Hepatic stellate cells (HSCs) are the primary extracellular matrix-producing cells within the liver and have numerous vital functions. A robust protocol for the isolation and culture of HSCs is important for further investigations of cell functions and related mechanisms in liver disease. The volume of the mouse liver is much smaller than that of the rat liver, which makes it much more difficult to isolate mouse HSCs (mHSCs) than rat HSCs. At present, isolating mHSCs is still a challenge because there is no efficient, robust method to isolate and culture these cells. In the present study, C57BL/6J mice were intravenously injected with liposome-encapsulated dichloromethylene diphosphate (CL2MDP) to selectively eliminate Kupffer cells from the liver. The mouse livers were then perfused in situ, and the mHSCs were isolated with an optimized density gradient centrifugation technique. In the phosphate buffer solution (PBS)-liposome group, the yield of mHSCs was (1.37 ± 0.23) × 106/g liver, the cell purity was (90.18 ± 1.61)%, and the cell survival rate was (94.51 ± 1.61)%. While in the CL2MDP-liposome group, the yield of mHSCs was (1.62 ± 0.34) × 106/g liver, the cell purity was (94.44 ± 1.89)%, and the cell survival rate was (94.41 ± 1.50)%. Based on the yield and purity of mHSCs, the CL2MDP-liposome treatment was superior to the PBS-liposome treatment (P < 0.05, P < 0.01). This study established successfully a robust and efficient protocol for the separation and purification of mHSCs, and both a high purity and an adequate yield of mHSCs were obtained.
1 January 2018 in Chinese Journal of Cancer Research
The aim of the present study was to investigate the effects of 5-fluorouracil (5-Fu) and oxaliplatin on the function and activation pathways of mouse dendritic cells (DCs), and to clarify whether 5-Fu/oxaliplatin combined with the CD1d-MC38/α-galactosylceramide (α-GC) tumor vaccine exhibits synergistic effects on the treatment of colon cancer in mice. The combination of the Toll like receptor (TLR) ligands and/or 5-Fu/oxaliplatin was added into myeloid-derived DCs in vitro culture. DC phenotypic changes were detected by flow cytometry, and the secretion of DC cytokines was detected by cytometric bead array (CBA). A MC38 mouse colon cancer model was constructed and the DCs were isolated from the spleen, tumor tissue and lymph nodes following intraperitoneal injection of 5-Fu/oxaliplatin. The cell phenotypes were detected by flow cytometry. The tumor infiltrating leukocytes, splenocytes and lymph node cells were co-cultured with the dead MC38 tumor cells, and the secretion levels of interferon-γ (IFN-γ) were detected. 5-Fu/oxaliplatin combined with our previously developed CD1d-MC38/α-GC tumor vaccine was used to inhibit the growth of MC38 colon cancer in mice, and the tumor growth rate and survival time were recorded. 5-Fu/oxaliplatin exerted no significant effect on the expression of the stimulating phenotypes of DCs in vitro, while it could reduce the expression of programmed death ligand 1/2 (PD-L1/L2) and promote interleukin-12 (IL-12) secretion by DCs. Furthermore 5-Fu/oxaliplatin was beneficial to the differentiation of T-helper 1 (Th1) cells. 5-Fu/oxaliplatin further enhanced the stimulating phenotypic expression of DCs in tumor bearing mice, decreased PD-L1/L2 expression, and specifically activated the lymphocytes. The CD1d-MC38/α-GC tumor vaccine combined with 5-Fu/oxaliplatin could exert a synergistic role that resulted in a significant delay of the tumor growth rate, and an increase in the survival time of tumor bearing mice. 5-Fu/oxaliplatin decreased the expression of the DC inhibitory phenotypes PD-L1/L2, promoted DC phenotypic maturation in tumor bearing mice, activated the lymphocytes of tumor bearing mice, and exerted synergistic effects with the CD1d-MC38/α-GC colon cancer tumor vaccine.
