An immuno-blocking agent targeting IL-1ß and IL-17A reduces the lesion of DSS-induced ulcerative colitis in mice.

In recent decades when biological agents have flourished, a part of patients suffering from inflammatory bowel disease (IBD) have received the treatment of tumor necrosis factor inhibitors or IL-1 antibodies. This study aims to investigate the anti-colitis effects of bispecific antibody (FL-BsAb1/17) targeting IL-1ß and IL-17A comparing with TNF-α soluble receptor medicine etanercept. IBD model in mice was established by drinking 3% DSS (dextran sulfate sodium salt). On the first day of drinking DSS, treatments with etanercept (5 mg/kg) or different doses of FL-BsAb1/17 (1 mg/kg, 5 mg/kg, and 10 mg/kg) were started by intraperitoneal injection every other day. The results demonstrated that FL-BsAb1/17 treatment was more effective than etanercept at the same dose (5 mg/kg) in relieving the typical symptom of ulcerative colitis induced by DSS (such as the severity score and intestinal shortening), and down-regulating the expression of inflammatory factors (IL-17A, IL-6, IL-12, IL-22, IL-1ß, IL-23, TNF-α) in the serum and colon. FL-BsAb1/17 could also reduce the degree of intestinal fibrosis. The same dose of FL-BsAb1/17 (5 mg/kg) performed better than etanercept in down-regulating MDA and up-regulating SOD (superoxide dismutase), CAT (catalase), and T-AOC (total antioxidant capacity) in serum. Both FL-BsAb1/17 and etanercept could reduce the transcription of Bax and increase the transcription of Bcl-2 and slow down apoptosis in colitis colon tissue. We conclude that the blocking of IL-1ß and IL-17A can inhibit DSS-induced ulcerative colitis and FL-BsAb1/17 may have potential to become a new dual-target candidate for colitis treatment.

Development and evaluation of a recombinant VP2 neutralizing epitope antigen vaccine candidate for infectious bursal disease virus.

Infectious bursal disease (IBD) is one of the most economically important infectious diseases. Currently, vaccination is the most effective method to prevent IBD. Medium-virulence vaccines can damage the bursa of Fabricius and result in immunosuppression. Therefore, it is essential to develop a safe and effective vaccine against infectious bursal disease virus (IBDV). In this study, the five neutralizing epitopes of the IBDV VP2 protein were confirmed by neutralizing single chain variable fragment antibodies. Then, the neutralizing epitopes antigen (NEA) protein was constructed with five neutralizing epitopes and expressed by pET-27b. Furthermore, the immune effect and protective immunity of the NEA protein with the following adjuvants were evaluated in specific-pathogen-free chickens: oil emulsion adjuvant (OEA), double emulsion adjuvant (DEA), granulocyte-macrophage colony-stimulating factor (GM-CSF) adjuvant and complete Freund's adjuvant (CFA). The experimental results demonstrated that chickens immunized with NEA vaccines elicited stronger humoral and/or cellular immune responses and inflammatory responses than those in the NEA protein group. Chickens were protected in OEA, CFA and GM-CSF adjuvant groups, which were challenged with virulent IBDV BC6/85. Furthermore, IBDV RNA was not measured, and there appeared to be little apoptosis in the bursa of Fabricius based on TUNEL histology and the expression of Bax and Bcl-2 in the OEA, CFA and GM-CSF adjuvant groups. Based on the experimental results, the advantages and disadvantages of adjuvants and industrial production methods, GM-CSF was found to be the optimal adjuvant. Therefore, NEA with GM-CSF adjuvant is a promising vaccine candidate against IBDV, and it provides a framework for developing other vaccines against infectious viral diseases.

Optimization of oncolytic effect of Newcastle disease virus Clone30 by selecting sensitive tumor host and constructing more oncolytic viruses.

