Distinguishing perforin-mediated lysis and granzyme-dependent apoptosis

Abstract

Perforin is an indispensable effector protein of primary cytotoxic lymphocytes (CTL or NK cells) that typically defend the host against virus infection, or gene-modified (chimeric antigen receptor—CAR) anticancer T cells. Perforin's pore-forming activity is necessary for the delivery of proapoptotic serine proteases, granzymes, into the cytosol of infected or cancerous target cells. The complete loss of perforin function is detrimental for the function of cytotoxic lymphocytes, and leads to fatal immune dysregulation in infants and predisposes the carriers of hypomorphic perforin mutations to various chronic inflammatory sequelae and blood cancers. Here, we describe several optimized and val..