Newcastle disease virus Malaysian strain AF2240 induces apoptosis in MCF-7 human breast carcinoma cells at an early stage of the virus life cycle

The Application of Newcastle Disease Virus (NDV): Vaccine Vectors and Tumor Therapy

Newcastle disease virus (NDV) is an avian pathogen with an unsegmented negative-strand RNA genome that belongs to the Paramyxoviridae family. While primarily pathogenic in birds, NDV presents no threat to human health, rendering it a safe candidate for various biomedical applications. Extensive research has highlighted the potential of NDV as a vector for vaccine development and gene therapy, owing to its transcriptional modularity, low recombination rate, and lack of a DNA phase during replication. Furthermore, NDV exhibits oncolytic capabilities, efficiently eliciting antitumor immune responses, thereby positioning it as a promising therapeutic agent for cancer treatment. This article comprehensively reviews the biological characteristics of NDV, elucidates the molecular mechanisms underlying its oncolytic properties, and discusses its applications in the fields of vaccine vector development and tumor therapy.

The haemagglutinin-neuraminidase protein of velogenic Newcastle disease virus enhances viral infection through NF-κB-mediated programmed cell death

The haemagglutinin-neuraminidase (HN) protein, a vital membrane glycoprotein, plays a pivotal role in the pathogenesis of Newcastle disease virus (NDV). Previously, we demonstrated that a mutation in the HN protein is essential for the enhanced virulence of JS/7/05/Ch, a velogenic variant NDV strain originating from the mesogenic vaccine strain Mukteswar. Here, we explored the effects of the HN protein during viral infection in vitro using three viruses: JS/7/05/Ch, Mukteswar, and an HN-replacement chimeric NDV, JS/MukHN. Through microscopic observation, CCK-8, and LDH release assays, we demonstrated that compared with Mukteswar and JS/MukHN, JS/7/05/Ch intensified the cellular damage and mortality attributed to the mutant HN protein. Furthermore, JS/7/05/Ch induced greater levels of apoptosis, as evidenced by the activation of caspase-3/8/9. Moreover, JS/7/05/Ch promoted autophagy, leading to increased autophagosome formation and autophagic flux. Subsequent pharmacological experiments revealed that inhibition of apoptosis and autophagy significantly impacted virus replication and cell viability in the JS/7/05/Ch-infected group, whereas less significant effects were observed in the other two infected groups. Notably, the mutant HN protein enhanced JS/7/05/Ch-induced apoptosis and autophagy by suppressing NF-κB activation, while it mitigated the effects of NF-κB on NDV infection. Overall, our study offers novel insights into the mechanisms underlying the increased virulence of NDV and serves as a reference for the development of vaccines.

Autophagy inhibition suppresses Newcastle disease virus-induced cell death by inhibiting viral replication in human breast cancer cells

Newcastle disease virus (NDV) is an oncolytic virus which selectively replicates in cancer cells without harming normal cells. Autophagy is a cellular mechanism that breaks down unused cytoplasmic constituents into nutrients. In previous studies, autophagy enhanced NDV-induced oncolysis in lung cancer and glioma cells. However, the effect of autophagy inhibition on NDV-induced oncolysis in breast cancer cells remains unknown. This study aimed to examine the effect of autophagy inhibition on NDV-induced oncolysis in human breast cancer cells, MCF7. To inhibit autophagy, we knocked down the expression of the autophagy protein beclin-1 (BECN1) by short interfering RNA (siRNA). The cells were infected with the recombinant NDV strain AF2240 expressing green fluorescent protein. We found that NDV induced autophagy and knockdown of BECN1 significantly reduced the NDV-induced autophagy in MCF7 cells. Importantly, BECN1 knockdown significantly suppressed cell death by inhibiting viral replication, as observed at 24 h post infection. Overall, our data suggest that autophagy inhibition may not be a suitable strategy to enhance NDV oncolytic efficacy against breast cancer.

