Prevention of radiation-induced pneumonitis by recombinant adenovirus-mediated transferring of soluble TGF-beta type II receptor gene.
To investigate whether radiation-induced pneumonitis in the mouse-irradiated lung could be prevented by recombinant adenovirus-mediated soluble transforming growth factor-beta (TGF-beta) type II receptor gene therapy. Radiation fibrosis-prone mice (C57BL/6J) were randomly divided into four groups consisting of a (1) control group (sham-irradiated); (2) radiation (RT)-alone group; (3) RT+AdCMVsTbetaR group and (4) RT+AdCMVluc group. The RT-alone and sham-irradiated mice were killed at several time points after thoracic irradiation with a single dose of 9 Gy, and then the TGF-beta1 concentrations in serum and broncho-alveolar lavage fluid (BALF) were quantified by enzyme-linked immunosorbent assay (ELISA). We used an adenoviral vector expressing a soluble TGF-beta type II receptor (AdCMVsTbetaR), which can bind to TGF-beta and then block the TGF-beta receptor-mediated signal transduction. The C57BL/6J mice were intraperitoneally (i.p.) injected with either 5 x 10(8) plaque-forming units of AdCMVsTbetaR or AdCMVluc, a control adenovirus-expressing luciferase, a week preceding and a week following the X-ray thoracic irradiation. Four weeks after irradiation, the mice were killed and the concentration of TGF-beta1 in the serum and BALF were then measured using ELISA and the lung tissue specimens were examined histopathologically. Following thoracic irradiation with a single dose of 9 Gy, radiation-induced TGF-beta1 release in the serum reached the first peak concentration at 12 h and then declined. It reached a maximal value at 2 weeks after irradiation. In the BALF, the TGF-beta1 concentration was appreciable within the first hour and thereafter declined. It reached a maximal value at 3 days after irradiation. A one-time i.p. injection of AdCMVsTbetaR 1 week before irradiation could not completely suppress the two peaks of the radiation-induced TGF-beta1 increase, whereas an injection a week preceding and a week following thoracic irradiation was able to suppress those two peaks thoroughly. The TGF-beta1 was completely suppressed in the AdCMVsTbetaR-treated mouse serum and BALF; however, no statistical difference was observed in the serum and BALF between the AdCMVluc-infected mice and the control mice at 4 weeks after irradiation (P < 0.05). A histopathological examination showed only mild radiation pneumonitis in the irradiated lungs of AdCMVsTbetaR-treated mice in comparison to the AdCMVluc-infected and RT-alone mice. Our results demonstrated that TGF-beta1 plays an important role in radiation pneumonitis, thus suggesting that the adenovirus-mediated overexpression in soluble TGF-beta type II receptor gene therapy may be a potentially feasible and effective strategy for the prevention of radiation pneumonitis.
Haiping
Z
Z
Research Institute for Diseases of the Chest, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
Takayama
K
K
Uchino
J
J
Harada
A
A
Adachi
Y
Y
Kura
S
S
Caicun
Z
Z
Tsuzuki
T
T
Nakanishi
Y
Y
D000256:Adenoviridae / Q000235:genetics*; D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D045744:Cell Line, Tumor; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005353:Fibronectins / Q000378:metabolism; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors / Q000235:genetics*; D006651:Histocytochemistry; D008156:Luciferases; D051379:Mice; D008810:Mice, Inbred C57BL; D017346:Protein Serine-Threonine Kinases; D017564:Radiation Pneumonitis / Q000235:genetics / Q000473:pathology / Q000517:prevention & control*; D000077294:Receptor, Transforming Growth Factor-beta Type II; D018125:Receptors, Transforming Growth Factor beta / Q000097:blood / Q000235:genetics* / Q000378:metabolism
D005353:Fibronectins; D018125:Receptors, Transforming Growth Factor beta; D008156:Luciferases; D017346:Protein Serine-Threonine Kinases; D000077294:Receptor, Transforming Growth Factor-beta Type II