Akbar Oghalaie - Venom and Biotherapeutics Molecules Laboratory, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
Alireza Shoari - Venom and Biotherapeutics Molecules Laboratory, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
Fatemeh Kazemi-Lomedasht - Venom and Biotherapeutics Molecules Laboratory, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
Fatemeh Rahimi-Jamnani - Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran
Fereidoun Mahboudi - Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
Hajarossadat Ghaderi - Venom and Biotherapeutics Molecules Laboratory, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
Mohammad Hosseininejad-Chafi - Venom and Biotherapeutics Molecules Laboratory, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
Reza Moaazami - Human Genetics Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
Arghavan Ardalan - Venom and Biotherapeutics Molecules Laboratory, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
Somayeh Piri-Gavgani - Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran
Delavar Shabazzadeh - Venom and Biotherapeutics Molecules Laboratory, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
Mahdi Behdani - Venom and Biotherapeutics Molecules Laboratory, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran

Programmed death ligand-۱ (PD-L۱, CD۲۷۴ and B۷-H۱) has been described as a ligand for immune inhibitory receptor programmed death protein ۱ (PD-۱). With binding to PD-۱ on activated T cells, PD-L۱ can prevent T cell responses via motivating apoptosis. Consequently, it causes cancers immune evasion and helps the tumor growth; hence, PD-L۱ is regarded as a therapeutic target for malignant cancers. The anti-PD-L۱ monoclonal antibody targeting PD-۱/PD-L۱ immune checkpoint has attained remarkable outcomes in clinical application and has turned to one of the most prevalent anti-cancer drugs. The present study aimed to develop polyclonal heavy chain antibodies targeting PD-L۱via Camelus dromedarius immunization. The extra-cellular domain of human PD-L۱ (hPD-L۱) protein was cloned, expressed, and purified. Afterwards, this recombinant protein was utilized as an antigen for camel immunization to acquire polyclonal camelid sera versus this protein. Our outcomes showed that hPD-L۱ protein was effectively expressed in the prokaryotic system. The antibody-based techniques, such as enzyme-linked immunosorbent assay, western blotting, and flow cytometry displayed that the hPD-L۱ protein was detected by generated polyclonal antibody. Due to the advantages of multi-epitope-binding ability, our study exhibited that camelid antibody is effective to be applied significantly for detection of PD-L۱ protein in essential antibody-based studies.

Camelid heavy-chain antibody, Immunization, Polyclonal antibody, Programmed death ligand-۱