Paraquat induces apoptosis, programmed necrosis, and immune dysfunction in CIK cells via the PTEN/PI3K/AKT axis

Paraquat (PQ) is a highly water-soluble, non-selective herbicide. Due to water pollution and lack of specific medicines, it is extremely harmful to humans and aquatic animals. Oxidative stress and apoptosis can affect the immune function of the body. However, the effects and mechanisms of PQ on the immune function, apoptosis and programmed necrosis on CIK cells are still unclear. Therefore, we constructed low (L, 50 μmol/L), medium (M, 100 μmol/L), and high (H, 150 μmol/L) dose models of PQ exposure on CIK cells. The expression of oxidative stress-related indexes (MDA, CAT, GSH-Px and SOD) and interrelated genes were examined by flow cytometry, qRT-PCR, and western blotting methods. Our data demonstrated that PQ treatment caused an increase in MDA content and the decreases in the activities of antioxidase and antioxidants (SOD, GSH-Px and CAT) on CIK cells (p < 0.05). We also discovered the PTEN/PI3K/AKT pathway was significantly activated in a dose dependent manner (p < 0.05). Furthermore, the proportion of programmed necrosis cells increased dramatically at PQ doses from 0 μmol/L to 150 μmol/L. Apoptosis and necrosis-related genes also showed dose-dependent changes (p < 0.05). Briefly, PQ exposure leads to apoptosis and programmed necrosis via the oxidative stress and PTEN/PI3K/AKT pathway, thereby causing immune dysfunction of CIK cells. This study enriches the toxic influences of PQ on the cells of aquatic organisms and provides a reference for comparative medicine.

Soy isoflavones and their metabolites modulate cytokine-induced natural killer cell function

Soybeans are a rich source of isoflavones that have been linked with anti-inflammatory processes and various health benefits. However, specific mechanisms whereby soy bioactives impact immune cell subsets are unclear. Isoflavones, such as genistein and daidzein, are metabolized by microbes to bioactive metabolites as O-desmethylangolensin (O-DMA) and equol, whose presence has been linked to health benefits. We examined how soy isoflavones and metabolites impact natural killer (NK) cell signaling and function. We observe no impact of isoflavones on viability of healthy donor peripheral blood mononuclear cells (PBMCs) or NK cells, even at high (25 µM) concentrations. However, pre-treatment of PBMCs with physiologically-relevant concentrations of genistein (p = 0.0023) and equol (p = 0.006) decreases interleukin (IL)-12/IL-18-induced interferon-gamma (IFN-γ) production versus controls. Detailed cellular analyses indicate genistein and equol decrease IL-12/IL-18-induced IFN-γ production by human NK cell subsets, but do not consistently alter cytotoxicity. At the level of signal transduction, genistein decreases IL-12/IL-18-induced total phosphorylated tyrosine, and phosphorylation MAPK pathway components. Further, genistein limits IL-12/IL-18-mediated upregulation of IL-18Rα expression on NK cells (p = 0.0109). Finally, in vivo studies revealed that C57BL/6 mice fed a soy-enriched diet produce less plasma IFN-γ following administration of IL-12/IL-18 versus control-fed animals (p < 0.0001). This study provides insight into how dietary soy modulates NK cell functions.

Down-regulation of Treg by interference of enhances the killing effect of CIK on leukemia cell HL-60

OBJECTIVE

Cytokine-induced killer cells (CIK) is a type of immune cell with antitumor activity induced by a variety of cytokines. Regulatory T cells (Treg) is a T cell subgroup featured as immunosuppressive function. Existing CIK cultivation system may inevitably induce Treg. Forkhead box protein 3 (Foxp3) is an essential transcription factor for Treg function. This study aimed to investigate the effects of CIK on the leukemia cell HL-60.

