Phenoscaping Reveals Multimodal γδ T-cell Cytotoxicity as a Strategy to Overcome Cancer Cell-Mediated...

Area of Science:

• Immunology and Cancer Therapy
• Cellular and Molecular Oncology

Background:

• Gamma delta (γδ) T cells possess dual cytotoxic mechanisms: antibody-independent cytotoxicity (AIC) and antibody-dependent cellular cytotoxicity (ADCC).
• Understanding the interplay between T cell donor variability, tumor heterogeneity, and γδ T cell killing is crucial for advancing immunotherapies.

Purpose of the Study:

• To investigate how inter-donor heterogeneity (IDH) of γδ T cells and inter-tumor heterogeneity (ITH) of colorectal cancer (CRC) influence multimodal cytotoxic mechanisms.
• To evaluate the efficacy of engineered γδ T cells in overcoming cancer cell-mediated immune evasion.

Main Methods:

• Systematic single-cell phenoscaping analysis of over 1,000 co-cultures of γδ T cells and patient-derived colorectal cancer organoids (PDOs).
• Analysis of post-translational modification (PTM) signaling, cell-cycle status, apoptosis, and T cell immunophenotypes.
• Utilized engineered IL-15Rα-IL-15 fusion protein (stIL15) γδ T cells and assessed B7-H3-targeted ADCC.

Main Results:

• Engineered stIL15 γδ T cells exhibited AIC against PDOs without external cytokine support.
• Colorectal cancer cells adapted to AIC by rewiring γδ T cell PTM signaling networks in an ITH-dependent manner, suppressing cytotoxicity.
• Combining AIC with B7-H3-targeted ADCC enabled stIL15 γδ T cells to overcome cancer-induced immunomodulation and kill chemoresistant colon cancer stem cells.

Conclusions:

• Multimodal cytotoxicity, combining AIC and ADCC, is essential for γδ T cells to overcome ITH-specific immune evasion strategies employed by cancer cells.
• Engineered γδ T cells with combined cytotoxic mechanisms demonstrate potential for targeting chemoresistant cancer stem cells, paving the way for novel immunotherapeutic approaches.