Newcastle disease virus LaSota strain induces apoptosis and activates the TNFα/NF-κB pathway in canine mammary carcinoma cells

Spontaneous canine mammary carcinomas (CMCs) have been widely considered a good research model for human breast cancers, which brings much attention to CMCs. In recent years, the oncolytic effect of Newcastle disease virus (NDV) on cancer cells has been widely studied, but its effect on CMCs is still unclear. This study aims to investigate the oncolytic effect of NDV LaSota strain on canine mammary carcinoma cell line (CMT-U27) in vivo and in vitro. The in vitro cytotoxicity and immunocytochemistry experiments showed that NDV selectively replicated in CMT-U27 cells, and inhibited cell proliferation and migration but not in MDCK cells. KEGG analysis of transcriptome sequencing indicated the importance of the TNFα and NF-κB signalling pathways in the anti-tumour effect of NDV. Subsequently, the significantly increased expression of TNFα, p65, phospho-p65, caspase-8, caspase-3 and cleaved-PARP proteins in the NDV group suggested that NDV induced CMT-U27 cells apoptosis by activating the caspase-8/caspase-3 pathway and the TNFα/NF-κB signalling pathway. Nude mice tumour-bearing experiments showed that NDV could significantly decrease the growth rate of CMC in vivo. In conclusion, our study demonstrates the effective oncolytic effects of NDV on CMT-U27 cells in vivo and in vitro, and suggests NDV as a promising candidate for oncolytic therapy.

Expression Profiles of Immune-Related Genes and Apoptosis Study of Avian Intraepithelial-Natural Killer Cells in Chickens Inoculated with Vaccine Strain of Newcastle Disease Virus (NDV) and Challenged with Virulent NDV

In spite of the available information on the role of natural killer (NK) cells in several viral infections, the interactions between chicken intraepithelial-NK (IEL-NK) cells and Newcastle disease virus (NDV) are poorly understood. In this study, we investigated these interactions following the inoculation of chickens with NDV vaccine strain LaSota and subsequent challenge with velogenic NDV (vNDV) genotype VII (GVII) and VIII (GVIII), through quantification of IEL-NK cell's apoptosis and expression profiling of its surface receptors. Specific-pathogen-free chickens were randomly divided into six groups, as follows: one group of an uninfected control, one group infected with NDV LaSota, two groups each infected with either GVII or GVIII, and two groups inoculated with NDV LaSota and challenged with either GVII (LaSota-genotype VII [LSGVII]) or GVIII (LaSota-genotype VIII [LSGVIII]). Avian intraepithelial lymphocytes (IEL) were isolated from the duodenal loops, and CD3- cells were characterized. Immunophenotyping and apoptosis analysis of CD3-/CD25+/CD45+IEL NK cells were conducted using a flow cytometer. In addition, a gene expression study was conducted using real-time quantitative PCR. Data were analyzed using two-way analysis of variance. The results showed that vNDV GVII or GVIII caused apoptosis of IEL-NK cells; however, following inoculation of LSGVII or LSGVIII, the effect of vNDV GVII and GVIII to cause a reduction in the population of viable IEL-NK cells was significantly reduced. Furthermore, the expression profiles of activating receptors CD69, NK-lysin, and IFN-γ, were generally upregulated in chickens inoculated with LSGVII or LSGVIII. In contrast, B-NK, an inhibitory receptor, was downregulated in these treatment groups. In NDV GVII- and GVIII-challenged groups, however, B-NK was upregulated, whereas the other receptors were generally downregulated. The findings of this study showed that NDV vaccine strain LaSota may prevent apoptosis and cause upregulation of activating receptors of chicken IEL-NK cells in velogenic virus-challenged settings.

Development of Molecular Mechanisms and Their Application on Oncolytic Newcastle Disease Virus in Cancer Therapy

