Sangwan,NirmalNeetu Bala2024-07-292024-07-292023-04https://krishikosh.egranth.ac.in/handle/1/5810212570Newcastle Disease (ND) is one of the endemic viral diseases of poultry worldwide and is caused by Newcastle Disease Virus (NDV). It is member of the genus Avulavirus in the family Paramyxoviridae. It can not only cause the death of birds but also has a great negative impact on the productivity of surviving birds, such as impaired growth, poor feed conversion, reduced egg production, and decreased fertility and hatchability of eggs. NDV has the ability to reproduce in a variety of cell types, including chicken embryo fibroblasts. Infecting host cells is essential for viral pathogenicity. Cytopathic effects (CPE) can be detected following NDV infection, and these effects are linked to the strain's virulence. ND is being managed and prevented via vaccines. About all commercially marketed ND vaccines need to be refrigerated and these start to lose their effectiveness after 1-2 hours at room temperature. Therefore, the present research was planned to study the role of cytokines in immune response to thermostable NDV, and to find out an effective potential candidate for a thermostable vaccine. The thermostable strain of NDV was developed in the laboratory which was isolated from duck and characterized as lentogenic strain. For this, analysis to elicitate cytokine response was necessary to characterize the thermostable strain of NDV, therefore a comparison was done with conventional lentogenic strain. Both the strains were cultivated in 9 days old embryonated SPF eggs and strains confirmation was done with hemagglutination titer (HA) test, outcomes of HA titer were 1:4 for thermostable strain, 1:8 for lentogenic strain and 1:16 for mesogenic strain. Chicken embryo fibroblast (CEF) culture was used to study cytokine expression of the thermostable and lentogenic strains of NDV. The CEF cells were infected with thermostable strain with 103 TCID50 and lentogenic strain with 104 TCID50. On RNA extraction from CEF cells, after being harvested at 0, 24 and 48 hours post infection, a real-time quantitative PCR was performed, to analyze expression of anti-viral (IFN-α), pro- inflammatory (IL-6) and anti- inflammatory (IL-10) cytokines. Relative expression analysis revealed non-significant change in expression of IL6 in infected CEF cells. However, relative expression of IFNα and IL10 were higher. On the basis of relative expression analysis of immune related cytokines, it can be concluded that the thermostable strain of NDV capable to elicit antiviral and anti-inflammatory cytokine response in CEF cells. Overall, our data signifies the potential of thermostable strain of NDV as vaccine candidate.EnglishThesis