Stochastic asymmetric repartition of lytic machinery in dividing CD8+ T cells generates heterogeneous killing behavior

Cytotoxic immune cells are endowed with a high degree of heterogeneity in their lytic function, but how this heterogeneity is generated is still an open question. We therefore investigated if human CD8(+) T cells could segregate their lytic components during telophase, using imaging flow cytometry, confocal microscopy, and live-cell imaging. We show that CD107a(+)- intracellular vesicles, perforin, and granzyme B unevenly segregate in a constant fraction of telophasic cells during each division round. Mathematical modeling posits that unequal lytic molecule inheritance by daughter cells results from the random distribution of lytic granules on the two sides of the cleavage furrow. Finally, we establish that the level of lytic compartment in individual cytotoxic T lymphocyte (CTL) dictates CTL killing capacity.

Automated summary

Research has found that during telophase, the lytic components in CD8(+) T cells are unevenly segregated. Mathematical modeling suggests that unequal inheritance of lytic molecules by daughter cells results from the random distribution of lytic granules on the two sides of the cleavage furrow. Furthermore, the level of lytic compartment in individual CTL dictates their killing capacity.