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Objective To investigate that Anti-monosialoganglioside antibody(Anti-GM1) inhibits the natural killing activity of natural killer(NK) cells in nude mice by regulating NK cell differentiation. Methods Multiplex immunofluorescence staining was used to identify the NK cell typing characteristics in human renal cancer tissue. Six male BALB/c mice were selected, and GM1 was injected subcutaneously once a week for three weeks to immunize the mice for the preparation of Anti-GM1. Six BALB/c-Nude nude mice were randomly divided into the control group (CON) and the experimental group (Anti-GM1) using a random number table. The CON group was treated with IgG by continuous intraperitoneal injection for 7 days; the Anti-GM1 group was treated with Anti-GM1 by continuous intraperitoneal injection for 7 days. After 7 days, the nude mice were sacrificed by cervical dislocation, the spleens of the nude mice were taken and made into a single-cell suspension, and the splenocytes were co-cultivated in YAC-1 for 4 hours. Killing viability of the NK cells was detected by LDH assay. Detection was performed using flow cytometry, with NK cell subsets defined based on the expression of CD27 and CD11b, and the expression of CD107a was also assessed. ELISA was used to detect the secretion levels of NK cell interferon-gamma (IFN-γ) and granzyme B (GzmB). Results There was an obvious NK cell infiltration in the human renal cancer tissue specimens, and GzmB was also positively expressed. Anti-GM1 can significantly inhibit the killing activity of NK cells. Compared with the CON group, the Anti-GM1 group can promote the differentiation of NK cells into mature subsets. The level of CD107a in NK cells of the Anti-GM1 group was significantly decreased. The secretion levels of IFN-γ and GzmB in NK cells of the Anti-GM1 group were decreased compared to the CON group. Conclusion NK cells can infiltrate into human renal cancer tissue and can secrete GzmB, exerting natural killing effects. Anti-GM1 can promote the maturation of NK cells but inhibit the killing activity of NK cells, which is related to its inhibition of NK cell CD107a expression and suppression of NK cell IFN-γ and GzmB secretion.

BACKGROUND: Our preliminary study has shown that methylene blue exerts toxic effect on human nucleus pulposus cells in a concentration-dependent manner, but the toxic range remains unclear. OBJECTIVE: To determine the critical range of the cytotoxicity of methylene blue to nucleus pulposus cells by cell counting-kit 8 (CCK-8) assay. METHODS: The nucleus pulposus was from a patient with intervertebral disc herniation. The nucleus pulposus cells were extracted and cultured. Passage 1 cells mere used to make cell suspensions. The cells were divided into nine groups for culture: blank control (only the medium, CCK-8 solution), control (only medium, cells and CCK-8 solution), and methylene blue groups (1%, 0.5%, 0.1%, 0.05%, 0.01% and 0.005% of methylene blue). The absorbance values were measured by CCK-8 assay at 24, 48, 72 and 96 hours after incubation. The cell viability was calculated, and the color was observed. RESULTS AND CONCLUSION: The color in the control group was the darkest, and the color in the methylene blue groups became lighter with the concentration of methylene blue increasing, and the 0.05%, 0.01%, 0.005% and 0.001% methylene blue groups showed darker color similar to the control group. The absorbance values in the 0.1% methylene blue group were significantly less than those in the control group (P < 0.05). There were no significant differences in the absorbance values and cell viability between 1% and 0.5% methylene blue groups (P > 0.05). The absorbance values and cell viability in the 0.1% methylene blue group were significantly higher than those in the 0.5% methylene blue group, but were significantly less than those in the 0.05% methylene blue group (P < 0.05). Thus, methylene blue exerts cytotoxicity to human nucleus pulposus cells, and the critical value of toxicity is between 0.1% and 0.05% and close to 0.05%. However, the exact value needs a further investigation. [ABSTRACT FROM AUTHOR]

BACKGROUND: Methylene blue is used as a developer to identify intervertebral disc degeneration in the transforaminal endoscopic surgery. However, many scholars have indicated that methylene blue can accelerate the degeneration process, whilst foreign researches have reported that it may play therapeutic effect on degenerative intervertebral discs under acidic conditions due to its acidophily. Therefore, whether methylene blue holds toxic effect on the disc remains controversial. OBJECTIVE: To determine whether methylene blue exerts toxic effect on nucleus pulposus cells by cell counting-kit 8 (CCK-8) assay. METHODS: The discarded nucleus pulposus from two patients with intervertebral disc herniation were selected. After digestion, nucleus pulposus cells were extracted and cultured until proliferated to 80% of the medium. Then, the cells were digested to make cell suspensions, divided into six groups and inoculated into the 96-well plates: blank control (only the medium, CCK-8 solution), control group (only medium, cells and CCK-8 solution), and the other groups were cultured with 1%, 2%, 3%, and 4% methylene blue, respectively. The absorbance values were measured by CCK-8 assay at 24, 48, 72 and 96 hours after incubation to calculate the cell viability, and the color change was observed. RESULTS AND CONCLUSION: The color in the control group was the deepest, and the color became lighter with the concentration of methylene blue increasing. The cell viability was the highest in the control group, and it was decreased with the concentration of methylene blue increasing. Thus, methylene blue may exert toxic effect on human nucleus pulposus cells. [ABSTRACT FROM AUTHOR]

Objective To clarify the effect and mechanism of tumor antigen-loaded dendritic cells (Ag-DCs) combined with cytokine-induced killers (CIKs) on the killing of esophageal cancer tumor cells. Methods Peripheral blood DCs and CIKs were induced and cultured, and the DCs were loaded with tumor antigen to obtain Ag-DCs, and Ag-DCs were co-cultured with CIKs. The experiment was divided into CIK group, DC combined with CIK group, Ag-DC combined with CIK group. Flow cytometry was used to detect the phenotype of cells. MTT assay was employed to determine the killing activity against EC9706 cells. Annexin V-FITC/PI double staining was used to detect the apoptosis rate of cells, immunofluorescence staining to detect the expression of phosphorylated apoptotic signal-regulated kinase 1 (p-ASK1) and Western blot analysis to detect the expression of ASK1 pathway related proteins. A nude mouse model of esophageal cancer transplantation tumor was constructed and divided into control group, DC combined with CIK group and Ag-DC combined with CIK group. The corresponding immune cells were injected into the tail vein for treatment and the tumor volume was measured every 2 days. After 21 days, all nude mice were sacrificed with the tumors taken out. HE staining was used to observe the tumor pathological changes and immunohistochemical staining was performed to detect the expression of ki67 and ASK1 in the tumor tissue. Results Comparedwith the CIK group alone and the DC combined with CIK group, the ratio of CD3 + CD8 + and CD3 + CD56 + in the cells significantly increased after Ag-DCs and CIKs co-culture, along with the increased killing rate of EC9706 cells, increased apoptosis rate of EC9706 cells, and the improved activation level of ASK1. Compared with the CIK group and the DC combined with CIK group, the growth of the transplanted tumor in nude mice treated with Ag-DCs combined with CIKs was significantly inhibited, and after 21 days, it was observed that the tumor tissue mass in this group was relatively smaller, with sparsely arranged cells in the tumor tissue and a decline in the positive rate of ki67 in tumor tissue, while the positive rate of ASK1 was significantly increased. Conclusion Co-cultivation of tumor antigen-loaded DCs with CIKs can significantly increase the killing activity of esophageal cancer tumor cells. The mechanism of action may be related to the activation of the ASK1 pathway.

Objective: To investigate the regulatory effects of Olaparib on natural killer cell activating receptor (NKG2D) ligands expression on human acute myeloid leukemia (AML) cell line HL-60, and to explore the molecular mechanism of Olaparib on HL-60 cells., Methods: After HL-60 cells in logarithmic growth phase were treated with Olaparib at different concentrations for different times (24, 48 h), the expression of NKG2D ligand on the surface of HL-60 cells was detected by flow cytometry. Western blot was used to dectect the expression of ERK expression in HL-60 cells. The killing effect of NK cells to HL-60 cells was detected by CFSE/PI method., Results: 10 μmol/L Olaparib could upregulate the expression of NKG2D ligand on the surface of HL-60 cell at 24 and 48 hours, while 5 μmol/L Olaparib could induce up-regulation of the expression of ULBP-2 and ULBP-3 at 48 hours. Western blot analysis showed that ERK phosphorylation of HL-60 cells was enhanced after treating with Olaparib. The killing effect of NK cells to HL-60 cells could be enhanced by Olaparib, however, ERK inhibitor could suppress the killing effect of NK cells to HL-60 cells., Conclusion: Olaparib can upregulate NKG2D ligands expression on the surface of HL-60 cells and enhance the cytotoxicity of NK cell to HL-60 cells. The mechanism may be related to Olaparib promoting ERK phosphorylation expression.

