Modular Design of T Cell Nanoengagers for Tumor Immunotherapy via Genetically Engineered Lipid‐Tagged Antibody Fragments

Abstract T cell engagers, which bind tumor‐associated antigens and T cell specific molecules, represent a promising class of immunotherapies for enhancing targeted immune responses. Here, a “plug‐and‐display” platform is introduced for engineering T cell nanoengagers by anchoring antibody fragments into lipid‐based nanoparticles. This approach utilizes a genetically engineered lipoprotein fused with single‐chain variable fragments (scFv) and nanobodies, which spontaneously integrate into lipid bilayer of the nanoparticles, achieving a high surface density of at least 0.102 scFv nm −2 (≈3200 scFv per particle). Modular bi‐specific (Lipo‐BiTE) and tri‐specific (Lipo‐TriTE) immunoliposomes are designed to enhance anti‐tumor T cell immune responses. The Lipo‐BiTE, integrating anti‐CD3 and anti‐HER2 scFv at an optimized surface density of 1.28 × 10 −3 scFv nm −2 , exhibits enhanced CD8 + T cell‐mediated cytotoxicity in HER2‐positive tumor models by simultaneously engaging tumor cells and T cells. Incorporating anti‐PD‐L1 nanobodies to create Lipo‐TriTE further addresses T cell exhaustion. This modular platform provides a robust foundation for designing immune cell engagers, with broad applications in targeted immunotherapy.