A highly selective humanized DDR1 mAb reverses immune exclusion by disrupting collagen fiber alignment in breast cancer.

BACKGROUND: Immune exclusion (IE) where tumors deter the infiltration of immune cells into the tumor microenvironment has emerged as a key mechanism underlying immunotherapy resistance. We recently reported a novel role of discoidin domain-containing receptor 1 (DDR1) in promoting IE in breast cancer and validated its critical role in IE using neutralizing rabbit monoclonal antibodies (mAbs) in multiple mouse tumor models. METHODS: To develop a DDR1-targeting mAb as a potential cancer therapeutic, we humanized mAb9 with a complementarity-determining region grafting strategy. The humanized antibody named PRTH-101 is currently being tested in a Phase 1 clinical trial. We determined the binding epitope of PRTH-101 from the crystal structure of the complex between DDR1 extracellular domain (ECD) and the PRTH-101 Fab fragment with 3.15 Å resolution. We revealed the underlying mechanisms of action of PRTH-101 using both cell culture assays and in vivo study in a mouse tumor model. RESULTS: PRTH-101 has subnanomolar affinity to DDR1 and potent antitumor efficacy similar to the parental rabbit mAb after humanization. Structural information illustrated that PRTH-101 interacts with the discoidin (DS)-like domain, but not the collagen-binding DS domain of DDR1. Mechanistically, we showed that PRTH-101 inhibited DDR1 phosphorylation, decreased collagen-mediated cell attachment, and significantly blocked DDR1 shedding from the cell surface. Treatment of tumor-bearing mice with PRTH-101 in vivo disrupted collagen fiber alignment (a physical barrier) in the tumor extracellular matrix (ECM) and enhanced CD8+ T cell infiltration in tumors. CONCLUSIONS: This study not only paves a pathway for the development of PRTH-101 as a cancer therapeutic, but also sheds light on a new therapeutic strategy to modulate collagen alignment in the tumor ECM for enhancing antitumor immunity.

Identification of a novel survival predictor, CSF2RB, for female lung cancer in never smokers (LCNS) by a bioinformatics analysis.

Lung cancer in never smokers (LCNS) has been considered as a separate disease and the 7th cause of cancer-related death worldwide. However, limited research has focused on "female" cohorts, which have presented a higher incidence rate. In this study, the microarray data of lung cancer tissues derived from 54 female lung cancer patients, consisting of 43 nonsmokers and 11 smokers, were selected from GSE2109 dataset. A total of 249 differentially expressed genes (DEGs) including 102 up- and 147 down-regulated genes were identified and further analyzed for gene ontology (GO) terms and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment. By constructing protein-protein interaction (PPI) network and calculating key modules, 10 hub genes were screened out. The module analysis of the PPI network presented that the progression of female LCNS was significantly associated with immune response as chemokine activity and lipopolysaccharide response, and these biological processes (BP) might be mediated by chemokine signaling pathway and cytokine-cytokine receptor interaction. Then, survival analysis by Kaplan-Meier (K-M) Plotter online platform presented down-regulated gene colony stimulating factor 2 receptor beta common subunit (CSF2RB) of female LCNS might be involved in poor clinical outcome. Female LCNS with high expression of CSF2RB might be relevant with relative risk reduction of mortality, longer median survival time and higher 5-year survival rate, while female LCNS with low expression of CSF2RB might be implicated in a poor clinical outcome. In short, our results support CSF2RB to be a candidate survival predictor for female LCNS.

Anti-GRP-R monoclonal antibody antitumor therapy against neuroblastoma.

