A PD-L1xCD3 bispecific nanobody as a novel T-cell engager in treating PD-L1 overexpression melanoma
Boping Li1, Shuang Wang1, Baihui Shan1
1Department of Dermatology, Second Affiliated Hospital of Jilin University, Changchun, China.
Abstract:
The development of Immune checkpoint blockade(ICB) therapy and BRAF- and MEK-targeted therapies has reshaped the survival outcomes of the patients with advanced melanoma. PD-1/PD-L1 blockade was an approved strategy in melanoma treatment. Here we design a PD-L1 xCD3 nanobody as a novel bispecific T cell engager (BiTE) in treating PD-L1 overexpression melanoma. BiTE PD-L1×CD3 Nb was predicted to bind near a large acidic surface on CD3-ε similar to UCHT1-scFv antibody based on alpha-fold and molecular docking. BiTE PD-L1×CD3 Nb and anti-CD3 Nb retained the ability to activate T cells to produce TNF-α and IFN-γ in a dose-dependent manner. The IC50 value of BiTE PD-L1×CD3 Nb was 4.208μg/mL. BiTE PD-L1×CD3 Nb showed obvious cytotoxic activity on both A375WT and A375PD-L1 related to PD-L1 expression level.
Insights
A novel bispecific T cell engager (BiTE) targeting PD-L1 and CD3 was developed for advanced melanoma. This PD-L1 xCD3 nanobody effectively activates T cells and demonstrates cytotoxic activity against melanoma cells.
Area of Science:
- Immunology
- Oncology
- Biotechnology
Background:
- Immune checkpoint blockade (ICB) and targeted therapies have improved advanced melanoma outcomes.
- PD-1/PD-L1 blockade is an established treatment strategy for melanoma.
Purpose of the Study:
- To design and evaluate a novel bispecific T cell engager (BiTE) using a PD-L1 xCD3 nanobody for treating PD-L1 overexpression melanoma.
- To assess the binding, T cell activation, and cytotoxic potential of the developed BiTE.
Main Methods:
- Computational prediction (alpha-fold, molecular docking) to guide nanobody design.
- In vitro assessment of T cell activation (TNF-α, IFN-γ production) and cytotoxic activity against melanoma cell lines (A375WT, A375PD-L1).
Main Results:
- The PD-L1 xCD3 BiTE was computationally predicted to bind CD3-ε effectively.
- The BiTE demonstrated dose-dependent T cell activation, inducing TNF-α and IFN-γ production with an IC50 of 4.208 μg/mL.
- The BiTE exhibited significant cytotoxic activity against both wild-type and PD-L1-expressing melanoma cells.
Conclusions:
- The novel PD-L1 xCD3 nanobody-based BiTE is a promising therapeutic candidate for PD-L1-expressing advanced melanoma.
- This approach leverages T cell engagement to target cancer cells, offering a new strategy in melanoma treatment.