Objective: To analyze the components of tumor infiltrating T lymphocyte (TIL) cells in malignant pleural effusion of lung adenocarcinoma, and evaluate their killing activities to autologous tumor cells. 
 Methods: Malignant pleural effusions were collected from 17 patients with lung adenocarcinoma. Mononuclear cells were isolated by Ficoll density gradient centrifugation and flow cytometer was used to analyze TIL cell components. TIL and tumor cells were separated through adherent culture. The tumor cells were identified via intramuscular injection of adherent cells into nude mice and the killing effect of cultured lymphocytes on autologous tumor cells was studied.
 Results: Of the TIL in malignant pleural effusions, T cells accounted for 60.6%-79.3%, while T helper cells were significantly higher than T killer cells (36.63%±1.90% vs 24.64%±2.32%, P<0.001). There were also natural killer (NK) cells and NK T cells in the effusions. Tumor cells were successfully isolated and cultured. The killing activity of cultured TIL to autologous tumor cells was 39.14%±12.04%, and the killing activity of TIL with high proliferation rate to autologous tumor cells was higher than that of low proliferation group (50.51%±3.80% vs 29.04%±5.77%, P<0.001).
 Conclusion: T lymphocytes are the major components of TIL in malignant pleural effusions derived from lung adenocarcinoma, and T helper cells are more than T killer cells. The killing activity of TIL with strong proliferation ability to autologous tumor cells is higher than that of TIL with weak proliferation ability. Therefore, cells from malignant pleural effusions could be used for cellular immunotherapy against tumor.

Objective: To investigate the expression of CD160 on the surface of human natural killer (NK) cells and its possible relationship with hematological malignancies., Methods: CD160 expression on human leukemia cell line NK92 cells was confirmed by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. The proliferation characteristics and cell surface markers of this cell line were determined. Cytotoxicity of NK92 against 2 human myeloid leukemia cell lines, K562 and THP-1 was analyzed ex vivo. CD160 blocking antibody CL1-R2 was employed to clarify its role in NK cell mediated cytolysis. Then, the expression of CD160 on NK cells in peripheral blood from various patients with hematological malignancies were measured by flow cytometry., Results: The mRNA and protein levels of CD160 expressions on NK92 cells were confirmed by RT-PCR and Western blot, respectively. The flow cytometry results demonstrated that the strong positive expression of CD160 could be detected on the NK92 cell surface. NK92 could effectively kill K562 and THP-1 cells, while the cytolysis effect was abrogated in the presence of CD160 blocking antibody CL1-R2. The high levels of HVEM were expressed on both target cells, but the HLA class I molecules were absent on K562. The expression of CD160 on CD3 - CD56 + NK cells in peripheral blood from patients with acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL) and allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients was significant lower than that in the normal controls (P<0.05)., Conclusion: The cytolysis function of human NK cells is mediated partially by CD160 molecule. The decrease of CD160 expression on NK cells from patients with various hematological malignancies implies that down-regulation of CD160 expression may be a novel mechanism of tumor immune escape.

Objective: To establish a novel method for ex vivo expansion of natural killer cells from human umbilical blood, so as to provide the basis for NK cell therapy., Methods: Mononucleated cells from human umbilical blood were harvested and suspended in a serum-free medium containing 5% autologous plasma, recombinant human IL-15 (50 ng/ml) and hydrocortisone sodium succinate (5×10 -8 mol/L) at a concentration of 1.5×10 6 /ml, then the cells were seeded into flasks pre-coated with heparin sodium (100 U/cm 2 ) or/and anti-human CD16 antibody (1 µg/cm 2 ). After culture for 2 weeks, the cells were harvested and counted. Ratios of CD3 - /CD56 + of the cells were determined by flow cytometry. MTT test was performed to assess the cytotoxicity against K562 cells with graded ratios of effector/target cells., Results: In contrast to the cells in flasks without pre-coating, the attached colonies appeared predominantly within 1 week of culture from heparin- and antibody-coated groups. The cell numbers from the pre-coated groups were significantly higher than that of uncoated one after culture for 2 weeks. Furthermore, the ratios of CD3 - /CD56 + cells were much higher in pre-coated groups, and that of the cells from flasks pre-coated with heparin and antibody were the highest (all the P values <0.01). MTT test showed that the cytotoxic activity of the cells stimulated by precoating were much more potent than that of the cells without the stimulation., Conclusion: Advantageous expansion of NK cells can be achieved by precoating with heparin and anti-CD16 antibody, and also by supplement with IL-15 and hydrocortisone into the media, so the umbilical NK cells with high purity and potent cytotoxicity can be obtained.

Objective: To investigate the allo-NK cell-mediated killing effect enhanced by decitabine on leukemia stem cells(LSC) and the underlying mechanisms., Methods: LSC were separated from KG1a cells by using immunomagnetic beads. Allo-NK cells were isolated and purified from PBMC of healthy donors. Cytotoxicity of allo-NK cells against LSC were measured by LDH releasing assay. The apoptosis induced by allo-NK cells in LSC and the expressions of NKG2D ligands including MICA/B and ULBP1-3 on LSC were detected by flow cytometry., Results: The killing rate of allo-NK cells to LSC treated with 10 µmol/L decitabine for 24 hours was significant higher than that to LSC without treatment(60.52%±3.52% vs 22.08%±2.07%, 73.93%±2.33% vs 28. 99%±3.13%, 83.08%±1.32% vs 36.44%±2.40%, respectively)at the effector-target ratios of 5:1, 10:1, 20:1 (P<0.05). At the effector-target ratio of 10:1, decitabine significantly enhanced the apoptosis of LSC induced by allo-NK cells (7.84%±0.34% vs 3.33%±0.64%)(P<0.05). The expressions of NKG2D ligands(MICA/B,ULBP1,ULBP2,ULBP3) on LSC treated with decitabine 10 µmol/L for 24 hours were significantly increased (P<0.05)., Conclusion: Decitabine may enhance the allo-NK cell-mediated killing effects on LSC by up-regulation of the expressions of NKG2D ligands on LSC.

Objective: To compare the cytotoxicity of ex vivo expanded NK cells detected by flow cytometry with 3 different staining methods., Methods: NK cells were collected from peripheral blood on the 17 th day after culture. The cultured cells were divided into 3 groups: group A , B, and C. The cells in group A were stained with CFSE/Annectin-V/7-AAD; the cells in group B were stained with Annectin-V/PI, and the cells in group C cells were stained with CFSE/PI. The E:T ratios in 3 groups were 10:1, 20:1 and 40:1, respectively, the K562 cells were incubated with NK cells for 4 hrs., Results: The purity of NK cells(CD3 - CD56 + ) reached to (16.34±10.51)% on day 0 and to (83.63±10.63)% on the day 17 after incubation(P<0.05); the cytotoxicity of group A was significantly higher than thay of group B at different E:T ratio (P<0.05). The cytotoxicities in A, B, C groups at E:T ratio=10:1 were (36.56±3.69)%, (10.85±2.09)% and (22.35±2.71)% respectively; the cytotoxicities in A, B, C groups at E:T ratio=9:1 were (47.83±5.52)%, (39.07±5.55)% and (29.61±4.81)%; the cytotoxicities in A, B, C groups at E:T ratio=40:1 were (67.7±4.77)%, (51.51±4.43)% and (44.12±5.62)% respectively. Meanwhile, the cytotoxicity in group A was significantly higher than that in group C at different E:T ratio (P<0.05), the percentage of cytotoxicity was (36.56±3.69)% vs (10.85±2.09)%, (47.83±5.52)% vs (29.61±4.81)%, (67.7±4.77)% vs (44.12±5.62)%, respectively., Conclusion: CFSE/Annectin-V/7-AAD is able to clearly show human NK cell cytotoxicity against human tumors. Moreover, this staining technique also allows to distinguish different stages of cytotoxic killing as early and late apoptotic phase.

Objective To evaluate the effects of cryopreservation on the proliferation and killing activity of lymphocytes, and explore a novel protocol of preparing autologous mouse cytotoxic T lymphocytes (CTLs). Methods Mononuclear cells derived from spleen (5.0×10 6 /mL) were cryopreserved in CELLBANKER2 for 6 days and recovered in water bath at 39DegreesCelsius. The fresh lymphocytes and post-cryopreservation lymphocytes were induced by CD3 mAb (100 ng/mL) and recombinant mouse interleukin 2 (rmIL-2, 100 ng/mL) to obtain cytokine-induced killer cells (CIKs). Dendritic cells (DCs) were co-cultured with fresh allogenic lymphocytes and post-cryopreservation autologous lymphocytes to obtain CTLs. The viable cells were counted by trypan blue staining; the percentages of CD3 + T cells and regulatory T cells (Tregs) were determined by flow cytometry; the levels of supernatant IFN-γ were detected through ELISA and the cytotoxicity was evaluated by lactate dehydrogenase (LDH) assay. Results The rate of viable lymphocytes declined to 78% after cryopreservation, and there were no significant differences in the percentages of CD3 + T cells and Tregs between pre-cryopreservation and post-cryopreservation. There were no significant differences in the proliferation of Tregs, the level of IFN-γ and the cytotoxicity between the fresh CIKs and cryopreservation CIKs, and the similar results were get between the autologous CTLs and allogenic CTLs. Conclusion The autologous CTLs acquired via cryopreservation of lymphocytes is equivalent to the allogenic CTLs with the similar proliferation and killing activity in vitro.

