Cell–extracellular matrix interactions: Unraveling the kinetics and strength of cellular adhesion
The z-Movi® is a useful tool to obtain insights into cell adhesion processes. Here, Kamsma et al. used the z-Movi® to resolve the adhesion forces and kinetics between CD4+ T lymphocytes (CD4) and fibronectin.
They identified three interaction states between the cells: unbound, binding, and bound. Interaction strengths below 30 pN were defined for unbound cells, between 30 pN and 55 pN for transiently binding and crawling cells, and 55 pN and above for bound cells (Figure 7).
The researchers then investigated how these properties are influenced by interleukin-7 (IL7), the main regulatory cytokine of CD4 cells. The results demonstrated that while IL7 accelerated CD4 adhesion, it did not influence CD4 avidity (Figures 8 and 9).
7 Cumulative probability distribution plot of the rupture forces shown for unbound, binding, and bound cells, IL7-activated and non-activated.
8 Adhesion of CD4 to the fibronectin-functionalized glass, challenged with increasing concentrations of peptide inhibitors (RGD; plain line GRGDS; dashed ine). This experiment was performed on three different blood donors (error bars denote SEM).
9 Fraction cells bound as a function of time, plotted for non-activated and IL-7-activated CD4 on glass functionalized or not with fibronectin.
