Construction Of Recombinant Adenovirus Expressing Full-length PD-1 Antibody,Nivolumab

Nivolumab,a fully human originated IgG4 immune checkpoint inhibitor antibody,binds to PD-1 on activated immune cells to disrupt PD-1 interaction with PD-L1 and PD-L2 ligands,thereby attenuating inhibitory signals and augmenting the host immune responses.In 2014,Nivolumab was approved by FDA and has been used to treat various types of cancers such as melanoma,non-small cell lung cancer,renal cell carcinoma,and classic Hodgkin’s lymphoma etc.Up to now,China has two imported PD-1 inhibitors and three domestic PD-1 antibodies approved by the CFDA.However,due to the high price of anti-PD-1 and the long cycle of treatment,many patients cannot afford to receive adequate treatment.Here,we generated a new,cheaper form of Nivolumab for immunotherapy,by cloning the full length Nivolumab antibody gene into two serotypes of adenoviral vectors,termed as AdHu5-Nivo and AdC68-Nivo.Ad vectors based on human serotype 5(AdHu5)has been approved to be safe and efficient in a lot of previous studies.Compared with AdHu5,chimpanzee Ads exhibit much lower seroprevalence in human beings,which makes them great alternative Ad vaccine vectors.In our study,we have detected a high expression of Nivolumab in vitro by Western Blot and sandwich ELISA.In vivo studies showed that a single dose of AdHu5-Nivo or AdC68-Nivo can induce sustained Nivolumab expression.The monoclonal antibody expressed by the recombinant adenovirus specifically recognizes and binds to PD-1 on the surface of mouse lymphocytes and human tumor cells.The biological activities of the two mAbs are analogous compared with commercial monoclonal antibody.In follow-up stuies,we will verify their antitumor effects or antiviral effects on influenza virus mouse model and melanoma animal models.