Objective: To study transfection efficiency of Ad5F11p-GFP and its influence on biological characteristics of CIK and NK-92 cells in order to predict the application of Ad5F11p vector in immunotherapy., Methods: Two kinds of immune cells, cytokine-induced killer (CIK) cells and natural-killer (NK) cell line NK-92 cells, were transfected by Ad5F11p-GFP at different multiplicity of transfection (MOI), and untransfected immune cells were used as negative control. GFP expression was determined by flow cytometry, the cell morphology was observed with microscope, the cell proliferation was analyzed by trypan blue staining, specific cytotoxicity of NK-92 cells was determined by LDH assay., Results: About 90% of transfection efficiency for NK-92 cells could be achieved at a MOI of 25, while the transfection efficiency for CIK was less than 40% at a MOI of 200. In addition, the transfection efficiency basically unchanged at the same MOI for 48 h and 96 h, and the immune cells transfected with the virus trended to form agglomeration, displaying slower proliferation, increase of IFN-γ release and enhancement of tumor killing activity., Conclusion: Ad5F11p- modified NK-92 shows a good prospect for adoptive immunotherapy.

Objective: To observe the effect of intraperitoneal injection of Newcastle disease virus (NDV) on tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) expression in mouse spleen NK cells and NK cells-mediated tumoricidal activity against mouse Novikoff hepatoma cell line, and explore the role of interferon (IFN)-γ in NDV-induced TRAIL expression and tumoricidal activity., Methods: NDV was injected intraperitoneally to BALB/c mice and IFN-γ receptor-deficient (IFN-γR-/-) B6.129S7 mice. Twelve hours after injection, the concentration of IFN-γ in peripheral blood from BALB/c mice was determined by ELISA. Mouse spleen NK cells were separated. The mRNA and protein expression of TRAIL in NK cells were detected through reverse transcription PCR (RT-PCR) and Western blotting. Lactate dehydrogenase (LDH) release assay was used to determine the cytotoxic activity of NK cells against mouse hepatoma cells., Results: NDV injection increased the IFN-γ concentration in peripheral blood of BALB/c mice, induced up-regulation of TRAIL at the mRNA and protein levels in mouse spleen NK cells, and enhanced the killing ability of mouse spleen NK cells towards Novikoff hepatoma cells. Blocking TRAIL by neutralizing antibody suppressed the cytotoxic activity of NK cells against Novikoff hepatoma cells. Furthermore, NDV injection in IFN-γR-/- B6.129S7 mice did not make significant difference from control group in TRAIL expression in spleen NK cells, and the tumoricidal activity of IFN-γR-/- B6.129S7 mouse spleen NK cells against Novikoff hepatoma cells was significantly lower than that of BALB/c mouse NK cells., Conclusion: Intraperitoneal injection with NDV could enhance tumoricidal activity of mouse spleen NK cells in vitro, and one of the mechanisms might be that NDV injection up-regulates TRAIL expression in NK cells through the IFN-γ receptor pathway.

In order to enhance the antitumor efficacy of recombinant Newcastle disease virus, rNDV-IL15 was rescued in this study. Recombinant plasmid prNDV-IL15 was constructed, and BHK21 cells were transfected with the recombinant plasmid. Finally, the recombinant Newcastle disease virus rNDV-IL15 was successfully rescued. The growth curves of these two recombinant viruses were determined. Murine melanoma B16F10 cells were infected with rNDV-IL15 at MOI of 0.1, and the expression level of IL15 in the supernatant was detected by ELISA. The antitumor efficacy of rNDV-IL15 and rNDV was compared in vitro and in vivo. Results showed that prNDV-IL15 was constructed and recombinant virus rNDV-IL15 was successfully rescued. The growth curve of rNDV-IL15 showed that the growth of rNDV-IL15 had not been changed after insertion of IL15 gene. Results showed that there was high level of IL15 expression in the supernatant of rNDV-IL5-infected B16F10 cells (1 044.3 +/- 27.7 ng x mL(-1)). rNDV-IL15 and rNDV significantly inhibited the growth of B16F10 cells in vitro in a time-dependent manner. However, there was no significant difference between them. In animal experiments, rNDV-IL15 efficiently suppressed tumor growth in vivo when compared with rNDV, and the difference was statistically significant. The results suggested that rNDV-IL15 is a more effective antitumor agent.

This study was aimed to investigate the cytotoxic effect of the Naja Naja Actra Venom Component (NNAVC) combined with activated immune cells on human acute myeloblastic leukemia line KG1a cells. The cytotoxic effects of NNAVC at different concentrations on KG1a cells were measured by CCK-8 method. LDH releasing assay was used to detect the cytotoxic effects of activated immune cells, NNAVC combined with activated immune cells on KG1a cells and the sensitivity of KG1a treated with NNAVC to activated immune cells. The results showed that the inhibitory rate of NNAVC on KG1a cells increased with the concentration enhancement, the cytotoxicity of activated immune cells at the different effector to target (E:T) ratios(6.25:1, 12.5:1, 25:1) on KG1a cells were 12.30%, 24.85% and 52.26%. The cytotoxicity of NNAVC combined with activated immune cells at the different E:T cell ratios (10:1, 20: 1) on KG1a cells were 56.21% and 85.59%, which were higher than that of NNAVC or activated immune cells alone. The cytotoxicity of activated immune cells at the E: T cell ratio of 10:1 on KG1a cells treated with NNAVC at different concentrations were 25.65%, 31.33%, 28.63% and 16.78%, respectively, and that at the E:T cell ratio of 20: 1 were 40.62%, 44.70%, 44.62% and 40.72%. It is concluded that:both of NNAVC and activated immune cells have lethal effect on KG1a cells, and the combination of NNAVC and activated immune cells can strengthen their effect on KG1a.

Objective: To investigate the cytotoxic effect of γδ T cells from osteosarcoma patients against interferon-γ (IFN-γ)-treated osteosarcoma cells in vitro., Methods: Human γδ T cells were amplified by zoledronate from peripheral blood cells of osteosarcoma patients. The expression of Fas on the osteosarcoma cells were measured by flow cytometry and quantitative real-time PCR analysis before and after IFN-γ treatment. The cytotoxicity of γδ T cells against osteosarcoma cells was evaluated with LDH assay., Results: IFN-γ significantly enhanced the susceptibility of the osteosarcoma cell lines HOS and U2OS to the cytotoxicity of γDelta; T cells from osteosarcoma patients (P<0.01). IFN-γ obviously up-regulated the expression of Fas in HOS and U2OS cells (P<0.01). Anti-FasL mAb failed to inhibit the cytotoxicity of γδ T cells in untreated osteosarcoma targets (P>0.05), but significantly impaired γδ T cell cytotoxicity in IFN-γ pre-treated osteosarcoma targets (P<0.01)., Conclusion: IFN-γ can enhance the cytotoxic effect of human γδ T cells from osteosarcoma patients against osteosarcoma cells in vitro.

Objective: To investigate the effects and the related immunological mechanisms of dendritic cells (DCs) modified by SOCS1siRNA gene and IL-12 gene on activating and inducing cytotoxic T lymphocyte (CTL) as well as specific immune critically killing laryngocarcinoma in vitro., Method: DCs were derived from human peripheral blood mononuclear cells (hPBMC), modified by recombinant SOCSlsiRNA adenoviral and IL-12 adenoviral and then pulsed with tumor antigen of repeated freeze-thaw method. The IL-12 and IFN-y levels in culture supernatant of DCs and CTILs were examined by ELISA., Result: DC were cultivated successfully and had special morphologic haracteristicistics. The rate of Ad-GFP carrying fluorescent expression was over 90%. The expression of SOCS1 protein in DCs were effectively decreased by being modified SOCSlsiRNA and IL-12 genetic while the expression of IL-12 protein were increased. The secretion rate of IL-12 factor was higher than that of SOCSlsiRNA and IL-12 transfection of single gene respectively in modified DCs which could prompt T cell proliferation activation significantly as well. IFN-y was secreted constantly in DC and CTL, resulting in Hep-2., Conclusion: DC modified by SOCSlsiRNA and IL-12 gene which pulsed with laryngeal carcinoma antigen could increased the production of IL-12 and IFN-y; DC modified by SOCSlsiRNA and IL-12 gene which pulsed with laryngeal carcinoma antigen could enhance the ability to stimulate proliferation of T cell, increase production of IFN-y, IL-12 by T cells and induce the stronger killing rate of CTL.