MATERIALS AND METHODS

This work silenced Foxp3 expression on the basis of CIK induction, aiming to investigate its killing effect on HL-60 cells. Peripheral blood mononuclear cells were separated and differentiated to CIK in vitro. CD3+CD56+ and CD4+CD25+Foxp3+ Treg cells were detected by flow cytometry. CIK cells were co-cultured with HL-60 cells under the effector-target ratio at 20:1, 10:1, and 5:1, respectively. The killing activity of CIK on HL-60 cells was determined by CCK-8 assay.

RESULTS

The ratio of CD3+, CD3+CD8+, and CD3+CD56+ cells gradually increased during CIK induction. Foxp3 interference significantly reduced Treg cell ratio on the 7th day (p < 0.05). Treg cell ratio was significantly lower in Foxp3 interference group at 1.62% ± 0.07% compared with control (p < 0.05). The killing activity of CIK on HL-60 cells enhanced following the increase of effector-target ratio. Interference of Foxp3 significantly elevated the killing activity of CIK on HL-60 cells with effector-target ratio dependence (p < 0.05). CIK can effectively suppress HL-60 cell growth. Treg significantly inhibited the anti-tumor effect of CIK.

CONCLUSIONS

Interference of Foxp3 expression significantly declined Treg level and attenuated its suppression impact on CIK, thus enhancing the killing effect of CIK on HL-60 cells.

Phase Ib/II study of safety and efficacy of low-dose decitabine-primed chemoimmunotherapy in patients with drug-resistant relapsed/refractory alimentary tract cancer

The pressing need for improved therapeutic outcomes provides a good rationale for identifying effective strategies for alimentary tract (AT) cancer treatment. The potential re-sensitivity property to chemo- and immunotherapy of low-dose decitabine has been evident both preclinically and in previous phase I trials. We conducted a phase Ib/II trial evaluating low-dose decitabine-primed chemoimmunotherapy in patients with drug-resistant relapsed/refractory (R/R) esophageal, gastric or colorectal cancers. Forty-five patients received either the 5-day decitabine treatment with subsequent readministration of the previously resistant chemotherapy (decitabine-primed chemotherapy, D-C cohort) or the aforementioned regimen followed by cytokine-induced killer cells therapy (D-C and cytokine-induced killer [CIK] cell treatment, D-C + CIK cohort) based on their treatment history. Grade 3 to 4 adverse events (AEs) were reported in 11 (24.4%) of 45 patients. All AEs were controllable, and no patient experienced a treatment-related death. The objective response rate (ORR) and disease control rate (DCR) were 24.44% and 82.22%, respectively, including two patients who achieved durable complete responses. Clinical response could be associated with treatment-free interval and initial surgical resection history. ORR and DCR reached 28% and 92%, respectively, in the D-C + CIK cohort. Consistently, the progression-free survival (PFS) of the D-C + CIK cohort compared favorably to the best PFS of the pre-resistant unprimed therapy (p = 0.0001). The toxicity and ORRs exhibited were non-significantly different between cancer types and treatment cohort. The safety and efficacy of decitabine-primed re-sensitization to chemoimmunotherapy is attractive and promising. These data warrant further large-scale evaluation of drug-resistant R/R AT cancer patients with advanced stage disease.

Comparative Proteomic Analysis of Lysine Acetylation in Fish CIK Cells Infected with Aquareovirus

Grass carp (Ctenopharyngodon idellus) is an important worldwide commercial freshwater culture species. However, grass carp reovirus (GCRV) causes serious hemorrhagic disease in fingerlings and yearlings of fishes. To understand the molecular pathogenesis of host cells during GCRV infection, intensive proteomic quantification analysis of lysine acetylation in Ctenopharyngodon idella kidney (CIK) cells was performed. Using dimethylation labeling-based quantitative proteomics, 832 acetylated proteins with 1391 lysine acetylation sites were identified in response to GCRV infection, among which 792 proteins with 1323 sites were quantifiable. Bioinformatics analysis showed that differentially expressed lysine acetylated proteins are involved in diverse cellular processes and associated with multifarious functions, suggesting that extensive intracellular activities were changed upon viral infection. In addition, extensive alterations on host-protein interactions at the lysine acetylation level were also detected. Further biological experiments showed that the histone deacetylases (HDAC) inhibitor suberoylanilide hydroxamic acid (SAHA) could significantly suppress the GCRV replication. To our knowledge, this is the first to reveal the proteome-wide changes in host cell acetylome with aquatic virus infection. The results provided in this study laid a basis for further understanding the host response to aquareovirus infection in the post-translational modification aspect by regulating cell lysine acetylation conducive to viral replication.

