Engineered T cells directed at tumors with defined allelic loss

Area of Science:

• Oncology
• Cancer Genetics
• Immunotherapy

Background:

• Cancer cells often exhibit genetic material loss, known as loss of heterozygosity (LOH).
• Distinguishing tumor cells from normal cells is a critical challenge in cancer therapy.
• Existing therapies face limitations in specificity and broad applicability across tumor types.

Purpose of the Study:

• To develop a novel cancer therapeutic strategy based on exploiting loss of heterozygosity (LOH) in tumor cells.
• To create a system capable of discriminating between tumor and normal cells for targeted therapy.
• To demonstrate the efficacy of this approach in both in vitro and in vivo cancer models.

Main Methods:

• Utilized modular activator/blocker elements designed to integrate cell surface ligand signals.
• Engineered T cells targeting the CD19 surface antigen.
• Incorporated a conditional 'brake' mechanism linked to the presence or absence of specific alleles (e.g., HLA-A*02).
• Validated the system in in vitro assays and a mouse cancer model.

Main Results:

• The developed targeting system demonstrated robust performance in in vitro experiments.
• In a mouse cancer model, the absence of the HLA-A*02 allele successfully released the 'brake' on engineered T cells.
• This conditional activation allowed for specific targeting of tumor cells while sparing normal cells.

Conclusions:

• The described therapeutic approach effectively leverages loss of heterozygosity for cancer cell targeting.
• This strategy offers a promising method for discriminating between tumor and normal cells, applicable to a wide range of cancers.
• The findings open new avenues for identifying and targeting novel cancer-specific vulnerabilities.