Standard treatment for patients with high-risk neuroblastoma remains multimodal therapy including chemoradiation, surgical resection, and autologous stem cell rescue. Immunotherapy has demonstrated success in treating many types of cancers; however, its use in pediatric solid tumors has been limited by low tumor mutation burdens. Gastrin-releasing peptide receptor (GRP-R) is overexpressed in numerous malignancies, including poorly-differentiated neuroblastoma. Monoclonal antibodies (mAbs) to GRP-R have yet to be developed but could serve as a potential novel immunotherapy. This preclinical study aims to evaluate the efficacy of a novel GRP-R mAb immunotherapy against neuroblastoma. We established four candidate anti-GRP-R mAbs by screening a single-chain variable fragment (scFv) library. GRP-R mAb-1 demonstrated the highest efficacy with the lowest EC50 at 4.607 ng/ml against GRP-R expressing neuroblastoma cells, blocked the GRP-ligand activation of GRP-R and its downstream PI3K/AKT signaling. This resulted in functional inhibition of cell proliferation and anchorage-independent growth, indicating that mAb-1 has an antagonist inhibitory role on GRP-R. To examine the antibody-dependent cellular cytotoxicity (ADCC) of GRP-R mAb-1 on neuroblastoma, we co-cultured neuroblastoma cells with natural killer (NK) cells versus GRP-R mAb-1 treatment alone. GRP-R mAb-1 mediated ADCC effects on neuroblastoma cells and induced release of IFNγ by NK cells under co-culture conditions in vitro. The cytotoxic effects of mAb-1 were confirmed with the secretion of cytotoxic granzyme B from NK cells and the reduction of mitotic tumor cells in vivo using a murine tumor xenograft model. In summary, GRP-R mAb-1 demonstrated efficacious anti-tumor effects on neuroblastoma cells in preclinical models. Importantly, GRP-R mAb-1 may be an efficacious, novel immunotherapy in the treatment of high-risk neuroblastoma patients.

Tumour DDR1 promotes collagen fibre alignment to instigate immune exclusion.

Immune exclusion predicts poor patient outcomes in multiple malignancies, including triple-negative breast cancer (TNBC)1. The extracellular matrix (ECM) contributes to immune exclusion2. However, strategies to reduce ECM abundance are largely ineffective or generate undesired outcomes3,4. Here we show that discoidin domain receptor 1 (DDR1), a collagen receptor with tyrosine kinase activity5, instigates immune exclusion by promoting collagen fibre alignment. Ablation of Ddr1 in tumours promotes the intratumoral penetration of T cells and obliterates tumour growth in mouse models of TNBC. Supporting this finding, in human TNBC the expression of DDR1 negatively correlates with the intratumoral abundance of anti-tumour T cells. The DDR1 extracellular domain (DDR1-ECD), but not its intracellular kinase domain, is required for immune exclusion. Membrane-untethered DDR1-ECD is sufficient to rescue the growth of Ddr1-knockout tumours in immunocompetent hosts. Mechanistically, the binding of DDR1-ECD to collagen enforces aligned collagen fibres and obstructs immune infiltration. ECD-neutralizing antibodies disrupt collagen fibre alignment, mitigate immune exclusion and inhibit tumour growth in immunocompetent hosts. Together, our findings identify a mechanism for immune exclusion and suggest an immunotherapeutic target for increasing immune accessibility through reconfiguration of the tumour ECM.

OxyR controls magnetosome formation by regulating magnetosome island (MAI) genes, iron metabolism, and redox state.

Magnetospirillum gryphiswaldense MSR-1 uses chains of magnetosomes, membrane-enveloped magnetite (Fe(II)Fe(III)2O4) nanocrystals, to align along magnetic field. The process of magnetosome biomineralization requires a precise biological control of redox conditions to maintain a balanced amounts of ferric and ferrous iron. Here, we identified functions of the global regulator OxyR (MGMSRv2_4250, OxyR-4250) in MSR-1 during magnetosome formation. OxyR deletion mutant ΔoxyR-4250 displayed reduced magnetic response, and increased levels of intracellular ROS (reactive oxygen species). OxyR-4250 protein upregulated expression of six antioxidant genes (ahpC1, ahpC2, katE, katG, sodB, trxA), four iron metabolism-related regulator genes (fur, irrA, irrB, irrC), a bacterioferritin gene (bfr), and a DNA protection gene (dps). OxyR-4250 was shown, for the first time, to directly regulate magnetosome island (MAI) genes mamGFDC, mamXY, and feoAB1 operons. Taken together, our findings indicate that OxyR-4250 helps maintain a proper redox environment for magnetosome formation by eliminating excess ROS, regulating iron homeostasis and participating in regulation of Fe2+/Fe3+ ratio within the magnetosome vesicle through regulating MAI genes.

Bacterial magnetosomes loaded with doxorubicin and transferrin improve targeted therapy of hepatocellular carcinoma.