The direct oncolytic effect of Newcastle disease virus (NDV) depends on the following two aspects: the susceptibility of cancer cells to virus infection and the ability of virus itself to lyse cancer cells. First, we investigate the susceptibility of cancer cells to NDV infection, HepG2, MDA-MB-231, and SH-SY5Y cells were susceptible, A549, MCF7, and LoVo cells were less susceptible. To investigate the molecular mechanism responsible for cancer cell susceptibility, transcriptome sequencing was carried out. We found that the levels of alpha-sialic acid acyltransferase were upregulated in MDA-MB-231 cells compared with MCF7 cells, and the interferon was downregulated. Second, to optimize the oncolytic capacity of the wild-type rClone30, a series of chimeric viruses rClone30-Anh(HN), rClone30-Anh(F), and rClone30-Anh(HN-F) were constructed by exchanging the HN gene, F gene or both of non-lytic rClone30 strain with lytic strain Anhinga. rClone30-Anh(F) and rClone30-Anh(HN-F) enhanced the oncolytic effect of the rClone30, and this enhancement is more obvious in the susceptible cells. The oncolytic mechanism of rClone30-Anh(F) was analyzed by transcriptome analyses, in comparison with rClone30, rClone30-Anh(F) upregulated the expression of ATG5, Beclin 1, and MAP1LC3B, thus activating autophagy and promoting the production of syncytia. In conclusion, our study provides a strategy to enhance the oncolytic effect of rClone30.

The recombinant Newcastle disease virus Anhinga strain expressing human TRAIL exhibit antitumor effects on a glioma nude mice model.

Oncolytic virus therapy is perhaps the next major breakthrough in cancer treatment following the success in immunotherapy using immune checkpoint inhibitors. However, the potential oncolytic ability of the recombinant newcastle disease virus (NDV) Anhinga strain carried with tumor necrosis factor-related apoptosis inducing ligand (TRAIL) has not been fully explored at present. In the present study, the recombinant NDV/Anh-TRAIL that secretes soluble TRAIL was constructed and the experiment results suggested NDV/Anh-TRAIL as a promising candidate for glioma therapy. Growth kinetic and TRAIL secreted quantity of recombinant NDV/Anh-TRAIL virus were measured. Cytotoxic and cell apoptosis were analyzed for its anti-glioma therapy in vitro. Nude mice were used for the in vivo evaluation. Both tumor volume and mice behavior after injection were observed. The recombinant virus replicated with the same kinetics as the parental virus and the highest expression of TRAIL (77.8 ng/L) was found at 48 hours. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, a tetrazole and flow cytometry data revealed that the recombinant NDV/Anh-TRAIL (56.1 ± 8.2%) virus could induce a more severe apoptosis rate, when compared with the NDV wild type (37.2 ± 7.0%) and mock (7.0 ± 1.8%) groups (P < .01), in U251 cells. Furthermore, in the present animal study, the average tumor volume was smaller in the NDV/Anh-TRAIL group (97.21 mm3 ), when compared with the NDV wild type (205.03 mm3 , P < .05) and PBS (310.30 mm3 , P < .01) groups.

A novel bispecific antibody alleviates bleomycin-induced systemic sclerosis injury.

Systemic sclerosis (SSc) is induced by variety of factors and eventually causes multiple organ damage. In recent years, biological agents targeting cytokines and cell surface molecules have gradually come to market. Here, the anti-inflammatory and antifibrotic effects of a novel bispecific antibody (FL-BsAb1/17) targeting interleukin-17A (IL-17A) and interleukin-1ß (IL-1ß) were detected. Bleomycin (BLM) was subcutaneously injected for 21 consecutive days to establish the SSc mouse model, and mice were subsequently treated with etanercept or different doses (1, 5, 10 mg/kg) of FL-BsAb1/17. The results showed that FL-BsAb1/17 treatment (10 mg/kg, 5 mg/kg) significantly attenuated BLM-induced SSc-like inflammation by inhibiting the expression of inflammatory factors (IL-17A, IL-1ß, IL-8, IL-22, IL-23, IL-6) and fibrosis, with specific outcomes of dermis thickening and lung fibrosis, by inhibiting the expression of fibrotic factors (TGF-ß, α-sma, Col-1, Col-3) in the serum, skin and lungs. In addition, FL-BsAb1/17 (10 mg/kg, 5 mg/kg) downregulated protein levels of TGF-ß and phosphorylated Smad2/3 in the skin and lungs and reduced collagen 1 protein levels. This indicated that FL-BsAb1/17 can inhibit the development of fibrosis by inhibiting the TGF-ß/Smad2/3 signaling pathway. FL-BsAb1/17 (10 mg/kg, 5 mg/kg) could also effectively reduce the content of MDA, increase the activity of SOD and CAT, and improve the total antioxidant capacity (T-AOC). In conclusion, FL-BsAb1/17 alleviated BLM-induced SSc by downregulating inflammatory cascades, relieving oxidative stress and inhibiting TGF-ß/Smad2/3 signaling. These data suggest that FL-BsAb1/17 has potential as a novel therapeutic candidate for SSc.