Knockdown of PD-L1 in Human Gastric Cancer Cells Inhibits Tumor Progression and Improves the Cytotoxic Sensitivity to CIK Therapy

Background/Abstract: PD-L1 has been an important target of cancer immunotherapy. We have showed that in human gastric cancer tissues, over-expression of PD-L1 was significantly associated with cancer progression and patients' postoperative prognoses. However, as of now, how PD-L1 regulates the biological function of gastric cancer cells still remains elusive.

METHODS

We constructed the stable PD-L1 knockdown expression gastric cancer cell lines by using RNAi method, and further investigated the changes of biological functions including cell viability, migration, invasion, cell cycle, apoptosis, tumorigenicity in vivo, and the cytotoxic sensitivity to CIK therapy, in contrast to the control cells.

RESULTS

In the current study, we demonstrated that the knockdown of PD-L1 expression in human gastric cancer cells could significantly suppress the cell proliferation, migration, invasion, apoptosis, cell cycle, tumorigenicity in vivo and the cytotoxic sensitivity to CIK therapy.

CONCLUSION

Our results indicate that PD-L1 contributes towards transformation and progression of human gastric cancer cells, and its intervention could prove to be an important therapeutic strategy against gastric cancer.

Immune checkpoint inhibitors enhance cytotoxicity of cytokine-induced killer cells against human myeloid leukaemic blasts

We studied whether blockade of inhibitory receptors on cytokine-induced killer (CIK) cells by immune checkpoint inhibitors could increase its anti-tumour potency against haematological malignancies. CIK cultures were generated from seven normal donors and nine patients with acute myeloid leukaemia (AML), acute lymphoblastic leukaemia (ALL) or multiple myeloma (MM). The inhibitory receptors B and T lymphocyte attenuator, CD200 receptor, lymphocyte activation gene-3 (LAG-3) and T cell immunoglobulin and mucin-domain-containing-3 (TIM-3) were present at variable percentages in most CIK cultures, while cytotoxic T lymphocyte-associated protein 4 (CTLA-4), programmed death-1 (PD-1) and killer cell immunoglobulin-like receptors (KIR2DL1/2/3) were expressed at low level in most cultures. Without blockade, myeloid leukaemia cells were susceptible to autologous and allogeneic CIK-mediated cytotoxicity. Blockade of KIR, LAG-3, PD-1 and TIM-3 but not CTLA-4 resulted in remarkable increase in killing against these targets, even in those with poor baseline cytotoxicity. ALL and MM targets were resistant to CIK-mediated cytotoxicity, and blockade of receptors did not increase cytotoxicity to a meaningful extent. Combination of inhibitors against two receptors did not further increase cytotoxicity. Interestingly, potentiation of CIK killing by blocking antibodies was not predicted by expression of receptors on CIK and their respective ligands on the targets. Compared to un-activated T and NK cells, blockade potentiated the cytotoxicity of CIK cells to a greater degree and at a lower E:T ratio, but without significant increase in cytotoxicity against normal white cell. Our findings provide the basis for clinical trial combining autologous CIK cells with checkpoint inhibitors for patients with AML.

