Enhanced transgene expression in quiescent and activated human CD8+ T cells

Area of Science:

• Gene Therapy
• Immunology
• Molecular Biology

Background:

• Expression of retroviral vector-encoded proteins in T cells decreases during quiescence, limiting clinical applications.
• Identifying robust promoter systems is crucial for sustained transgene expression in primary human CD8(+) T cells.

Purpose of the Study:

• To identify promoter systems that enhance the strength and persistence of transgene expression in primary human CD8(+) T cells.
• To evaluate the efficacy of the beta-interferon scaffold attachment region (SAR) in combination with different promoters.

Main Methods:

• Designed Moloney retroviral vectors expressing a destabilized enhanced green fluorescent protein (d4EGFP) reporter.
• Tested phosphoglycerate kinase (Pgk), beta-actin, and long terminal repeat (LTR) promoters.
• Assessed the impact of the beta-interferon (IFN) scaffold attachment region (SAR) on gene expression in proliferating and quiescent T cells.

Main Results:

• Pgk, beta-actin, and LTR promoters showed high expression in proliferating T cells but declined in quiescent cells.
• The IFN-beta SAR augmented expression from mammalian promoters in cycling T cells.
• Combining the IFN-beta SAR with the LTR promoter significantly enhanced expression in both resting and cycling T cells.

Conclusions:

• The combination of the IFN-beta SAR and LTR promoter offers a promising strategy for sustained gene expression in resting primary human CD8(+) T cells.
• This approach can enhance gene expression in activated T cells, potentially improving the clinical utility of retroviral vectors.