Generation of Genetically Engineered Precursor T-Cells From Human Umbilical Cord Blood Using an Optimized Alpharetroviral Vector Platform

Mol Ther. 2016 Aug;24(7):1216-26. doi: 10.1038/mt.2016.89. Epub 2016 May 3.

Abstract

Retroviral engineering of hematopoietic stem cell-derived precursor T-cells (preTs) opens the possibility of targeted T-cell transfer across human leukocyte antigen (HLA)-barriers. Alpharetroviral vectors exhibit a more neutral integration pattern thereby reducing the risk of insertional mutagenesis. Cord blood-derived CD34+ cells were transduced and differentiated into preTs in vitro. Two promoters, elongation-factor-1-short-form, and a myeloproliferative sarcoma virus variant in combination with two commonly used envelopes were comparatively assessed choosing enhanced green fluorescent protein or a third-generation chimeric antigen receptor (CAR) against CD123 as gene of interest. Furthermore, the inducible suicide gene iCaspase 9 has been validated. Combining the sarcoma virus-derived promoter with a modified feline endogenous retrovirus envelope glycoprotein yielded in superior transgene expression and transduction rates. Fresh and previously frozen CD34+ cells showed similar transduction and expansion rates. Transgene-positive cells did neither show proliferative impairment nor alteration in their lymphoid differentiation profile. The sarcoma virus-derived promoter only could express sufficient levels of iCaspase 9 to mediate dimerizer-induced apoptosis. Finally, the CD123 CAR was efficiently expressed in CD34+ cells and proved to be functional when expressed on differentiated T-cells. Therefore, the transduction of CD34+ cells with alpharetroviral vectors represents a feasible and potentially safer approach for stem cell-based immunotherapies for cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alpharetrovirus / genetics*
  • Antigens, CD34 / metabolism
  • Apoptosis
  • Bacterial Outer Membrane Proteins
  • Biomarkers
  • Cell Differentiation
  • Fetal Blood / cytology*
  • Gene Expression
  • Gene Transfer Techniques
  • Genes, Reporter
  • Genetic Engineering*
  • Genetic Vectors / genetics*
  • Hematopoietic Stem Cells / cytology
  • Hematopoietic Stem Cells / metabolism
  • Humans
  • Interleukin-3 Receptor alpha Subunit / immunology
  • Phenotype
  • Precursor Cells, T-Lymphoid / cytology*
  • Precursor Cells, T-Lymphoid / metabolism*
  • Promoter Regions, Genetic
  • Receptors, Antigen, T-Cell / genetics
  • Receptors, Antigen, T-Cell / immunology
  • T-Lymphocytes / cytology
  • T-Lymphocytes / immunology
  • T-Lymphocytes / metabolism
  • Transduction, Genetic
  • Transgenes

Substances

  • Antigens, CD34
  • Bacterial Outer Membrane Proteins
  • Biomarkers
  • Interleukin-3 Receptor alpha Subunit
  • Receptors, Antigen, T-Cell
  • membrane protein, 75kDa