Expression of high levels of human proteinase inhibitor 9 blocks both perforin/granzyme and Fas/Fas ligand-mediated cytotoxicity
TD Cunningham, X Jiang, DJ Shapiro - Cellular immunology, 2007 - Elsevier
Proteinase inhibitor 9 (PI-9, SerpinB9) is the only known human intracellular granzyme B
inhibitor. Whether expression of PI-9 is sufficient to block cytolysis induced by cytotoxic T
lymphocytes (CTLs) and natural killer (NK) cells remains controversial. To evaluate the roles
of PI-9, we isolated and tested three lines of stably transfected HeLa cells expressing wild-
type PI-9 and one line expressing an inactive mutant PI-9. Expressions of wild-type PI-9, but
not the inactive mutant PI-9, inhibited cytolysis induced by human NK92 and NKL natural …
inhibitor. Whether expression of PI-9 is sufficient to block cytolysis induced by cytotoxic T
lymphocytes (CTLs) and natural killer (NK) cells remains controversial. To evaluate the roles
of PI-9, we isolated and tested three lines of stably transfected HeLa cells expressing wild-
type PI-9 and one line expressing an inactive mutant PI-9. Expressions of wild-type PI-9, but
not the inactive mutant PI-9, inhibited cytolysis induced by human NK92 and NKL natural …