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.
Original language | English |
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Pages (from-to) | 43-49 |
Number of pages | 7 |
Journal | FEMS Microbiology Letters |
Volume | 258 |
Issue number | 1 |
DOIs | |
Publication status | Published - May 2006 |