Different sugar residues of the lipopolysaccharide outer core are required for early interactions of Salmonella enterica serovars Typhi and Typhimurium with epithelial cellsReportar como inadecuado




Different sugar residues of the lipopolysaccharide outer core are required for early interactions of Salmonella enterica serovars Typhi and Typhimurium with epithelial cells - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Resumen

The role of lipopolysaccharide LPS in entry of Salmonella Typhimurium into epithelial cells remainsunclear. In this study, we tested the ability of a series of mutants with deletions in genes for the synthesisand assembly of the O antigen and the outer core of LPS to adhere to and invade HeLa, BHK, and IB3epithelial cells lines. Mutants devoid of O antigen, or that synthesized only one O antigen unit, or withaltered O antigen chain lengths were as able as the wild type to enter epithelial cells, indicating that thispolysaccharide is not required for invasion of epithelial cells in vitro. In contrast, the LPS core plays a rolein the interaction of S. Typhimurium with epithelial cells. The minimal core structure required foradherence and invasion comprised the inner core and residues Glc IeGal I of the outer core. A mutant ofS. Typhimurium that produced a truncated LPS core lacking the terminal galactose residue hada significant lower level of adherence to and ingestion by the three epithelial cell lines than did strainswith this characteristic. Complementation of the LPS production defect recovered invasion to parentallevels. Heat-killed bacteria with a core composed of Glc IeGal I, but not bacteria with a core composed ofGlc I, inhibited uptake of the wild type by HeLa cells. A comparison of the chemical structure ofthe S. Typhi core with the published chemical structure of that of S. Typhimurium indicated that theGlc IeGal IeGlc II backbone is conserved in both serovars. However, S. Typhi requires a terminal glucosefor maximal invasion. Therefore, our data indicate that critical saccharide residues of the outer core playdifferent roles in the early interactions of serovars Typhi and Typhimurium with epithelial cells.



Autor: Bravo, Denisse; - Hoare, Anilei; - Silipo, Alba; - Valenzuela, Camila; - Salinas, Catalina; - Álvarez Armijo, Sergio Aníbal; -

Fuente: http://repositorio.uchile.cl/



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