Aim: To study the mechanism underlying the IL-12-induced cytotoxic function of NK cells to Jurkat cells., Methods: NK cells from peripheral blood mononuclear cells (PBMCs) were purified by magnetic sorting and stimulated with or without IL-12. The expression of genes on IL-12-treated and non-IL-12-treated NK cells was analyzed by gene chips and the expression of cytolytic molecules was evaluated by flow cytometry., Results: Seventeen genes were up- (5/17) or down-regulated (12/17) on IL-12-treated NK cells compared with non-IL-12-treated NK cells (fold change≥10). IL-12-induced expression of TRAIL on NK cells mediated the cytotoxicity to Jurkat cells. The expression of TRAIL on subsets of CD56(+);CD16(+); and CD56(-);CD16(+); NK cells significantly increased after the stimulation with IL-12 and Jurkat cells expressed high level of TRAIL receptor 2 (TRAIL-R2). Importantly, the neutralizing mAbs against TRAIL (RIK-2) significantly inhibited the cytotoxicity of NK cells induced by IL-12., Conclusion: The expression of TRAIL on human NK cells induced by IL-12 was one of the major mechanisms of cytotoxicity to Jurkat cells.

Objective: To investigate the apoptosis of NK cells induced by the erythroleukemia cell line K562 in vitro., Methods: Primary NK cells isolated from the peripheral blood of healthy donors by magnetic-activated cell sorting were cultured with stem cell medium containing recombinant human interleukin-2 (rhIL-2). The NK cells and K562 cells were mixed and co-cultured at different E:T ratios for different time lengths. The apoptosis of NK cells and K562 cells were detected using PE-AnnexinV/7-AAD labeling and flow cytometry., Results: The purity of isolated NK cells reached (93.99∓4.22)%. At the same E: T ratio, the apoptotic rate of NK cells induced by K562 cells increased significantly with time. As the E:T ratio reduced, the apoptotic rate of the NK cells increased and their cytotoxic activity against K562 cells was attenuated., Conclusion: K562 cells can induce the apoptosis of activated NK cells, which is one of the probable mechanisms of immune escape of tumors.

Objective: To assess the immunotoxicologic effects of genetically modified drought resistant wheat T349 with GmDREB1 gene., Methods: A total of 250 female BALB/c mice (6-8 week-old, weight 18-22 g) were divided into five large groups (50 mice for each large group) by body weight randomly. In each large group, the mice were divided into five groups (10 mice for each group) by body weight randomly, which were set as negative control group, common wheat group, parental wheat group, genetically modified wheat group and cyclophosphamide positive control group, respectively. Mice in negative control and positive control group were fed with feedstuff AIN-93G, mice in common wheat group, non-genetically modified parental wheat group and genetically modified wheat group were fed with feedstuffs added corresponding wheat (proportion up to 76%) for 30 days, then body weight, organ coefficient of spleen and thymus, peripheral blood lymphocytes phenotyping, serum cytokine, serum immunoglobulin, antibody plaque-forming cell (PFC), serum 50% hemolytic value (HC50), mitogen-induced splenocyte proliferation, delayed-type hypersensitivity (DTH) reaction and phagocytic activities of phagocytes were detected respectively., Results: After 30 days raise, among negative control group, common wheat group, non-genetically modified parental wheat group, genetically modified wheat group and cyclophosphamide positive control group, mice body weight were (21.0±0.3), (20.4±0.7), (21.1±1.0), (21.1±1.0), (19.4±1.0) g, respectively (F=7.47, P<0.01); organ coefficient of spleen were (0.407±0.047)%, (0.390±0.028)%, (0.402±0.042)%, (0.421±0.041)%, (0.304±0.048)%, respectively (F=12.41, P<0.01); organ coefficient of thymus were (0.234±0.032)%, (0.246±0.028)%, (0.249±0.040)%, (0.234±0.034)%, (0.185±0.039)%, respectively (F=5.58, P<0.01); the percentage of T cell in peripheral blood were (70.43±4.44)%, (68.33±5.37)%, (73.04±2.68)%, (74.42±2.86)%, (90.42±1.66)%, respectively (F=57.51, P<0.01); the percentage of B cell were (13.89±3.19)%, (15.34±4.84)%, (13.06±4.22)%, (12.93±2.36)%, (3.01±0.96)%, respectively (F=12.79, P<0.01); the percentage of Th cell were (55.87±3.80)%, (55.24±4.60)%, (57.92±3.70)%, (59.57±2.54)%, (77.37±2.31)%, respectively (F=68.58, P<0.01);the Th/Ts ratio were 4.16±0.29, 4.73±0.96, 4.19±0.78, 4.52±0.40, 6.34±0.73, respectively (F=17.57, P<0.01);the serum IgG were (1046.38±210.67), (1065.49±297.22), (1517.73±299.52), (1576.67±241.92), (1155.88±167.05) µg/ml, respectively (F=10.53, P<0.01); the serum IgM were (333.83±18.97), (327.73±27.72), (367.47±27.18), (363.42±46.14), (278.71±24.42) µg/ml, respectively (F=12.11, P<0.01); the serum IgA were (51.69±10.10), (42.40 ± 8.35), (32.11±4.22), (37.12±4.90), (41.45±8.89) µg/ml, respectively (F=8.25, P<0.01); the PFC were (29.2±14.6), (28.0±20.0), (34.8±30.9), (33.2±25.1), (4.8±5.3) per 10(6) splenocyte, respectively (F=3.33, P<0.05); the HC50 were 82.3±6.5, 79.7±4.6, 75.8±4.1, 74.9±3.6, 70.8±2.1, respectively (F=9.99, P<0.01);the LPS-induced splenocyte proliferation were 0.21±0.10, 0.21±0.14, 0.26±0.12, 0.25±0.14, 0.07±0.06, respectively (F=4.18, P<0.05)., Conclusion: The genetically modified drought-resistant wheat T349 was substantially equivalent to parental wheat in the effects on immune organs and immunologic functions of mice, and it didn't show immunotoxicity.

Objective: To establish a novel flow cytometry-based assay for measuring the expression of lysosomal-associated membrane protein 1 (LAMP-1, CD107α) on the cell surface of natural killer (NK) cells and cytotoxic T lymphocyte (CTL) and evaluate the screening value of this assay for cytotoxic defects-related diseases such as familial hemophagocytic lymphopro-liferative (FHL) syndrome., Method: Three suspected Chediak-Higashi Syndrome (CHS) patients, three suspected FHL patients and 10 healthy children were enrolled in the study from October 2010 to June 2011. Their PBMCs were separated and activated overnight with IL-2. After the granule release of NK cells activated by phytohemagglutinin (PHA) and CD8+T cells by anti-CD3, the CD107α expression were analyzed by flow cytometry. The peripheral blood DNA and RNA of the patients were extracted to analyze the pathogenic genes via DNA-PCR/RT-PCR and direct sequencing., Result: The CD107α expression on CTL in the ten healthy children significantly increased after activation by anti-CD3 [(0.18 ± 0.07)% vs. (4.47 ± 2.36)%, P < 0.05] and NK cells after activation by PHA [(0.27 ± 0.07)% vs. (5.80 ± 2.83)%, P < 0.05]. The frequency of CD107α-expression NK cells in three suspected CHS after activation was significantly elevated when compared with the healthy control [0.5%, 0.6% vs. (5.80 ± 2.83)%] except patient 2. After the anti-CD3 activation, the frequency of CD107α expression on CTL cells also showed no significant difference [0.3%, 0.9%, 0.2% vs. (4.47 ± 2.36)%] in three patients. All of their mean fluorescence intensity (MFI) showed the same trend. Patient 1 and 3 were identified to have LYST mutations (Patient 1: c.5411-5414 del TTTC, L1741fsX1758 and c.7975 C > T, R2596X; Patient 3: c.4863G > A, R1563H and c.5392-5393delAA, E1739fsX1756). There was no mutation identified in the LYST gene for patient 2. CD107α expression of NK cells and CTL in the suspected FHL patients and in mirror of these findings, no underlying gene variation of PRF, MUNC13-4 and STX11 were identified., Conclusion: We developed a method to quantitatively assess cytotoxicity of the NK cells and CTL by measuring the expression of CD107α on the cell membrane, which appeared to be an effective and rapid screening test for cytotoxic defects-related diseases such as FHL and other HLH secondary to primary immunodeficiency.

Objective: To study the effect of bacillus Callmette-Guérin (BCG) on cytotxicity of cytotoxic T lymphocyte (CTL) from human peripheral blood of children with acute lymphoblastic leukemia (ALL) for killing HL-60 cells in vitro., Methods: The mononuclear cells were isolated from peripheral blood of ALL children and healthy children, and were cultured with RPMI1640, interleukin-2 (IL-2), phytohemagglutinin (PHA) and BCG.The growth of CTLs was observed by light microscopy. The proportions of CD3, CD3+CD4+ and CD3+CD8+ were determined by flow cytometry 10 days after culture. MTT method was performed to detect the cytotoxicity of CTLs for killing HL-60 cells., Results: Neither the cell number nor the volume of CTLs changed significantly within 2 days of culture, but both began increasing on the 3rd day of culture and reached a peak on the 6-10th days. On the 10th day of culture, the cell number of CTLs in the BCG treatment group was much higher than in the group without BCG treatment. The CD3+CD8+ proportion in the leukemia group was much higher than in the control group. With the effect of BCG, the CD3+CD8+ proportion of the two groups became much higher. The cytotoxicity of CTLs for killing HL-60 cells in the leukemia group was weaker than in the control group., Conclusions: BCG along with IL-2 and PHA promotes the proliferation of CTLs and enhances the ability of CTLs in killing HL-60 cells.

