[Research progress of platelet bacteriostatic effects].

Platelets not only have hemostatic function, but can also directly or indirectly recognize pathogenic microorganisms and the signals they produce to capture and destroy them through membrane receptors. They can collaborate with various components of the body's immune system by releasing of intraplatelet particulate matter, cytokines and chemokines to perform bactericidal functions. And it can also play a bactericidal role by swallowing pathogens, releasing antimicrobial proteins and chemokines and activating and enhancing other specialized anti-inflammatory cells bactericidal effect, such as leukocytes and so on. However, the bacteriostatic composition and bacteriostatic mechanism of platelets remain unclear, so attention should be paid to the immune mechanism and bacteriostatic effect of platelets.

T-lymphoblastic lymphoma/leukemia without clonal TCR gene rearrangements: case report and literature review.

T-lymphoblastic lymphoma (T-LBL) is a highly aggressive malignancy originating from T-lymphocyte precursors. Incidence is highest in children and adolescents. T-cell receptor (TCR) gene rearrangement is usually present. TCR gene rearrangement-negative cases are considered rare. Here, we investigated the clinicopathological features, differential diagnosis, therapy, and prognosis of TCR gene rearrangement-negative T-lymphoblastic lymphoma/leukemia (T-LBL/ALL) by case report and literature review. An 18-year-old male with polyglandular lymphadenopathy underwent an excisional lymph node biopsy and bone marrow aspiration that disclosed diffuse distribution of round, small to medium sized cells with scant cytoplasm, delicate chromatin, and frequent mitotic figures. Immunophenotyping showed expression of TDT, CD3, CD7, and CD5, no CD34, CD20, CD56, bcl-6, CD4, CD8, or MPO in lymph node tissue. Immunohistochemical staining for pathological consultation was performed by Streptavidin peroxidase (SP) method, EB virus coded small RNA (EBER) tested by in situ hybridization (ISH), (EBER-ISH). And flow cytometry of bone marrow aspirate showed that tumor cells expressed CD3, CD5, CD7; partial expression of CD2, CD10, CD38, TDT; and no expression of CD1a, CD34, CD4, CD8, mCD3, CD33, CD56, CD19, CD79a, HLA-DR and MPO. These findings led to the diagnosis of T-LBL/-ALL. Molecular genetic testing showed no TCR gene rearrangement. The patient received chemotherapy consisting of vinorelbine, pirarubicin, cyclophosphamide, asparaginase, and prednisone. Prophylactic chemotherapy of the central nervous system and radiotherapy of the mediastinum were also given. And responded to combined chemotherapy and radiotherapy. Although T-LBL/ALL typically features TCR gene rearrangement, rare cases without rearrangement may occur. Diagnosis is based on clinical characteristics, histopathology, immunotyping, and molecular genetics.

Bioactivity of umbilical cord blood dendritic cells and anti-leukemia effect.

OBJECTIVE: We investigated the effect of umbilical cord blood dendritic cells (DCs) on in vitro proliferation, immunophenotypes and levels of homologous cytokine-induced killer cells (CIK) and the toxicity on leukemia cells. METHOD: Mononuclear cell-induced DC-CIK cells derived from umbilical cord blood were collected and co-cultured in the proportion of 1:5. Cord blood CIK cells or peripheral blood DC-CIK cells were used as control. Phenotypes were analyzed by flow cytometry; vial cell counting was performed using trypan blue, and the killing activity of effector cells against leukemia cells was measured by MTT assay. The levels of interferon-r (IFN-r), tumor necrosis factor-a (TNF-α) and interleukin-12 (IL-12) were determined by ELISA. RESULTS: The proliferative capacity of DC-CIK cells was obviously improved compared with cord blood CIK cells and peripheral blood DC-CIK cells (P<0.05, P<0.05). During the co-culture of cord blood DC-CIK cells, the ratios of CD 3 (+) CD 8 (+) and CD 3 (+) CD 56 (+) cells were obviously higher than that of CIK cells under the same conditions (P<0.05). On day 3 of co-culture, the levels of IL-12, IFN-r and TNF-a in cultured supernatant of cord blood DC-CIK cells were all higher than those secreted by CIK cells cultured alone (P<0.01, P<0.05, P<0.05). When the effector to target ratio was 2.5-20:1, the killing effect of cord blood DC-CIK cells against each subtype of acute leukemia cells was obviously higher than that of CIK cells (P<0.05). No significant differences in killing effect were observed for different subtypes. This finding was consistent with the killing effect of peripheral blood DC-CIK cells against leukemia cells. CONCLUSION: Cord blood DCs can enhance the proliferative capacity of homologous CIK cells and its anti-leukemia effect. Though cord blood DC-CIK cells showed a higher proliferative capacity than peripheral blood DC-CIK cells, the two types of DC-CIK cells did not differ significantly in terms of cytoxicity. With a high availability and the low probability of graft rejection reaction, cord blood DC-CIK cells have a brighter prospect for application in immunotherapy.

