The Different Expression Of Partial Cytokine Genes In Response To Velogenic And Lentogenic Newcastle Disease Viruses Infection In Chicken Peripheral Blood

Newcastle disease virus (NDV) is an important pathogen hazardous to poultry industry, and the pathogenicity of NDV strains varies with different virulence. Peripheral blood serves as an important producer and carrier of viruses and cytokines in the process of NDV pathogenesis. In order to explore the difference of cytokine expression in the peripheral blood between velogenic strain and lentogenic strain infection, NDV virulent strain F48E9 and vaccine strain Lasota were used to infect special-pathogen-free (SPF) chickens separately, and peripheral blood was collected on 0,3,7,10,14 and 21 days post-infection (d.p.i.).Real-time PCR was used to detect the expression of nine kinds of immune-related cytokine genes. For the F48E9 group, a sharp increase of the expression of interferon-alpha (IFN-α), interferon-gamma (IFN-γ), interleukin-10 (IL-10), IL-13, IL-16 and IL-18 was observed on 3 d.p.i. before the NDV blood peak (7 d.p.i.), followed by a rapid decline to the level lower than that of control group, then the expression of IFN-a, IL-10 and IL-13 increased slowly and reached or exceed the level of control group in the later phase of the whole period, while the expression of IFN-y, IL-16 and IL-18 fluctuated at the level of control group for the rest of study period. The increase of IL-2 expression was not obvious, and no increase of IL-15 expression was noted. For the Lasota (vaccine) group, the picture was quite different, a sharp increase of IFN-y (but not IFN-α), IL-2 and IL-13 (but not IL-10) was observed on 7 dayes p.i. before the NDV blood peak (10 d.p.i.). On the contrary, there was no dramatic increase of IL-16 and IL-18. Interestingly, in contrast to the F48E9 group, there was a increase of IL-15 on day 10 d.p.i., but it remain modest. There was an increase of IFN-αon day 21 d.p.i.. In conclusion, infection with NDV strains of different virulence was associated with distinct cytokine expression patterns in peripheral blood and modulation of cytokine responses may play a key role in mediation of NDV pathgenesis.