Calponin family members are actin filament–associated regulatory proteins with distinct expression patterns. Previous studies on CNN2 (calponin 2) have demonstrated that CNN2 is expressed in a broad range of tissues and cell types, exhibiting potential regulatory roles in a number of cellular activities, including cell proliferation, cell migration, and platelet adhesion. In this work, we found that both messenger RNA and protein expression levels of CNN2 were remarkably upregulated in 60%–70% of gastric cancer tissues by comparison with those of neighboring non-tumorous mucosa. By utilizing specific shCNN2 (small hairpin RNA targeting CNN2), the potential role of CNN2 in regulating AGS gastric cancer cell growth was then further investigated. AGS cells infected with shCNN2 exhibited significantly decreased cell growth ability by comparison with control cells in vitro. Moreover, while there was no obvious difference in cell cycle distribution between two groups, enhanced cell apoptosis was detected in cells with reduced CNN2 expression. Consistently, caspase 3/7 activity was also remarkably activated upon shCNN2 lentivirus infection. Taken together, our results demonstrated that knockdown of endogenous CNN2 in AGS cells could significantly activate cell apoptosis pathway and therefore suppress cell growth in vitro. The deletion of CNN2 might be a potential therapeutic approach to inhibit aggressive growth of gastric cancer.
Dendritic cells (DCs) and invariant natural killer T (iNKT) cells play important roles in linking innate immunity and adaptive immunity. Mature DCs activated by Toll-like receptor (TLR) agonists directly activate iNKT cells and the iNKT ligand α-galactosylceramide (α-Galcer) can induce DC maturation, resulting in enhanced protective immune responses. In the present study, we aimed to boost anti-tumour immunity in a murine colon cancer model by synergizing DCs and iNKT cells using α-Galcer-loaded tumour cells (tumour–Gal) and the TLR9 agonist cytosine-phosphorothioate-guanine (CpG1826). The vaccine strategy was sufficient to inhibit growth of established tumours and prolonged survival of tumour-bearing mice. Importantly, the immunization induced an adaptive memory immune response as the survivors from primary tumour inoculations were resistant to a tumour re-challenge. Furthermore, injection of tumour–Gal with CpG1826 resulted in iNKT cell activation and DC maturation as defined by interferon (IFN)-γ secretion by iNKT, natural killer (NK) cells and interleukin (IL)-12 by DCs. Immunohistochemistry analysis revealed that cluster of differentiation (CD)4+ T-cells and CD8+ T-cells played important roles in anti-tumour immunity. Additionally, the vaccine redirected Th2 (T-helper cell type 2) responses toward Th1 (T-helper cell type 1) responses with increases in IL-2, IFN-γ expression and decreases in IL-4 and IL-5 expression after immunization with tumour–Gal with CpG1826. Taken together, our results demonstrated a novel vaccination by synergizing tumour–Gal and CpG1826 against murine colon cancer, which can be further developed as tumour-specific immunotherapy against human cancer.
10 July 2012 in International Journal of Colorectal Disease
Dendritic cell (DC)-based cancer vaccine represents a promising immunotherapy against cancer. There has been recent evidence which have suggested that toll-like receptor (TLR) ligands may be critical for DC preparation; this was usually omitted in the past. Our study is designed to investigate if the vaccination of synergistical toll-like receptors activated DCs can induce more potent cytotoxic T Lymphocytes (CTL) responses and antitumor activity in carcinoembryonic antigen (CEA) transgenic mouse tumor models. We involved combination of TLR3 and TLR7/8 ligands in culture protocol of DCs. The DCs’ surface molecules expression, IL-12 secretion and proliferation capacity of lymphocytes were tested. We also investigate the CTL activity against MC38-CEA colon tumor cells and the prophylactic and therapeutic effects of DC vaccination in subcutaneous mouse colon tumor models. Compared with conventionally generated DCs, we showed synergistic TLR-activated DCs exhibited higher surface molecule expression, significantly higher secretion of IL-12 and more potent proliferating capacity of lymphocytes. Synergistic TLR-activated DCs were also able to induce lymphocytes possessing the specific cytotoxicity against MC38-CEA cells in vitro. Vaccination with CEA epitope pulsed TLR-activated DCs elicited antigen-specific preventive effect on MC38-CEA tumors, but failed to cure the tumor-bearing mice, that may be due to the suboptimal epitope selected and host immunosuppression. Our results have proved that combined activation of TLRs can lead to better maturation status of DCs and also induce more effective antitumor immune responses against colon cancer, suggesting this may be a potential strategy to develop more powerful DC cancer vaccines.
18 September 2017 in World Chinese Journal of Digestology