Differential expression of granzyme A and granzyme B proteases and their secretion by fresh rat natural killer cells (NK) and lymphokine-activated killer cells with NK phenotype (LAK-NK).
Granzymes A-G are a family of serine proteases localized in the cytoplasmic granules of cytotoxic T lymphocytes (Masson, D. et al. Cell 1987. 49: 679) and granzyme A is secreted by T lymphocytes in response to antigenic stimulation. Granzyme A is also expressed by natural killer (NK) and lymphokine-activated killer (LAK) cells. Here we show that fresh rat NK cells constitutively express granzyme B and that granzyme A and granzyme B are differentially regulated in unstimulated NK cells vs. LAK cells with NK phenotype (LAK-NK cells). We also show that both granzymes A and B are secreted in a calcium-dependent manner, by NK and LAK-NK cells in response to stimuli which trigger NK cell functions.
Velotti
F
F
Department of Experimental Medicine, University La Sapienza, Rome, Italy.
Palmieri
G
G
D'Ambrosio
D
D
Piccoli
M
M
Frati
L
L
Santoni
A
A
D000818:Animals; D015152:Blotting, Northern; D015870:Gene Expression; D053804:Granzymes; D015979:Killer Cells, Lymphokine-Activated / Q000201:enzymology*; D007694:Killer Cells, Natural / Q000201:enzymology*; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D011916:Rats, Inbred F344; D012697:Serine Endopeptidases / Q000378:metabolism*
D012333:RNA, Messenger; D053804:Granzymes; C509215:Gzmb protein, rat; D012697:Serine Endopeptidases