FGF21 attenuates pulmonary fibrogenesis through ameliorating oxidative stress in vivo and in vitro.

Pulmonary fibrosis (PF) is a chronic, progressive lung disease, characterized by excessive matrix formation, destruction of the normal lung architecture, dysfunction and finally death. Fibroblast growth factor 21 (FGF21) is a promising pleiotropic regulator in glucolipid metabolism. Recently, we reported that FGF21 attenuates hepatic fibrogenesis. However, the role of FGF21 on PF is unknown. In this study, mice endotracheal instilled with bleomycin (BLM) were used to study the effect of FGF21 on PF. Bleomycin-instilled mice were administered with pirfenidone (PFD) or FGF21 daily for 3 weeks from 7 days after instillation of BLM. Results showed FGF21 and PFD attenuated the dense deposition of collagen, intense infiltration of inflammatory cells and destruction of tissue architecture in lungs caused by BLM, and also alleviated the increased expression of TGF-ß, Col I and α-SMA and decreased the expression of E-cadherin. At the same time, FGF21 also markedly reversed the activity of SOD and T-AOC, decreased the enhanced content of MDA and increased the expression of Nrf-2 in the lungs of BLM-treated mice. To further explore the mechanisms of FGF21 attenuate PF by amelioration of oxidative stress, we examined the effect of FGF21 in A549 cells treated with paraquat (PQ). A549 cells were incubated with PQ plus FGF21 or PFD for 48 h. The results showed that FGF21 and PFD reduced the expression of TGF-ß, Col I and α-SMA and increased the expression of E-cadherin in PQ-treated A549 cells. FGF21 also suppressed oxidative stress in PQ-treated A549 cells, as evidenced by a decrease of the MDA level, a reversed activity of antioxidant enzymes and an increased expression of Nrf-2. We conclude that FGF21 inhibits pulmonary fibrosis through activating Nrf-2 pathway, subsequently suppressing oxidative stress, inhibiting ECM deposition and pulmonary fibrogenesis, suggesting that FGF21 has potential as therapeutic agent for treatment of pulmonary fibrosis.

A recombinant avian antibody against VP2 of infectious bursal disease virus protects chicken from viral infection.

A stable cell-line was established that expressed the recombinant avian antibody (rAb) against the infectious bursal disease virus (IBDV). rAb exhibited neutralization activity to IBDV-B87 strain in DF1 cells. The minimum rAb concentration required for inhibition of the cytopathic effect (CPE) was 1.563µg/mL. To test the efficacy of rAb, a 168-h cohabitation challenge experiment was performed to transmit the disease from the chickens challenged with vvIBDV (HLJ0504 strain) to three test groups of chickens, i.e. (1) chickens treated with rAb, (2) chickens treated with yolk antibody, and (3) non-treatment chickens. The survival rates of chickens treated with rAb, yolk antibody and without treatment were 73%, 67% and 20%, respectively. Another batch of chickens was challenged with IBDV (BC6/85 strain) and then injected with rAb (1.0mg/kg) 6, 24 and 36h post-challenge. Non-treatment chickens had 100% morbidity, whereas those administered with rAb exhibited only 20% morbidity. Morbidity was evaluated using clinical indicators and bursal histopathological section. This study provides a new approach to treating IBDV and the rAb represents a promising candidate for this IBDV therapy.

Recombinant Newcastle disease virus expressing human TRAIL as a potential candidate for hepatoma therapy.

Newcastle disease virus (NDV) have shown oncolytic therapeutic efficacy in preclinical studies and are currently proved for clinical trials. We have previously reported, for the first time, NDV Anhinga strain has an efficient cancer therapeutic efficacy in hepatoma. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) functions as a cytokine to selectively kill various cancer cells without toxicity to most normal cells. Numerous studies have demonstrated the potential use of recombinant soluble TRAIL as a cancer therapeutic agent. In this study, we have showed administration of a recombinant NDV Anhinga strain expressing soluble TRAIL (NDV/Anh-TRAIL) results in an efficient suppression of hepatocellular carcinoma without significant toxicity. The results show that recombinant NDV Anhinga strain expressing soluble TRAIL is a promising candidate for hepatoma therapy.