Experimental Studies on Some Immunotoxicological Aspects of Aflatoxins Containing Diet and Protective Effect of Bee Pollen Dietary Supplement

Aflatoxins (AFs), widely distributed food-borne mycotoxins, affect quality and safety of food and cause economic losses in livestock. In this study, the protective effect of Bee Pollen (BP) against some immunotoxic hazards elucidated from eating of AFs-containing diet was investigated in Wistar rats. Rats were randomly classified intofour groups and treated for 30 days, Group 1; control negative, Group 2; Total AFs (3 mg kg(-1) basal diet), Group 3; BP (20 g kg(-1) basal diet) and Group 4; AFs+BP in basal diet. The immunoprotective effect of BP was revealed in terms of increasing (relative to levels seen in Group 2 rats that consumed the AFs diet) serum total protein and globulin levels, restored normal neutrophil (PMN)/lymphocyte ratio, increased PMN phagocytic activity and increased lymphocyte proliferative capacity. Also, the use of the BP reduced spleen H2O2 levels and increased GSH content while maintaining normal levels of NO formation. Histopathologic analysis showed thatthe AFs caused lymphocytic depletion in the spleen; however, BP induced lymphocytic hyperplasia and reduced the levels of AFs-inducible cellular exhaustion or depletion. These results provide evidence of a protective effect of BP against some immunotoxic actions induced in situ by consumption of AFs.

[Selection of storage time, temperature and anticoagulants of peripheral blood samples for culturing cytokine-induced killer cells]

OBJECTIVE

To investigate the effects of anticoagulants, preservation time and temperature of peripheral blood samples on the culture of cytokine-induced killer (CIK) cells so as to provide the experimental evidences for peripheral blood storage in autologous immunotherapy.

METHODS

Four samples of 60 mL peripheral blood were collected. After being added with heparin sodium, cell preservation liquid (sodium citrate) and EDTA solution, they were separately stored under 4°C, 22°C, and 30°C for 0, 4, 8, 24 hours. We divided the orthogonal experiments into 12 groups, and then separated mononuclear cells and induced them into CIK cells. The proliferation efficiency and IFN-γ secretion were compared in the 12 groups.

RESULTS

The proliferation of CIK cells was not obvious in EDTA group, but obvious in heparin sodium group and sodium citrate group, especially better in sodium citrate group. The storage time of blood did not have a significant impact on CIK cell culture, however the longer storage time, the lower cell proliferation efficiency. The proliferation efficiency decreased apparently after 16-day culture if preservation time exceeded 8 hours. After the culture period of 16 days, the efficiency of CIK cell proliferation was the highest at 22°C, followed by that at 4°C, and the lowest was at 30°C. It was not apparent that the temperature of blood storage affected CIK cell proliferation within 16-day culture period.

CONCLUSION

Both heparin sodium and sodium citrate can be used in blood sample anticoagulation for CIK cell culture. Blood samples are suitable for CIK cell culture which are stored within 24 hours between 4°C and 30°C.

Involvement of oxidative stress and cytoskeletal disruption in microcystin-induced apoptosis in CIK cells

The outbreak of cyanobacterial blooms induces the production and release of microcystins (MCs) into water, representing a health hazard to aquatic organisms and even humans. Some recent studies have suggested that kidney is another important target organ of MCs except liver, however, the potential toxicity mechanisms are still unclear. In this study, we first investigated the collaborative effect of oxidative stress and cytoskeletal disruption in microcystin-induced apoptosis in CIK (Ctenopharyngodon idellus kidney) cells in vitro. CIK cells were treated with 0, 1, 10, and 100μg/L microcystin-LR (MC-LR) for 24 and 48h. Cell viability was increased by MC-LR in 1μg/L group, while decreased in 100μg/L group at 48h. Cell cycle assay showed that 1 and 10μg/L MC-LR induced cell cycle through G1 into S and G2/M phases, while 100μg/L MC-LR reduced G2/M phase population. MC-LR markedly induced apoptosis in 10 and 100μg/L groups. Elevated reactive oxygen species (ROS) production, increased malondialdehyde (MDA) contents, decreased glutathione (GSH) levels, and modulated antioxidant enzymes including catalase (CAT) and superoxide dismutase (SOD) were observed in CIK cells exposed to MC-LR. These alterations were more pronounced at higher doses (10 and 100μg/L), indicating that oxidative stress was induced by MC-LR. Laser scanning confocal microscope observation showed aggregation and collapse of microfilaments (MFs) and microtubules (MTs) in CIK cells, and even loss of some cytoskeleton structure. Moreover, transcriptional changes of cytoskeletal genes (β-actin, lc3a, and keratin) were also determined, which have a high probability with cytoskeleton structure damage. Our data suggest that oxidative stress and cytoskeletal disruption may interact with each other and jointly lead to apoptosis and renal toxicity induced by MCs.