BMI­1 is important in bufalin­induced apoptosis of K562 cells.

The purpose of this study was to analyze the effects of bufalin on the gene expression of K562 cells and on the expression of BMI­1 pathway constituents in K562 cell apoptosis. K562 cells were treated with bufalin, and the inhibition rate and apoptosis were detected by an MTT assay, flow cytometry and a microarray assay. BMI­1, p16INK4a and p14ARF were examined by quantitative polymerase chain reaction (qPCR). Bufalin induced significant changes in the gene expression of the K562 cells; 4296 genes were differentially expressed, 2185 were upregulated and 2111 were downregulated. The most upregulated genes were associated with transcription regulation, while the most downregulated genes were associated with the non-coding RNA metabolic processes and DNA repair. qPCR analysis demonstrated that BMI­1 was overexpressed in the K562 cells. Bufalin is able to downregulate BMI­1 expression levels in K562 cells prematurely and cause an increase in the expression levels of p16INK4a and p14ARF. Moreover, bufalin downregulated BCR/ABL expression levels in a time­dependent manner, and the expression of BCR/ABL was not associated with the upregulation or downregulation of BMI­1 expression. Bufalin may induce K562 cell apoptosis by downregulating BMI­1 expression levels and accordingly upregulating the expression levels of p16INK4a and p14ARF. Bufalin may also induce K562 cell apoptosis via downregulating BCR/ABL expression levels, and this pathway may be independent of the BMI­1 pathway.

Influence of dendritic cells on biological activity of the homologous CIK cells and its anti-leukemia effect in vitro.

This study was aimed to investigate the effect of cord blood dendritic cells (DCs) on the in vitro proliferation capability, immunophenotype changes, level of secreted cytokines and activity against leukemia cells of the homologous cytokine-induced killer (CIK) cells. DCs and CIK cells were induced from cord blood mononuclear cells. They were co-cultured at the ratio of 1:5, and CIK cells from cord blood or DC-CIK cells from peripheral blood were cultured as controls. Immunophenotypic changes were analyzed by flow cytometry, increased number of cells were counted by trypan-blue staining, the killing activity to leukemia cells was assayed by MTT, the levels of interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α) and interleukin-12 (IL-12) in the cultured supernatant were detected by ELISA. The results showed that the proliferation capability of cord blood DC-CIK cells was significantly higher than that of cord blood CIK cells and peripheral blood DC-CIK cells (p < 0.05 and p < 0.05). Under the same condition, the rate of double positive cells with CD3(+)CD8(+) and CD3(+)CD56(+) in CIK cells was significantly enhanced by co-culture with cord blood DCs (p < 0.05). The level of IL-12, IFN-γ, and TNF-α in cultured supernatants of cord blood DC-CIK cells increased noticeably on day 3 as compared with CIK cells cultured alone (p < 0.01, p < 0.05, p < 0.05). Within the effector-target ratio range between 2.5:1 to 20:1, the activity of cord blood DC-CIK cells against all subtypes of acute leukemia cells was much higher than that of CIK cells (p < 0.05), and there was no significant difference among all subtypes of acute leukemia cells, which was the same with the killing effect of peripheral blood DC-CIK cells against leukemia cells. It is concluded that the proliferation capability and anti-leukemia effect of the homologous CIK cells can be enhanced by cord blood DCs. The proliferation capability of cord blood DC-CIK cells is stronger than that of peripheral blood DC-CIK cells, but there is no significant differences of cytotoxicity between DCs and CIK cells. As the cord blood is easily gained and does not easily cause a serious graft rejection, the DC-CIK cells should be clinically applied more extensively as novel immune therapy.

Biological activity of DC-CIK cells and its effect against leukemia cells in vitro.