Objective: To investigate the effect on natural killer (NK) and cytotoxic T lymphocyte (CTL)-mediated cytotoxicity by genetic overexpression of MHC class I chain-related protein A (MICA) in oral squamous cell carcinoma (OSCC)., Methods: The OSCC cells by genetic overexpression of MICA were detected to identify the biological features including cell growth curve, cell cycle distribution, plate clone forming rate and tumorigenicity in nude mice. The expression of natural killer group 2, member D (NKG2D) receptor and the cytotoxicity to target tumor cells of NK92 and CTL cells, which co-cultured with the transfected OSCC cells or the non-transfected or blank vector-transfected controls, were measured by flow cytometry and lactate dehydrogenase (LDH) release assay., Results: There was no difference in biological features before and after MICA gene transfection to OSCC cells. Flow cytometry and LDH release assay showed that MICA-overexpressed OSCC cells enhanced the cytotoxicity to target tumor cells and up-regulated the expression of NKG2D on NK92 and CTL (P<0.05)., Conclusion: MICA may be considered as a promising immunotherapy target of OSCC.

As the leading cause of cancer-related death among human beings, lung cancer seriously threats peoples' health all over the world. Cytokine-induced killer cells (CIK) is a new kind of adaptive immune cells characterized by its dramatic proliferation ability and cytotoxicity, non-major histocompatibility antigens (MHC) restriction and low side effects, which draw an increasing attention in recent years. The review is to introduce the basic features and mechanism of CIK cells briefly and summarize the researches of CIK cells used in the clinical therapy for lung cancer. Finally, we discuss several problems that should be addressed before CIK cells are widely applied to clinical patients.

Natural killer (NK) cells are important innate immune effector cells with broad applications in killing the tumor cells and pathogens due to its cytotoxicity without prior immune sensitization. Unfortunately, in humans, the activity of NK cells against fungi is poorly characterized. Insight progress in the fields of NK cells activating, pattern recognition receptors, signal modulating and correlated cell factors (IFN-γ, GM-CSF, IL-10 and so on) has revolutionized understanding of the selective killing fungi by NK cells. Different morphotypes also can affect the immune status of NK cells. This article reviews the mechanism of fungi immune reaction, and the interaction between NK cells and fungi, and provides some new ideas for further study on pathogenesis of fungus and other infectious diseases and NK cell adoptively transferred immunotherapy.

This study was aimed to investigate the expression level of perforin in cord blood NK cells and the relation of perforin expression after IL-2, IL-15 stimulation to cytotoxicity of NK cells. NK cells were isolated from cord blood MNC by depleting CD3(+) cells and then enriching CD56(+) cells using immunomagnetic separation (CD3 and CD56 cell isolation kit, autoMACS, miltenyi). The purity was analysed by flow cytometry. According to the different combination of cytokines, there were two groups: group A (IL-2) and group B (IL-2 + IL-15). The cytotoxicity and perforin expression rate of fresh and different cultured CB-NK cells against K562/Jurkat cell lines were estimated by LDH release test (cytotoxic 96 non-radioactive cytotoxicity assay). The results showed that the purity of NK cells after separation was more than 90%. The cytotoxicity towards both tumor lines in group B was higher than that in group A (p < 0.05), and cytotoxicity in group A was higher than that of fresh NK cells (p < 0.05). Perforin expression rate of group A (84.55%) was higher than that of fresh NK cells (67.21%) (p < 0.05), and there was no significant difference between group A and B (84.55% versus 87.22%) Cytotoxic activity of CB-NK cells was positively correlated with perforin expression rate (r = 0.886, p < 0.05). It is concluded that IL-2 can enhance cytotoxicity of CB/BM-NK cells by increasing the perforin expression.

Aim: To study the antigen specific anti-tumor effect of cytotoxic T lymphocytes(CTLs), which was induced by human telomerase reverse transcriptase (hTERT)-related multiple epitope peptides impulsed myeloid dendritic cells(mDCs), against human leukocyte antigen (HLA)-A24(+) tumor cells., Methods: Four branches of multiple antigen peptides (MAPs) of hTERT epitopes and three separate peptides were solid-phase artificially synthesized, phlebotomize peripheral blood from HLA-A24(+) healthy volunteers, sorted the blood through MACS MicroBeads and cultured mDCs, Nylon fiber column purified T lymphocytes, mDCs impulsed with each type of peptides were co-cultured with T lymphocytes to induce CTLs specifically killing effect, and the resultant CTLs were used as effector cells, SMMC-7721 with hTERT and HLA-A24 positive and SKOV3 which are hTERT-positive but HLA-A24-negative tumor cells were used as target cells. The level of human IL-12, TNF-α in the culture supernatant was determined by ELISA. Flow cytometry assay was used to assess the killing ability of CTLs against tumor cells., Results: MAPs of hTERT epitopes including I540 (ILAKFLHWL), V461 (VYGFVRACL), L766 (LTDLQPYMRQFVAHL) and three separate peptides could impulse mDCs and then induce CTLs to specifically kill SMMC-7721, CTLs induced by MAPs had stronger cytotoxic effect compared with three separate peptides mixed(P < 0.05)., Conclusion: mDCs-impulsed with hTERT-associated MAPs can induce production and proliferation of allogenic CTLs, which show antigen specific anti-tumor effect against HLA-A24(+) tumor cells. This result has significantly meaning in tumor immunotherapy.

Objective: The aim of this study is to explore the cytotoxic effect of CD8+ T subsets in peripheral blood with chronic hepatitis B subjects who are at immune tolerance phase and immune clearance phase (before and after three months' treatment with interferon-alpha), further to investigate their impact in the pathogenesis of chronic hepatitis B and antiviral therapy., Methods: The subjects of chronic hepatitis B, including 20 subjects of immune tolerance phase and 20 subjects of immune clearance phase, are enrolled in the study. And we use flow cytometry to detect Lysosome-associated membrane protein-1 (LAMP-1, CD107a) and Granzyme B (GrB) expression of CD8(high) and CD8(low) T cells in peripheral blood with chronic hepatitis B subjects., Results: (1) At immune clearance phase, the CD8+ T subsets expressing GrB and CD107a are higher than counterpart of immune tolerance phase. (2) At immune tolerance phase and immune clearance phase in HBV infection, the CD8(low) T cells expressing GrB and CD107a are higher than that of CD8(high) T cells. (3) After three months' treatment with interferon-a, except for GrB+ CD107a+ CD8(high) T cells, CD8(high) T cells expressing GrB and CD107a present a tendency of ascensus at the same time with that of CD8(low) T cells a tendency of descensus except for GrB(-)CD107a+ CD8(low) T cells. (4) The CD8+ T cell expressing GrB and CD107a, correlate positively with HBV DNA load at immune tolerance phase, but correlated negatively at immune clearance phase., Conclusions: (1) GrB and CD107a molecule expressed by different CD8+ T cell subsets play an important role in disease evolution and antivirus therapy of chronic hepatitis B, the cytotoxic effect of CD8(high) T cell subset became more and more stronger during the treatment of IFN-alpha, and the cytotoxic effect of CD8(low) T cell subset couldn't be neglected before antivirus therapy. (2) To some degree, the correlation between HBV-DNA load and the expression of GrB and CD107a at different CD8+ T cell subsets, could hint the relationship between virus and immune response.

Objective: The efficiency of antitumor immunity induced by dendritic cells (DCs) transfected with total RNA of laryngeal carcinoma cells was explored., Method: DCs, induced from human peripheral blood mononuclear cells, were transfected with total RNA of laryngeal carcinoma cells. The specific antitumor immunity of cytotoxic T Lymphocytes (CTLs) that were actived by RNA-transfected DCs were detected by MTT methods in vitro. In vivo, antitumor-specific CTLs were subcutaneously injected into the nude mice previously. After 7 days, the laryngeal carcinoma cells were seeded and the tumor occurrence rate was observed. Tumor-loaded nude mice were treated by specific CTLs once (the treated group) or twice (the retreated group). The growth of the implanted tumor was observed too., Result: DCs that transfected with tumor RNA can significantly active CTLs which induced antitumor-specific immune response against laryngeal carcinoma in vitro. In vivo, the tumor occurrence rate of the treatment group was predominantly reduced compared with that of the control (P < 0.01). The implanted tumor size of the treated and retreated groups were both significantly reduced (P < 0.05, P < 0.01) compared with the control too, especially the retreated ones (P < 0.05)., Conclusion: The tumor RNA loaded DCs can significantly active CTLs and the antitumor specific CTLs can both induce antitumor specific immune response against laryngeal carcinoma in vitro and inhibit the growth of the implanted tumor in vivo.

