LY6G6D is a selectively expressed colorectal cancer antigen that can be used for targeting a therapeutic T-cell...

Area of Science:

• Oncology
• Immunology
• Molecular Biology

Background:

• Colorectal cancer (CRC) is a leading cause of cancer mortality globally.
• There is a critical need for novel, targeted therapeutic strategies for CRC, particularly for the microsatellite stable (MSS) subtype.
• Tumor-selective antigens are key targets for developing immunotherapies.

Purpose of the Study:

• To identify and characterize tumor-selective colorectal cancer antigens for targeted immunotherapy.
• To evaluate the therapeutic potential of targeting the novel antigen LY6G6D using a T cell engager (TcE).
• To investigate the mechanisms of tumor cell lysis and bystander killing mediated by the LY6G6D/CD3 TcE.

Main Methods:

• Transcriptomic and immunohistochemical analyses to identify tumor-selective antigens.
• Generation and in vitro characterization of a LY6G6D/CD3 T cell engager (TcE).
• Ex vivo analysis of patient-derived CRC tumor slice cultures and in vivo preclinical mouse models.
• 2D and 3D co-culture systems to assess bystander killing effects.

Main Results:

• LY6G6D was identified as a colorectal cancer antigen selectively expressed, primarily in the MSS subtype.
• The LY6G6D/CD3 TcE demonstrated potent in vitro tumor cell killing and T cell activation.
• Ex vivo and in vivo studies confirmed TcE efficacy, including tumor regressions and IFNγ secretion.
• The TcE induced bystander killing of LY6G6D-negative cells via cytokines (IFNγ, TNFα) and Fas/FasL pathway.

Conclusions:

• LY6G6D is a promising tumor-selective antigen for colorectal cancer immunotherapy.
• The LY6G6D/CD3 TcE effectively redirects cytotoxic T-cells to eliminate CRC cells.
• The observed bystander killing effect suggests potential for enhanced therapeutic efficacy in heterogeneous tumors.