This study was aimed to investigate the effect of dendritic cells (DC) on the proliferation capability, immunophenotype changes, level of secreted cytokines and activity against leukemia of cytokine-induced killer (CIK) cells in vitro. DCs and CIK cells were induced from peripheral blood mononuclear cells of healthy volunteers. They were co-cultured meanwhile CIK cells were cultured alone as controls. Increased number of cells were counted by trypan-blue staining; the killing activity was detected by MTT assay; immunophenotype changes were analyzed by flow cytometry; the IL-12 and INF-gamma levels of the cultured supernatants were detected by ELISA kits. The results showed that the proliferation capability of DC-CIK cells was significantly higher than that of CIK cells (p < 0.05). Under the same condition, the ratio of double positive cells such as CD3(+) CD8(+), CD3(+) CD56(+) in CIK cells was significantly enhanced by co-cultured with DC cells (p < 0.05). The levels of IL-12 and INF-gamma in cultured supernatants of DC-CIK cells increased noticeably on day 3 as compared with CIK cells cultured alone (p < 0.01, p < 0.05). Within the effector-target ratio range between 5:1 to 40:1, the activity of DC-CIK cells against leukemia cells were much higher than that of CIK cells (p < 0.05), and this effect showed a positive correlation with the effector-target ratio. It is concluded that the proliferation capability of DC-CIK cells, the level of their secreted cytokines and their activity against leukemia cells are significantly higher than those of CIK cells. This research may suggest an approach for clinical immunotherapy against leukemia with DC-CIK cells.

Influence of interferon alpha on expression of Fas and Fas ligand in dendritic cells from patients with chronic myeloid leukemia.

The study was aimed to investigate the influence of interferon alpha (IFN-alpha) on the expressions of Fas and Fas ligand (FasL) in dendritic cells (DCs) from patients with chronic myeloid leukemia (CML). In addition to adding stem cell factor (SCF), granulocyte-macrophage colony-stimulating factor (GM-CSF), tumor necrosis factor alpha (TNF-alpha) and interleukin 4 (IL-4), the IFN-alpha was added to the serum-free medium for DCs. After culturing for 10 - 14 days, cell phenotype and percentage of Ph(1) chromosome were detected by different methods. The expression of Fas or FasL on CML-DCs and cell cycle of DCs labeled with propidium iodine (PI) were measured by flow cytometry. The concentration of sFas in supernatants was analyzed by enzyme-linked immunosorbent assay (ELISA). The results indicated that the expression of co-stimulatory molecules were improved significantly while the percentages of Ph(1) positive cells decreased. The level of Fas on cells was up-regulated and the concentration of sFas decreased. However, the expression of FasL was negative. The ratio of apoptosis rose gradually while the concentration of IFN-alpha increased. It is concluded that IFN-alpha can accelerate the apoptosis of Ph(1) positive cells through Fas/FasL pathway, so the number of Ph(1) negative cells increases relatively.

Influences of interferon-alpha on expression of Th cytokines and CCR7 in dendritic cells from patients with chronic myeloid leukemia in vitro.

This study was aimed to investigate the influences of interferonalpha (IFN-alpha) on expressions of CCR7, interleukin10 (IL-10) and IL-12p70 in dendritic cells (DCs) from patients with chronic myeloid leukemia (CML). In addition to stem cell factor (SCF), granulocyte-macrophage colony stimulating factor (GM-CSF), tumor necrosis factor-alpha (TNF-alpha) and IL-4, IFN-alpha was added to the serum-free medium of DCs. After culture for 10-14 days, phenotypes and function of CML-DCs were evaluated respectively by flow cytometry and methyl thiazolyl tetrazolium (MTT) assay. Chromosome of DCs was analyzed by displaying G banding assay. The concentrations of IL-10 and IL-12P70 in supernatants were evaluated by enzyme-linked immunosorbent assay (ELISA). The results showed that the expressions of CD40, CD83, CD86 and CCR7 and the OD value in allogeneic mixed-lymphocyte reaction (MLR) in group with IFN-alpha (300 U/ml) were twice as high as those in group without IFN-alpha. The percentage of Ph1 positive cells and concentrations of IL-10 and IL-12 P70 were reduced in group with IFN-alpha. It is concluded that the defective phenotypes and functions of CML-DCs can be recruited partly by IFN-alpha. The mechanism may lie in the facts that expression of CCR7 and co-stimulatory molecules is promoted and the inhibitory effect of IL-10 on CML-DCs is relieved partly through the regulation of IFN-alpha.

[Influence of IFN-alpha on function of CML-DC in vitro and expression of chemokine with its receptor].

