Transcriptional profiling avian beta-defensins in chicken oviduct epithelial cells before and after infection with Salmonella enterica serovar Enteritidis.
BACKGROUND
Salmonella enterica serovar Enteritidis (SE) colonizes the ovary and oviduct of chickens without causing overt clinical signs which can lead to SE-contamination of the content and membrane of shell-eggs as well as hatchery eggs. The organism utilizes the Salmonella Pathogenicity Island-2 encoded type III secretion system (T3SS-2) to promote persistence in the oviduct of laying hens. In this study, reverse transcriptase-polymerase chain reaction (RT-PCR) was carried out to determine the expression profiles of 14 known avian beta defensins (AvBDs) in primary chicken oviduct epithelial cells (COEC) before and after infections with a wild type SE strain and T3SS mutant SE strains carrying an inactivated sipA or pipB gene.


RESULTS
Based on the expression levels in uninfected COEC, AvBDs can be loosely grouped into three categories with AvBD4-5 and AvBD9-12 being constitutively expressed at high levels; AvBD1, AvBD3, and AvBD13-14 at moderate levels; and AvBD2 and AvBD6-8 at minimal levels. Infection with the wild type SE strain temporarily repressed certain highly expressed AvBDs and induced the expression of minimally expressed AvBDs. The pipB mutant, compared to the wild type strain, had reduced suppressive effect on the expression of highly expressed AvBDs. Moreover, the pipB mutant elicited significantly higher levels of the minimally expressed AvBDs than the wild type SE or the sipA mutant did.


CONCLUSIONS
Chicken oviduct epithelial cells express most of the known AvBD genes in response to SE infection. PipB, a T3SS-2 effector protein, plays a role in dampening the beta-defensin arm of innate immunity during SE invasion of chicken oviduct epithelium.
Ebers
Katie L
KL
Department of Pathobiology and Population Medicine, College of Veterinary Medicine, Mississippi State University, PO Box 97813, Pearl, MS 39288, USA. kleech@cvm.msstate.edu
Zhang
C Yan
CY
Zhang
M Zhenyu
MZ
Bailey
R Hartford
RH
Zhang
Shuping
S
D000818:Animals; D017209:Apoptosis; D002478:Cells, Cultured; D002645:Chickens / Q000235:genetics* / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism* / Q000382:microbiology; D005260:Female; D020869:Gene Expression Profiling; D010057:Oviducts / Q000166:cytology / Q000382:microbiology; D011201:Poultry Diseases / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012481:Salmonella Infections, Animal / Q000235:genetics* / Q000378:metabolism; D012477:Salmonella enteritidis / Q000472:pathogenicity*; D023083:beta-Defensins / Q000235:genetics* / Q000378:metabolism
D023083:beta-Defensins