Related Experiment Video
Updated: Mar 5, 2026
Production of E. coli-expressed Self-Assembling Protein Nanoparticles for Vaccines Requiring Trimeric Epitope Presentation
Published on: August 21, 2019
An Anti-Programmed Death-1 Antibody (αPD-1) Fusion Protein That Self-Assembles into a Multivalent and Functional
Peng Zhao1, Djordje Atanackovic2, Shuyun Dong1
1Department of Pharmaceutics and Pharmaceutical Chemistry, The University of Utah , Salt Lake City, Utah 84112, United States.
Abstract:
Cancer immune checkpoint therapy has achieved remarkable clinical successes in various cancers. However, current immune checkpoint inhibitors block the checkpoint of not only the immune cells that are important to cancer therapy but also the immune cells that are irrelevant to the therapy. Such an indiscriminate blockade limits the efficacy and causes the autoimmune toxicity of the therapy. It might be beneficial to use a carrier to target immune checkpoint inhibitors to cancer-reactive immune cells. Here, we explore a method to load the inhibitors into carriers. We used the anti-programmed death-1 antibody (αPD-1) as a model immune checkpoint inhibitor. First, we generated a recombinant single-chain variable fragment (scFv) of αPD-1. Then, we designed and generated a fusion protein consisting of the scFv and an amphiphilic immune-tolerant elastin-like polypeptide (iTEP). Because of the amphiphilic iTEP, the fusion was able to self-assemble into a nanoparticle (NP). The NP was proved to block the PD-1 immune checkpoint in vitro and in vivo. Particularly, the NP exacerbated diabetes development in nonobese diabetic mice as effectively as natural, intact αPD-1. In summary, we successfully expressed αPD-1 as a recombinant protein and linked αPD-1 to a NP, which lays a foundation to develop a delivery system to target αPD-1 to a subpopulation of immune cells.
Insights
Researchers developed a nanoparticle delivery system for cancer immune checkpoint inhibitors like anti-programmed death-1 (αPD-1). This targeted approach aims to improve therapy efficacy and reduce autoimmune side effects by concentrating the inhibitor on cancer-reactive immune cells.
Area of Science:
- Immunology
- Biotechnology
- Nanomedicine
Background:
- Cancer immune checkpoint therapy shows promise but suffers from limited efficacy and autoimmune toxicity due to indiscriminate blockade of immune cells.
- Targeting immune checkpoint inhibitors to cancer-reactive immune cells could enhance therapeutic outcomes and mitigate side effects.
Purpose of the Study:
- To develop a novel nanoparticle (NP) delivery system for immune checkpoint inhibitors, specifically anti-programmed death-1 (αPD-1).
- To create a targeted delivery method that concentrates αPD-1 on cancer-reactive immune cells, thereby improving therapeutic specificity.
Main Methods:
- Generated a recombinant single-chain variable fragment (scFv) of αPD-1.
- Designed and produced a fusion protein linking the αPD-1 scFv with an amphiphilic immune-tolerant elastin-like polypeptide (iTEP).
- Demonstrated self-assembly of the fusion protein into nanoparticles (NPs) and evaluated their ability to block the PD-1 immune checkpoint in vitro and in vivo.
Main Results:
- The developed NP effectively blocked the PD-1 immune checkpoint both in vitro and in vivo.
- The αPD-1 loaded NPs demonstrated comparable efficacy to intact αPD-1 in exacerbating diabetes in a mouse model, indicating potent biological activity.
- Successful expression of recombinant αPD-1 and its linkage to a NP was achieved.
Conclusions:
- A novel nanoparticle system for delivering anti-PD-1 immune checkpoint inhibitors has been successfully developed.
- This NP system provides a foundation for targeted delivery of αPD-1 to specific immune cell subpopulations, potentially enhancing cancer immunotherapy.
- The findings suggest a promising strategy to improve the safety and efficacy of immune checkpoint blockade therapy.
