title: Transient proteasome inhibition as a strategy to enhance lentiviral transduction of hematopoietic CD34(+) cells and T lymphocytes: implications for the use of low viral doses and large-size vectors.
abstract: The proteasome system restricts lentiviral transduction of stem cells. We exploited proteasome inhibition as a strategy to enhance transduction of both hematopoietic stem cells (HSC) and T lymphocytes with low dose or large-size lentiviral vectors (LV). HSC showed higher transduction efficiency if transiently exposed to proteasome inhibitor MG132 (41.8% vs 10.7%, p<0.0001). Treatment with MG132 (0.5 μM) retained its beneficial effect with 3 different LV of increasing size up to 10.9 Kb (p<0.01). We extended, for the first time, the application of proteasome inhibition to the transduction of T lymphocytes. A transient exposure to MG132 significantly improved lentiviral T-cell transduction. The mean percentage of transduced T cells progressively increased from 13.5% of untreated cells, to 21% (p=0.3), 30% (p=0.03) and 37% (p=0.01) of T lymphocytes that were pre-treated with MG132 at 0.1, 0.5 and 1 μM, respectively. MG132 did not affect viability or functionality of HSC or T cells, nor significantly increased the number of integrated vector copies. Transient proteasome inhibition appears as a new procedure to safely enhance lentiviral transduction of HSC and T lymphocytes with low viral doses. This approach could be useful in settings where the use of large size vectors may impair optimal viral production.
authors.affiliation: Laboratory of Cell Therapy of Cancer, Department of Oncological Sciences, University of Torino Medical School, Institute for Cancer Research and Treatment, Provinciale 142, 10060 Candiolo, Torino, Italy.
authors.forename: Valeria
authors.initials: V
authors.lastname: Leuci
authors.forename: Giulia
authors.initials: G
authors.lastname: Mesiano
authors.forename: Loretta
authors.initials: L
authors.lastname: Gammaitoni
authors.forename: Cristina
authors.initials: C
authors.lastname: Cammarata
authors.forename: Sonia
authors.initials: S
authors.lastname: Capellero
authors.forename: Maja
authors.initials: M
authors.lastname: Todorovic
authors.forename: Noela
authors.initials: N
authors.lastname: Jordaney
authors.forename: Paola
authors.initials: P
authors.lastname: Circosta
authors.forename: Angela
authors.initials: A
authors.lastname: Elia
authors.forename: Marina
authors.initials: M
authors.lastname: Lesnikova
authors.forename: George E
authors.initials: GE
authors.lastname: Georges
authors.forename: Wanda
authors.initials: W
authors.lastname: Piacibello
authors.forename: Franca
authors.initials: F
authors.lastname: Fagioli
authors.forename: Alessandro
authors.initials: A
authors.lastname: Cignetti
authors.forename: Massimo
authors.initials: M
authors.lastname: Aglietta
authors.forename: Dario
authors.initials: D
authors.lastname: Sangiolo
mesh_terms: D018952:Antigens, CD34; D002478:Cells, Cultured; D005434:Flow Cytometry; D005822:Genetic Vectors; D006412:Hematopoietic Stem Cells / Q000502:physiology; D006801:Humans; D016086:Lentivirus; D061988:Proteasome Inhibitors; D060888:Real-Time Polymerase Chain Reaction; D013601:T-Lymphocytes / Q000502:physiology; D014161:Transduction, Genetic / Q000379:methods*
chemical_list: D018952:Antigens, CD34; D061988:Proteasome Inhibitors