title: Gamma-retroviral vector design for the co-expression of artificial microRNAs and therapeutic proteins.
abstract: To generate γ-retroviral vectors for stable conjoint expression of artificial microRNAs (amiR) and therapeutic genes in primary human lymphocytes, and to identify the design parameters that are key for successful vector generation. Gamma-retroviral vectors were designed to co-express both amiRs and a linked reporter gene, truncated CD34 (tCD34). Artificial miRs based on microRNAs miR-16, miR-142, miR-146b, miR-150, miR155, and miR-223 were inserted into sites within the intron of the vector and tested for tCD34 expression by flow cytometry (FACS). Different constructs were assembled with amiRs targeted to knockdown expression of suppressor of cytokine signaling 1 (SOCS1) or programmed cell death 1 (PDCD1, PD-1). Three of the six amiRs maintained tCD34 expression. Expansion of primary human T cells transduced with these amiR vectors, as well as transgene expression, were equivalent to control engineered T cells over a 40-day period. Knockdown of SOCS1 RNA and PD-1 expression by FACS was shown to vary between constructs, dependent on either the specific short interfering RNA sequence used in the amiR, or the microRNA backbone and location in the vector intron. Gamma-retroviral vectors that both efficiently knockdown endogenous gene expression and maintain linked transgene production can be produced, but empirical vector evaluations were best suited for optimal construct analysis.
authors.affiliation: Surgery Branch, Center for Cancer Research, National Cancer Institute , Bethesda, Maryland.
authors.forename: Tristen S
authors.initials: TS
authors.lastname: Park
authors.forename: Daniel
authors.initials: D
authors.lastname: Abate-Daga
authors.forename: Ling
authors.initials: L
authors.lastname: Zhang
authors.forename: Zhili
authors.initials: Z
authors.lastname: Zheng
authors.forename: Richard A
authors.initials: RA
authors.lastname: Morgan
mesh_terms: D018952:Antigens, CD34 / Q000235:genetics / Q000378:metabolism; D049109:Cell Proliferation; D005434:Flow Cytometry; D017988:Gammaretrovirus / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D017930:Genes, Reporter; D005822:Genetic Vectors / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D007438:Introns; D035683:MicroRNAs / Q000138:chemical synthesis / Q000235:genetics* / Q000378:metabolism; D061251:Primary Cell Culture; D061026:Programmed Cell Death 1 Receptor / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D013329:Structure-Activity Relationship; D000071222:Suppressor of Cytokine Signaling 1 Protein; D050826:Suppressor of Cytokine Signaling Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D013601:T-Lymphocytes / Q000166:cytology / Q000378:metabolism
chemical_list: D018952:Antigens, CD34; D035683:MicroRNAs; C105992:PDCD1 protein, human; D061026:Programmed Cell Death 1 Receptor; C108944:SOCS1 protein, human; D000071222:Suppressor of Cytokine Signaling 1 Protein; D050826:Suppressor of Cytokine Signaling Proteins