Recombinant NDV expressing cytokines or fliC confers a quick immune response against NDV challenge and resistance to maternal antibody.

Currently, there are two major bottleneck problems which seriously affect prevention of the Newcastle disease (ND): interference of maternal antibody on NDV vaccination and slow production of neutralization antibody. To overcome these problems, in present study, four rNDV vaccine strains expressing bio-adjuvants chIL2, chIL15, chGM-CSF or fliC gene were constructed and rescued using reverse genetics approach. The HI antibody titers of SPF birds immunized with rNDV reached to 5.5log2, 4.7log2, 6.5log2 and 5.8log2, respectively at the 8th day post immunization, while the antibody titers of the parental virus and control were 3.3log2 and 1log2, respectively. The immunized chickens were challenged by 104ELD50 dose of the virulent NDV BJ strains at the 7th day post immunization. The protection rate of the four rNDVs bio-adjuvant groups was 100%, while the protection rate of the parental group was 80%. We also examined the anti-maternal antibody activity of these adjuvant vaccines by detection HI titer after vaccination of chickens with high (8.4log2) or low (5log2) maternal antibody levels. In chicken flock with higher maternal antibody, parental strain could not resist the influence of the maternal antibody and induce any notable change of HI antibody kinetics. However, both rClon30-chGM-CSF and rClon30-flic were able to resist the influence of the maternal antibody and maintained the HI antibody above the protection level during the 14day's experiment. In chicken flock with lower maternal antibody, the parental rclone30 strain could not induce HI titer to the protection level until the 14th day, but both rClon30-GM-CSF and clone30-fliC raised the HI antibody to above the protection level at the 7th day post vaccination.

Screening scFv antibodies against infectious bursal disease virus by co-expression of antigen and antibody in the bacteria display system.

We have previously reported an antigen and antibody co-expression (AAC) technology to demonstrate the interaction between a known antigen and antibody. To validate the co-expression system for screening antibody libraries, a single chain fragment variable(scFv)antibody library was constructed from chickens immunized with the VP2 protein of infectious bursal disease virus (IBDV). The genes of both VP2 and scFv antibodies were inserted into the pBFD-Ab-Ag vector. The co-expression library was subjected to three rounds of screening by flow cytometry (FCM) using a polyclonal antibody against VP2 through a bacteria display system. We achieved enrichment of scFv specific for IBDV. 110 individual clones were initially selected and sequenced. Twenty clones were selected based on fluorescence intensity by FCM. The scFv antibodies were expressed by pET-27b in E.coli and purified. The specificity and affinity of the selected scFv antibodies were confirmed by western blotting assay and ELISA analysis. What's more, the neutralizing capacity was measured with IBDV-B87(100 TCID50) in vitro. Four scFvs (clone 8(1), Y8, L10 and L7) showed significant neutralizing capacity. Two of the four scFvs (clone 8(1) and Y8) demonstrated a higher neutralizing activity to IBDV-B87 and the titers were 16,384 and 8,192, respectively. The two scFvs had higher neutralizing capacity than those obtained in previous studies. We demonstrated that the AAC technology could be applied to screen antibody libraries without baiting antigen to make antibody screening process easier and obtain scFvs with higher neutralizing capacity.

Recombinant Newcastle disease virus expressing P53 demonstrates promising antitumor efficiency in hepatoma model.

BACKGROUND: Numerous studies have demonstrated that the NDV-mediated gene therapy is a promising new approach for treatment of cancers. P53 plays a vital role in tumor suppression and surveillance. Therefore, we hypothesize that a recombinant NDV expressing P53 would be an ideal agent for the hepatoma therapy. RESULTS: In the essay, the human P53 gene was incorporated into the genome of a lentogenic strain (named rNDV-P53), which did not affect viral replication kinetics and magnitude in HepG2 cells. Compared to the vehicle virus, rNDV-P53 increased cell growth suppressor ratio and early apoptosis by 2 folds, and decreased the mitochondrial membrane potential in HepG2 cells. In vivo studies, treatment with rNDV-P53 reduced tumor volume of tumor-bearing mice by more than 4 folds, tumor weight by more than 5 folds comparing with rNDV. The 120-day survival rate of rNDV-P53-treated mice was 75 %, survival rate of rNDV-treated mice was 12.5 %. TUNEL analysis showed a significant increase in the apoptosis rate in the tumor tissues of rNDV-P53-treated mice than that of rNDV-treated mice. Moreover, serum chemistries revealed an insignificant change of blood urea nitrogen (BUN), creatinine levels, alanine aminotransferase (ALT) and aspartate transaminase (AST) in rNDV-P53-treated group compared to normal mice, suggesting treatment with the recombinant virus was not toxic. CONCLUSION: rNDV-P53 is a potent candidate for carcinoma therapy especially for hepatocarcinoma.

