Send to

Choose Destination
Biochem Biophys Res Commun. 2008 Feb 15;366(3):617-23. Epub 2007 Nov 26.

Vesicle-associated membrane protein 7 (VAMP-7) is essential for target cell killing in a natural killer cell line.

Author information

Pulmonary Research Group, Department of Medicine, University of Alberta, 550A Heritage Medical Research Centre, Edmonton, Alta., Canada.


Natural killer cells recognize and induce apoptosis in foreign, transformed or virus-infected cells through the release of perforin and granzymes from secretory lysosomes. Clinically, NK-cell mediated killing is a major limitation to successful allo- and xenotransplantation. The molecular mechanisms that regulate the fusion of granzyme B-containing secretory lysosomes to the plasma membrane in activated NK cells, prior to target cell killing, are not fully understood. Using the NK cell line YT-Indy as a model, we have investigated the expression of SNAP REceptors (SNAREs), both target (t-) and vesicular (v-) SNAREs, and their function in granzyme B-mediated target cell killing. Our data showed that YT-Indy cells express VAMP-7 and SNAP-23, but not VAMP-2. VAMP-7 was associated with granzyme B-containing lysosomal granules. Using VAMP-7 small interfering RNA (siRNA), we successfully knocked down the expression of VAMP-7 protein in YT-Indy to less than 10% of untreated cells in 24h. VAMP7-deficient YT-Indy cells activated via co-culture with Jurkat cells released <1ng/mL of granzyme B, compared to 1.5-2.5 microg/mL from controls. Using Jurkat cells as targets, we showed a 7-fold reduction in NK cell-mediated killing by VAMP-7 deficient YT-Indy cells. Our results show that VAMP-7 is a crucial component of granzyme B release and target cell killing in the NK cell line YT-Indy. Thus, targeting VAMP-7 expression specifically with siRNA, following transplantation, may be a viable strategy for preventing NK cell-mediated transplant rejection, in vivo.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center