Objective: To investigate the influence of mutual interactions between FasL expressed by colon carcinoma cells and endogenous cytokines interleukin-18 on liver metastasis and invasion of human colon cancer cells., Methods: Using immunohistochemical streptavidin-biotin complex (SABC) method, the expressions of Fas receptor and Fas ligand in SW620 colon carcinoma cells and Chang liver cells were observed so as to provide morphological evidence for the functions of Fas receptor and Fas ligand. In an effort to examine the cytotoxicity of effector cells, CytoTox(96) Non-Radioactive Cytotoxicity Assay was adopted to measure the LDH releasing value after the SW620 cells were co-cultured with Chang liver cells., Results: It was shown that the Fas ligand of colon carcinoma SW620 cells was positive and the positive substances were distributed in the cell membrane and cytoplasm, and the Fas receptor of colon carcinoma SW620 cells was negative. The Fas receptor of Chang liver cells turned out to be positive and the positive substances were distributed in the cell membrane, and the Fas ligand of Chang liver cells was negative. At 6 hours after co-culture of IFN-γ-stimulated Chang liver cells with interleukin-18-stimulated (for 36 h) SW620 cells or unstimulated SW620 cells, the cytotoxicity of SW620 cells to IFN-stimulated Chang liver cells at effector-to-target ratios of 10:1, 5:1, 2.5:1 and 1.25:1 was 68.3%, 49.8%, 21.1%, 9.7% (F = 76.87, P < 0.05) and 32.7%, 21.8%, 11.1%, 6.7% (F = 7.27, P < 0.05), respectively. The non-radioactive cytotoxicity assay showed that the apoptotic rate of Chang liver cells was remarkably increased with the increase of planting concentration of SW620 after the SW620 cells were co-cultured with Chang liver cells. The cytotoxicity was significantly enhanced by interleukin-18., Conclusion: The FasL expression of human colon cancer cells may be regulated by endogenous interleukin-18 in the host microenvironment and enhance the liver colonization competence of colon cancer cells through induction of apoptosis in the Fas-expressing hepatocytes.

Objective: To investigate if granulocyte-macrophage colony stimulating factor (GM-CSF) gene-modified dendritic cells (DC) enhance antitumor immunity in vitro., Methods: Mice were injected with chemokine ligand 3 (CCL3) via the tail vein. Fresh B220(-)CD11c(+) cells were sorted from the peripheral blood mononuclear cells (PBMCs) and cultured into DCs by cytokines.DCs were transfected with AdGM-CSF gene at different ratios of multiplicity of infection (MOI) to determine the optimal gene transfection conditions, and the expression of GM-CSF was detected after transfection. The variation of GM-CSF gene-modifiedDCs were analyzed by morphological examination, phenotype analysis, and mixed lymphocyte reaction (MLR).DCs were loaded with gastric cancer antigen obtained by freezing and thawing method. The killing effect of DCs vaccine-stimulated T lymphocytes on gastric cancer cells was assessed by MTT assay. INF-gamma production was determined with the INF-gamma ELISA kit., Results: B220(-)CD11c(+) cells increased obviously after CCL3 injection. The ELISA results showed that after GM-CSF gene modification, DCs could produce high level of GM-CSF. When DCs were transfected with AdGM-CSF gene at MOI equal to 100, the GM-CSF level in culture supernatants reached saturation [(130.00 +/- 12.61) pg/ml]. After GM-CSF gene-modification, DCs tend to be more maturated as detected by morphological observation and phenotype analysis. At the same time, the capacity of activating the proliferation of allogeneic T lymphocytes was enhanced greatly. T lymphocytes stimulated by DCs transfected with GM-CSF gene showed a specific killing effect on gastric carcinoma cells and produced high level of INF-gamma [(1245.00 +/- 13.75) pg/ml]., Conclusion: After GM-CSF gene modification, DCs can produce high level of GM-CSF, which tend to be more maturated, and the capacity of activating the proliferation of allogeneic T lymphocytes is enhanced greatly. GM-CSF gene modified DCs can induce specific CTL to target tumor cells in vitro.

Objectives: To compare the in vitro killing effects of cytotoxic T lymphocytes (CTLs) induced by dendritic cells(DCs) that modified with 4 different specific hAFP-derived peptides., Methods: DCs derived from normal human peripheral monocytes were activated by GM-CSF and IL-4. MTT assay was applied to analyse the proliferation activities of the DCs. To induce the specific CTLs, DCs modified with four immunodominant epitopes from alpha fetoprotein (AFP) were cocultured with MNC derived CD8+ lymphocytes. The acquired specific CTLs were cocultured with SMMC-7721 cells at different dilutions, and the killing effects were detected by flow-cytometry and Non-Radioactive Cytotoxity kit., Results: The CTLs stimulated by DCs modified with the four immunodominant epitopes from alpha fetoprotein (AFP) had specific killing activities on the SMMC-7721 cells. And statistical differences of the killing effects existed between the hAFP(158-166) (FMNKFIYEI) group and the other three groups., Conclusion: CTLs induced by the DCs modified with the four immunodominant peptides had significant killing effects on the hepatocellular cancer cells in vitro. The hAFP(158-166) (FMNKFIYEI) peptide had a relatively higher efficiency in inducing DCs and stimulating specific CTLs.

Objective: Dendritic cell vaccines are one of the important active immunotherapies for neoplasms. The aim of this study was to observe the killing effect of specific cytotoxic T lymphocytes (CTL) on liver carcinoma HepG2 and SMMC-7721 cells in vitro. The CTL was induced by human peripheral blood mononuclear cells-originated dendritic cells (DC) transfected by recombinant adeno-associated virus (rAAV) with hAFP gene fragment (137-145)., Methods: Immature DCs were generated from peripheral blood mononuclear cells of healthy volunteers and then transfected by rAAV with AFP gene fragment. The CTL was thereafter induced. The activities of DC and CTL were measured and the killing effect of the CTL on HepG2 cells was detected using M1Tr assay., Results: The mature DC, transfected or not, highly expressed CD40, CD86 and IL-12. IFN-gamma was highly expressed in the CTL. The DC-induced CTL could effectively recognize and destroy the HepG2 and SMMC-7721 cells., Conclusion: DC transfected by rAAV can stimulate the proliferation and differentiation of lymphocytes and also induce the proliferation of CTL, and their own phenotypes are not significantly altered. The DC vaccine can be effectively used as an adjuvant immunotherapy for patients with hepatocellular carcinoma.

Objective: To prepare a vaccine of IL-12-anchored exosomes derived from renal cancer cells and to evaluate its antitumor effect in vitro., Methods: A mammalian co-expression plasmid of glycolipid-anchor-IL-12 (GPI-IL-12) was constructed by subcloning IL-12A chain gene (P35 subunit) and a fusion gene containing GPI-anchor signal sequence and IL-12B chain gene (P40 subunit) in pBudCE4.1. Confocal laser scanning microscopy and flow cytometry were used to analyze the expression of the fusion proteins. Transmission electron microscopy and Western blot were used to identify the morphology and characteristic molecules of exosomes separated by ultrafiltration and sucrose gradient centrifugation. The function of IL-12-anchored exosomes was determined by IFN-gamma release assay., Results: Mammalian co-expression plasmids were successfully constructed. Confocal laser scanning microscopy and flow cytometric analysis of the RC-2-GPI-IL-12 transfectants showed the expression of IL-12 on the cell surface. Exosomes were purified by ultrafiltration and sucrose gradient centrifugation, which were 30-80 nm in diameter, typically saucer-shaped, and expressing HSP70, ICAM-1, G250 and GPI-IL-12. (80.0 +/- 9.6) pg/ml of IL-12 was detected in 10 microg/ml exosomes and it significantly induced the release of IFN-gamma. Stimulation with EXO-IL-12 could efficiently induce antigen-specific cytotoxic T lymphocytes (CTL), resulting in more significant cytotoxic effects in vitro., Conclusion: A vaccine of exosomes-GPI-IL-12 can be obtained from the culture supernatant of renal cancer cells modified to express anchored IL-12. This vaccine expressing IL-12 and tumor associated antigen G250 may become a new strategy for the treatment of renal cancer.

Cellular immunity is an important component of human immune system and plays a crucial role in the fight against tumor cell or invasive pathogens. Researches on cell-based immunotherapy have long been focused on eliciting tumor-specific CD8+ cytotoxic T lymphocytes (CTL) because of their potent killing activity and their ability to reject transplanted organs. However, the resulting treatments have been surprisingly poor at inducing complete tumor rejection, in both the experimental models and clinical trials. The CD4+ T cells has been studied mainly for their role as helpers for CD8+ CTL, even suggesting that the tumor-specific CD4 T regulatory cells could act as suppressors of antitumor responses. Recent studies indicated that CD4+T cells are not a pure cell lineage with single function, but a cell population with complex functions. Moreover CD4+ T cells may not only be helper cells, but also act as potent effector cells or partners with NK cells that can clear a wide variety of tumors. In a word, the antitumor potential of effector CD4+ T cells might have been underestimated. In this article, the classification and differentiation of CD4+ T cells, the function and secreted cytokines of CD4+ T cells, the CD4+ T cells and tumor immune, the tumor-immuno regulatory effects of CD4+ T cells, and clinical researches of CD4+ T cells are reviewed.