High metastatic rate and recurrence of tumor because of tumor circulating cells are seriously hinders for clinical tumor therapy. Herein, we develop a novel, active-targeting nanotherapeutic by simultaneously loading doxorubicin (DOX) and transferrin (Tf) onto bacterial magnetosomes (Tf-BMs-DOX) and investigate its antitumor efficacy in vitro and in vivo. Drug release profiles indicated that Tf-BMs/BMs loaded with DOX were capable of sustained drug release, suggesting that reduce drugs required frequency of administration and enhance their therapeutic effect. The results of cellular uptake revealed that Tf-BMs-DOX recognized hepatocellular carcinoma HepG2 cells more specifically compared to HL-7702 normal hepatocytes because of high expression of transferrin receptor (TfR) on the surface of HepG2 cells. Tf-BMs-DOX increased tumor cytotoxicity and apoptosis more significantly than free DOX or BMs-DOX by regulating the expression of tumor-related and apoptosis-related genes. Following intravenous injection in HepG2 cell-bearing mice, Tf-BMs-DOX displayed tumor suppression rate of 56.78%, significantly higher than that of the BMs-DOX (41.53%) and free DOX (31.26%) groups. These results suggest that Tf-BMs-DOX have the potential to actively target to tumor sites, as well as the ability to kill circulating tumor cells via intravenous injection. Our findings provide a promising candidate for the clinical treatment of metastatic cancer.

Growth-inhibitory effects of anthracycline-loaded bacterial magnetosomes against hepatic cancer in vitro and in vivo.

Aim: This study aimed to develop anthracycline-loaded bacterial magnetosomes (BMs) with enhanced anticancer efficiency and elucidate their endocytosis mechanism. Methods: Drug-loaded BMs (DBMs) were successfully prepared and characterized. DBMs endocytosis was investigated within HepG2 cells. The anticancer effect of DBMs was studied both in vitro and in vivo. Results: Doxorubicin-BMs and daunorubicin-BMs showed enhanced growth inhibitory effect in vitro and in vivo with no notable toxicity to normal tissues. The DBMs were internalized into cells through caveolae-mediated endocytosis and macropinocytosis. The loaded drugs were released from DBMs in cytoplasm and entered the nucleus to exert their activity. Conclusion: Our findings offer promising candidates for improved cancer therapy with a clear mechanism of DBMs endocytosis and working principle.

Mesenchymal stem cell sheets: a new cell-based strategy for bone repair and regeneration.

Mesenchymal stem cells (MSCs), a class of adult stem cells, are considered a promising source for bone regeneration. Although combining MSCs with biomaterial scaffolds offers an interesting clinical strategy for bone tissue engineering, the presence of the scaffolds could induce an undesirable effect on cell-cell interactions. Moreover, before the application of scaffold materials in bone tissue reconstruction, cells must be manipulated with proteolytic enzymes, such as trypsin or dispase that degrade extracellular matrix (ECM) molecules and cell surface proteins, which can result in the cell damage and loss of cellular activity. Therefore, the development of alternative strategies for bone regeneration is required to solve these problems. Recently, a novel tissue engineering technology named 'cell sheet' has been efficaciously utilized in the regeneration of bone, corneal, cardiac, tracheal and periodontal ligament-like tissues. The cell sheet is a layer of cells, which contains intact ECM and cell surface proteins such as growth factor receptors, ion channels and cell-to-cell junction proteins. MSC sheets can be easily fabricated by layering the recovered cell sheets without any scaffolds or complicated manipulation. This review summarizes the current state of the literature regarding the use of MSCs to produce cell sheets and assesses their applicability in bone tissue regeneration and repair.

Artesunate enhances γδ T-cell-mediated antitumor activity through augmenting γδ T-cell function and reversing immune escape of HepG2 cells.

