Cytokine responses in primary chicken embryo intestinal cells infected with Campylobacter jejuni strains of human and chicken origin and the expression of bacterial virulence-associated genes

Yi-Ping Li¹ , Hanne Ingmer³ , Mogens Madsen² and Dang D Bang¹

¹Department of Poultry, Fish and Fur Animals, National Veterinary Institute (VET), Technical University of Denmark (DTU), Hangøvej 2, DK-8200 Aarhus N, Denmark

²Dianova, Technical University of Denmark (DTU), Hangøvej 2, DK-8200 Aarhus N, Denmark

³Department of Veterinary Pathobiology, Life Science Faculty, University of Copenhagen, Stigboejlen 4, DK-1870 Frederiksberg C, Denmark

author email corresponding author email

BMC Microbiology 2008, 8:107doi:10.1186/1471-2180-8-107


Published:	27 June 2008

Abstract

Background

Campylobacter jejuni is a major cause of inflammatory diarrhoea in humans and is considered a commensal of the gastroenteric tract of the avian host. However, little is known about the interaction between C. jejuni and the avian host including the cytokine responses and the expression of the bacterial genes. We have investigated the invasiveness of primary chicken embryo intestinal cells (CEICs) by C. jejuni strains of human and chicken origins and the production of pro-inflammatory cytokines as well as the expression of the bacterial virulence-associated genes during co-cultivation.

Results

C. jejuni strains are capable of invading the CEICs and stimulate these cells in a pro-inflammatory manner and during this interaction the expression of the bacterial virulence-associated genes ciaB, dnaJ and racR is increased. Furthermore, incubation of bacteria with conditioned cell- and bacteria-free media from another co-cultivation experiment also increased the expression of the virulence-associated genes in the C. jejuni chicken isolate, indicating that the expression of bacterial genes is regulated by component(s) secreted upon co-cultivation of bacteria and CEICs.

Conclusion

We show that under in vitro culture condition C. jejuni strains of both human and chicken origins can invade avian host cells with a pro-inflammatory response and that the virulence-associated genes of C. jejuni may play a role in this process.