Fate of the DNA in plasmid-containing Escherichia coli minicells ingested
by human neutrophils
HB Fox, P De Togni, G McMahon, SB Levy, JS Robinson, MJ Karnovsky and BM Babior
Escherichia coli minicells containing the plasmid pSC101 (approximately 10
kb) or pBR322 (approximately 4 kb) were opsonized and incubated with human
neutrophils. The neutrophils responded to the minicells as they would to
native E coli: they ingested the minicells, discharged their granule
contents into the minicell-containing phagosomes, and expressed a
respiratory burst. After one hour of incubation, the fate of the ingested
plasmid DNA was examined. No DNA degradation was detected by
trichloroacetic acid precipitation or agarose gel electrophoresis.
Moreover, when pBR322 recovered from ingested minicells was transformed
into E coli, no mutations in either of the antibiotic resistance genes
carried by the plasmid were detected out of many thousand transformants
screened. These findings confirm the surprisingly limited effect of
neutrophils on ingested DNA.
Volume 69,
Issue 5,
pp. 1394-1400,
05/01/1987
Copyright © 1987 by The American Society of Hematology