To study the influence of IFN-alpha on function of CML-DC cultured in vitro and expression of chemokine and its chemokine receptor, bone marrow mononuclear cells from 13 CML patients were cultured in the fetal calf serum culture system supplemented with rhSCF, rhFlt-3L for expansion system, and adding rhGM-CSF, rhTNF-alpha, rhIL-4, with or without rhIFN-alpha to induce DCs. After incubation for two weeks, the phenotypes of CML-DC were analyzed by direct immunofluorescence and flow cytometry. The concentration of MIP-3beta expressed by CML-DC in the supernatant were analyzed by ELISA. The proliferative ability of T cells from healthy volunteers stimulated by CML-DCs were measured by MTT assay. The results showed that expression of CD86, CD83, CD40, MHC-I class molecules, CCR7, the concentration of MIP-3beta expressed by CML-DC, and the proliferative ability of T cells stimulated by CML-DCs in IFN-alpha group were all significantly higher than that in control group (P < 0.01). It is concluded that the immunophenotype of CML-DCs can be partially changed by IFN-alpha to accelerate the maturation of CML-DCs, enhance the capacity of CML-DCs, and stimulate allogeneic T lymphocyte proliferation.

Expansion in vitro and cytotoxicity of dendritic cells from patients with chronic myeloid leukemia.

The study was aimed to investigate the extensive amplification and the cytotoxicity of dendritic cells (DC) derived from chronic myeloid leukemia cells. DC were cultured in two steps: firstly, extensive amplification in primary culture of CD34(+) or mononuclear cells isolated from CML patients' bone marrow and peripheral blood with rhFlt3-L and rhTPO for 7 days; secondly, inducing culture of DC with rhGM-CSF, rhTNF and rhIL-4 for 14 days. A system inducing DC directly were established for comparison. DC were identified by immunophenotype with flow cytometry, chromosome analysis by displaying G banding and electric microscopy analysis. The function of stimulating T cells proliferation and cytotoxicity of CML cells were confirmed through MTT assay. The results showed that after first extensive amplification in primary culture with rhFlt3-L and rhTPO for 7 days, CD34(+) cells had a total cell number with (77 +/- 5) fold expansion, and DC were (39 +/- 8)% of total cell respectively after induction culture of DC with rhGM-CSF, rhTNF and rhIL-4 for 14 days. Both the amplification of cell number and yield of DC were higher than the system without extensively culture (P < 0.01). Such DC could stimulate T cells to proliferate and kill leukemia cells finally. In conclusion, two-step culture method can obviously improve the cell number of DC required, that is better than inducing them directly. DC derived from CML cells induce the generation of anti-leukemia immunization.

Serum-free culture of dendritic cells from patients with chronic myeloid leukemia in vitro and estimation of their cytotoxicity.

OBJECTIVE: To establish a serum-free culture system of dendritic cells (DCs) from chronic myeloid leukemia (CML) cells so that DCs vaccine may be applied to the adoptive immunotherapy of CML in the near future. METHODS: Fetal calf serum, serum-free medium and autologous serum were used for culture of DCs. The usage of cytokines was classified into two groups: group A (stem cell factor, granulocyte/macrophage colony-stimulating-factor, tumor necrosis factor-alpha and interleukin-4) and group B (granulocyte/macrophage colony-stimulating-factor, tumor necrosis factor-alpha and interleukin-4). The phenotypes of DCs were analyzed by using indirect immunofluorescence and flow cytometry. Mixed leukocyte responses were performed by methyl thiazolyl tetrazolium (MTT) assay. Chromosome analysis of DCs can be achieved by displaying G banding. T cells from CML patients were stimulated with autologous DCs and T-cell cytotoxicity was measured by (MTT) assay. RESULTS: CD34(+) cells or mononuclear cells were obtained from peripheral blood or bone marrow samples of eight patients of chronic-phase CML. Group A of serum-free medium was better than group B in expansion of total cell numbers and the rate of DCs. These results of serum-free medium were not significantly different from those of fetal calf serum medium, but the results of autologous serum medium were inferior to two groups above. The expression of major histocompatibility complex class II antigen on the surface of DCs was notable (> 50%), but the expression of CD83 and the costimulatory molecules CD86 was not noticeable (10% - 50%). Although CD1a(+)/CD14(-) DCs were potent stimulators of allogeneic lymphocytes, expansion of T cells from normal volunteers were not significant (average 27.2 fold at DCs: T cells ratio of 1:10). At day 12, CD1a(+) cells from three patients were studied by displaying G banding and Ph(+) cells in these populations were 100%, 98% and 60%, respectively. At an effector: target ratio of 40:1, 32% to 45% cytotoxicity was noted with DC-stimulated T cells against autologous leukemia cells. CONCLUSIONS: A stable serum-free culture system of CML-DCs was established. The expression of CD83 and CD86 on the surface of CML-DCs and DCs' potent stimulation of allogeneic lymphocytes were not notable. DCs in CML patients can be derived from the malignant clone and these malignant DCs could induce anti-leukemic reactivity in autologous T lymphocytes without the necessity for additional exogenous antigens.