Contrasting Gene Expression Profiles of Monocytes and Lymphocytes From Peste-Des-Petits-Ruminants Virus Infected Goats

In this study, transcriptome analysis of PPRV infected PBMC subsets-T helper cells, T cytotoxic cells, monocytes, and B lymphocytes was done to delineate their role in host response. PPRV was found to infect lymphocytes and not monocytes. The established receptor for PPRV-SLAM was found downregulated in lymphocytes and non-differentially expressed in monocytes. A profound deviation in the global gene expression profile with a large number of unique upregulated genes (851) and downregulated genes (605) was observed in monocytes in comparison to lymphocytes. ISGs-ISG15, Mx1, Mx2, RSAD2, IFIT3, and IFIT5 that play a role in antiviral response and the genes for viral sensors-MDA5, LGP2, and RIG1, were found to be upregulated in lymphocytes and downregulated in monocytes. The transcription factors-IRF-7 and STAT-1 that regulate expression of most of the ISGs were found activated in lymphocytes and not in monocytes. Interferon signaling pathway and RIG1 like receptor signaling pathway were found activated in lymphocytes and not in monocytes. This contrast in gene expression profiles and signaling pathways indicated the predominant role of lymphocytes in generating the antiviral response against PPRV in goats, thus, giving us new insights into host response to PPRV.

Dysregulated miRNAome and Proteome of PPRV Infected Goat PBMCs Reveal a Coordinated Immune Response

In this study, the miRNAome and proteome of virulent Peste des petits ruminants virus (PPRV) infected goat peripheral blood mononuclear cells (PBMCs) were analyzed. The identified differentially expressed miRNAs (DEmiRNAs) were found to govern genes that modulate immune response based on the proteome data. The top 10 significantly enriched immune response processes were found to be governed by 98 genes. The top 10 DEmiRNAs governing these 98 genes were identified based on the number of genes governed by them. Out of these 10 DEmiRNAs, 7 were upregulated, and 3 were downregulated. These include miR-664, miR-2311, miR-2897, miR-484, miR-2440, miR-3533, miR-574, miR-210, miR-21-5p, and miR-30. miR-664 and miR-484 with proviral and antiviral activities, respectively, were upregulated in PPRV infected PBMCs. miR-210 that inhibits apoptosis was downregulated. miR-21-5p that decreases the sensitivity of cells to the antiviral activity of IFNs and miR-30b that inhibits antigen processing and presentation by primary macrophages were downregulated, indicative of a strong host response to PPRV infection. miR-21-5p was found to be inhibited on IPA upstream regulatory analysis of RNA-sequencing data. This miRNA that was also highly downregulated and was found to govern 16 immune response genes in the proteome data was selected for functional validation vis-a-vis TGFBR2 (TGF-beta receptor type-2). TGFBR2 that regulates cell differentiation and is involved in several immune response pathways was found to be governed by most of the identified immune modulating DEmiRNAs. The decreased luciferase activity in Dual Luciferase Reporter Assay indicated specific binding of miR-21-5p and miR-484 to their target thus establishing specific binding of the miRNAs to their targets.This is the first report on the miRNAome and proteome of virulent PPRV infected goat PBMCs.

In vitro study on role of σB protein in avian reovirus pathogenesis

Avian reoviruses, members of Orthoreovirus genus was known to cause diseases like tenosynovitis, runting-stunting syndrome in chickens. Among eight structural proteins, the proteins of S-class are mainly associated with viral arthritis but the significance of σB protein in arthritis is not established till date. In this infection pathological condition together with infection of joints often leads to arthritis because joints consists of cartilage which forms lubricating surface between two bones, and has limited metabolic, replicative and repair capacity. To establish the role of σB protein in arthritis, an in-vitro microarray study was conducted consisting four groups viz. virus infected and control; pDsRed-Express-N1-σB and empty pDs-Red transfected, CEF cells. With cut-off value as FC ≥2, p value <0.05, 6709 and 4026 numbers of DEGs in virus and σB, respectively were identified. The Ingenuity Pathway Analysis gave an idea about the involvement of σB protein in "osteoarthritis pathway", which was activated with z-score with 3.151. The pathway "Role of IL-17A in arthritis pathway" was also enriched with -log (p-value) 1.64. Among total 122 genes involved in osteoarthritis pathway, 28 upregulated and 11 downregulated DEGs were common to both virus and σB treated cells. Moreover, 14 upregulated and 7 downregulated were unique in σB transfected cells. Using qRT-PCR for IL-1B, BMP2, SMAD1, SPP1 genes, the microarray data was validated. We concluded that during ARV infection σB protein, if not fully partially leads to molecular alteration of various genes of host orchestrating the different molecular pattern in joints, leading to tenosynovitis syndrome.

