Nanobody-based CAR T cells targeting intracellular tumor antigens

Area of Science:

• Oncology
• Immunotherapy
• Molecular Biology

Background:

• Chimeric antigen receptor (CAR) T-cell therapy is a promising cancer treatment.
• Conventional CAR T-cells face limitations due to the restricted number of accessible tumor surface antigens.
• Many tumor-associated antigens are intracellular, making them untargetable by current CAR T-cell strategies.

Purpose of the Study:

• To investigate the potential of nanobody (Nb)-based T cell receptor (TCR)-like CAR T cells for targeting intracellular tumor antigens.
• To explore the efficacy of targeting major histocompatibility complex (MHC)/peptide complexes presenting intracellular oncoproteins on tumor cells.
• To develop and validate TCR-like CAR T cells targeting specific intracellular antigens, Glypican-3 (GPC3) and Wilms tumor 1 (WT1).

Main Methods:

• Development of human leukocyte antigen (HLA)-A2/GPC3- and HLA-A2/WT1-specific nanobodies using immune nanobody phage display.
• Engineering of two TCR-like CARs by incorporating the developed nanobodies.
• In vitro and in vivo evaluation of TCR-like Nb CAR-redirected T cells against MHC/peptide complex-expressing tumor cells.

Main Results:

• Successfully developed novel HLA-A2/GPC3 and HLA-A2/WT1 specific nanobodies.
• Constructed TCR-like CARs utilizing these nanobodies.
• Demonstrated that TCR-like Nb CAR T cells selectively recognize and lyse tumor cells presenting target MHC/peptide complexes in vitro and in mouse models.

Conclusions:

• Nanobody-based TCR-like CAR T cells offer a viable strategy for targeting intracellular tumor antigens.
• This approach significantly expands the potential applications of CAR T-cell therapy in oncology.
• The study provides a novel method for overcoming the limitations of targeting intracellular tumor antigens.