Cutting Edge: Rapid and Efficient In Vivo Cytotoxicity by Cytotoxic T Cells Is Independent of Granzymes A and B

Independent of Granzymes A and B Cytotoxicity by Cytotoxic T Cells Is Cutting Edge: Rapid and Efficient In Vivo

Cutting edge: rapid and efficient in vivo cytotoxicity by cytotoxic T cells is independent of granzymes A and B.

Cytotoxic T (Tc) cells lyse target cells via exocytosis of granules containing perforin (perf) and granzymes (gzm). In vitro, gzm delivery into the target cell cytosol results in apoptosis, and in the absence of gzm A and B the induction of apoptosis is severely impaired. However, using in vivo Tc cell killing assays, we find that virus-immune, gzm A x B-deficient (gzmAxB(-/-)) mice are compete...

Differential expression of granzymes A and B in human cytotoxic lymphocyte subsets and T regulatory cells.

Cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells use the perforin/granzyme pathway as a major mechanism to kill pathogen-containing cells and tumor cells.(1,2) Dysregulation of this pathway results in several human diseases, such as hemophagocytic lymphohistiocytosis. Here we characterize the single-cell expression pattern of granzymes A and B in human lymphocytes using a flow cytom...

In Vivo Elimination of MHC-I-Deficient Lymphocytes by Activated Natural Killer Cells Is Independent of Granzymes A and B

NK cells kill target cells mainly via exocytosis of granules containing perforin (perf) and granzymes (gzm). In vitro, gzm delivery into the target cell cytosol results in apoptosis, and induction of apoptosis is severely impaired in the absence of gzm A and B. However, their importance for in vivo cytotoxicity by cytotoxic T cells has been questioned. We used an in vivo NK cytotoxicity assay, ...

Cutting edge: rapid in vivo killing by memory CD8 T cells.

In this study, we examined the cytotoxic activity of effector and memory CD8 T cells in vivo. At the peak of the CTL response following an acute lymphocytic choriomeningitis virus infection, effector CD8 T cells exhibited extremely rapid killing and started to eliminate adoptively transferred target cells within 15 min by a perforin-dependent mechanism. Although resting memory CD8 T cells are p...