OBJECTIVE: To explore the effect and mechanism of artesunate on γδ T cell-mediated antitumor immune responses against hepatoma carcinoma cells (HepG2) in vitro. METHODS: Human γδ T cells or HepG2 were respectively treated with artesunate, subjected to co-culture as appropriate, and the following assays were subsequently conducted: CCK8 to examine cell viability; LDH release assay to detect the killing effect of γδ T cells on HepG2 cells; flow cytometry to examine the expression of perforin (PFP) and granzyme B (GraB) of γδ T cells; ELISA to evaluate the levels of TGF-ß1 and IL-10 in the collected supernatant of HepG2 cells pretreated with artesunate; and Western blot analysis to examine Fas, FasL, STAT3, p-STAT3 expression of HepG2 cells induced by artesunate. Results: The results showed that the cytotoxicity effect of γδ T cells pretreated with artesunate on HepG2 cells was augmented via elevating the expression of GraB in γδ T cells. Furthermore, treatment with artesunate reversed the inhibition of HepG2 cells on γδ T cells by reducing the secretion of TGF-ß1 in HepG2 cells supernatant and enhanced the antitumor effect of γδ T cells against HepG2 cells through increasing the expression of Fas on HepG2 cells, which may be attributed to the inhibition of STAT3 signaling protein. CONCLUSION: Artesunate has several mechanisms for augmenting the antitumor immune responses mediated by γδ T cells. These results suggested artesunate may be an efficacious agent in the treatment of hepatocellular carcinoma.

Wnt pathway activator TWS119 enhances the proliferation and cytolytic activity of human γδT cells against colon cancer.

γδT cells are a distinct T-cell subset that display unique characteristics regarding T-cell receptor gene usage, tissue tropism and antigen recognition. Adoptive γδT cell transfer therapy has recently been gaining importance as an efficient approach in cancer immunotherapy. However, exploiting γδT cell response for tumour immunotherapy is a challenge due to cell numbers, activities and differentiation states that minimize the clinical therapeutic effects. Previous studies have indicated that the wnt/ß-catenin signalling pathway plays a crucial role in the differentiation, survival and enhancement of the immune response of T lymphocytes. In this study, we sought to evaluate whether the activation of the wnt/ß-catenin pathway through inhibition of glycogen synthase kinase-3ß (GSK-3ß) using 4,6-disubstituted pyrrolopyrimidine (TWS119) could be an efficient strategy to improve the proliferation, differentiation and cytolytic activity of γδT cells against colon cancer cells. Remarkably, we found that TWS119 significantly enhanced the proliferation and survival of γδT cells via activation of the mammalian target of rapamycin (mTOR) pathway, upregulation of the expression of the anti-apoptotic protein Bcl-2 and inhibition of cleaved caspase-3 in addition to the Wnt pathway. Our results also showed that enhancement of the cytolytic activity of γδT cells against human colon cancer cells by TWS119 was chiefly associated with upregulation of the expression of perforin and granzyme B in vitro and in vivo. Additionally, TWS119 can induce the expression of CD62L or CCR5 to generate a population of CD62L+γδT or CCR5+γδT cells in a dose-dependent manner. These findings suggested that TWS119 could be a useful complementary agent for improving γδT cell-based immunotherapy.

Enhancement of CD3AK cell proliferation and killing ability by α-Thujone.

Thujone is a monoterpene ketone natural substance found mainly in wormwood and sage. Previous studies have shown that Thujone has various pharmacological effects, such as anti-tumor, analgesic, and insecticide. The effect of α-Thujone to human immune cells is still unknown. Our study focuses on investigating the effects and mechanism of α-Thujone to CD3AK (anti- CD3 antibody induced activated killer) cells proliferation and cytotoxicity to colon cancer cell lines. With cell proliferation and FCM assay, it is found that α-Thujone could significantly enhance CD3AK cell proliferation and expression of CD107a in a dose-dependent manner. The cytotoxicity to colon cancer cells detected by CCK-8 assay is also improved. The expressions of TNF-α and FasL detected with ELISA assay were not significantly changed. Mechanically, the study shows that α-Thujone could enhance the expression of p-ERK1/2 and p-Akt. In addition, α-Thujone has no cytotoxicity to HCT116 and SW620 cells proliferation. In a word, α-Thujone enhances CD3AK cell proliferation and cytotoxicity via the improvement of expression of CD107a, p-Akt and p-ERK1/2.

[Resveratrol inhibits cell proliferation and up-regulates MICA/B expression in human colon cancer stem cells].