[Thymoglobulin efficiently expands cytokine-induced killer cells in a clinical-grade culture protocol]

OBJECTIVE

To study the effect of thymoglobulin (TG) on proliferation, immune cell phenotype and cytotoxicity of cytokine-induced killer (CIK) cells in a clinical-grade culture protocol.

METHODS

Peripheral blood mononuclear cells (PBMCs) isolated from 11 healthy donors were primed with IFN-γ on day 0 and treated with either TG or CD3 mAb on day 1. Thereafter, the cells were fed with IL-2 every 3 days until day 21. Aliquots of cells were harvested weekly. The cell number and viability were measured using trypan blue exclusion. The expressions of CD3, CD4, CD8, CD16/CD56, NK activating/inhibitory receptor, and the CD25⁺ Foxp3⁺ regulatory T cells (Tregs) were analyzed with flow cytometry. The cytotoxicity of CIK cells against K562 cells were determined by lactate dehydrogenase (LDH) release assay on day 16 and day 21.

RESULTS

Both TG and CD3 mAb stimulated the growth of CIK cells. However, the effect of CD3 mAb was weaker than that of TG. Flow cytometric analysis showed that the percentages of CD3⁺ CD16⁺ CD56⁺ cells and CD3⁻ CD16⁺ CD56⁺ cells and the expression of NK activating/inhibitory receptor recovered and increased continuously until the end of culture (day 21) following a transient decrease at day 7. Noticeably, on day 7, 14 and 21, the percentages of CD3⁺ CD 16⁺ CD56⁺ cells and CD3⁻ CD16⁺ CD56⁺ cells as well as the expression of NK activating/inhibitory receptor were higher in TG-induced CIK cells than those in CD3 mAb-induced CIK cells (P<0.05); Moreover, LDH release assay revealed that the cytotoxicity of CIK cells against K562 cells in TG-induced CIK cells was significantly higher than that of CD3 mAb-induced CIK cells (P<0.05). In both CD3 mAb-induced CIK cell culture system and TG-induced CIK cell culture system, Treg increased transiently at day 7; moreover, the percentage of Treg in TG-induced CIK cells was significantly higher than that of CD3 mAb-induced CIK cells (P<0.05). In addition, both CD3 mAb and TG reduced the percentage of CD3⁺ CD4⁺ cells continuously, meanwhile increased the percentage of CD3⁺ CD8⁺ cells. There was no significant difference in the changes of CD3⁺ CD4⁺ cells and CD3⁺ CD8⁺ cells between the two CIK cell culture systems.

CONCLUSION

Compared with CD3 mAb, TG more selectively expanded CD3⁺ CD16⁺ CD56⁺ cells and CD3⁻ CD16⁺ CD56⁺ cells (CIK effector cells) and promoted the differentiation and maturation of these CIK effector cells with more powerful cytotoxic activity. Therefore, it is feasible for TG to substitute CD3 mAb to prepare the clinical grade products of CIK cells. Both CD3 mAb and TG increased negative regulatory cells, Tregs, transiently in CIK culture system and depleting or reducing Tregs might be helpful for increasing the production efficacy of the main effector cells in CIK cells.

