A novel single-chain-Fv antibody against connective tissue growth factor attenuates bleomycin-induced pulmonary fibrosis in mice.
OBJECTIVE
Connective tissue growth factor (CTGF) has been identified as playing critical roles in fibrosis and is a promising therapeutic target. In a previous study, we used a phage display library to develop a humanized single-chain variable fragment antibody (scFv) against CTGF. In the present study, the protective effect of anti-CTGF scFv against bleomycin (BL)-induced pulmonary fibrosis was investigated in mice.


METHODS
The expression of α-smooth muscle actin in human embryonic lung fibroblast (HELF) cells was analysed by western blotting. A mouse model of pulmonary fibrosis was established by tracheal injection of BL (5 mg/kg). Mice received anti-CTGF scFv (4 mg/kg, three times a week) by i.v. injection. The effects of anti-CTGF scFv were evaluated by leukocyte counts in BAL fluid, hydroxyproline measurements in lung tissue and pathological examination.


RESULTS
α-Smooth muscle actin expression was decreased in HELF cells treated with anti-CTGF scFv. Anti-CTGF scFv significantly reduced the numbers of inflammatory leukocytes (total and differential count) in BAL fluid, as well as the hydroxyproline content of lung tissue. The severity of alveolitis and fibrosis in the mouse model was markedly attenuated by treatment with anti-CTGF scFv.


CONCLUSIONS
Anti-CTGF scFv may potentially be developed as a useful inhibitor of pulmonary fibrosis.
Respiratory Department, Institute of Biotechnology and Clinical Pharmacy, China Pharmaceutical University, Nanjing, China.
Xihua
X
Wang
Guoqiu
G
Wu
Lixia
L
Gou
Zhaozhao
Z
Liu
Xiyong
X
Wang
Xiaobo
X
Fan
Linyuan
L
Wu
Naifeng
N
Liu
D000199:Actins / Q000378:metabolism; D000818:Animals; D001761:Bleomycin / Q000009:adverse effects / Q000633:toxicity; D001992:Bronchoalveolar Lavage Fluid / Q000276:immunology; D055513:Connective Tissue Growth Factor / Q000276:immunology*; D006909:Hydroxyproline / Q000378:metabolism; D007958:Leukocyte Count; D008297:Male; D051379:Mice; D011658:Pulmonary Fibrosis / Q000139:chemically induced / Q000628:therapy*; D012720:Severity of Illness Index; D057127:Single-Chain Antibodies / Q000627:therapeutic use*
D000199:Actins; C526318:CCN2 protein, mouse; D057127:Single-Chain Antibodies; C544013:alpha-smooth muscle actin, mouse; D001761:Bleomycin; D055513:Connective Tissue Growth Factor; D006909:Hydroxyproline