Cancer is caused by the destruction or mutation of cellular genetic materials induced by environmental or genetic factors. It is defined by uncontrolled cell proliferation and abnormality of the apoptotic pathways. The majority of human malignancies are characterized by distant metastasis and dissemination. Currently, the most common means of cancer treatment include surgery, radiotherapy, and chemotherapy, which usually damage healthy cells and cause toxicity in patients. Targeted therapy is an effective tumor treatment method with few side effects. At present, some targeted therapeutic drugs have achieved encouraging results in clinical studies, but finding an effective solution to improve the targeting and delivery efficiency of these drugs remains a challenge. In recent years, oncolytic viruses (OVs) have been used to direct the tumor-targeted therapy or immunotherapy. Newcastle disease virus (NDV) is a solid oncolytic agent capable of directly killing tumor cells and increasing tumor antigen exposure. Simultaneously, NDV can trigger the proliferation of tumor-specific immune cells and thus improve the therapeutic efficacy of NDV in cancer. Based on NDV’s inherent oncolytic activity and the stimulation of antitumor immune responses, the combination of NDV and other tumor therapy approaches can improve the antitumor efficacy while reducing drug toxicity, indicating a broad application potential. We discussed the biological properties of NDV, the antitumor molecular mechanisms of oncolytic NDV, and its application in the field of tumor therapy in this review. Furthermore, we presented new insights into the challenges that NDV will confront and suggestions for increasing NDV’s therapeutic efficacy in cancer.

Intratumoral Virotherapy with Wild-Type Newcastle Disease Virus in Carcinoma Krebs-2 Cancer Model

The results of experimental and clinical trials of the agents based on oncolytic Newcastle disease virus (NDV) strains provided hope for the development of virotherapy as a promising method for treating human tumors. However, the mechanism of the antitumor effect of NDV and realization of its cytotoxic potential in a cancer cell remains to be elucidated. In the current work, we have studied the antitumor effect of NDV in a syngeneic model of mouse Krebs-2 carcinoma treated with intratumoral injections of a wild-type strain NDV/Altai/pigeon/770/2011. Virological methods were used for preparation of a virus-containing sample. Colorimetric MTS assay was used to assess the viability of Krebs-2 tumor cells infected with a viral strain in vitro. In vivo virotherapy was performed in eight-week-old male BALB/c mice treated with serial intratumoral injections of NDV in an experimental model of Krebs-2 solid carcinoma. Changes in the tumor nodes of Krebs-2 carcinoma after virotherapy were visualized by MRI and immunohistological staining. Light microscopy examination, immunohistochemical and morphometric analyses have shown that intratumoral viral injections contribute to the inhibition of tumor growth, appearance of necrosis-like changes in the tumor tissue and the antiangiogenic effect of the virus. It has been established that a course of intratumoral virotherapy with NDV/Altai/pigeon/770/2011 strain in a mouse Krebs-2 carcinoma resulted in increased destructive changes in the tumor tissue, in the volume density of necrotic foci and numerical density of endothelial cells expressing CD34 and VEGFR. These results indicate that intratumoral NDV injection reduces tumor progression of an aggressive tumor.

Synergy between hemagglutinin 2 (HA2) subunit of influenza fusogenic membrane glycoprotein and oncolytic Newcastle disease virus suppressed tumor growth and further enhanced by Immune checkpoint PD-1 blockade

Background

Newcastle disease virus (NDV) has shown noticeable oncolytic properties, especially against cervical cancer. However, in order to improve the spread rate and oncotoxicity of the virus, employment of other therapeutic reagents would be helpful. It has been shown that some viral fusogenic membrane glycoproteins (FMGs) could facilitate viral propagation and increase the infection rate of tumor cells by oncolytic viruses. Additionally, immune checkpoint blockade has widely been investigated for its anti-tumor effects against several types of cancers. Here, we investigated for the first time whether the incorporation of influenza hemagglutinin-2 (HA2) FMG could improve the oncolytic characteristics of NDV against cervical cancer. Next, we added anti-PD-1 mAb to our therapeutic recipe to assess the complementary role of immune checkpoint blockade in curbing tumor progression.

Methods

For this purpose, TC-1 tumor cells were injected into the mice models and treatment with NDV, iNDV, HA2, NDV-HA2, iNDV-HA2 began 10 days after tumor challenge and was repeated at day 17. In addition, PD-1 blockade was conducted by injection of anti-PD-1 mAb at days 9 and 16. Two weeks after the last treatment, sample mice were sacrificed and treatment efficacy was evaluated through immunological and immunohistochemical analysis. Moreover, tumors condition was monitored weekly for 6 weeks intervals and the tumor volume was measured and compared within different groups.

