Enhanced growth suppression of TERT-positive tumor cells by oncolytic adenovirus armed with CCL20 and CD40L.

Conditionally replicating adenoviruses (CRAds) selectively replicate in cancer cells and induce cell lysis, which represents a potential platform for cancer immunotherapy. The chemokine CCL20 exerts antitumor activity via chemoattraction of immature dendritic cells (DCs) and lymphocytes. However, the activation and maturation status of DCs is a limiting factor in the DCs -based immunity response. CD40L induces the phenotypic maturation of DCs, mediates DCs cytokine secretion, and increases the expression of FasL, which mediates apoptosis. We constructed a CCL20/CD40L co-expression CRAds (Ad-CCL20-CD40L) based on the AdEasy system. Ad-CCL20-CD40L was constructed from three plasmids, pGTE-CD40L, pShuttle-CMV-CCL20 and AdEasy-1, and was homologously recombined and propagated in the Escherichia coli strain BJ5183 and the packaging cell line HEK-293, respectively. Ad-CCL20-CD40L selectively replicates in TERT-positive tumor cells because the pGTE-CD40L plasmid contains the telomerase reverse transcriptase promoter (TERTp). Our results showed that Ad-CCL20-CD40L induced oncolytic effects and tumor-specific cytotoxicity of cytotoxic T lymphocytes (CTLs) in vitro. This study suggests that Ad-CCL20-CD40L can induce the antitumor immune response and that this platform can be modified to generate novel CRAds with other transgenes.

Enhanced antitumor immunity is elicited by adenovirus-mediated gene transfer of CCL21 and IL-15 in murine colon carcinomas.

The chemokine CCL21 is a potent chemoattractant for T cells and dendritic cells. IL-15 elicits powerful antitumor immune responses through the stimulation of natural killer cells. We constructed a CCL21/IL-15-expressing adenovirus (Ad-CCL21-IL-15) and evaluated its antitumor effects in vitro and in vivo. We found that the intratumoral injection of Ad-CCL21-IL-15 into murine colon carcinomas significantly inhibited tumor growth. Splenocytes from mice treated with Ad-CCL21-IL-15 developed tumor-specific cytotoxic T cells and were protected from subsequent challenges with tumor cells. This study indicates that providing cancer therapy by combining CCL21 and IL-15 can induce antitumor immune responses and is an effective strategy for cancer immunotherapy.

Adenovirus-mediated CCL20/IL-15 gene transfer enhances antitumor immunity in mice.

The CCL20 chemokine has potent antitumor activities through chemoattracting immature dentritic cells. But the maturation status of tumoral dentritic cells is important limiting factors in DC-based immunity. The endogenous availability of IL-15 was effective in inducing the dentritic cells maturation and IL-15 also shows tumor-specific antitumor activities. We constructed a CCL20/IL-15 bicistronic adenovirus (Ad-CCL20-IL-15) and confirmed its combined antitumor effect in vitro and in vivo. Intratumoral injection of Ad-CCL20-IL-15 into both CT-26 and B16F10 cells resulted in marked reduction of tumor growth in our model. Splenocytes treated by Ad-CCL20-IL-15 developed tumor-specific cytotoxic T cells and IFN-γ secretion could protect mice from rechallenging. This study suggests that CCL20/IL-15 can induce a strong antitumor immune response in tumor tissues and it is a suitable candidate for cancer immunotherapy.

[ShRNA-mediated silencing of MDM2 inhibits growth of HepG2 hepatocellular carcinoma cells xenografted in nude mice].

OBJECTIVE: To construct a short hairpin (sh)RNA targeting the gene encoding the MDM2 oncoprotein in order to investigate its role in human hepatocellular carcinoma (HCC) and its potential for use as a gene therapy strategy to inhibit HCC growth in vivo. METHODS: Small interfering (si)RNAs were designed targeting the MDM2 gene (siMDM2-1 and siMDM2-2) and unrelated sequences (negative control) and cloned into the expression plasmid pGCSilencer-U6-neo-GFP. A HCC mouse model was established by subcutaneous inoculation of HepG2 cells (2 x 10(6) in 0.2 ml) into 20 nude mice. The inoculated mice were divided into four equal groups for tumor-localized injections of saline, negative control siRNA plasmid, siMDM2-1 plasmid, and siMDM2-2 plasmid. Tumor growth was observed daily (by caliper measurement) for one month, when mice were sacrificed by cervical dislocation. The tumor mass was resected for analysis of tumor inhibition rate (% = [(average tumor weight of control group - average tumor weight of treatment group) / average tumor weight of control group x 100]) and effects on MDM2 and p53 mRNA and protein expression (by reverse transcription- PCR and western blotting, both normalized to beta-actin). Significance of between-group differences was assessed by one-way ANOVA or LSD test; pairwise comparisons were made by the Chi-squared test. RESULTS: siMDM2-1 and siMDM2-2 suppressed the xenografted tumor growth remarkably (60.6% and 54.6% inhibition rates, respectively), significantly reduced the expression ofMDM2 gene (62.8% and 61.6%) and protein (60.7% and 59.5%), and significantly increased p53 gene (47.1% and 45.6%) and protein (45.9% and 44.3%) (all, P < 0.05). CONCLUSION: shRNA-mediated silencing of the MDM2 gene effectively inhibits HCC tumorigenesis of subcutaneously xenografted HepG2 cells in nude mice, and the mechanism may involve p53.

