Calcium-binding loops of S100A9 and epithelial cell resistance to
Listeria and Salmonella invasion. KB-sham,
KB-S100A8/A91–114, KB-S100A8/A9E36Q,
KB-S100A8/A9E378Q, and KB-S100A8/A9E36Q,E78Q were
analyzed for bacterial invasion using an antibiotic protection assay.
Monolayers were incubated with L. monocytogenes ATCC 10403S
(A) or S. typhimurium ATCC 14028 (B) at an m.o.i.
of 100:1 and 1:1, respectively, for 2 h. Each experiment was performed in
triplicate wells. Values are means ± S.E. of viable intracellular
bacteria, relative to KB-sham (100%), from at least three independent
experiments. C, immunofluorescence staining for intracellular and
extracellular Listeria in KB-sham,
KB-S100A8/A91–114, KB-S100A8/A9E36Q,
KB-S100A8/A9E78Q, and KB-S100A8/A9E36Q,E78Q
transfectants. Monolayers were incubated with L. monocytogenes for 2
h. The intracellular bacteria were enumerated and reported as means ±
S.E. relative to KB-sham (100%) as in the legend of
Fig. 5. The results shown are
from three independent experiments (**, p < 0.01; #,
p < 0.001).