Lentiviral Vector Pseudotypes: Precious Tools to Improve Gene Modification of Hematopoietic Cells for Research and Gene Therapy

Abstract

Viruses have been repurposed into tools for gene delivery by transforming them into viral vectors. The most frequently used vectors are lentiviral vectors (LVs), derived from the human immune deficiency virus allowing efficient gene transfer in mammalian cells. They represent one of the safest and most efficient treatments for monogenic diseases affecting the hematopoietic system. LVs are modified with different viral envelopes (pseudotyping) to alter and improve their tropism for different primary cell types. The vesicular stomatitis virus glycoprotein (VSV-G) is commonly used for pseudotyping as it enhances gene transfer into multiple hematopoietic cell types. However, VSV-G pseudotyped LVs are not able to confer efficient transduction in quiescent blood cells, such as hematopoietic stem cells (HSC), B and T cells. To solve this problem, VSV-G can be exchanged for other heterologous viral envelopes glycoproteins, such as those from the Measles virus, Baboon endogenous retrovirus, Cocal virus, Nipah virus or Sendai virus. Here, we provide an overview of how these LV pseudotypes improved transduction efficiency of HSC, B, T and natural killer (NK) cells, underlined by multiple in vitro and in vivo studies demonstrating how pseudotyped LVs deliver therapeutic genes or gene editing tools to treat different genetic diseases and efficiently generate CAR T cells for cancer treatment.

Lentiviral Vector Bioprocessing

“…LVs are commonly pseudotyped whereby the envelope protein of the vector is exchanged with that of another virus (see Table 2 ), in effect, enrobing the viral particle with proteins from other viruses [ 28 , 29 ] which provide varying characteristics to the vector, affecting its tropism and intended cell target as well as possibly impacting success in bioprocessing. When transducing a cell, the envelope protein must contact and bind to a surface receptor on the recipient cell.…”

Vesicular Stomatitis Virus: From Agricultural Pathogen to Vaccine Vector

“…It is worth noting that, while pseudotyped rVSVs are common molecular tools, the converse use of VSV G to pseudotype other viral particles is also common [ 48 ]. Indeed, its wide-ranging tropism and good stability have made VSV G one of the most widely used viral glycoproteins to pseudotype lentiviruses.…”

Designing Lentiviral Vectors for Gene Therapy of Genetic Diseases

“…The desired regulation of transgene expression can be obtained at the level of transcription by the use of tissue-, cell type- or differentiation stage-specific promoters/enhancers, and/or post-transcriptionally, by adding 5′ or 3′ untranslated regions (UTRs) enhancing ribosome binding or mRNA stability or target sequences for specific micro RNAs (miRNAs) to regulate protein expression by physiological RNA interference mechanisms. Viral particle pseudotyping with alternative envelope proteins has also been developed to improve transduction of specific cell types [ 43 , 44 , 45 ], but is rarely used in clinical applications where VSV-G is considered a standard for vector manufacturing.…”