The normal chain length distribution of the O antigen is required for the interaction of Shigella flexneri 2a with polarized Caco-2 cells

Anilei Hoare, Denisse Bravo, Mara Martinic, Miguel A. Valvano, Ines Contreras, Sergio A. Alvarez

Research output: Contribution to journalArticlepeer-review

6 Citations (Scopus)
63 Downloads (Pure)

Abstract

Shigella flexneri causes bacillary dysentery in humans. Essential to the establishment of the disease is the invasion of the colonic epithelial cells. Here we investigated the role of the lipopolysaccharide (LPS) O antigen in the ability of S. flexaeri to adhere to and invade polarized Caco-2 cells. The S. flexneri 2a O antigen has two preferred chain lengths: a short O antigen (S-OAg) regulated by the WzzB protein and a very long O antigen (VL-OAg) regulated by Wzz(pHS2). Mutants with defined deletions of the genes required for O-antigen assembly and polymerization were constructed and assayed for their abilities to adhere to and enter cultured epithelial cells. The results show that both VL- and S-OAg are required for invasion through the basolateral cell membrane. In contrast, the absence of O antigen does not impair adhesion. Purified LPS does not act as a competitor for the invasion of Caco-2 cells by the wild-type strain, suggesting that LPS is not directly involved in the internalization process by epithelial cells.

Original languageEnglish
Pages (from-to)21-26
Number of pages6
JournalBiological Research
Volume45
Issue number1
DOIs
Publication statusPublished - 2012
Externally publishedYes

Keywords

  • Shigella
  • epithelial cells
  • O antigen

ASJC Scopus subject areas

  • Agricultural and Biological Sciences(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Medicine(all)

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