Sunitinib indirectly enhanced anti-tumor cytotoxicity of cytokine-induced killer cells and CD3⁺CD56⁺ subset through the co-culturing dendritic cells

Cytokine-induced killer (CIK) cells have reached clinical trials for leukemia and solid tumors. Their anti-tumor cytotoxicity had earlier been shown to be intensified after the co-culture with dendritic cells (DCs). We observed markedly enhanced anti-tumor cytotoxicity activity of CIK cells after the co-culture with sunitinib-pretreated DCs over that of untreated DCs. This cytotoxicity was reliant upon DC modulation by sunitinib because the direct exposure of CIK cells to sunitinib had no significant effect. Sunitinib promoted Th1-inducing and pro-inflammatory phenotypes (IL-12, IFN-γ and IL-6) in DCs at the expense of Th2 inducing phenotype (IL-13) and regulatory phenotype (PD-L1, IDO). Sunitinib-treated DCs subsequently induced the upregulation of Th1 phenotypic markers (IFN-γ and T-bet) and the downregulation of the Th2 signature (GATA-3) and the Th17 marker (RORC) on the CD3⁺CD56⁺ subset of CIK cells. It concluded that sunitinib-pretreated DCs drove the CD3⁺CD56⁺ subset toward Th1 phenotype with increased anti-tumor cytotoxicity.

[Effect of Achyranthes bidentata polysaccharides stimulated dendritic cells co-cultured with cytokine induced killer cells against SW480 cells]

Achyranthes bidentata polysaccharides (ABPS) was extracted from the root of A. bidentata. Dendritic cells (DC), which were stimulated with ABPS and/or tumor antigen SW480, were co-cultured with cytokine induced killer cells (CIK) to test the cytotoxic effect on colon cancer cell line SW480. Peripheral blood mononuclear cells (PBMNCs) which were separated from human peripheral blood were cultured to DC and CIK separately. (1) DC were divided into four groups: pure DC served as control group; ABPS (50 mg x L(-1)) stimulated DC served as experimental group; SW480 tumor antigen stimulated DC served as the second experimental group; ABPS (50 mg x L(-1)) and SW480 tumor antigen co-stimulated DC served as the third experimental group. Flow cytometry was used to detect the difference of the positive rate of molecules in the cell surface of DC, include CD80, CD86, CD1c, CD40, HLA-DR (6 samples for each group). (2) The four DC groups were mixed with CIK at the ratio 1:5 and acted as effect cells (DC + CIK groups), and the colon cancer cell line SW480 acted as target cells. The effect cells and the target cells were mixed together at the ratio 30: 1, 20:1 and 10:1 separately, and the CCK-8 kit was used to test the cytotoxic effect on colon cancer cell line SW480. (3) At the mixing ratio 30:1 of effect cells and target cells, ELISA was used to test the level of cytokines secretion, including IL-2, IL-12p70, IL-17 and TNF-alpha, in the liquid supernatant of every test group (3 duplication per sample). The results showed as following: (1) The positive rates of CD80, CD11c, HLA-DR, in the cell surface of DC which was co-stimulated by ABPS (50 mg x L(-1)) and SW480 tumor antigen, were obviously higher than the other DC groups (P < 0.05), and the positive rates of CD86, CD40 were obviously higher than the pure DC group (P < 0.05), and there was no remarkable difference with the other two DC groups. (2) At the mixing ratio 30:1, 20:1 and 10:1 of the effect cells and the target cells, the cytotoxic effect of ABPS stimulated DC + CIK group and SW480 tumor antigen stimulated DC + CIK group was obviously higher than DC + CIK group (P < 0.05), the cytotoxic effect of ABPS and SW480 tumor antigen co-stimulated DC + CIK group was obviously higher than all the other groups. (3) At the mixing ratio 30:1 of the effect cells and the target cells, the secretion levels of IL-12p70 and TNF-alpha in the liquid supernatant of the ABPS and SW480 tumor antigen co-stimulated DC + CIK group were obviously higher than all the other groups (P < 0.05), the secretion levels of IL-2 and IL-17 in the liquid supernatant of every test group have no remarkable difference. The cytotoxic effect of ABPS stimulated DC + CIK on SW480 was obviously increased. The cytotoxic effect of ABPS and SW480 tumor antigen co-stimulated DC + CIK group was obviously higher than all the other.