Staphylococcus aureus infection of intestinal epithelial cells induces human umbilical cord-derived mesenchymal stem cell migration.

There is a growing interest in umbilical cord blood (UCB)-derived mesenchymal stem cells (MSCs) for cellular therapy in regenerative medicine. To aid in tissue repair, MSCs are recruited to sites of inflammation induced by a bacterial infection. The primary objective of this study was to explore the mechanisms of MSC recruitment to intestinal epithelial cells infected with Staphylococcus aureus. First, we isolated and characterized the UCB-derived MSCs used in our experiments. Next, we determined the ability of S. aureus infected intestinal epithelial cells to induce migration of UCB-derived MSCs. Expression analysis of cytokines secreted by infected epithelial cells indicated that MSC migration occurred predominately via a nuclear factor-kappa B (NF-κB)-dependent signaling pathway. Altogether, our data provide the first evidence for a role of S. aureus infection in MSC migration and reveal the function of UCB-derived MSCs in intestinal pathophysiology.

Identification and characterization of antigenic epitope of Staphylococcus aureus ClfA adhesin.

Staphylococcus aureus ClfA adhesin is a protective antigen that induces partial immunity against S. aureus infection in mice. To identify the antigenic epitope of ClfA, a monoclonal antibody (mAb) D01 against the recombinant protein was produced by the hybridoma technique. The mAb was used to immunoscreen a random phage-displayed peptide library as the immunogen. After three rounds of biopanning, 41 positive clones were identified. Sixteen phage clones were sequenced and their amino acids were deduced. One mimotope (SKVGIDKRRGTA) showed good match with ClfA adhesin at 383-394 aa and the serum of mice induced by the phage clone clearly recognized ClfA adhesin.

Proteomic alteration of Marc-145 cells and PAMs after infection by porcine reproductive and respiratory syndrome virus.

Viral infections usually result in alterations in the host cell proteome, which determine the fate of infected cells and the progress of pathogenesis. To uncover cellular protein responses in porcine reproductive and respiratory syndrome virus (PRRSV), infected pulmonary alveolar macrophages (PAMs) and Marc-145 cells were subjected to proteomic analysis involving two-dimensional electrophoresis (2-DE) followed by MALDI-TOF-MS/MS identification. Altered expression of 44 protein spots in infected cells was identified in 2D gels, of which the 29 characterised by MALDI-TOF-MS/MS included 17 up-regulated and 12 down-regulated proteins. Some of these proteins were further confirmed at the mRNA level using real-time RT-PCR. Moreover, Western blot analysis confirmed the up-regulation of HSP27, vimentin and the down-regulation of galectin-1. Our study is the first attempt to analyze the cellular protein profile of PRRSV-infected Marc-145 cells using proteomics to provide valuable information about the effects of PRRSV-induced alterations on Marc-145 cell function. Further study of the affected proteins may facilitate our understanding of the mechanisms of PRRSV infection and pathogenesis.

Using CT imaging to delineate the prostatic apex for radiation treatment planning.

BACKGROUND AND OBJECTIVE: In computed tomography (CT)-based radiotherapy planning for prostate cancer, it is difficult to precisely delineate the prostatic apex because of its relationship with the urogenital diaphragm and bulbospongiosus musculature. In this retrospective study, we analyzed the magnetic resonance imaging (MRI) and CT scans of the patients with prostate cancer to investigate the relationship between the prostatic apex and the anatomic structure visible on CT, and to provide evidence for localizing the prostatic apex in radiotherapy planning. METHODS: MRI and CT scans of 108 patients with prostate cancer were analyzed to measure the distances between the prostatic apex and the bottom of ischial tuberosities, the bottom of obturator foramen, the bottom of pubic symphysis, and the bulb of the penis. The volume of the prostate was measured to analyze its relationship with the localization of the prostatic apex. RESULTS: The prostatic apex was located (13.1±3.3) mm above the bulb of the penis, (11.0±5.4) mm above the bottom of the obturator foramen, (31.3±5.5) mm above the ischial tuberosities, and (7.1±4.7) mm above the bottom of the symphysis pubis. There was no correlation between the size of the prostate and the localization of the prostatic apex. CONCLUSIONS: The variance of the distance between the prostatic apex and the bulb of the penis is smaller than that of the distance between the apex and bony anatomy. Delineating the target to 6 mm above the bulb of the penis can cover the prostatic apex in 95% of the patients with prostate cancer, delineating to the bottom of obturator foramen can cover the prostatic apex in 100% of the patients.