Results

The results of co-treatment with NDV and HA2 gene revealed that these agents act synergistically to induce antitumor immune responses against HPV-associated carcinoma by enhancement of E7-specific lymphocyte proliferation, inducement of CD8⁺ T cell cytotoxicity responses, increase in splenic cytokines and granzyme B, decrease in immunosuppressive cytokines and E6 oncogene expression, and upregulation of apoptotic proteins expression, in comparison with control groups. Moreover, incorporation of PD-1 blockade as the third side of our suggested therapy led to noticeable regression in tumor size and augmentation of cytokine responses.

Conclusions

The invaluable results of synergy between NDV virotherapy and HA2 gene therapy suggest that tumor-selective cell killing by oncolytic NDV can be enhanced by combining with FMG gene therapy. Moreover, the adjunction of the PD-1 blockade proves that checkpoint blockade can be considered as an effective complementary therapy for the treatment of cervical cancer.

Oncolytic Newcastle disease virus delivered by Mesenchymal stem cells-engineered system enhances the therapeutic effects altering tumor microenvironment

Background

Human papillomavirus (HPV)-associated malignancy remain a main cause of cancer in men and women. Cancer immunotherapy has represented great potential as a new promising cancer therapeutic approach. Here, we report Mesenchymal stem cells (MSCs) as a carrier for the delivery of oncolytic Newcastle disease virus (NDV) for the treatment of HPV-associated tumor.

Methods

For this purpose, MSCs obtained from the bone marrow of C57BL mice, then cultured and characterized subsequently by the flow cytometry analysis for the presence of cell surface markers. In this study, we sought out to determine the impacts of MSCs loaded with oncolytic NDV on splenic T cell and cytokine immune responses, caspase-3 and -9 expression, and myeloid and myeloid-derived suppressor cells (MDSCs) by histological and immunohistochemical studies in the tumor microenvironment (TME).

Results

Our findings proved that MSCs possess both migratory capacity and tumor tropism toward transplanted tumor tissue after peritumoral administration. Tumor therapy experiments indicated that oncolytic NDV delivered by MSCs-engineered system significantly reduces tumor growth, which is associated with the enhancement of E7-specific lymphocyte proliferation, CD8+ T cell cytolysis responses, and splenic IFN-γ, IL-4 and IL-12 responses compared with control groups. Moreover, the treatment upregulated the concentration of apoptotic proteins (caspase 9) and increased infiltration of tumor microenvironment with CD11b + myeloid and Gr1 + MDSCs cells.

Conclusions

Our data suggest MSCs carrying oncolytic NDV as a potentially effective strategy for cancer immunotherapy through inducing splenic Th1 immune responses and apoptosis in the tumor microenvironment.

Liver Pathology in Rats Treated with Newcastle Disease Virus Strains AF2240 and V4-UPM

BACKGROUND

Treatment of cancer with chemo-radiotherapy causes severe side effects due to cytotoxic effects towards normal tissues which often results in morbidity. Therefore, developing anticancer agents which can selectively target the cancer cells and cause less side effects are the main objectives of the new therapeutic strategies for treatment advanced or metastatic cancers. Newcastle disease virus strains AF2240 and V4-UPM were shown to be cytolytic against various cancer cells in-vitro and very effective as antileukemicagents.

METHODS

45 rats at 6 weeks of age, were randomly assigned to nine groups with 5 rats in each group, both azoxymethane (AOM) and 5-Fluorouracil (5-FU) were given to rats according to the body weight. NDV virus strains (AF2240 and V4-UPM) doses were determined to rats according to CD50 resulted from MTT assay. After 8 doses of NDV strians and 5-FU, tissue sections preparations and histopathological study of rats' organs were done.

RESULTS

In this article morphological changes of rats' organs, especially in livers, after treatment with a colon carcinogen (azoxymethane) and Newcastle disease virus strains have been recorded. We observed liver damage caused by AOM evidenced by morphological changes and enzymatic elevation were protected by the oncolytic viruses sections. Also we found that combination treatment NDV with 5-FU had greater antitumor efficacy than treatment with NDV or 5-FU alone.

CONCLUSION

We noted morphological changes in liver and other rats' organs due to a chemical carcinogen and their protection by NDV AF2240 and NDV V4-UPM seems to be most protective.

