Targeting focal adhesions: Helicobacter pylori-host communication ...

Cell Communication and Signaling 2008, 6:2
http://www.biosignaling.com/content/6/1/2
lished that FAs exist in vivo, mediating cell-matrix junctions
at the basolateral surface of polarized cells [57]. The
fact that CagA injection requires integrin activation leads
to the question of whether H. pylori can contact FAs at the
basolateral membrane in vivo. Several studies have shown
that CagA is necessary for the disruption of the intercellular
tight junctions of polarized cells [58-60]. Furthermore,
it has been demonstrated that injected CagA preferentially
localizes to the apical membrane of T84 cells [61].
Detailed models have been proposed in recent reviews
[11,62], suggesting that moderate amounts of CagA might
be injected across the apical membrane without the need
of integrins in early phases of infection. Together with
other secreted bacterial and/or host factors (e.g. soluble H.
pylori factors or cellular matrix metalloproteases), injected
CagA then supports the disruption of intercellular adhesions
[25,63,64] allowing H. pylori to enter the intercellular
space. In fact, in biopsies from patients with intestinal
metaplasia and gastric cancer, H. pylori was found in the
intercellular space and lamina propria [65], indicating
that H. pylori has access to FAs at later time points of infection
in vivo. Consequently, it is important to analyze the
consequences of CagA injection and FA deregulation in
vivo. CagA PY -associated cell elongation possibly hinders
H. pylori-mediated cell migration, since failure of tail
retraction might result in a reduced migration speed. In
contrast, elongation allows cells to pass tissues more easily,
which would support invasive growth of single cells.
Therefore, analyzing the consequences of cell elongation
and migration in vivo should lead to novel insights into H.
pylori pathogenesis.
Competing interests
The authors declare that they have no competing interests.
Authors' contributions
SS and SW drafted and wrote the manuscript. CW participated
in the design of the manuscript and prepared the
figures. All authors read and approved the final manuscript.
Acknowledgements
We thank Catherine Haynes for critical reading of the manuscript. The
work is supported by the Deutsche Forschungsgemeinschaft (We2843/2-
1).
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