Genome wide host gene expression analysis in mice experimentally infected with Pasteurella multocida

Pasteurella multocida causes acute septicemic and respiratory diseases, including haemorrhagic septicaemia, in cattle and buffalo with case fatality of 100%. In the present study, mice were infected with P. multocida (1.6 × 10³ cfu, intraperitoneal) to evaluate host gene expression profile at early and late stages of infection using high throughput microarray transcriptome analyses. Several differentially expressed genes (DEGs) at both the time points were identified in P.multocida infected spleen, liver and lungs. Functional annotation of these DEGs showed enrichment of key pathways such as TLR, NF-κB, MAPK, TNF, JAK-STAT and NOD like receptor signaling pathways. Several DEGs overlapped across different KEGG pathways indicating a crosstalk between them. The predicted protein—protein interaction among these DEGs suggested, that the recognition of P. multocida LPS or outer membrane components by TLR4 and CD14, results in intracellular signaling via MyD88, IRAKs and/or TRAF6 leading to activation of NFκB and MAPK pathways and associated cytokines.

Modulation of Host miRNAs Transcriptome in Lung and Spleen of Peste des Petits Ruminants Virus Infected Sheep and Goats

Peste des petits ruminants (PPR) is one of the highly contagious viral disease, characterized by fever, sore mouth, conjunctivitis, gastroenteritis, and pneumonia, primarily affecting sheep and goats. Reports suggested variable host response in goats and sheep and this host response vis-a-vis the expression of microRNAs (miRNAs) has not been investigated. Here, miRNAs were sequenced and proteomics data were generated to identify the role of differentially expressed miRNA (DEmiRNA) in PPR virus (PPRV) infected lung and spleen tissues of sheep and goats. In lungs, 67 and 37 DEmiRNAs have been identified in goats and sheep, respectively. Similarly, in spleen, 50 and 56 DEmiRNAs were identified in goats and sheep, respectively. A total of 20 and 11 miRNAs were found to be common differentially expressed in both the species in PPRV infected spleen and lung, respectively. Six DEmiRNAs—miR-21-3p, miR-1246, miR-27a-5p, miR-760-3p, miR-320a, and miR-363 were selected based on their role in viral infections, apoptosis, and fold change. The target prediction analysis of these six selected DEmiRNAs from the proteome data generated, revealed involvement of more number of genes in lung and spleen of goats than in sheep. On gene ontology analysis of host target genes these DEmiRNAs were found to regulate several immune response signaling pathways. It was observed that the pathways viz. T cell receptor signaling, Rap1 signaling, Toll-like receptor signaling, and B cell receptor signaling governed by DEmiRNAs were more perturbed in goats than in sheep. The data suggests that PPRV-induced miR-21-3p, miR-320a, and miR-363 might act cooperatively to enhance viral pathogenesis in the lung and spleen of sheep by downregulating several immune response genes. The study gives an important insight into the molecular pathogenesis of PPR by identifying that the PPRV—Izatnagar/94 isolate elicits a strong host response in goats than in sheep.

HN protein of Newcastle disease virus sensitizes HeLa cells to TNF-α-induced apoptosis by downregulating NF-κB expression

Hemagglutinin neuraminidase (HN) is a membrane protein of Newcastle disease virus (NDV) with the ability to induce apoptosis in many transformed cell lines. TNF-α is a multi-factorial protein that regulates cell survival, differentiation and apoptosis. In a previous study, we reported that HN protein induces apoptosis by downregulating NF-κB expression. Further, we speculated that downregulation of NF-κB expression might sensitize HeLa cells to TNF-α-mediated apoptosis. Therefore, the present study was undertaken to investigate if HN protein could sensitize HeLa cells to TNF-α and to examine the apoptotic potential of the HN protein and TNF-α in combination. The results revealed that the pro-apoptotic effects were more pronounced with the combination of HN and TNF-α than with HN or TNF-α alone, which indicates that the HN protein indeed sensitized the HeLa cells to TNF-α-induced cell death. The results of the study provide a mechanistic insight into the apoptotic action of HN protein along with TNF-α, which could be valuable in treating tumor types that are naturally resistant to TNF-α.

