Cytokine Gene Expression of Peritoneal Tissues in Response to Mixed Infection of Bacteroides fragilis and Escherichia coli

Bacteroides fragilis와 대장균의 혼합 감염에 의한 복강 조직의 Proinflammatory Cytokine 유전자 발현 조절

  • Kim, Jung-Mogg (Department of Microbiology and Institute of Biomedical Science, Hanyang University College of Medicine) ;
  • Kim, Young-Jeon (Department of Life Sciences, Joongbu University) ;
  • Park, Hwon-Kyum (Department of General Surgery, Hanyang University College of Medicine) ;
  • Cho, Yang-Ja (Department of Microbiology and Institute of Biomedical Science, Hanyang University College of Medicine)
  • 김정목 (한양대학교 의과대학 미생물학교실 및 의과학 연구소) ;
  • 김영전 (중부대학교 생명공학부) ;
  • 박훤겸 (한양대학교 의과대학 외과학교실) ;
  • 조양자 (한양대학교 의과대학 미생물학교실 및 의과학 연구소)
  • Published : 2000.02.28

Abstract

Bacteroides fragilis and Escherichia coli, normal colonic inhabitants, are the most frequently isolated bacteria in infected tissues, particularly in intraabdominal abscesses. This study was designed to determine whether enteric bacteria may alter the B. fragilis-induced expression of pro inflammatory cytokines in mouse peritoneal tissue (MPT). After C57BL/6 mice were inoculated with abscess-forming mixture containing B. fragilis in the presence or absence of E. coli, RNA was extracted from MPT. Expression of interleukin (IL)-$1{\alpha}$ and tumor necrosis factor $(TNF){\alpha}$ mRNA was assessed using RT-PCR and standard RNA. Each cytokine protein was also measured by ELISA. The co-inoculation of E. coli into mouse peritoneal cavity advanced the onset of abscess development by B. fragilis infection. When mouse was co-infected with E. coli and B. fragilis intraperitoneally, there was a synergistic increase in the expression of IL-$1{\alpha}$ and $TNF{\alpha}$ mRNA in MPT and this was paralleled by increased cytokine protein secretion. Mixed inoculation of heat-killed E. coli and B. fragilis did not cause a synergistic increase in those cytokine mRNA expression. These results suggest that enteric bacteria may significantly affect proinflammatory cytokine signal produced by host peritoneal cavity in response to B. fragilis infection.

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