Bio‐Orthogonal T Cell Targeting Strategy for Robustly Enhancing Cytotoxicity against Tumor Cells

Abstract

T cells can kill tumor cells by cell surface immunological recognition, but low affinity for tumor‐associated antigens could lead to T cell off‐target effects. Herein, a universal T cell targeting strategy based on bio‐orthogonal chemistry and glycol‐metabolic engineering is introduced to enhance recognition and cytotoxicity of T cells in tumor immunotherapy. Three kinds of bicycle [6.1.0] nonyne (BCN)‐modified sugars are designed and synthesized, in which Ac4ManN‐BCN shows efficient incorporation into wide tumor cells with a BCN motif on surface glycans. Meanwhile, activated T cells are treated with Ac4GalNAz to introduce azide (N3) on the cell surface, initiating specific tumor targeting through a bio‐orthogonal click reaction between N3 and BCN. This artificial targeting strategy remarkably enhances recognition and migration of T cells to tumor cells, and increases the cytotoxicity 2 to 4 times for T cells against different kinds of tumor cells. Surprisingly, based on this strategy, the T cells even exhibit similar cytotoxicity with the chimeric antigen receptor T‐cell against Raji cells in vitro at the effector: target cell ratios (E:T) of 1:1. Such a universal bio‐orthogonal T cell‐targeting strategy might further broaden applications of T cell therapy against tumors and provide a new strategy for T cell modification.

T Cell Membrane Mimicking Nanoparticles with Bioorthogonal Targeting and Immune Recognition for Enhanced Photothermal Therapy

“…To investigate the immune recognition and bioorthogonal dual‐targeting ability of the N 3 ‐TINPs, Raji tumor cells were pretreated with Ac 4 ManN‐BCN for 2 days to label them with the BCN group (Figure S4, Supporting Information). Ac 4 ManN‐BCN was previous reported by our group as a novel BCN modified unnatural sugar, which can efficient and nondestructive incorporated into wild tumor cell surface glycans, including human lung carcinoma cell line (A549 cells), human rhabdomyoma cell line (RD cells), human hepatocarcinoma cell line (HepG2 cells), and human breast cancer cell line (MCF‐7 cells) . The confocal imaging exhibited that cells treated with N 3 ‐TINPs showed obvious ICG fluorescence and that was higher than that observed in cells treated with TINPs, whereas cells treated with free ICG and INPs had very weak fluorescence ( Figure A).…”

“…Particularly, this technique can artificially generate bioorthogonal groups on the tumor as artificial “receptor‐like” target, using for selective targeting in complex environments . Based on this, our group reported a novel bicyclo [6.1.0] nonyne (BCN) modified unnatural sugars (Ac 4 ManN‐BCN), which can efficiently and nondestructively be incorporated into wild tumor cell surface glycans . The BCN motif on the cell surface act as an excellent targeting tag and effectively enhanced the tumor recognition of T cells modified with azide (N 3 ) though bioorthogonal click chemistry.…”

“…[12] The BCN motif on the cell surface act as an excellent targeting tag and effectively enhanced the tumor recognition of T cells modified with azide (N 3 ) though bioorthogonal click chemistry. [12] The BCN motif on the cell surface act as an excellent targeting tag and effectively enhanced the tumor recognition of T cells modified with azide (N 3 ) though bioorthogonal click chemistry.…”

Click CAR-T cell engineering for robustly boosting cell immunotherapy in blood and subcutaneous xenograft tumor

“…The BCN group modified sugar Ac 4 ManNBCN was synthesized as our previously described methods [ 25 ]. Raji cells were incubated with Ac 4 ManNBCN at the different concentrations (10, 15, 20 μM), and cultured for 48 h. The BCN group modified on Raji cells was detected by N 3 -Cy5.5 (Click Chemistry Tools, AZ) using a confocal laser scanning microscope (TSC SP5II Leica, Ernst-Leitz-Strasse, Germany).…”

“…Azide molecules conjugated monosaccharides are wildly used for glycometabolic labeling of target cells, due to its accessibility, small size, inertness and near absence in living system [ [22] , [23] , [24] ]. Additionally, our previous studies also showed the bicycle [6.1.0] nonyne (BCN) motif modified on mannose (Ac 4 ManNBCN), a complementary group of azide molecule, exhibited high efficiency for introducing BCN group into tumor cell surface [ 25 , 26 ]. As a result, once the paired chemical reporters (-N 3 /-BCN) are introduced to CAR-T and tumor cells separately, bioorthogonal chemistry-guided specific targeting could facilitate connection and activation of CAR-T cell to tumor, thereby further enhancing their antitumor capability.…”