ABSTRACT
Objective: To screen human single chain antibodies against human C3d from phage-displayed single-chain variable fragment(scFv)library, and analyze their binding activities. Methods: The phage display library was exposed to 3-round selections in immunotubes coated with recombinant C3d at a decreasing concentration range and progressively stringent washing conditions. The positive clones were identified by ELISA, followed with sequencing to determine the specific genes which were then cloned intoex-pression vectors. The single chain antibodies were expressed in the FreeStyleTM 293-F system and harvested by affinity purification. The binding activities with recombinant C3d were determined by using Bio-Layer Interferometry technology. Results: These experiments resulted in three novel single chain antibodies(that is, A1, A3 and B6)against C3d with high affinity ranging from 22.7 to 171 pmol/ L. Conclusion: The high affinity human single chain antibodies against human C3d were obtained.
ABSTRACT
<p><b>OBJECTIVE</b>To study the radioprotective effect of catechines against radiation injury in mice.</p><p><b>METHODS</b>Catechines were administered in mice intragastrically at the daily dose of 200 mg/kg for 10 consecutive days before whole body irradiation with 6 Gy X-rays. The body weight changes, survival time, 30-day survival rate, and counts of peripheral white blood cells were recorded.</p><p><b>RESULTS</b>The mice with catechine pre-treatment before X-ray exposure suffered less body weight loss than those without the treatment before exposure. Catechines markedly increased the survival time of the irradiated mice, and raised the 30-d survival rate of the irradiated mice to 53.33% as compared with the rate of 13.33% in the radiated mice without catechine pre-treatment. Catechines significantly promoted recovery of peripheral white blood cells.</p><p><b>CONCLUSION</b>Catechines have definite radioprotective effect against radiation injury in mice.</p>