Bacteria-host cell interaction mediated by cellular cholesterol/glycolipid-enriched microdomains.

Published

Journal Article

Gram negative bacterial infection is a leading cause of fatality and is attributed, at least in part, to the bacteria's capacity to persist in the host in spite of appropriate antibiotic therapy. It has been suggested that bacteria evade antibiotics by hiding within host cells. We sought to investigate this important aspect of infections in mast cells, which are inflammatory cells found in close proximity to the host-environment interface and which have recently been reported to play a crucial role in the early innate immune response to bacteria. We examined mast cell interactions with FimH-expressing E. coli, one of the major opportunistic pathogens of humans. We determined that in serum free conditions, these bacteria were able to trigger mast cell uptake without loss of bacterial viability. CD48, a mannose containing GPI (glycosylphosphatidylinositol)-linked molecule was found to be the receptor of FimH-expressing E. coli in mouse mast cells. We found that the internalization via CD48 was blocked by filipin, a cholesterol binding drug known to disrupt cholesterol/glycolipid-enriched microdomains and the bacteria-encasing vacuoles were rich in cholesterol inside cells. Interestingly, we found that mast cells subsequently expelled majority of the intracellular bacteria in 24 hours. This expulsion process was blocked by lovastatin/cyclodextrin treatment, which is known to inhibit cellular trafficking of cholesterol/glycolipid-enriched microdomains. Thus, the bacterial entry into and expulsion from mast cells were critically dependent on cholesterol/glycolipid-enriched microdomains, which represents a novel mode of tussle between the pathogen and the mast cell occurring in opsonin deficient sites in the body or even at other sites in naive or immunocompromised hosts which have low systemic levels of E. coli specific antibody.

Full Text

Duke Authors

Cited Authors

  • Shin, JS; Gao, Z; Abraham, SN

Published Date

  • October 1999

Published In

Volume / Issue

  • 19 / 5

Start / End Page

  • 421 - 432

PubMed ID

  • 10763810

Pubmed Central ID

  • 10763810

International Standard Serial Number (ISSN)

  • 0144-8463

Digital Object Identifier (DOI)

  • 10.1023/a:1020216323271

Language

  • eng

Conference Location

  • England