Selection of affinity-improved neutralizing human scFv against HBV PreS1 from CDR3 VH/VL mutant library.

A CDR3 mutant library was constructed from a previously isolated anti-HBV neutralizing Homo sapiens scFv-31 template by random mutant primers PCR. Then the library was displayed on the inner membrane surface in Escherichia coli periplasmic space. Seven scFv clones were isolated from the mutant library through three rounds of screening by flow cytometry. Competition ELISA assay indicates that isolated scFv fragments show more efficient binding ability to HBV PreS1 compared with parental scFv-31. HBV neutralization assay indicated that two clones (scFv-3 and 59) show higher neutralizing activity by blocking the HBV infection to Chang liver cells. Our method provides a new strategy for rapid screening of mutant antibody library for affinity-enhanced scFv clones and the neutralizing scFvs obtained from this study provide a potential alternative of Hepatitis B immune globulin.

Recombinant Newcastle disease virus (NDV/Anh-IL-2) expressing human IL-2 as a potential candidate for suppresses growth of hepatoma therapy.

Newcastle disease virus (NDV) have shown oncolytic therapeutic efficacy in preclinical study and are currently approved for clinical trials. NDV Anhinga strain which is a mesogenic strain should be classified as lytic strain and has a therapeutic efficacy in hepatocellular cancer. In this study, we evaluated the capacity of NDV Anhinga strain to elicit immune reaction in vivo and the possibility for using as a vaccine vector for expressing tumor therapeutic factors. Interleukin-2 (IL-2) could boost the immune response against the tumor cells. Therefore, we use NDV Anhinga strain as backbone to construct a recombinant virus (NDV/Anh-IL-2) expressing IL-2. The virus growth curve showed that the production of recombinant NDV/Anh-IL-2 was slightly delayed compared to the wild type. The NDV/Anh-IL-2 strain could express soluble IL-2 and effectively inhibit the growth of hepatocellular carcinoma in vivo. 60 days post-treatment, mice which were completely cured by previous treatment were well protected when rechallenged with the same tumor cell. From the H&E-stained sections, intense infiltration of lymphocyte was observed in the NDV Anhinga strain treated group, especially in NDV/Anh-IL-2 group. The NDV Anhinga strain could not only kill the tumor directly, but could also elicit immune reaction and a potent immunological memory when killing tumor in vivo. In conclusion, the Anhinga strain could be an effective vector for tumor therapy; the recombinant NDV/Anh-IL-2 strain expressing soluble IL-2 is a promising candidate for hepatoma therapy.

Newcastle disease virus chimeras expressing the Hemagglutinin- Neuraminidase protein of mesogenic strain exhibits an enhanced anti-hepatoma efficacy.

Newcastle disease virus (NDV) is an intrinsically tumor-specific virus, many researchers have reported that lentogenic NDV is a safe and effective agent for human cancer therapy. It had been demonstrated that the amino acid sequence of the fusion protein cleavage site is a major factor in the pathogenicity and anti-tumor efficacy of rNDV. However, the role of Hemagglutinin-Neuraminidase (HN) gene that contributes to virulence and anti-tumor efficacy remains undefined. To assess the role of HN gene in virus pathogenicity and anti-tumor efficacy, a reverse genetic system was developed using the lentogenic NDV Clone30 strain to provide backbone for gene exchange. Chimeric virus (rClone30-Anh(HN)) created by exchange of the HN gene of lentogenic strain Clone30 with HN gene of mesogenic strain produce no significant changes in virus pathogenicity as assessed by conducting the mean death time (MDT) and intracerebral pathogenicity index (ICPI) assays. In vitro, infection with chimeras could induce the formation of syncytium relative significantly in HepG2 cells. Furthermore, chimeras was shown to induce the cell apoptosis via MTT and Annexin V-PI assays, reduce mitochondrial membrane potential and increase the mRNA transcription level of caspase 3. In vivo, ICR mice carrying tumor of hepatoma H22 cells were treated via intratumoral injection of chimeric virus. The treatment of chimera shows an obvious suppression in tumor volume. These results suggest that it could be an ideal approach to enhance the antitumor ability of Newcastle disease virus and highlighted the potential therapeutic application of rClone30-Anh(HN) as a viral vector to deliver foreign genes for treatment of cancers.