Combined administration of the apoptin gene and poly (I:C) induces potent anti-tumor immune response and inhibits growth of mouse mammary tumors

BACKGROUND

Many viral proteins exhibit selective cytotoxicity for tumor cells without affecting the normal diploid cells. The apoptin protein of chicken infectious anemia virus is one of such proteins, which has been shown to kill tumor cells specifically. However, an effective cancer treatment strategy also requires assistance from the immune system. Recently, poly (I:C) has been shown to be an effective cancer vaccine adjuvant.

AIM

In this study, we assessed the anti-tumor potential of apoptin gene transfer alone and in combination with poly (I:C) in a 4T1 mouse mammary tumor model.

METHODS

4T1 cells were used to induce mammary tumor in Balb/c mice. Mice bearing tumors were divided into 6 groups, and each group received six intratumoral injections during a period of one month. After the last immunization, the animals were sacrificed, and peripheral blood, spleen, lungs, liver, heart, kidney and tumor tissues were collected for immunological, molecular and pathological analysis.

RESULTS

We report that intratumoral administration of apoptin plasmid along with poly (I:C) not only significantly inhibited the growth of mammary tumor, but also induced a potent anti-tumor immune response as indicated by the increase in blood CD4+, CD8+ cells and infiltration of immune cells in the tumor tissue. Further, blood serum analysis of the cytokines revealed increased secretion of Th1 cytokines (IFN-γ and IL-2).

CONCLUSIONS

The results of our study demonstrate that the inclusion of poly (I:C) significantly enhanced the anti-tumor activity of apoptin mainly by inducing a potent anti-tumor immune response. Therefore, we report the use of apoptin and poly (I:C) combination as a novel and powerful strategy for cancer immunotherapy.

Production and characterization of monoclonal antibodies to Newcastle Disease Virus

Newcastle Disease (ND) is one of the major causes of economic loss in the poultry industry. Newcastle Disease Virus (NDV) is a single-stranded, negative-sense enveloped RNA virus (Fam. Paramyxoviridae; Order Mononegavirales). In the present study three monoclonal antibodies (MAbs) were produced by polyethyleneglycol (PEG)-mediated fusion of lymphocytes sensitized to NDV Bareilly strain and myeloma cells. NDV possesses ability to agglutinate erythrocytes of avian species. All the three MAbs designated as 2H7, 3E9 and 3G6 caused hemagglutination inhibition of NDV by specifically binding to NDV. The reactivity for all the 3 MAbs on indirect ELISA was found to be significantly higher than the antibody and antigen controls. On flowcytometry of HeLa cells infected with NDV using the MAbs as primary antibodies, there was a significant difference in the percentage of cells showing positive fluorescence compared to the mock control. One of the MAbs (3E9) was found to react with hemagglutinin-neuraminidase (HN) protein on western blot.

Characterization and evaluation of apoptotic potential of double gene construct pVIVO.VP3.NS1

Viral gene oncotherapy, targeted killing of cancer cells by viral genes, is an emerging non-infectious therapeutic cancer treatment modality. Chemo and radiotherapy in cancer treatment is limited due to their genotoxic side effects on healthy cells and need of functional p53, which is mutated in most of the cancers. VP3 (apoptin) of chicken infectious anaemia (CIA) and NS1 (Non structural protein 1) of Canine Parvovirus-2 (CPV-2) have been proven to have oncolytic potential in our laboratory. To evaluate oncolytic potential of VP3 and NS1 together these genes needed to be cloned in a bicistronic vector. In this study, both these genes were cloned and characterized for expression of their gene products and its apoptotic potential. The expression of VP3 and NS1 was studied by confocal microscopy and flowcytometry. Expression of VP3 and NS1 in pVIVO.VP3.NS1 transfected HeLa cells in comparison to mock transfected cells indicated that the double gene construct expresses both the products. This was further confirmed by flowcytometry where there was increase in cells expressing VP3 and NS1 in pVIVO.VP3.NS1 transfected group in comparison with the mock control group. The apoptotic inducing potential of this characterized pVIVO.VP3.NS1 was evaluated in human cervical cancer cell line (HeLa) by DNA fragmentation assay, TUNEL assay and Hoechst staning. This double construct was observed to induce apoptosis in HeLa cells.

