Engineering immunotoxin-equipped effector cells and evaluation in primary human immune cells

Area of Science:

• Biotechnology
• Cancer Therapeutics
• Molecular Biology

Background:

• Lethal toxins show promise as cancer therapies but cause severe side effects when administered systemically.
• Targeted delivery of toxins by effector cells to the tumor microenvironment could mitigate adverse events.
• A key challenge is ensuring effector cells are resistant to the toxins they deliver.

Purpose of the Study:

• To engineer effector cells resistant to bacterial adenosine diphosphate ribosylating toxins (ADPRTs).
• To develop a platform for targeted cancer immunotoxin delivery using resistant effector cells.
• To establish a foundation for equipping therapeutic cells with potent toxin delivery capabilities.

Main Methods:

• Genetically engineered transformed human cell lines for resistance to ADPRTs, including *Pseudomonas aeruginosa* exotoxin A (PE).
• Achieved resistance via knockout of diphthamide biosynthesis pathway genes (*DPH1-4*) or mutation of eukaryotic elongation factor 2 (*EEF2*).
• Demonstrated that engineered resistance is crucial for robust effector cell function.

Main Results:

• Engineered effector cells produced targeted immunotoxins that specifically kill cancer cells expressing tumor-associated antigens.
• Resistance to ADPRTs was successfully conferred by modifying the EEF2 target.
• The armored effector cell lines demonstrated robust function, essential for therapeutic efficacy.

Conclusions:

• Engineering resistance to potent toxins like ADPRTs is vital for developing effective cancer-targeting effector cells.
• This study presents a novel platform for creating toxin-resistant therapeutic cells.
• The findings pave the way for future investigations into autologous or allogeneic therapeutic cell types for cancer treatment.