Recombinant Newcastle Disease Virus Encoding IL-12 and/or IL-2 as Potential Candidate for Hepatoma Carcinoma Therapy.

Interleukins as immunomodulators are promising therapeutic agents for cancer therapy. Previous studies showed that there was an improved antitumor immunity in tumor-bearing mice using recombinant Newcastle disease virus carrying for interleukin-2. Interleukin-12 is a promising antitumor cytokine too. So we investigated and compared the antitumor effect of genetically engineered Newcastle disease virus strains expressing both interleukin-12 and/or interleukin-2 (rClone30-interleukin-2, rClone30-interleukin-12, and rClone30-interleukin-12-interleukin-2). In vitro studies showed that rClone30s could efficiently infect tumor cells and express interleukin-12 and/or interleukin-2. 3-(4,5-Dimethylthiazol-2-y)-2,5-diphenyl-tetrazolium bromide results showed rClone30s possessed strong cytotoxic activities against multiple tumor cell lines (U251, HepG2, A549, and Hela). Animal studies showed that rClone30-interleukin-12-interleukin-2 was more effective in inhibition of murine hepatoma carcinoma tumors, with the mean tumor volume (day 14) of 141.70 mm(3) comparing 165.67 mm(3) of rClone30-interleukin-12 group, 210.47 mm(3) of rClone30-interleukin-2 group, 574.70 mm(3) of rClone30 group, and 1206.83 mm(3) of phosphate-buffered saline group. Moreover, the rClone30-interleukin-12-interleukin-2 treated mice secreted more interferon γ (333.518 pg/mL) and its downstream cytokine interferon-γ induced protein 10 (16.006 pg/mL) in tumor than the rClone30-interleukin-12 group (interferon γ: 257.548 pg/mL; interferon-γ induced protein 10: 13.601 pg/mL), rClone30-interleukin2 group (interferon γ: 124.601 pg/mL; interferon-γ induced protein 10: 9.779 pg/mL), or rClone30 group (interferon γ: 48.630 pg/mL; interferon-γ induced protein 10:1.650 pg/mL). For the survival study, rClone30-interleukin12-interleukin2 increased the survival rate (12 of 16) of the tumor-bearing mice versus 11 of 16 in rClone30-interleukin-12 group, 10 of 16 in rClone30-interleukin-2 group, 7 of 16 in Clone30 group, and 0/16 in phosphate-buffered saline group, respectively. To determine whether the mice treated with recombinant virus developed protective immune response, the mice were rechallenged with the same tumor cells. The results showed that viral-treated mice were significantly protected from rechallenge. These results suggest that expressing both interleukin-2 and/or interleukin-12 could be ideal approaches to enhance the antitumor ability of Newcastle disease virus, and rClone30-interleukin-12-interleukin-2 is slightly superior over rClone30-interleukin-12 and rClone30-interleukin-2 alone.

Recombinant Newcastle Disease virus Expressing IL15 Demonstrates Promising Antitumor Efficiency in Melanoma Model.

Recombinant Newcastle Disease Virus (rNDV) has shown oncolytic therapeutic effect in preclinical studies. Previous data indicate that rNDV carrying IL2 has shown promise in cancer therapy. Due to the significant side effects of IL2, IL15 has been introduced into cancer therapy. A number of studies have suggested that IL15 efficiently enhances the activities of CTL and NK cells and inhibits the tumor recurrence and metastasis. Furthermore, IL15 is less toxic than IL2. Therefore, we hypothesize that a recombinant NDV expressing IL15 would be a promising agent for the treatment of malignant tumors. The human IL15 gene or IL2 gene was incorporated into the genome of lentogenic LaSota strain at the position between the HN and L genes (namely rNDV-IL15 or rNDV-IL2). The two viruses efficiently infected tumor cells and expressed IL15 or IL2 protein. Melanoma tumor-bearing mice were treated by intra-tumoral (i.t.) injection of rNDV-IL15 or rNDV-IL2. Both rNDV-IL15 and rNDV-IL2 effectively suppressed tumor growth compared with rNDV. The 120-day survival rate of rNDV-IL15- treated group was 12.5% higher than that of rNDV-IL2 group, although the difference was not statistically significant, both recombinant viruses had strong abilities to induce CD41 T cell and CTL cell responses. However, rNDV-IL15 significantly induced more IFN-γ release and stimulated more CD81 T cells infiltration in the tumor sites compared with rNDV-IL2. In the tumor re-challenged experiment, the survival rates of rNDV-IL15 group and rNDV-IL2 group were statistically higher than that of PBS group. The survival rate of rNDV-IL15 group was 26.67% higher than that of rNDV-IL2 group although the difference was not statistically significant. In conclusion, rNDV-IL15 is a promising antitumor agent against melanoma.