Non-replicating Newcastle Disease Virus as an adjuvant for DNA vaccine enhances antitumor efficacy through the induction of TRAIL and granzyme B expression

The potential of non-replicating Newcastle Disease Virus (NDV) as an adjuvant for DNA vaccination remains to be elucidated. To assess the therapeutic effects of DNA vaccine (HPV-16 E7 gene) adjuvanted with NDV, female C57/BL6 mice were inoculated with murine TC-1 cells of human papillomavirus (HPV)-related carcinoma, expressing human papillomavirus 16 (HPV-16) E6/E7 antigens, and immunized with DNA vaccine alone or pretreated with NDV. One week after third immunization, Cytotoxic T lymphocytes (CTLs), splenocyte proliferation, cytokine balance (IFN-γ, IL-4 and IL-12 secretions) and intratumoral expression of cytotoxicity related proteins in tumor lysates were investigated. The results showed that treatment with non-replicating NDV prior to DNA vaccine induced tumor-specific cytolytic and splenocyte proliferation responses. The levels of cytokines IL-12, IL-4 and IFN-γ after treating with combined E7-DNA -non-replicating NDV (NDV-DNA Vaccine) were significantly higher than those of control groups. The intratumoral granzyme B and Tumor Necrosis Factor Related Apoptosis Inducing Ligand (TRAIL)-mediated apoptosis was also significantly increased. Tumor therapeutic experiments showed that the NDV pretreatment could reduce the tumor progression of established E7-expressing TC-tumors. Taken together these data suggest that the significant antitumor responses evidenced during treatment with non-replicating NDV prior to DNA vaccine are due, in part, to strong E7-induced cellular immunity and enhanced expression of cytotoxicity related proteins in the tumor microenvironment. These observations indicated the potential of non-replicating NDV as an adjuvant for enhancing therapeutic DNA vaccines -induced immunity and antitumor responses.

Newcastle disease virus strain AF2240 as an oncolytic virus: A review

The discovery of tumour selective virus-mediated apoptosis marked the birth of an alternative cancer treatment in the form of oncolytic viruses. Even though, its oncolytic efficiency was demonstrated more than 50 years ago, safety concerns which resulted from mild to lethal side effects hampered the progress of oncolytic virus research. Since the classical oncolytic virus studies rely heavily on its natural oncolytic ability, virus manipulation was limited, thereby, restricted efforts to improve its safety. In order to circumvent such restriction, experiments involving non-human viruses such as the avian Newcastle disease virus (NDV) was conducted using cultured cells, animal models and human subjects. The corresponding reports on its significant tumour cytotoxicity along with impressive safety profile initiated immense research interest in the field of oncolytic NDV. The varying degree of oncolytic efficiency and virulency among NDV strains encouraged researchers from all around the world to experiment with their respective local NDV isolates in order to develop an oncolytic virus with desirable characteristics. Such desirable features include high tumour-killing ability, selectivity and low systemic cytotoxicity. The Malaysian field outbreak isolate, NDV strain AF2240, also currently, receives significant research attention. Apart from its high cytotoxicity against tumour cells, this strain also provided fundamental insight into NDV-mediated apoptosis mechanism which involves Bax protein recruitment as well as death receptor engagement. Studies on its ability to selectively induce apoptosis in tumour cells also resulted in a proposed p38 MAPK/NF-κB/IκBα pathway. The immunogenicity of AF2240 was also investigated through PBMC stimulation and macrophage infection. In addition, the enhanced oncolytic ability of this strain under hypoxic condition signifies its dynamic tumour tropism. This review is aimed to introduce and discuss the aforementioned details of the oncolytic AF2240 strain along with its current challenges which outlines the future research direction of this virus.

