Inhibition of TGF-β1−/− and smad3−/−
T cells by CTLA-4. (A) Purified T cells from
TGF-β1+/+ (Left) and
TGF-β1−/− (Right) were cultured with
latex microspheres coated with antibody to CD3 alone (open bars),
anti-CD3/anti-CTLA-4 antibody (solid bars), anti-CD3/anti-CD28
antibody (shaded bars), or anti-CD3/anti-CD28/anti-CTLA-4 antibody
(hatched bars). Proliferation (Upper) and IFN-γ
secretion (Lower) were assessed at 72 h.
(B) Purified T cells from smad3+/+
(Left) and smad3−/−
(Right) mice were stimulated with soluble control Ig
(open bars), anti-CD3/anti-CD28 antibody (solid bars),
anti-CD3/anti-CD28/anti-CTLA-4 antibody (shaded bars), and
anti-CD3/anti-CD28 antibody plus rHuTGF-β1 (2.5 ng/ml) (hatched
bars). Proliferation was assessed at 72 h.