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Functional analysis of lymphostatin homologues in enterohaemorrhagic Escherichia coli

Research output: Contribution to journalArticle

  • A B Abu-Median
  • P M van Diemen
  • F Dziva
  • I Vlisidou
  • T S Wallis
  • M P Stevens

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Original languageEnglish
Pages (from-to)43-49
Number of pages7
JournalFEMS Microbiology Letters
Volume258
Issue number1
DOIs
Publication statusPublished - May 2006

Abstract

Enteropathogenic Escherichia coli contain a large chromosomal gene (lifA) that encodes lymphostatin, a predicted 365 kDa protein that inhibits the mitogen-activated proliferation of peripheral blood lymphocytes and lamina propria mononuclear cells and the synthesis of proinflammatory cytokines. Non-O157 serotypes of enterohaemorrhagic E. coli (EHEC) contain a highly homologous gene, designated efa1 (EHEC factor for adherence), which influences adherence to epithelial cells in vitro and intestinal colonization in calves. Serotype O157:H7 EHEC strains contain a truncated version of this gene (efa1') and a pO157-encoded homologue of lifA/efa1 (toxB). Here we report for the first time that efa1 inhibits mitogen-activated proliferation of bovine peripheral blood lymphocytes by EHEC O103:H2, but that E. coli K-12 strains expressing the N-terminal and central portions of the protein lack activity. While a Shiga toxin-negative E. coli O157:H7 strain was shown to possess lymphostatin-like activity, deletion of efa1' or toxB, singly or in combination, failed to significantly relieve the inhibitory effect.

ID: 4078549