A technique for the assessment of the cytotoxic capacity of CD8+ lymphocytes based on phase images

Abstract

A novel technique for the assessment of cytotoxic capacity, which is a characteristic of the state of immune-system cells, has been proposed. Using coherent phase microscopy, perforin granules have been detected and described in the cytoplasm of live CD8+ lymphocytes. According to the analysis of phase images, the parameters of perforin granules in the cell were quantitatively assessed. Their average values were calculated as follows: the projected area on the image plane, 15 ± 7 μm²; phase volume, 0.94 ± 0.24 μm³; and the dry weight of the granules, 0.52 ± 0.11 pg. Taking the advantage of this technique, it appears possible to determine cytotoxic capacity using a small number of live cells without employing fluorescent-labeled probes.