Table 1.

Comparison of retroviral and lentiviral platforms for T cell engineering

Feature	Retroviral vectors	Lentiviral vectors
Infection targets	Activated T cells (mitosis-required)	Both dividing and non-dividing T cells
Integration profile	Favors transcription start sites and regulatory regions	Favors intron and intergenic regions
Transgene capacity	About 8 kb	About 10 kb
Tropism (envelope)	VSV-G or specific (ecotropic or amphotropic)	VSV-G or other pseudotypes possible
Typical use in T cells	Common in preclinical mouse models; cost-effective; strong expression	Widely used for chimeric antigen receptor T (CAR-T) cells or TCR-T cells; flexible timing, larger inserts
Advantages	Efficient in early blasts; Retronectin synergy; Cost-effective	Works across wider activation windows; consistent transduction across diverse donors
Disadvantages	Narrow timing; mitosis-dependent; risk of insertional mutagenesis	Complex packaging; higher cost; risk of biosafety by wide tropism