TABLE 1.

Effects of various signal transduction stimulants and inhibitors on JCV activity in PDA

Chemical tested	Final concn	Action	% Vp-1a
Control (no treatment)	0	None	100
Phorbol-12-myristate-13-acetate	100 ng/ml	Activates protein kinase C	100
Interleukin-1β	1 ng/ml	Stimulates inflammatory and immune response	105
Tumor necrosis factor alpha	1 ng/ml	Activates JNK	110
Forskolin	5 μM	Activates adenylate cyclase	110
Sphingosylphosphorylcholine	5 μM	Stimulates DNA binding activity of AP-1	110
Lipopolysaccharide	1 μg/ml	Stimulates various immune defense mechanisms	110
TGF-β1	5 ng/ml	Regulates proliferation, differentiation, and other cellular functions	200
Bisindolylmaleimide II	25 nM	Inhibits protein kinase C	100
H-89, dihydrochloride	100 nM	Inhibits protein kinase A	90
N-Nitro-l-arginine	100 μM	Inhibits nitric oxide synthases, bNOS and eNOS	90
SP600125	100 nM	Inhibits JNK	90
SB203580	1 μM	Inhibits p38 MAPK	90
PD98059	20 μM	Inhibits MEK1/2	5
U0126	10 μM	Inhibits MEK1/2	2

^aA measure of the viral activity observed in PDA cultures 4 days post-JCV exposure using ImageJ software (open-source program distributed by the National Institutes of Health) for quantitation of late viral protein (Vp-1) expression determined by intensity of immunoblot banding and represented here as a percentage-based comparison with the control value (no treatment). bNOS, brain nitric acid synthase; eNOS, endothelial nitric acid synthase.