[Effects of humanized interleukin 21 on anti-leukemic activity of cytokine induced killer cells and the mechanism]

OBJECTIVE

To explore the effects of humanized interleukin 21 (IL-21) on anti-leukemic activity of cytokine induced killer(CIK) cells derived from peripheral blood(PB) and the mechanism.

METHODS

Mononuclear cells were separated from peripheral blood and cultured with cytokines to induce CIK cells. Proliferation of CIK cells with or without IL-21 stimulation and their cytotoxic activity against K562 cells was measured by MTT method. IL-21 receptor (IL-21R) and immunophenotypes of CIK cells were measured by flow cytometry. The expression of interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), tumor necrosis factor-β (TNF-β), perforin, granzyme A, granzyme B, FasL and NKG2D mRNA were measured by semi-quantitative RT-PCR. FasL on the surface of CIK cells and intra-cellular perforin and granzyme B of CIK cells were measured by flow cytometry. The concentration of IFN-γ and TNF-α in the cultured supernatant were measured by enzyme immunoassay. JAK-STAT signalling pathway of CIK cells were measured by Western-blot.

RESULTS

After IL-21 stimulation, the proportion of CIK cells increased from (17.5 ± 4.7)% to (26.5 ± 2.1)%. Cytotoxic activity against K562 cells by CIK cells increased from (22.8 ± 2.8)% to(44.6 ± 8.3)%. The expression of IL-21R increased about 2 folds. The mRNA expression of IFN-γ increased almost 2 folds from (0.3760 ± 0.2358) to (0.7786 ± 0.2493), TNF-α increased almost 2 folds from (0.6557 ± 0.1598) to (1.3145 ± 0.2136), perforin increased almost 1.5 folds from (0.6361 ± 0.1457) to (0.9831 ± 0.1265), granzyme B increased almost 2 folds from (0.4084 ± 0.1589) to (0.7319 ± 0.1639), FasL increased almost 2 folds from (0.4015 ± 0.2842) to (0.7381 ± 0.2568), the expression of granzyme A, TNF-β and NKG2D were similar with control. Flow cytometry analysis showed that the expression of FasL of CIK cells was higher than that of control (0.19% vs 0.04%), the expression of perforin increased from 35.28% to 53.16%, and the expression of granzyme B increased from 43.16% to 78.82%. The concentration of IFN-γ in the culture supernatant increased almost 2 folds from (25.8 ± 6.1) ng/L to (56.0 ± 2.3) ng/L, and TNF-α increased almost 3 folds from (5.64 ± 0.61) µg/L to (15.14 ± 0.93) µg/L. Western blot showed that the expression of STAT1 and STAT5a had no significant differences, but the expression of STAT3 and STAT5b were higher than that of control.

CONCLUSION

Humanized IL-21 could enhance the anti-leukemic activity of CIK cells via increasing IL-21R, perforin, granzyme B, FasL, IFN-γ and TNF-α, as well as activating JAK-STAT signaling pathway. These data indicate that IL-21 has a potential clinical value in the enhancement of anti-leukemic immunotherapy.

[Studies on IFN-gamma-mediated reversion of CIK killing sensitivity to edited human lung cancer A549 cells]

AIM

To explore IFN-gamma-mediated reversion of CIK killing sensitivity to immunoedited lung cancer A549 cells.

METHODS

RT-PCR and MTT methods were used to detect the effect on MICA mRNA expression induced by IFN-gamma in the edited A549 cells and the change of CIK killing sensitivity to A549 cells, respectively.

RESULTS

Low expression of cell surface MICA and low killing sensitivity of CIKs were observed in edited A549 cells. IFN-gamma could significantly increase MICA mRNA expression in the edited A549 cells and improve CIK cell cytotoxicity.

CONCLUSION

IFN-gamma could reverse CIK killing sensitivity to the edited A549 cells by enhancing the MICA mRNA expression.