WT1-specific T cell receptor gene therapy: improving TCR function in transduced T cells

Area of Science:

• Immunotherapy
• Molecular Biology
• Oncology

Background:

• Adoptive T cell therapy faces challenges due to difficulties in isolating patient-specific T lymphocytes.
• T-cell receptor (TCR) gene transfer offers a method to engineer T cells for desired antigen specificity.
• The WT1 protein is a promising immunotherapy target due to its overexpression in various hematological malignancies and solid cancers.

Purpose of the Study:

• To evaluate the efficacy and safety of TCR gene therapy targeting the WT1 protein for cancer treatment.
• To develop improved TCR gene transfer methods, including lentiviral vectors and strategies to enhance expression and avoid mis-pairing.

Main Methods:

• Cloned TCR alpha and beta genes from WT1-specific cytotoxic T lymphocytes (CTLs).
• Transduced human peripheral blood T lymphocytes using retroviral vectors.
• Assessed anti-leukemia activity in WT1-expressing leukemia-bearing NOD/SCID mice.
• Developed lentiviral TCR gene transfer and strategies to optimize TCR expression and prevent endogenous TCR mis-pairing.

Main Results:

• TCR gene-modified T cells persisted long-term and reduced tumor burden in initial human trials.
• Treatment with WT1-specific TCR-transduced T cells eliminated leukemia cells in the bone marrow of most treated mice.
• T cells transduced with irrelevant TCRs did not reduce leukemia burden, confirming specificity.
• Developed lentiviral vectors and strategies to enhance TCR expression and safety.

Conclusions:

• TCR gene therapy targeting WT1 is a viable strategy for treating malignancies.
• Lentiviral TCR gene transfer and optimized constructs offer potential for safer and more effective cancer immunotherapy.
• Further development of TCR gene constructs holds significant promise for advancing cancer treatment.