This invention is a humanized, llama-derived nanobody (single-domain antibody) that mimics the human CD4 receptor and binds the HIV envelope protein. Its human-like framework is designed to lower immunogenicity risk, making it a promising candidate for HIV treatment through direct administration or engineered cell-based delivery.
The camelid nanobody J3 has been humanized. Following affinity maturation, these novel humanized antibodies (4E2) have demonstrated exceptional HIV-1 binding and neutralization potency and could be promising therapeutics to achieve viral suppression for HIV-infected people.
Description
The technology is a nanobody originally obtained from a llama and engineered to be more human-like. The three antigen-binding loops (complementarity-determining regions) of the original nanobody were grafted onto a human antibody scaffold. A small number of llama-derived framework residues were deliberately retained to preserve loop conformation, stability and solubility. The resulting humanized nanobody binds the HIV envelope protein gp120 at the same site used by the human CD4 receptor. HIV needs this site to enter cells, so the nanobody is designed to block viral entry.
The humanized nanobody was then optimized using a computational antibody-design workflow. The workflow builds 3D models of the antibody–antigen complex, identifies the residues most important for binding, and predicts point mutations that could strengthen binding. A subset of the predicted variants was expressed and tested experimentally. The nanobody can be used as a standalone protein in a pharmaceutical composition, or as the targeting component of engineered CAR-T cells or engineered B cells.
Applications
- Antibody-based therapeutics for treating HIV-1 infection
- Pharmaceutical compositions formulated for parenteral administration
- Engineered CAR-T cell therapies expressing the nanobody
- Engineered B-cell therapies expressing the nanobody
- Components for combination antibody regimens aimed at limiting viral escape
Advantages
- Humanized framework with higher similarity to the human antibody repertoire, indicating reduced immunogenicity risk
- Binds the CD4-binding site on gp120, which HIV requires for cell entry, so escape mutations may carry a fitness cost to the virus
- Small single-domain format that is amenable to recombinant production and to engineering into cell-based formats
- Computationally guided optimization produced a variant (E44R) with improved binding and neutralization relative to the humanized parent
- Versatile delivery options: soluble protein, CAR-T cell or engineered B cell
Invention Readiness
The humanized nanobody and several designed variants have been generated and characterized in vitro. Data generated include structural modeling of the nanobody–gp120 complex, with predicted hydrogen-bond contacts at the same gp120 residues engaged by CD4. They also include ELISA binding to HIV-1 envelope protein and neutralization of HIV-1 (BaL strain) in a cell-based infection assay. The E44R variant showed improved binding and neutralization potency over the humanized parent.
IP Status
https://patents.google.com/patent/WO2026038164A1Related Publication(s)
Liang, T., Sun, Z.-Y., Ishima, R., Xie, X.-Q., Xue, Y., Li, W., & Feng, Z. (2025). ProstaNet: A Novel Geometric Vector Perceptrons–Graph Neural Network Algorithm for Protein Stability Prediction in Single- and Multiple-Point Mutations with Experimental Validation. Research, 8. https://doi.org/10.34133/research.0674
Liang, T., Sun, Z.-Y., Hines, M. G., Penrose, K. J., Hao, Y., Chu, X., Mellors, J. W., Dimitrov, D. S., Xie, X.-Q., Li, W., & Feng, Z. (2024). AI-based IsAb2.0 for antibody design. Briefings in Bioinformatics, 25(5). https://doi.org/10.1093/bib/bbae445
