Evaluation of biological activity of an eukaryotic expressed anti-H5N1-M1 cell entry single molecule antibody / 中国生物制品学杂志

ABSTRACT

@#Objective To evaluate the biological activity of a eukaryotic expressed anti-H5N1-M1 cell entry single molecule antibody(TAT-ScFv-mFc). Methods The immune binding activity and affinity of TAT-ScFv-mFc to H5N1-M1 protein were detected by Western blot and localized surface plasmon resonance(LSPR)respectively;The inhibitory effect of TAT-ScFv-mFc on influenza virus H1N1 was detected by CCK-8 assay;The membrane penetration ability of TAT-ScFv-mFc to MDCK cells was verified by immunofluorescence assay. A total of 30 female BALB/c mice were injected with TAT-ScFv-mFc via tail vein,200 μL per mouse. Blood samples were collected at 5,60,120,240 and 360 min after injection. Serum samples were separated and detected for the titers by ELISA,and the half-life of TAT-ScFv-mFc was calculated according to the half-life curve drawn by Origin 2021 software. Results TAT-ScFv-mFc showed specific binding to H5N1-M1 protein with a binding rate constant of 6. 67 × 10~4[1/（M*s）]. The survival rate of MDCK cells infected by H1N1 increased gradually with the increase of TAT-ScFv-mFc concentration in a dose-dependent manner,which obviously inhibited the replication of H1N1. TAT-ScFv-mFc penetrated the cell membrane of MDCK cells in a short time,entered the cell and bound to virus M1protein,thus inhibiting virus replication and assembly. The half-life of TAT-ScFv-mFc in mice was 212 min. Conclusion TAT-ScFv-mFc has good immune binding activity and affinity with H5N1-M1,can effectively inhibit the replication of H1N1,has good penetration ability to MDCK cell membrane,and has a long half-life in mice,which lays a foundation of the drug treatment,vaccine research and preventive treatment of H5N1 infection.