Submitted to: Avian Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 11, 2011
Publication Date: N/A
Interpretive Summary: We have previously described differences in the immune systems between commercial turkeys and wild-type turkeys and differences in some of the signals involved in an immune response. The current study further describes some of the factors that result in the commercial line’s decreased immune functions as compared to wild-type turkeys. Specifically, the current study further describes the signals that go on inside the cell when a white blood cell encounters a foreign invader, such as a bacterium. We show that cells from commercial turkey lines have deficiencies in their cell signaling response to foreign invaders as compared to cells from wild-type turkeys. These deficiencies aid in explaining why commercial turkeys are more susceptible to diseases and colonization with food borne pathogens as compared to their wild-type counterparts.
Technical Abstract: Studies comparing signaling in wild-type turkey (WT) leukocytes and commercial turkey (CT) leukocytes found that the activity of protein tyrosine kinases (PTK) and MAP kinases, ERK 1/2 and p38, were significantly higher in WT leukocytes compared to CT lines upon exposure to both SE and OPSE on days 4 and 7 post-hatch. To further characterize intracellular signaling in turkeys, leukocytes were isolated from 4 and 7 day-old turkey poults (commercial Lines A and C; WT). Leukocytes were exposed to Salmonella enteritidis (SE) and opsonized SE (OPSE). After exposure to SE or OPSE, SRC, JNK, and NF-kappaBp65 signaling activity in turkey leukocytes were compared using commercially available ELISA. JNK activity in Lines A, C, and WT leukocytes were similar, except on day 4 post-hatch where Line C had higher JNK activity than did the WT and Line A. SRC activity was higher in all Lines on day 7 post- hatch and was similar between all Lines on day 4. On day 4 post-hatch, WT turkey leukocytes had higher levels of nuclear NF-kappaB compared to CT lines. On day 7 post-hatch, nuclear levels of NF-kappaB were similar between all lines of turkeys. The data presented here, in combination with previous signaling and functional studies, indicates that wild- type turkeys have more effective innate immune mechanisms than do commercial turkeys, although not all parameters of functionality are dissimilar. These studies help to form the basis for further investigations of the commercial turkey immune system and subsequent development of genetic and/or modulation strategies to improve immune deficiencies in commercial turkeys and reduce disease and carriage of food-borne pathogens.