Plasticity of Cell Migration In Vivo and In Silico

Abstract

Cell migration results from stepwise mechanical and chemical interactions between cells and their extracellular environment. Mechanistic principles that determine single-cell and collective migration modes and their interconversions depend upon the polarization, adhesion, deformability, contractility, and proteolytic ability of cells. Cellular determinants of cell migration respond to extracellular cues, including tissue composition, topography, alignment, and tissue-associated growth factors and cytokines. Both cellular determinants and tissue determinants are interdependent; undergo reciprocal adjustment; and jointly impact cell decision making, navigation, and migration outcome in complex environments. We here review the variability, decision making, and adaptation of cell migration approached by live-cell, in vivo, and in silico strategies, with a focus on cell movements in morphogenesis, repair, immune surveillance, and cancer metastasis.

Tissue Dimensionality Influences the Functional Response of Cytotoxic T Lymphocyte-Mediated Killing of Targets

“…Despite the enhanced adhesion and stopping rule, and contrary to our published 2D simulations (8), the conjugates in both cube and slab simulations are relatively unstable, i.e., they resemble the short-lived cytotoxic kinapses described in Ref. (21, 22). Apart from the videos, this can also be seen from the “killing signal” distribution: for monogamous simulations with targets in excess of CTLs (e.g., $\overline{E}MathClass-rel=100$, $\overline{T}MathClass-rel=1500$), the number of targets that are accumulating killing signal would be similar to the number of CTLs if the conjugates were stable.…”

How cells respond to environmental cues – insights from bio-functionalized substrates

“…The existence of leader cells is also an indication that cells can migrate by using different modes of motility. Indeed, it has been shown that switching between different modes of migration can be elicited by environmental cues (te Boekhorst et al, 2016).…”

A coherent modeling procedure to describe cell activation in biological systems

“…Such a function, that hereafter will be denoted as shape function, has to satisfy the following property (2) Ω w xs (y)dy = m and has units µg/µm 2 . Obviously, cell activation, and the relative switch between the two mathematical descriptive instances, is possible only if there is a sufficient amount of mass over the support I xs of w xs , i.e., if ρ(t, y) ≥ w xs (y), ∀ y at time t. If this condition is satisfied, the updated cell density is given by (3) ρ(t, y) = ρ(t, y) − w xs (y) ∀ y ∈ Ω, whereas, as already explained, at the same time t, a localized material point "appears" in x s , giving rise to a hybrid description of the system. In this respect, we remark that the activated cell takes places in the barycenter of the shape function and carries the same amount of mass.…”

“…For instance, few specialized cells typically behave as a patterning guidance for the unspecialized part of the aggregate [1][2][3]. Such mechanisms are mainly regulated by temporary activations and/or longlasting differentiation processes, that define the leader/differentiated individuals within the cell group [4].…”