| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Previous Article | Next Article ![]()
Antimicrobial Agents and Chemotherapy, June 1998, p. 1476-1483, Vol. 42, No. 6
Canadian Bacterial Diseases Network,
Department of Microbiology, College of Biological
Science, University of Guelph, Guelph, Ontario N1G 2W1, Canada
Received 29 September 1997/Returned for modification 7 February
1998/Accepted 25 March 1998
We developed a model to test whether non-membrane-permeative
therapeutic agents such as gentamicin could be delivered into mammalian
cells by means of bacterial membrane vesicles. Many gram-negative
bacteria bleb off membrane vesicles (MVs) during normal growth, and the
quantity of these vesicles can be increased by brief exposure to
gentamicin (J. L. Kadurugamuwa and T. J. Beveridge, J. Bacteriol. 177:3998-4008, 1995), which can be entrapped within the
MVs. Gentamicin-induced MVs (g-MVs) were isolated from Shigella
flexneri and contained 85 ± 2 ng of gentamicin per µg of
MV protein. Immunogold electron microscopic labeling of thin sections
with antibodies specific to S. flexneri lipopolysaccharide (LPS) demonstrated the adherence and subsequent engulfment of MVs by
the human Henle 407 intestinal epithelial cell line. Further incubation
of g-MVs with S. flexneri-infected Henle cells revealed that the g-MVs penetrated throughout the infected cells and reduced the
intracellular pathogen by ~1.5 log10 CFU in the first
hour of incubation. Antibiotic was detected in the cytoplasms of host cells, indicating the intracellular placement of the drug following the
penetration of g-MVs. Soluble antibiotic, added as a fluid to the
tissue culture growth medium, had no effect on intracellular bacterial
growth, confirming the impermeability of the cell membranes of the
tissue to gentamicin. Western blot analysis of MVs with S. flexneri Ipa-specific antibodies demonstrated that the invasion protein antigens IpaB, IpaC, and IpaD were present in MVs. Being bilayered, with outer faces composed of LPS and Ipa proteins, these MVs
were readily engulfed by the otherwise impermeable membranes and
eventually liberated their contents into the cytoplasmic substance of
the host tissue.
0066-4804/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.
Delivery of the Non-Membrane-Permeative Antibiotic
Gentamicin into Mammalian Cells by Using Shigella flexneri
Membrane Vesicles
*
Corresponding author. Present address: Roche Vitamins
Inc., Research and Development, Building 102, 340 Kingsland Street, Nutley, NJ 07110-1199. Phone: (973) 284-5904. Fax: (973) 284-6060. E-mail: Jag.Kaduru{at}roche.com.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»