Induced pluripotent reprogramming from promiscuous human stemness related factors.

Area of Science:

• Stem Cell Biology
• Developmental Biology
• Gene Therapy

Background:

• Ectopic expression of pluripotency genes induces nuclear reprogramming to generate induced pluripotent stem (iPS) cells.
• Investigating the evolutionary conservation of stemness orthologs across species is crucial for understanding reprogramming mechanisms.

Purpose of the Study:

• To test the conserved function of stemness orthologs through interspecies transduction.
• To engineer lentiviral vectors for efficient cross-species gene delivery and reprogramming.

Main Methods:

• Designed HIV-based lentiviral vectors with modified capsid regions for enhanced infectivity and trans-species tropism.
• Transduced non-human fibroblasts with human pluripotency genes (OCT3/4, SOX2, KLF4, c-MYC) using engineered vectors.
• Assessed reprogramming by evaluating cell morphology, in vitro differentiation, in vivo teratoma formation, and contribution to chimeric embryos.

Main Results:

• Human pluripotent genes were consistently expressed in non-human fibroblasts, yielding cell lines with embryonic stem cell-like morphology.
• Transduced fibroblasts differentiated in vitro into all three germ layers and formed teratomas with multi-lineage potential in vivo.
• Reprogrammed cells contributed to chimeric embryos, demonstrating competent organogenesis.

Conclusions:

• Ectopic xeno-transduction across species effectively reprograms somatic cells, highlighting the conserved nature of stemness induction.
• This model system provides a prototypic approach to study human stemness factor reprogramming within normal embryonic development.
• The promiscuous nature of stemness induction suggests evolutionary selection of core reprogramming processes.