Ex vivo detection of primary leukemia cells resistant to granule cytotoxin-induced cell death: a rapid isolation method to study granzyme-B-mediated cell death.

Cytotoxic T lymphocytes and natural killer cells (CTL/NK) induce cell death in leukemia cells by the granzyme B (grB)-dependent granule cytotoxin (GC) pathway. Resistance to GC may be involved in immune evasion of leukemia cells. The delivery of active grB into the cytoplasma is dependent on the presence of perforin (PFN) and grB complexes.