OBJECTIVE: To investigate the effect of resveratrol (Res) on the proliferation, apoptosis and immunogenicity of colorectal cancer stem cells (CCSCs). METHODS: The CCSCs were induced from colon cancer cell line HCT116 in serum-free medium (SFM). The expressions of CD133 and CD44 were detected by flow cytometry to identify CCSCs. After treatment with Res at (12.5-200.0) µmol/L, the effect of Res on CCSC proliferation was detected by MTT assay ; cell apoptosis was examined by flow cytometry combined with annexin V-FITC/PI staining; cell cycle and the expression of major histocompatibility complex class I-related chain A and B (MICA/B) were assessed by flow cytometry. RESULTS: HCT116 cells formed cancer stem cell spheres in SFM. The proportion of CD133⁺ cells in cell spheres was (91.07 ± 1.79)%, and CD44⁺ cells was (90.33 ± 1.78)%. Compared with control groups, Res significantly inhibited CCSC proliferation in a time- and dose-depended manner. After treatment with Res for 48 hours, the proportion of cells increased in the G0/G1 phase and decreased in the S phase, both in a dose-depended manner. Apoptosis rate of CCSCs and the expression of MICA/B were raised with the increasing concentration of Res. CONCLUSION: CCSCs were successfully induced from HCT116 colon cancer cell line. Res could depress CCSC proliferation in a time-and dose-depended manner, arrest cell cycle in the G0/G1 phase and promote cell apoptosis. Res could up-regulate the expression of MICA/B in CCSCs and enhance cell immunogenicity.

Shikonin inhibits prostate cancer cells metastasis by reducing matrix metalloproteinase-2/-9 expression via AKT/mTOR and ROS/ERK1/2 pathways.

Metastasis is one of the most important factors related to prostate cancer therapeutic efficacy. In previous studies, shikonin, an active naphthoquinone isolated from the Chinese medicine Zi Cao, has various anticancer activities both in vivo and in vitro. However, the mechanisms underlying shikonin's anticancer activity are not fully elucidated on prostate cancer cells. In the present study, we aimed to investigate the potential effects of shikonin on prostate cancer cells and the underlying mechanisms by which shikonin exerted its actions. With cell proliferation, flow cytometric cell cycle, migration and invasion assays, we found that shikonin potently suppressed PC-3 and DU145 cell growth by cell cycle arrest at the G2 phase and metastasis in a dose-dependent manner. Mechanically, we presented that shikonin could suppress the metastasis of PC-3 and DU145 cells via inhibiting the matrix metalloproteinase-2 (MMP-2) and MMP-9 expression and activation. In addition, shikonin significantly decreased the phosphorylation of AKT and mTOR in a dose-dependent manner while it induced extracellular signal-regulated kinase (ERK), p38 mitogen activated protein kinase (MAPK) and c-Jun N terminal kinase (JNK) phosphorylation. Further investigation of the underlying mechanism revealed that shikonin also induced the production of reactive oxygen species (ROS) that was reversed by the ROS scavenger dithiothreitol (DTT). Additionally, DTT reversed the shikonin induced activation of ERK1/2, thereby maintaining MMP-2 and MMP-9 expression and restoring cell metastasis. Together, shikonin inhibits aggressive prostate cancer cell migration and invasion by reducing MMP-2/-9 expression via AKT/mTOR and ROS/ERK1/2 pathways and presents a potential novel alternative agent for the treatment of human prostate cancer.

[Expression of coxsackie-adenovirus receptor in keratinocytes of mouse skin after heat stimulation and the effect of coxsackie-adenovirus receptor on dendritic epidermal T lymphocytes].