Objective: To investigate the antitumor effect of recombinant IFN-alpha-2b-BCG on mouse bladder cancer MB49 cells in vitro, and to explore its antitumor mechanisms., Methods: MB49 cells were co-cultured with recombinant BCG or wild BCG, and than were examined by light and transmission electron microscopy. The cell growth was assessed by MTT assay, and apoptosis rate and MHC-I of the MB49 cells was detected by flow cytometry using AO and Hoechst33258 fluorescence immunostaining., Results: The hIFN-alpha-2b-BCG-treated tumor cells showed slow growth, detachment of some cells, and various degree of degeneration. Light microscopy revealed organelle disorganization, chromatin aggregation, nuclear pyknosis, and cytolysis in some cells. Cellular membrane bulged and some bubbles were seen under fluorescence microscope using AO staining. Hoechst33258 assay also depicted frequent apoptosis in the tumor cells. The MTT assay showed that rBCG more actively than the wild BCG inhibited the proliferation of MB49 cells. The apoptosis rate of the recombinant BCG group was 19.7% and 46.6% at the time point of 24 h and 48 h, respectively, significantly higher than 10.8% and 20.9%, respectively, in the wild BCG group. The results of flow cytometry indicated that both types of BCG enhanced the expression of MHC-I in the MB49 cells, but more effective in the recombinant BCG group., Conclusion: The recombinant hIFN-alpha-2b-BCG has more strong immuno-modulatory properties, anti-tumor effect on MB49 cells and induces apparent cytotoxicity in the bladder cancer cells in vitro.

Objective: Functional defects in NK cells have been proposed to be responsible for the impairment of anti-tumor immune responses. However, it remained unclear whether the function of NK cells were impaired in patients with hepatocellular carcinoma. To address this issue, we analyzed the frequency and function of peripheral NK cell subsets in hepatocellular carcinoma (HCC) patients., Methods: 35 HCC patients and 24 healthy controls (HC) were enrolled in the study. Peripheral NK frequency was analyzed using flow cytometry. In addition, the capacity of NK cells to produce IFN gamma and to lyse K562 cells was evaluated., Results: In contrast with the healthy controls, the frequency of peripheral NK cells in hepatocellular carcinoma patients was decreased (12.19%+/-10.85% vs 24.01%+/-8.78%, u = 4.01, probability value less than 0.01), while the frequency of CD56(bright)CD16(neg) NK cells was increased (0.62%+/-0.39% vs 0.48%+/-0.28%, u = 1.96, probability value less than 0.05), and the frequency of CD56(dim)CD16(pos) NK cells was significantly decreased (11.59%+/-7.49% vs 22.66%+/-8.84%, u = 3.92, probability value less than 0.01). In addition, peripheral NK cells from HCC patients exhibited decreased capacity to produce IFN gamma (effective cells 13.31%) and to lyse K562 cells (mixed ratio 30:1, 10:1, 1:1, effective cells 16.72%+/-7.33% vs 26.29%+/-12.36%, u = 2.52, P less than 0.05, 8.01%+/-4.40% vs 13.09%+/-5.03%, u = 3.32, probability value less than 0.05, 3.51%+/-2.82% vs 3.42%+/-1.64%, u = 1.56, probability value more than 0.05, respectively) as compared with healthy subjects., Conclusion: Anti-tumor activity of NK cells in HCC patients was impaired.

Aim: To prepare Nano-Liposome encapsulated MAGE3/HSP70(NL M3H) and study its character and antitumor immunity in mouse., Methods: NL M3H was prepared by the thin film-dispersion ultrasonic. The shape and size of NL M3H were detected by electron microscope. The encapsulation rate, drug-carrying capacity, stability and the releasing character were tested by Sephedex-G100 gel filtration. The mouse was immunized by NL M3H, and the antitumor immunity was detected by ELISPOT and LDH release assay., Results: The mean size of NL M3H was lower than 100 nm. The encapsulation rate was 38%.The drug content was 0.038 g/L. NL M3H has good stability after stored in 4 degrees C for 6 months. The releasing profile showed that 74 percent of proteins was released during the first 24 hours in saline. The results of ELISPOT and LDH release assay showed that NL M3H generated tumor specific cytotoxic T lymphocyte(CTL)to damage tumor cell., Conclusion: NL M3H has novel characters, it can generate specific CTL to kill tumor cell, and can be used as new kind of vaccine against tumor.

Aim: To study the effects of recombinant soluble MHC class I chain-related protein A (sMICA) on the cytotoxicity, secretion of IFN-gamma, proliferation and apoptosis of peripheral NK cells., Methods: After NK cells were co-cultured with recombinant soluble MICA proteins overnight, the cytotoxicity of NK cell on target cells was detected by flow cytometry. The supernant was collected to determine the concentration of IFN-gamma by ELISA. The proliferation of NK cells to sMICA was detected by MTS/PMS. NK cells were labeled with annexin V and PI to analyze their apoptosis., Results: Soluble MICA inhibited the cytotoxicity of NK cells and down-regulated the secretion of IFN-gamma, but it showed no effects on the proliferation and apoptosis of freshly isolated peripheral NK cells., Conclusion: The soluble MICA shedding from tumor cells could be a pathway of cancer immune evasion by down-regulating the biologic activities of NK cells.

The purpose of this study was to investigate the lethal effect of cytotoxic lymphocytes against U266 cells induced by DCs pulsed with multiple myeloma (MM) U266 lysate and transfected with GM-CSF recombinant adenovirus. The cytotoxic lymphocytes against U266 cells were induced by culturing with DCs, which pulsed with MM U266 antigens and transfected with GM-CSF recombinant adenovirus. The effect of cytotoxic lymphocytes against U266 cells were measured by LDH release detection. Experiments were divided into 3 groups: N-DC group as control in which DCs were normal; U-DC group in which DCs were pulsed by U266 soluble antigen, and G-U-DC group in which DCs were stimulated by U266 soluble antigen and GM-CSF transfected with Ad-CMV. The results showed that there was significant difference on killing rate against U266 cells between 3 groups (F = 10.939, p < 0.05). The killing rate of G-U-DC group was the highest (p < 0.001), and killing rate of U-DC group was higher than that of N-DC group (p < 0.001). It is concluded that the cytotoxic lymphocytes against U266 cells can be induced by DCs pulsed with U266 lysate, and the lethal effect of CTLs can be enhanced when DCs transfected by recombinant adenovirus with exogenous gene GM-CSF.

Objective: To explore the activation and proliferation of specific T cells induced by artificial antigen-presenting cells (aAPCs) simulated dendritic cells (DCs) and to observed the effect of these T cells on leukemic cell killing., Methods: aAPCs were developed by coating a human leukocyte antigen-immunoglobulin fusion protein ( HLA-lg), which was connected each one of the four CML28 antigen epitopes (DLMSSTKGL, DLMSSTKGL, ALFCGVACA, VLTFALDSV), and CD28-specific antibody, to magnet-beads CML cell specific peptides (CML28) served as target peptides. Bone marrow (BM) or peripheral blood (PB) mononuclear cells (MNCs) were isolated from HLA-A2 healthy volunteers, and co-cultured with aAPCs. Specific T lymphocyte were detected by flow cytometry. The fresh acute leukemic cells were used as target cells. The specific T cells incubated with leukemic cells for 4 h at ratios of 5:1, 10:1, 20:1, 40:1, 80: 1, respectively. The effect of leukemic cells killing was detected by lactate dehydrogenase release test., Results: The average ratio of CML-28 specific T lymphocyte in control group was (2.2 +/- 0.4)% and in experimental groups (DLMSSTKGL, DLMSSTKGL, ALFCGVACA, VLTFALDSV) were (13.5 +/- 1.6)%, (15.2 +/- 1.5)%, (14.7 +/- 1.8)% and (34.3 +/- 3.5)%, respectively, being significantly higher than that in control group (P < 0.01). Induction efficiencies of acute leukemic cells killing were significantly enhanced by increase of effector cells. The cytotoxic activity of specific T lymphocyte in one experimental group (VLTFALDSV) was much higher than that in other three experimental group (P < 0.05)., Conclusion: This "prime and expand" regimen should be an alternative method for large scale amplification of rare tumor-specific CTLs and aAPCs might be a useful tool for leukemia immunotherapy.