Viral genes as oncolytic agents for cancer therapy

Many viruses have the ability to modulate the apoptosis, and to accomplish it; viruses encode proteins which specifically interact with the cellular signaling pathways. While some viruses encode proteins, which inhibit the apoptosis or death of the infected cells, there are viruses whose encoded proteins can kill the infected cells by multiple mechanisms, including apoptosis. A particular class of these viruses has specific gene(s) in their genomes which, upon ectopic expression, can kill the tumor cells selectively without affecting the normal cells. These genes and their encoded products have demonstrated great potential to be developed as novel anticancer therapeutic agents which can specifically target and kill the cancer cells leaving the normal cells unharmed. In this review, we will discuss about the viral genes having specific cancer cell killing properties, what is known about their functioning, signaling pathways and their therapeutic applications as anticancer agents.

Development of dog mammary tumor xenograft in immunosuppressed Swiss albino mice

Development and study of dog mammary tumour xenograft in immunosuppressed Swiss Albino Mice adds a new dimension in cancer research as dog tumors have many similarities with human tumors regarding progression, histopathology, molecular mechanism, immune response and therapy. Failure of the immune system to recognize and eliminate cancer cells leads to cancer progression and the fight between immune cells and cancer cells has a great role in understanding the mechanism of cancer progression and elimination. Rejection and acceptance of tumour xenograft depends on efficiency of CD4+, CD8+ and NK cell populations. In the present investigation, dog mammary tumor xenograft in cyclosporine-A and gamma-irradiated, immunosuppressed Swiss Albino mice was developed and the immune cell status of graft accepted and rejected mice was assessed. It was observed that all the major immune cells (CD4+, CD8+ and NK cells) play an equal role in tumour rejection.

Rapid label-free visual assay for the detection and quantification of viral RNA using peptide nucleic acid (PNA) and gold nanoparticles (AuNPs)

A rapid label-free visual assay for the detection of viral RNA using peptide nucleic acid (PNA) probes and gold nanoparticles (AuNPs) is presented in this study. Diagnosis is a crucial step for the molecular surveillance of diseases, and a rapid visual test with high specificity could play a vital role in the management of viral diseases. In this assay, the specific agglomerative behavior of PNA with gold nanoparticles was manipulated by its complementation with viral RNA. The assay was able to detect 5-10 ng of viral RNA from various biological samples, such as allantoic fluids, cell culture fluids and vaccines, in 100 μl of test solution. The developed assay was more sensitive than a hemagglutination (HA) test, a routine platform test for the detection of Newcastle disease virus (NDV), and the developed assay was able to visually detect NDV with as little as 0.25 HA units of virus. In terms of the specificity, the test could discriminate single nucleotide differences in the target RNA and hence could provide visual viral genotyping/pathotyping. This observation was confirmed by pathotyping different known isolates of NDV. Further, the PNA-induced colorimetric changes in the presence of the target RNA at different RNA to PNA ratios yielded a standard curve with a linear coefficient of R(2)=0.990, which was comparable to the value of R(2)=0.995 from real-time PCR experiments with the same viral RNA. Therefore, the viral RNA in a given samples could be quantified using a simple visual spectrophotometer available in any clinical laboratory. This assay may find application in diagnostic assays for other RNA viruses, which are well known to undergo mutations, thus presenting challenges for their molecular surveillance, genotyping and quantification.

Cloning and expression analysis of multiple proteins encoding P gene of Newcastle disease virus

Viral gene oncotherapy is emerging as a biotherapeutic cancer treatment modality based on targeted killing of cancer cells by viral genes. Newcastle disease virus (NDV) has the property to cause selective oncolysis of tumor cells sparing normal cells. NDV has a single stranded negative sense RNA genome, which is 15,186 nucleotide long and consists of six genes, which codes for eight proteins. NDV like other paramyxoviruses has the ability to generate multiple proteins from the P gene. P protein is encoded by an unedited transcript of the P gene, whereas the V and W protein are the results of RNA editing event in which one and two G residues are inserted at a conserved editing site within the P gene mRNA resulting in V and W transcripts, respectively. Although NDV is known to cause oncolysis by triggering apoptosis, the role of different viral proteins in selective oncolysis is still unclear. P gene edited products are known for its anti-apoptotic property in homologous host. In the present study, NDV P gene and its RNA edited products were amplified, cloned, sequenced and in vitro expression was done in HeLa cells. Further constructs were assayed for their apoptosis inducing ability in HeLa cells. Preliminary study suggested that P, V and W proteins are not apoptotic to HeLa cells.