OBJECTIVE: To study the influence of heat stimulation on expression of coxsackie-adenovirus receptor (CAR) in keratinocytes (KCs) of mouse skin and the effect of CAR on production of cell growth factors by dendritic epidermal T lymphocytes (DETCs). METHODS: (1) Twenty BALB/c mice were divided into heat stimulation group (HS) and control group (C) according to the random number table, with 10 mice in each group. Mice in group HS were inflicted with scald milder than superficial-thickness by dressing wet hot gauze, which had been soaked in 100°C hot water for 3 min, in the hair removed area on the back for 1 to 3 s, while mice in group C were sham injured by dressing a wet gauze which had been soaked in water of room temperature for 3 min in the hair removed area on the back for 1 to 3 s. Square full-thickness skin specimens measuring 2.0 cm × 2.0 cm in size were obtained from the center of the bare skin. The expression of CAR in skin tissue sections were detected by immunohistochemistry staining. The mRNA and protein expression levels of CAR in skin tissue sections were respectively determined by real-time fluorescent quantitation RT-PCR and Western blotting. (2) KCs were isolated and cultured from full-thickness skin obtained from the trunk of 2 fetal BALB/c mice, and they were divided into 2 groups according to the random number table, with 5 wells in each group. The cells in group HS and group C were respectively cultured in 42°C and 37°C, 5% CO2 incubator for 1 h, and then all the cells were cultured in 37 °, 5% CO2 incubator for 6 h. The apoptosis of the cells and their expression of CAR were detected by flow cytometer. (3) Five BALB/c mice were sacrificed, and full-thickness skin was obtained from the trunk. The DETCs were divided into 7 groups according to the random number table after being isolated and purified from the skin specimens. Cells in group C were cultured without any stimulation, and cells in the 0.5, 1.0, 2.0, 4.0, 8.0, and 16.0 mg/L CAR groups were respectively cultured with corresponding concentration of recombinant mice CAR nutrient solutions, with 5 wells in each group. The contents of insulin-like growth factor I (IGF-I) and keratinocyte growth factor (KGF) were determined with ELISA. Data were processed with independent samples t test and one-way analysis of variance. RESULTS: (1) The immunohistochemistry staining showed that there was mild positive staining in the skin tissue sections of mice in group C, while the positive staining was more obvious in group HS. The positive staining was mainly located in KCs, hair follicles, and sweat gland epithelial cells, while no positive staining was observed in fibroblasts. The mRNA expression levels of CAR in skin tissue sections in group C and group HS were respectively 0.157 ± 0.027 and 0.773 ± 0.029. There was statistically significant difference between them (t = 3.052, P < 0.01). The protein expression levels of CAR in skin tissue sections in group C and group HS were respectively 0.23 ± 0.09 and 0.89 ± 0.14. There was statistically significant difference between them (t = 2.556, P < 0.05). (2) The apoptosis rates of KCs in group C and group HS were respectively (5.7 ± 1.3)% and (7.4 ± 1.7)% (t = 0.464, P > 0.05). The expression rates of CAR in KCs in group C and group HS were respectively (48 ± 6)% and (80 ± 8)%. There was statistically significant difference between them (t = 2.585, P < 0.05). (3) The contents of IGF-Iin culture supernatants in group C and 0.5, 1.0, 2.0, 4.0, 8.0, 16.0 mg/L CAR groups were respectively (23.1 ± 1.8), (22.5 ± 2.1), (31.2 ± 2.5), (39.7 ± 2.3), (61.8 ± 3.5), (45.1 ± 2.8), and (29.0 ± 2.0) µg/L. There was statistically significant difference among 7 groups (F = 3.414, P < 0.05). The contents of KGF in culture supernatants in group C and 0.5, 1.0, 2.0, 4.0, 8.0, 16.0 mg/L CAR groups were respectively (131 ± 9), (217 ± 12), (355 ± 21), (563 ± 21), (535 ± 34), (292 ± 20), and (245 ± 10) ng/L. There was statistically significant difference among 7 groups (F = 5.063, P < 0.01). CONCLUSIONS: The expression of CAR in KCs would rise after HS. The optimum CAR concentration to increase IGF-I and KGF production in DETCs is low.

Effects of heat stress on the expression of the coxsackievirus and adenovirus receptor in mouse skin keratinocytes.

The aim of this study was to investigate the effects of heat stress on the expression of the coxsackievirus and adenovirus receptor (CAR) in mouse skin keratinocytes. Twenty BALB/c mice were randomly divided into two groups: the sham heat (control) and scald groups. Skin specimens were obtained 6 h after the treatments. Changes in the expression of CAR in skin keratinocyte samples were detected by immunohistochemistry, quantitative polymerase chain reaction and western blotting. In an in vitro assay, mouse skin keratinocytes were cultured and randomly divided into two groups: the normal control and heat stress groups. Six hours subsequently, the changes in CAR expression in the two groups were estimated by flow cytometry to determine the differences between the two groups. Heat stress significantly increased the expression of CAR in the mouse skin keratinocytes (P<0.05). The upregulation of CAR in mouse keratinocytes in burn wounds may be beneficial for restoring healing in organisms.

[Effects of different stimulatory factors on functions of CIK cells].

