Conditional Immortalization Using SV40 Large T Antigen and Its Effects on Induced Pluripotent Stem Cell...

Area of Science:

• Biomedical Engineering
• Stem Cell Biology
• Ophthalmology

Background:

• Retinal degenerative diseases lack effective treatments, with cell replacement therapy using retinal progenitor cells (RPCs) showing promise.
• Developing these therapies requires large quantities of RPCs, but their large-scale production from human induced pluripotent stem cells (iPSCs) is resource-intensive.
• Current methods for generating sufficient RPCs for research and therapeutic development are limited.

Purpose of the Study:

• To create a conditionally immortalized human RPC cell line from iPSCs to overcome production barriers.
• To investigate the impact of SV40 large T (SV40-T) antigen-mediated immortalization on RPC proliferation and differentiation.
• To assess the feasibility of using Tet-On SV40-T immortalized RPCs for in vitro testing of retinal therapies.

Main Methods:

• Human iPSCs were transduced with a Tet-On SV40-T system for conditional immortalization.
• RPC proliferation and differentiation markers (PAX6, SOX2, CHX10) were analyzed with and without doxycycline.
• The reversibility of differentiation changes after doxycycline removal was evaluated.

Main Results:

• SV40-T antigen expression significantly increased RPC proliferation.
• Immortalization led to a substantial loss of RPC identity and multipotency, indicated by reduced expression of key markers.
• The observed de-differentiation was irreversible, even after doxycycline withdrawal.

Conclusions:

• Conditional immortalization using Tet-On SV40-T antigen presents challenges in maintaining RPC identity and differentiation potential.
• Balancing enhanced proliferation with preserved differentiation capacity is critical for developing reliable RPCs for research and therapy.
• Further optimization of immortalization techniques and culture conditions is necessary for advancing stem cell-based retinal disease treatments.