of the purified target recombinant proteins showed a single protein band in SDS-PAGE. The signal peptides of OmpL1s, LipL32/1 and LipL32/2, and LipL41s were located at the N ends of 1-24, 1-21 and 1-24, and 1-24 amino acid residuals, respectively. OmpL1s, LipL32s and LipL41s displayed 2,2 and 1 same major epitopes of MHC-II binding peptides and lymphocyte B and OmpL1/2 had another one (59-78). The different dosages of rOmpL1s, rLipL32s and rLipL41s increased the secretion of IL-1alpha , IL-8 and TNF-alpha (P<0.05) in EVC-304 cells. The IL-1alpha levels reached the highest at the 24 h and then declined,while the IL-8 and TNF-alpha levels after 48 h treatment were higher that those after 24 h.

CONCLUSIONThe expression products in ompL1/1, lipL32 or lipL41 genotypes of L.interrogans contain similar immune functional epitopes. rOmpL1/1 and rOmpL1/2, rLipL32/1 and rLipL32/2, and rLipL41/1 and rLipL41/2 are able to directly induce inflammatory reaction in EVC-304 cells.

Bacterial Outer Membrane Proteins ; immunology ; pharmacology ; Cells, Cultured ; Endothelial Cells ; cytology ; Epitopes ; Genotype ; Humans ; Inflammation ; etiology ; Interleukin-1 ; biosynthesis ; Leptospira interrogans ; genetics ; immunology ; Lipoproteins ; immunology ; pharmacology ; Recombinant Proteins ; immunology ; Tumor Necrosis Factor-alpha ; biosynthesis ; Umbilical Veins ; cytology

The basic route and mechanism for diapedesis has not yet to be fully defined. Here we present evidence that "cell-cell separation" between endothelial cells (ECs) may provide a route for leukocyte diapedesis. We unexpectedly found that extensive interaction between peripheral blood leukocytes and ECs that were activated by TNF-alpha induced the opening of EC contacts and, surprisingly, resulted in cell-cell separation. This event was specific to the intercellular adhesion molecules-1 (ICAM-1)/leukocyte function-associated antigen-1 interaction, as demonstrated by the following: (1) ICAM-1 expression correlated with increased EC contraction; and (2) the blocking of ICAM-1 selectively inhibited EC separation. Thus, we suggest that "cell-cell separation" could be a mechanism for diapedesis in situations that may require massive leukocyte infiltration.
Cell Movement ; Cells, Cultured ; Endothelial Cells/*cytology/metabolism ; Flow Cytometry ; Fluorescent Antibody Technique ; Humans ; Intercellular Adhesion Molecule-1/*metabolism ; Leukocytes/cytology/*immunology ; Lymphocyte Function-Associated Antigen-1/*metabolism

The basic route and mechanism for diapedesis has not yet to be fully defined. Here we present evidence that "cell-cell separation" between endothelial cells (ECs) may provide a route for leukocyte diapedesis. We unexpectedly found that extensive interaction between peripheral blood leukocytes and ECs that were activated by TNF-alpha induced the opening of EC contacts and, surprisingly, resulted in cell-cell separation. This event was specific to the intercellular adhesion molecules-1 (ICAM-1)/leukocyte function-associated antigen-1 interaction, as demonstrated by the following: (1) ICAM-1 expression correlated with increased EC contraction; and (2) the blocking of ICAM-1 selectively inhibited EC separation. Thus, we suggest that "cell-cell separation" could be a mechanism for diapedesis in situations that may require massive leukocyte infiltration.
Cell Movement ; Cells, Cultured ; Endothelial Cells/*cytology/metabolism ; Flow Cytometry ; Fluorescent Antibody Technique ; Humans ; Intercellular Adhesion Molecule-1/*metabolism ; Leukocytes/cytology/*immunology ; Lymphocyte Function-Associated Antigen-1/*metabolism