Intracellular ice formation is affected by cell interactions

Abstract

Cell-to-cell and cell-to-surface interactions are important to the structure and function of tissues. These interactions are also important determinants of low-temperature responses in tissues. Four in vitro models using hamster fibroblast cells in tissue culture were used to investigate the influence of cell– cell and cell–surface interactions on intracellular ice formation in these systems. The four models were: (a) single cells in suspension; (b) cells individually attached to glass with only cell-to-surface adhesion; (c) colonies of cells attached to glass with both cell– cell and cell–surface interactions; and (d) multicellular spheroids with extensive cell– cell contacts. Cryomicroscopy was used to monitor the prevalence and kinetics of intracellular ice formation after ice nucleation in the extracellular solution. The temperature for intracellular freezing in 50% of the cells was significantly affected by both cell– cell and cell–surface interactions. There was also evidence of intercellular nucleation through cell– cell interactions. The results indicate that cell– cell and cell–surface interactions play a significant role in the low-temperature response of tissue systems.