ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

Illustration 1: A two-dimensional schematic of a cell where the points on the surface
are connected to each other as well as to the cell centre.
present earlier. The transition of the cell going back to its original geometry is
determined by the cell stiffness, α, which also takes into account tangential forces. In
[1], the equations are presented, as well as many simulation case studies are discussed
including an experimental validation.
4. SIMULATION RESULTS
First, we present a case in which one spherical cell deforms and migrates as a result of
the chemo-attractant that is released by three bacteria. The initial configuration of the
spherical cell in the extra-cellular matrix is a spherical cell with radius of 0.4 mm at the
origin and three bacteria as point sources at locations (-1.5,0,0), (0,1.5,0) and (1.5,0,0).
In Fig. 2, it can be seen that the cell (α = 0.15, β = 5) has deformed as a result of the
chemical that is secreted by the three bacteria. The cell shape index, not shown here,
changes significantly during the process of bacterial engulfment. For stiffer cells, i.e.
cells with a higher α-value, the cell deforms less, which implies that the cell, including
the cell centre, has to migrate over a larger distance and hence the time needed to engulf
the bacteria increases. This makes the immune response less efficient. Furthermore, the
cellular motility coefficient β determines the velocity at which the cell moves and hence
also determines the efficiency of the immune response. This possibility decreases the
efficiency of biological processes like wound healing, and it may lead to further tissue
degradation.