High activity of N-alpha-benzyloxycarbonyl-L-lysine thiobenzyl ester serine esterase and cytolytic perforin in cloned cell lines is not demonstrable in in-vivo-induced cytotoxic effector cells.

Abstract

Recent observations have suggested striking similarities between complement-mediated and cell-mediated lysis. Both pathways share the terminal insertion of channels into target membranes, and unique esterases have been postulated to participate in the activation of cytolytic effector molecules. Since killer-specific esterases and channel-forming proteins can be demonstrated in in vitro cell lines, it is important to ascertain that the described esterase and channelforming proteins are also present in killer cells from in vivo sources. Results presented here show that killer cell-specific Na-benzyloxycarbonyl-L-lysine thiobenzyl ester serine esterase is induced in vitro concomitant with the sensitization of cytotoxic effector cells. In contrast, in vivo-primed cytotoxic T cells or natural killer (NK) cells fail to express high levels of this enzyme. Assay of different cytotoxic effector cells reveals the presence of Na-benzyloxycarbonyl-L-lysine thiobenzyl ester serine esterase in clones with T killer and NK activity, but enzyme levels do not correlate with cytolytic activity nor does inhibition of esterase activity interfere with granule-mediated cell lysis. A similar result is seen with granule-mediated cytolytic activity. Cloned NK and T killer cell lines possess granules that are able to lyse erythrocyte targets. However, T killer cells sensitized in mixed lymphocyte culture or in vivo have no detectable cytotoxic granules. Cytotoxic granules are also not detected in NK cells isolated from animals.

Expression of perforin in infiltrating cells in murine hearts with acute myocarditis caused by coxsackievirus B3.

“…Natural killer cells and cytotoxic T lymphocytes are known to contain perforin in their cytoplasmic granules in vitro.69 However, until recently, there has been no evidence showing the role of perforin in cell-mediated cytotoxicity primed in vivo. [22][23][24] et a125 demonstrated the expression of perforin mainly in CD8 positive cytotoxic T lymphocytes and in a small population of natural killer-like cells during lymphocytic choriomeningitis virus infection. Later, this was confirmed at the transcriptional level by in situ hybridization.…”

Novel Molecular Subtypes of Serous and Endometrioid Ovarian Cancer Linked to Clinical Outcome

“…More specifically, evidence of adaptive immune response was found among those genes significantly overexpressed within C2 cancers, including markers of T-cell activation (CD8A, Granzyme B; ref. 29…”

Detection of Perforin in Human Peritoneal Fluid T-Lymphocytes

“…Initial studies had reported few, if any, cytolytic granules in mouse primary peritoneal exudate lymphocytes, suggesting that these cells use a different lytic mechanism. [9][10][11][12] Podack and coworkers, however, had demonstrated perforin mRNA in mouse primary peritoneal exudate T-lymphocytes, supporting the evidence that all cytolytic T-cells tested expressed perforin. 13 A strong correlation exists between cytolytic potential and perforin mRNA expression in human large granular lymphocytes, NK cells, gamma/delta T-cells and CD8-positive Tcells.…”