Objective: To explore the anti-tumor immune responses of dendritic cells (DCs) loaded with intact wild-type p53 to mice challenged with tumor cells expressing p53 genes with mutations at different sites., Methods: Ad-p53-DC immunization function was assessed by the expression of surface molecules and allogeneic MLR. DCs derived from bone marrow were transduced with adenovirus or a human wild-type p53 containing recombinant adenovirus (Ad-DC and Ad-p53-DC) and immunized C57BL/6 mice. Splenocytes were separated and cell cytotoxicity was measured against tumor cells expressing mutant p53 (MethA, D459 and P815) in a standard 6-h(51)Cr-release assay. Effector and target cells were incubated in the presence of anti-CD(4) or anti-CD(8) antibody. Ad-p53-DC was immunized in control Ad-DC before or after mice were challenged with either D459 tumor or with MethA sarcoma cells to observe whether immune response would provide tumor protection., Results: Immunization with Ad-p53-DC developed significantly higher substantial CTL responses against Ad-p53-P815, D459 and MethA cells (effectors: target cells = 50:1), (27.8 +/- 3.4)%, (23.5 +/- 2.7)%, (58.3 +/- 9.2)% than with Ad-DC (9.3 +/- 1.8)%, (4.6 +/- 1.0)%, (23.5 +/- 3.7)% (t(d) = 5.79, 3.68, 5.02, all P < 0.05). In Ad-p53-DC immunized mice, anti-CD(8) antibody blocked the cytotoxicity against Ad-p53-P815 (26.7 +/- 2.8)% or D459 (6.1 +/- 1.2)%, but not anti-CD(4) antibody [(59.8 +/- 4.6)%, (18.9 +/- 2.4)%, t(d) = 8.79 or 9.18, all P < 0.05]. Ad-p53-DC immunization provided complete tumor protection in 80% of mice challenged with D459 and in 70% of mice challenged with MethA, while none protected in Ad-DC immunization group (chi(2) = 6.72, 5.86, all P < 0.05). Treated with Ad-p53-DC after D459 inoculation subcutaneously, mice were killed due to the bulky tumor more than 2 weeks later than the mice in the Ad-DC treatment group during 7 week observation (chi(2) = 9.48, P < 0.05)., Conclusion: DCs transfected with 100 MOI Ad-p53 induced intense CTL responses against P815, D459 and MethA. This CTL response is mediated by CD(8)(+) T cells. Treatment with Ad-p53-DC significantly developed tumor immunology and slowed the growth of established tumors.

Background & Objective: Alpha-fetoprotein (AFP) is a good candidate antigen for the immunotherapy of hepatocellular carcinoma (HCC). How to overcome the immune tolerance induced by autologous antigen is one of key points for inducing effective antitumor immune reaction. This research was to investigate the effect of human AFP-derived peptide-pulsed dendritic cells (hAFP-DCs) on immunity against mouse HCC., Methods: Bone marrow-originated DCs were prepared routinely. The activity of hAFP-DC-stimulated cytotoxic T lymphocyte (CTL) against Hepa1-6 cells was examined by MTT assay. C57BL/6 mice were inoculated subcutaneously with 7 x 10(6) Hepa1-6 cells to develop hepatoma, and received intratumor injection of hAFP-DCs, DCs and PBS, respectively, twice a week. Tumor volume was evaluated and the survival of mice after inoculation was observed., Results: We successfully prepared DCs from bone marrow of mice. The cytotoxic activity of CTLs stimulated by hAFP-DCs and DCs showed stronger tendency than that of control, but without significance. The mean tumor volume at 31 days after inoculation with Hepa1-6 cells was (195.04+/-155.22) mm3 in hAFP-DCs group, (360.65+/-209.02) mm3 in DCs group and (756.19+/-503.24) mm3 in PBS group. The differences among these three groups were significant (P < 0.001). The survival rate of mice at 40 days after inoculation was 100% in hAFP-DCs group, 90% in DCs group and 50% in PBS group (P=0.008)., Conclusion: Human AFP-derived peptide-pulsed DCs can efficiently enhance immunity against HCC in mice.

Aim: To determine the expression of soluble MICA (sMICA) in serum of patients with breast tumor, and explore the roles of sMICA in immune escape., Methods: ELISA was used to examine the sMICA in peripheral blood. The expression of NKG2D were identified by Flow cytometry. The cytotoxicity of NK cells to breast cancer cells was observed with MTT assay., Results: sMICA was not detected in the serum of healthy person, but(76.8+/-22.3) ng/L in breast benign tumor patients and (205.4+/-71.3) ng/L in breast malignant tumor patients. There was positive correlation between sMICA levels and breast cancer stage. After incubation with sMICA, NK cells got decrease in cytotoxicity from (76.2+/-6.7) % to (48.4+/-4.1) % .The expression of NKG2D and secretion of IFN-gamma decreased at the same time. IL-15 up-regulated the expression of NKG2D on NK cells and increased NK cells cytotoxicity to breast cancer cells., Conclusion: sMICA level is positive correlated with breast cancer TNM stage. sMICA reduced the expression of NKG2D, impaired NK-mediated immune surveillance and led to immune escape of breast tumor. IL-15 could up-regulate the expression of NKG2D and increase NK cells cytotoxicity.

Objective: To investigate the influence of hepatitis B virus C protein on the function of natural killer cell., Methods: Recombinant eukaryotic expression plasmid pHBI-CMV-HBC was constructed and confirmed by double restrictive enzyme digestion and DNA sequencing analysis. Then the recombinant plasmid was transfected into NK-92 cells with lipofectamine encapsuled. The transfected NK-92 cells containing expressive HBV C protein was confirmed by Western Blot analysis. ELISA was employed to determine the IFN-gamma level secreted by NK-92 cells. And finally the cytotoxicities of NK cells were analysed by MTT colorimetry, with the hepatoblastoma cell line (HepG2) as target cell., Results: Western blotting confirmed the expression of HBV C protein in the NK-92 cells transfected with pHBI-CMV-HBC. NK cytotoxicities and IFN-gamma secretion level of NK-92 cells transfected with recombinant plasmid significantly increased compared to control NK-92 cells transfected with blank plasmid (P < 0.01) and untransfected NK-92 cells(P < 0.01)., Conclusion: Transient expression of HBC can increase IFN-gamma secretion and cytotoxicities of NK-92 cells.

To investigate the immunologic characteristics and cytotoxicity of the RetroNectin-activated cytokine-induced killer cells (CIK) against drug-resistant lung cancer cell lines DDP-A549 (DDP: Cisplatin). Peripheral blood mononuclear cells (PBMC) were collected from healthy donors and divided into two groups: group I and group II. Seeded samples of group I into culture flask precoated with RetroNectin and CD3MAb to induce the CIK cells while seeded the group II into culture flask precoated with CD3MAb. In both groups, IFN-gamma was put into the flask on the same day and then IL-2 on the second day. The proliferation of CIK cells was tested by cytometirc analysis. The cytotoxicity activity of CIK cells was determined by MTT assays. The phenotype changes of CIK cells were identified by flow cytometric analysis. Scanning electron microscope (SEM) and transmission electron microscope (TEM) were used to view the cytotoxicity against DDP-A549 of CIK cells and the changes of DDP-A549. The total CIK cells significantly increased by 524.77 fold in cell proliferation number due to the activation to CIK cells of RetroNectin. The expression rate of CD3+CD56+ cells was (31.40 +/- 1.91)%. The cytotoxicity of CIK cells showed statistically significance between DDP-A549 and the sensitive strains of parental generation A549 (P < 0.01). There was no significant difference of CIK cells' cytotoxicity between two groups when the effector: target ratio was fixed (P > 0.05). RetroNectin can significantly improve the proliferation activity of CIK cells. There was no evident influence to the cytotoxicity of CIK cells. CIK cells may be used as the immuotherapy to lung adenocarcinoma owing to its significant inhibition to the proliferation of DDP-A549.

Background & Objective: Suppressor of cytokine signaling 1 (SOCS1) plays a critical role in antitumor immunity. Down-regulating SOCS1 in antigen-presenting dendritic cells (DCs) could enhance antigen-specific antitumor immunity. This study was to investigate the antigen-specific antitumor effect and mechanism of DCs with siRNA-mediated inhibition of SOCS1, stimulated by OK-432 and pulsed with hepatocellular carcinoma cell line HepG2 antigens., Methods: The expression of SOCS1 in immature DCs was down-regulated by RNA interference (RNAi). DCs were pulsed with lysate of HepG2 cells and stimulated with OK-432. The morphology of DCs was observed under converted phase microscopy. Phenotypic changes in cells after stimulation were characterized by flow cytometry (FCM). The Alamar Blue assay was adopted to evaluate the activation and proliferation of autologous lymphocytes induced by mature DCs. The cytotoxicity of cytotoxic T lymphocytes (CTLs) elicited by modified DCs to HepG2, EC109 and K562 cells was tested by the lactate dehydrogenase (LDH) assay., Results: Cells displaying a typical morphology and phenotypic properties of mature DCs were obtained successfully. The expression of SOCS1 in DCs was down-regulated by SOCS1 RNAi. Mature DCs showed high expressions of CD80, CD83, CD86, and HLA-DR. Pulsing of DCs with lysate of HepG2 had no influence on the phenotypic properties of DCs. Down-regulating SOCS1 expression enhanced the maturation of DCs. The modified DC tumor vaccine stimulated the proliferation of autologous lymphocytes effectively, and the proliferation rate of T cells was (110.7+/-22.2)%. After being activated by modified DCs, TCLs exerted a specific and effective killing effect on HepG2 cells, but not on EC109 and K562 cells., Conclusion: Mature DCs could induce antigen-specific antitumor immunity against hepatocellular carcinoma after silencing of SOCS1 by siRNA, stimulation by OK-432 and pulsing of DCs with HepG2 cell antigens.