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 Li,Dang D Bang,Mogens Madsen,Hanne Ingmer

doi:10.1186/1471-2180-8-107

Abstract

BackgroundCampylobacter 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.ResultsC. 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.ConclusionWe 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.

Highlights

Campylobacter jejuni is a major cause of inflammatory diarrhoea in humans and is considered a commensal of the gastroenteric tract of the avian host
Cells grown at equivalent levels (1.7 × 105 cells/well) were inoculated at an multiplicity of infection (MOI) of 100:1 with either C. jejuni strain SC11 or HM5040
The results clearly show that both C. jejuni strains of chicken (SC11) and clinical (HM5040) origin can invade chicken embryo intestinal cells (CEICs) to a level approximate to that seen with human-derived cell lines [21]

Summary

Introduction

Campylobacter jejuni is a major cause of inflammatory diarrhoea in humans and is considered a commensal of the gastroenteric tract of the avian host. 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 proinflammatory cytokines as well as the expression of the bacterial virulence-associated genes during co-cultivation. Campylobacter jejuni is recognized as the leading cause of bacterial food-borne and water-borne enteric diarrhea in humans. The clinical symptoms of Campylobacter infection include watery to bloody diarrhea, abdominal pain, fever, headache, nausea and vomiting in acute infection, even a severe inflammation of the intestinal mucosa with an (page number not for citation purposes). Knowledge about the organism and host responses to infection has been growing rapidly in the past decades, the pathogenesis of C. jejuni is not yet well understood

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