Tumor site-directed A1R expression enhances CAR T cell function and improves efficacy against solid tumors

Area of Science:

• Immunology
• Oncology
• Molecular Biology

Background:

• Solid tumor microenvironments contain immunosuppressive factors like adenosine.
• Adenosine suppresses Chimeric Antigen Receptor T cells via A2A receptor activation.
• Current Chimeric Antigen Receptor T cell therapies face challenges in solid tumor treatment.

Purpose of the Study:

• To engineer Chimeric Antigen Receptor T cells to overcome adenosine-mediated suppression.
• To investigate the role of A1 receptor signaling in enhancing T cell function.
• To develop a novel strategy for improving Chimeric Antigen Receptor T cell efficacy in solid tumors.

Main Methods:

• Engineering Chimeric Antigen Receptor T cells to overexpress A1 receptor.
• Utilizing CRISPR/Cas9 homology directed repair for tumor-localized A1 receptor expression.
• Assessing anti-tumor efficacy and T cell function in murine and human models.

Main Results:

• Constitutive A1 receptor overexpression enhanced Chimeric Antigen Receptor T cell effector function but reduced persistence.
• Tumor-localized A1 receptor expression via knock-in approach improved anti-tumor efficacy.
• A1 receptor expression was dependent on the transcription factor IRF8 and showed unique transcriptional profiles.

Conclusions:

• Tumor-localized A1 receptor expression is a viable strategy to enhance Chimeric Antigen Receptor T cell therapy for solid tumors.
• This approach offers a novel method for site-directed expression of factors to promote effector T cell differentiation.
• The findings provide a proof of principle for overcoming immunosuppression in the tumor microenvironment.