This study was aimed to investigate the effects of different stimulatory factors on proliferation and function of cytokine induced killer (CIK) cells. Peripheral blood mononuclear cells (PBMNC) were separated by Ficoll-Hypacue gradient. According to supplement of different stimulatory factors (CD28 mAb, IL-15 and IL-21), the experiment was divided into five groups:control group (CIK), CB28+IL-15+IL-21 group, IL-15+IL-21 group, CD28+IL-15 group and CD28+IL-21 group. Effects of different stimulatory factors on the proliferation of CIK cells were assayed by an automated hematology analyzer. Changes of granzyme B,perforin and CD107a were detected by flow cytometry. IL-10, IL-12, INF-γ and TNF-α were quantified by ELISA. Cytotoxicities on lung cancer cell line A549, breast adenocarcinoma cell line MFC-7 and human melanoma cell line HME1 were examined by lactate dehydrogenase release method. The results showed that there were significant differences among different groups. The highest proliferation index on days 10 was observed in group CD28mAb, IL-15 and IL-21(255.3 ± 6.3), which was higher than control group, IL-21+IL-15 group and CD28 mAb+IL-21 group (166.6 ± 13.5, 199.4 ± 15.0 and 228.8 ± 16.6) (P < 0.05). The expression of perforin in CD28 mAb+IL-15 group was higher than the other groups. The expression of perforin,GranB and CD107a of costimulatory groups was higher than control group. The cytotoxicities of CD28 mAb+IL-15 group on A549, MFC-7 and HME1 cells (82.2%, 59.3% and 70.6%) were much higher than that of control group (60.9%, 49.6% and 48.4%) (P < 0.05). The highest IFN-γsecretion was found in CD28 mAb, IL-15 and IL-21 groups. It is concluded that there are significant difference of proliferative capacity, cytokine secretion and cytotoxicity after being activated by different stimulatory factors. Adding corresponding stimulatory factors into the culture system displays a great value for target cells culture.

The enhanced effect of lupeol on the destruction of gastric cancer cells by NK cells.

Lupeol, a triterpene, was reported to possess beneficial effects as a therapeutic and preventive agent for a range of disorders. Many studies have confirmed that lupeol possesses strong activities such as antioxidative, antiinflammatory, antiarthritic, antimutagenic, and antimalarial, both in vitro and in vivo, and at its effective therapeutic doses exhibit no toxicity to normal cells and tissues. Lupeol was observed to inhibit the proliferation of gastric tumour cells in a dose-dependent manner, as assessed by MTT assay, and induce the proliferation of NK cells, as assessed by flow cytometry and Western blotting. The killing effect of NK cells on gastric tumour cells was assessed by LDH. Our experiment demonstrated that lupeol at appropriate concentrations could promote the proliferation of NK cells, inhibit the proliferation of gastric cancer cell lines BGC823, N87 and HGC27, and increase the killing effect of NK cells on gastric cancer cells. We speculated that lupeol might increase the expression of PFP, IFN-γ, and CD107a via the activation of PI3K/Akt and Wnt/ß-catenin signalling pathways. Lupeol could serve as a potential agent against gastric cancer; however, further in-depth in vivo studies are still required.

The effect of phloretin on human γδ T cells killing colon cancer SW-1116 cells.

OBJECTIVE: To explore the effect and mechanism of Phloretin on human γδ T cells killing colon cancer SW-1116 cells. METHODS: γδ T cells were amplified in vitro from human peripheral blood mononuclear cells through isopentenyl pyrophosphate method (IPP). After cocultured different concentrations of Phloretin with γδ T cells or SW-1116 cells for 48h respectively, MTT assay was used to test the growth curve of these two cells; Flow cytometry to test the expression of Granzyme B (GraB), perforin (PFP), CD107a and IFN-γ of γδ T cells; Lactate dehydrogenase (LDH) release assay to test the cytotoxic activity of the γδ T cells on SW-1116 cells; and Western blot to test the Wnt3a expression of the γδ T cells. RESULTS: After cultured with IPP for ten days, the percentage of γδ T cells increased from 3.31±3.00% to 78.40±10.30%. Compared to the control group, when the concentration of Phloretin increased from 2.35µg/ml to 18.75µg/ml, it could significantly proliferate the γδ T cell growth (P<0.05) and inhibit the growth of SW-1116 cells in dose-response, and the expression of GraB, PFP, CD107a and Wnt3a significantly increased (P<0.05). Significant positive relationships were observed among CD107a and PFP, GraB, cytotoxicity (P<0.05). The percentage of IFN-γ producing γδ T cells treated with Phloretin was significantly higher than control group. CONCLUSION: Phloretin can enhance the killing effect of γδ T cells on SW-1116 cells; the mechanism may be that Phloretin could proliferate the γδ T cell growth, increase the expression of PFP and GraB, activate the Wnt signaling pathway, and produce higher level of IFN-γ. Indeed CD107a expression probably correlates quite well with antitumor activity.

