Immunotherapy: Open Access
Open Access

Abstract

A Novel PD-L1 Nanobody Validates that Immune Cell Suppressed by Pd-L1 May Always Exist in the Body

Chuangfu Chen*, Peng Wu and Jiao Jiao

Background: PD-L1 is expressed widely in the body. PD-1-PD-L1 interaction is known to drive T cell dysfunction, which can be blocked by anti-PD-1/PD-L1 antibodies. Researchers have shown that blocking PD-L1 in both the early and chronic stages of the disease may increase T cell activity. What’s more, we tried to find the improvement of PD-L1 on the body's immunity.

Methods: Nanobody binding to PD-L1 was prepared, and the PD-L1 nanobody was verified by SDS-PAGE and Western-Blot. Affinity detection of PD-L1 Nanobody and PD-L1 receptor was made by ELISA and flow cytometry. The cytotoxicity of the PD-L1 nanobody was tested by BHK-21, MDBK, and sheep kidney cells. The inhibitory effect on tumor model was verified. PD-L1 nanobody activated the macrophages was tested. Staphylococcus aureus was used to test the protective effect of the mice.

Results: PD-L1 nanobody was successfully made and had a high affinity with PD-L1 receptor. PD-L1 has no cytotoxicity to many cells. It could decrease the tumor in weight. We also find PD-L1 nanobody activated the macrophages and protected the mouse from the challenge of Staphylococcus aureus.

Conclusion: The PD-L1 nanobody improved the immunity of animals. It was verified that PD-L1 inhibited T cells may be always present in mice, and the activation of these cells improved the immunity and survival rate of mice.

Published Date: 2021-11-22; Received Date: 2021-11-01