RIP1 is a central signaling protein in regulation of TNF-α/TRAIL mediated apoptosis and necroptosis during Newcastle disease virus infection

Newcastle disease virus (NDV) is an oncolytic virus which selectively replicates in tumor cells and exerts anti-tumor cytotoxic activity by promoting cell death. In this study, we focus on characterization of the underlying mechanisms of NDV-induced cell death in HeLa cells. We find that NDV Herts/33 strain triggers both extrinsic and intrinsic apoptosis at late infection times. The activation of NF-кB pathway and subsequent up-regulation of TNF-α/TRAIL initiates extrinsic apoptosis, leading to activation of caspase 8 and cleavage of Bid into tBid. tBid transmits the extrinsic apoptotic signals to mitochondria and mediates intrinsic apoptosis, which is hallmarked by cleavage of caspase 9. Moreover, RIP1 is cleaved into RIP1-N and RIP1-C at D324 by caspase 8, and this cleavage promotes apoptosis. Surprisingly, over expression of RIP1 reduces apoptosis and depletion of RIP1 promotes apoptosis, suggesting full length RIP1 is anti-apoptotic. Moreover, necroptosis hallmark protein MLKL is activated by phosphorylation at 12-24 h.p.i., and RIP1 regulates the level of phosphor-MLKL. Immunostaining shows that RIP1 aggregates to stress granules (SGs) at 8-24 h.p.i., and phosphor-MLKL is also recruited to SGs, instead of migrating to plasma membrane to exert its necrotic function. Immunoprecipitation study demonstrates that RIP1 bind to phosphor-MLKL, and depletion of RIP1 reduces the aggregation of MLKL to SGs, suggesting that RIP1 recruits MLKL to SGs. Altogether, NDV infection initiates extrinsic apoptosis via activation of NF-кB and secretion of TNF-α/TRAIL. Activation of caspase 8 by TNF-α/TRAIL and subsequent cleavage of Bid and RIP1 transmit the death signals to mitochondria. Meanwhile, virus subverts the host defensive necroptosis via recruiting phosphor-MLKL by RIP1 to SGs. Thus, RIP1 is a central signaling protein in regulation of apoptosis and necroptosis during NDV infection.

Oncolytic effect of wild-type Newcastle disease virus isolates in cancer cell lines in vitro and in vivo on xenograft model

Oncolyic virotherapy is one of the modern experimental techniques to treat human cancers. Here we studied the antitumor activity of wild-type Newcastle disease virus (NDV) isolates from Russian migratory birds. We showed that NDV could selectively kill malignant cells without affecting healthy cells. We evaluated the oncolytic effect of 44 NDV isolates in 4 histogenetically different human cell lines (HCT116, HeLa, A549, MCF7). The safety of the isolates was also tested in normal peripheral blood mononuclear (PBMC) cells. The viability of tumor cell lines after incubation with NDV isolates was evaluated by MTT. All cell lines, except for normal PBMC primary cells, had different degrees of susceptibility to NDV infection. Seven NDV strains had the highest oncolytic activity, and some NDV strains demonstrated oncolytic selectivity for different cell lines. In vivo, we described the intratumoral activity of NDV/Altai/pigeon/770/2011 against subcutaneous non-small cell lung carcinoma using xenograft SCID mice model. All animals were responsive to therapy. Histology confirmed therapy-induced destructive changes and growing necrotic bulk density in tumor tissue. Our findings indicate that wild-type NDV strains selectively kill tumor cells with no effect on healthy PBMC cells, and intratumoral virotherapy with NDV suppresses the subcutaneous tumor growth in SCID mice.

The therapeutic effect of death: Newcastle disease virus and its antitumor potential

Programmed cell death is essential to survival of multicellular organisms. Previously restricted to apoptosis, the concept of programmed cell death is now extended to other mechanisms, as programmed necrosis or necroptosis, autophagic cell death, pyroptosis and parthanatos, among others. Viruses have evolved to manipulate and take control over the programmed cell death response, and the infected cell attempts to neutralize viral infections displaying different stress signals and defensive pathways before taking the critical decision of self-destruction. Learning from viruses and their interplay with the host may help us to better understand the complexity of the self-defense death response that when altered might cause disorders as important as cancer. In addition, as the fields of immunotherapy and oncolytic viruses advance as promising novel cancer therapies, the programmed cell death response reemerges as a key point for the success of both therapeutic approaches. In this review we summarize the research of the multimodal cell death response induced by Newcastle disease viruses (NDV), considered nowadays a promising viral oncolytic therapeutic, and how the manipulation of the host programmed cell death response can enhance the NDV antitumor capacity.