[Co-stimulation of multiple activating factors on proliferation and phenotype of T lymphocytes in peripheral blood in vitro].

AIM: To observe the costimulation of multiple activating factors effects on the proliferation and phenotype of T lymphocytes in vitro. METHODS: Peripheral blood mononuclear cells (PBMCs) were separated by fractionation on Ficoll-Hypaque gradient. According to adding different cytokines (CD3 mAb, CD28 mAb, IFN-γ, IL-1α, IL-2 and IL-15), the experiments were divided into seven groups. Effects of different cytokines on the proliferation of PBMC were counted by automated hematology analyzer five categories. The phenotypes (CD3, CD4, CD8, CD28, CD16, CD56(+);CD16, CD3(+);CD8(+);, CD3(+);CD4(+);, CD3(+); CD56(+);, CD45RO) expressing on the surface of costimulatory cells were detected by flow cytometry, and the cytotoxicity of costimulatory cells on SGC-7901, SW-1990 and SW-116 cell lines was examined by lactate dehydrogenase release method. RESULTS: The proliferation has significant difference when adding different cytokines into PBMCs culture system, the highestest proliferation multiples group is the one contains cytokines CD3, CD28, IFN-γ, IL-2, IL-1α, IL-15 and IL-21, which proliferation multiple is 255.3±6.3 at the tenth day of cell culture, obviously higher than the other culture systems which only contains CD3, IFN-γ and IL-2 (166.6±5.5) (P<0.05). Part of cells'phenotype changed when adding different activating factors. Without IL-15, the proportion of CD16(+);CD56(+);(NK) cells and CD3(+);CD56(+); cells was higher than the other groups; CD45RO(+); memory cells is most evident when delayed adding IL-15 and IL-21 for three days. The cytotoxicity of PBMCs cultured for ten days with different activating factors had significant difference, the highest was the one which delayed adding IL-15 and IL-21 for three days (76.2%, 60.3% and 70.6%, respectively.), higher than the cell culture groups containing CD3, IFN-γ and IL-2 (54.9%, 44.6% and 50.4%, respectively) (P<0.05). The cultured cells had the strongest cytotoxicity on SGC-7901 gastric adenocarcinoma cells. CONCLUSION: The PBMCs' proliferation, phenotype and cytotoxicity had significant difference after being activated by different stimulating factors, adding matching stimulating factors into the culture system have great value on cell-directed culture.

Effects of pituitary adenylate cyclase activating polypeptide on CD4(+)/CD8(+) T cell levels after traumatic brain injury in a rat model.

BACKGROUND: The effect of pituitary adenylate cyclase activating polypeptide (PACAP) during traumatic brain injury (TBI) and whether it can modulate secondary injury has not been reported previously. The present study evaluated the potential protective effects of ventricular infusion of PACAP in a rat model of TBI. METHODS: Male Sprague Dawley rats were randomly divided into 3 treatment groups (n=6, each): sham-operated, vehicle (normal saline)+TBI, and PACAP+TBI. Normal saline or PACAP (1 µg/5 µL) was administered intracerebroventricularly 20 minutes before TBI. Right parietal cortical contusion was produced via a weight-dropping method. Brains were extracted 24 hours after trauma. Histological changes in brains were examined by HE staining. The numbers of CD4(+) and CD8(+) T cells in blood and the spleen were detected via flow cytometry. RESULTS: In injured brain regions, edema, hemorrhage, inflammatory cell infiltration, and swollen and degenerated neurons were observed under a light microscope, and the neurons were disorderly arrayed in the hippocampi. Compared to the sham group, average CD4(+) CD8(-) lymphocyte counts in blood and the spleen were significantly decreased in rats that received TBI+vehicle, and CD4(-) CD8(+) were increased. In rats administered PACAP prior to TBI, damage was attenuated as evidenced by significantly increased CD4(+), and decreased CD8(+), T lymphocytes in blood and the spleen. CONCLUSION: Pretreatment with PACAP may protect against TBI by influencing periphery T cellular immune function.