TNF-related Apoptosis-inducing Ligand Delivered by rNDV is a Novel Agent for Cancer Gene Therapy.

Recombinant Newcastle disease virus (rNDV) as antitumor agent has been shown to be effective for cancer therapy. And TNF-related apoptosis-inducing ligand (TRAIL) also has been demonstrated potentially cancer-therapeutic effects. In this study, we constructed TRAIL delivered by rNDV (rNDV-TRAIL) and investigated whether TRAIL would generate the potential synergistic therapeutic effects with rNDV for cancer therapy. In vitro experiments indicated that TRAIL expressed by rNDV demonstrated good biological activity. TRAIL significantly enhanced inducing apoptosis of rNDV in death receptor expression cancer cell lines. Experiments in malignant melanoma-bearing mice demonstrated that expression of TRAIL delivered by rNDV significantly inhibited the tumor growth and prolonged the survival of treated animals compared to control. In conclusion, oncolytic capacity of rNDV was augmented by TRAIL and the inherent anti-neoplastic properties of NDV were enhanced by the introduction of therapeutic TRAIL gene.

[The synergism and mechanism of action of rClone30-hDR5 in combination with TRAIL on HCC].

To investigate the cell-killing effect and its possible mechanism of rClone30-hDR5 in combination with TRAIL on human hepatic carcinoma (HCC) cell line, first of all, recombinant plasmid pee12.4-hDR5 was introduced into HepG2 cells by liposome transfection. After five rounds of screening by flow cytometry, HepG2 cells expressing high levels of DR5 on cell surface were isolated. The cytotoxicity of TRAIL to selected cells was higher than that of TRAIL to HepG2 cells by MTT method (P < 0.01). The result suggested that the cloned hDR5 gene had biological activity. MTT assay showed that, rClone30- hDR5 in combination with TRAIL more efficiently inhibited the tumor growth of HepG2 cells compared to rClone30-hDR5 or TRAIL in vitro. The results of Annexin V-FITC/PI staining and Quantitative Real-time PCR indicated that rClone30-hDR5 in combination with TRAIL significantly increased the mRNA levels of caspase 3 and caspase 8, and induced the apoptosis of tumor cells. HepG2 cells were infected with rClone30-hDR5 or rClone30 at MOI of 1. The expression of hDR5 on tumor surface increased significantly by rClone30-hDR5 compared to that by rClone30, which contributed to the sensitivity to TRAIL. In conclusion, rClone30-hDR5 in combination with TRAIL has potential application value in cancer treatment.

[Antitumor efficacy of the recombinant Newcastle disease virus rNDV-IL15 on melanoma models].

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.

Anchored periplasmic expression (APEx)-based bacterial display for rapid and high-throughput screening of B cell epitopes.

We truncated the VP2 protein of infectious bursal disease virus into five fragments: V1-5. All fragments were displayed on the inner membrane of the Escherichia coli periplasm. After disruption of the outer membrane, spheroplasts that had anchored with the VP2 fragment were incubated with an anti-VP2 polyclonal antibody (pAb). Prey pairs were detected and quantitated by flow cytometry with V1, V3, V4 and V5 fragments reacting with the pAb. The antigenicity of all five fragments was analyzed, and our results indicated that epitopes were localized in V1, V3, V4 and V5, consistent with our flow cytometry analysis. Antigenicity analysis of purified VP2 fusion proteins using Western blots confirmed this. Our method provides a rapid, quantitative and simple strategy for identifying linear B cell epitopes.