[The effect of anti-transforming growth factor-beta1 antibody on fibroblast proliferation in vitro]

Using anti-transforming growth factor-beta(1) antibody binding to transforming growth factor-beta(1) (TGF-beta(1)) in conditioned supernatant obtained from alveolar macrophages (AM) in broncho-alveolar lavage fluid (BALF) in bleomycin-induced rats, we investigated the effect of binding of TGF beta(1) to anti-TGF beta(1) antibody on proliferation and synthesis of collagen by fibroblast in pulmonary fibrosis.

Bleomycin (0.75 mg/100 BW) was instilled intratracheally into wistar rats, then broncho-alveolar lavage (BAL) was performed 7 days later. AMs (5 x 10(5)/ml) were cultured in 0.2% FCS RPMI-1640 medium in vitro for 24 hours and conditioned medium was obtained. L929 fibroblast (7 x 10(3)/well) was cultured in 96-well microtiter plate with conditioned medium and in different doses of anti- TGF beta(1) antibody (1, 5, 10, 20 microg/ml) and IgG for 24 hours respectively. (3)H-Tdr was added 1 microCi per well for 6 hours before culture finished. The proliferation of fibroblast was studied by (3)H-Tdr incorporation rate and synthesis of collagen type IV was tested by ELISA.

(1) Fibroblast proliferation which was induced by AM conditioned medium could be significantly depressed by anti-TGF beta(1) antibody in vitro (P < 0.01), and it appeared in a dose-dependent manner. (2) Synthesis of collagen type IV was depressed about 32% by 10 microg/ml anti-TGF beta(1) antibody.

Fibroblast proliferation and collagen synthesis could be depressed by anti-TGF beta(1) antibody in vitro. It seems possible to provide a new way for the treatment of pulmonary fibrosis.