Abstract

Background: Studies on Philippine Banaba native chickens and Philippine Mallard ducks were generally focused on their production and management. However, little is known on their immune responses to pathogens like Riemerella anatipestifer (R. anatipestifer), one of the economically important infectious disease-causing pathogens in Philippine Banaba native chickens and Philippine Mallard ducks. Methods: Chicken and duck embryonic fibroblasts (CEFs and DEFs) isolated from 11-day old healthy embryos were stimulated with heat-inactivated R. anatipestifer for 4, 8 and 24 h. The cells were collected at each time point and subjected to qRT-PCR for gene expression analyses. Results: Comparative gene expression analyses of immune-related cytokines revealed that the ex- pression levels of IL-17A, IL-17F, IL-1ß and IL-6 were significantly upregulated in both CEFs and DEFs stimulated with heat-inactivated R. anatipestifer serotype 7. However, levels were higher in DEFs compared to the corresponding levels in heat-inactivated R. anatipestifer stimulated CEFs. On the other hand, IFN-g, IL-2, IL-4 and IL-10 expression levels of stimulated DEFs were also upregulated. In CEFs, it is interesting to note that IFN-g level was significantly downregulated at 24 h while upregulated in DEFs. Conclusion: Results showed that the Philippine Banaba native chickens and Mallard ducks are also susceptible to R. anatipestifer infection.

Keywords

R. anatipestifer, Philippine Banaba, Mallard duck, Cytokines, Immunity

4 PLT 12122023 Download