Velogenic newcastle disease virus as an oncolytic virotherapeutics: in vitro characterization

Cancer is one of the killer diseases in humans and needs alternate curative measures despite recent improvement in modern treatment modalities. Oncolytic virotherapy seems to be a promising nonconventional way to treat cancers. Newcastle disease virus (NDV), a poultry virus, is nonpathogenic to human and domestic animals and has a long history of being used in oncotherapy research in several preclinical studies. The ability of NDV to successfully infect and destroy cancer cells is dependent on the strain and the pathotype of the virus. Adaptation of viruses to heterologous hosts without losing its replicative and oncolytic potential is prerequisite for use as cancer virotherapeutics. In the present study, velogenic NDV was adapted for replication in HeLa cells, and its cytotoxic potential was evaluated by observing morphological, biochemical, and nuclear landmarks of apoptosis. Our results indicated that the NDV-induced apoptosis in HeLa cells was dependent on upregulation of TNF-related apoptosis-inducing ligand (TRAIL) and caspases activation. Different determinants of apoptosis evaluated in the present study indicated that this strain could be a promising candidate for cancer therapy in future.

Characterization and in vitro expression of non-structural 1 protein of canine parvovirus (CPV-2) in mammalian cell line

Parvoviruses are small, 260-A-diameter, icosahedral, non-enveloped, single-stranded DNA viruses with a genome of approximately 5 kb. Non structural protein, (NS-1) is especially relevant, being both essential for virus replication and the main factor responsible for virus pathogenicity and cytotoxicity. This protein has also been reported to possess the property of killing of transformed cells. The present study was carried out to clone, characterize and express the NS-1 gene of canine parvovirus. NS-1 complete CDS 2020bp was amplified, cloned into eukaryotic expression vector pcDNA 3.1(+), sequenced and characterized by in vitro expression analysis. Functional activity of recombinant construct, pcDNA.cpv.NS-1, was evaluated by RT-PCR and flow cytometry for the expression of NS-1 specific mRNA and NS-1 protein, respectively, in transfected HeLa cells. This recombinant plasmid may serve as an important tool to evaluate the apoptotic potential of NS-1 protein of canine parvovirus in cultured HeLa cells.

Development and in vitro characterization of a bivalent DNA containing HN and F genes of velogenic Newcastle disease virus

Newcastle disease (ND) is highly contagious, economically important viral disease affecting most of avian species worldwide. Newcastle disease virus (NDV) has single stranded negative sense RNA genome which encodes for six structural and two non-structural proteins. Envelope glycoproteins i.e. hemagglutinin-neuraminidase (HN) and the fusion (F), elicit protective immune response. In this study, HN and F genes of velogenic (virulent) strain were amplified and cloned at multiple cloning sites A and B, respectively into pIRES bicistronic vector for use as bivalent DNA vaccine against ND. The recombinant plasmid was characterized for its orientation by restriction enzyme digestion and PCR. Expression of HN and F genes was assessed in transfected Vero cells at RNA level using RT-PCR in total RNA as well as protein level using IFAT, IPT and western blot using NDV specific antiserum. All these experiments confirmed that HN and F genes cloned in recombinant pIRES.nd.hn.f are functionally active. The recombinant construct is being evaluated as DNA vaccine against ND.

Cloning and expression of chicken granulocyte-macrophage colony stimulating factor (GMCSF) gene

Granulocyte-macrophage colony stimulating factor (GMCSF), a multifunctional cytokine can enhance immune responses when administered along with DNA vaccine. Aim of the present study was to clone and express the chicken GMCSF cytokine for use as 'genetic adjuvant'. Chicken GMCSF gene 435bp was amplified using specific primers in which restriction sites of BamHI and HindIII were at forward and reverse primers respectively. The PCR product was cloned into eukaryotic expression vector pcDNA 3.1(+) and clones were confirmed by restriction digestion and nucleotide sequencing. Functional activity of recombinant GMCSF was checked by expression of GMCSF specific mRNA in transfected Vero cells by RT-PCR of total RNA isolated from transfected Vero cells. The recombinant plasmid can be used as genetic adjuvant in chicken.