Sleeping Beauty Transposition of Chimeric Antigen Receptors Targeting Receptor Tyrosine Kinase-Like Orphan Receptor-1 (ROR1) into Diverse Memory T-Cell Populations.

Authors:
Deniger DC, Yu J, Huls MH, Figliola MJ, Mi T, Maiti SN, Widhopf GF 2nd, Hurton LV, Thokala R, Singh H3, Olivares S, Champlin RE, Wierda WG, Kipps TJ, Cooper LJ.
In:
Source: PLoS Genet
Publication Date: (2015)
Issue: 10(6): e0128151
Research Area:
Cancer Research/Cell Biology
Immunotherapy / Hematology
Cells used in publication:
PBMC, human
Species: human
Tissue Origin: blood
Experiment
Cryopreserved PBMC, obtained from healthy donors after informed consent, were thawed the day of the electroporation (designated day 0) and rested for 2 hours at 37°C. PBMC for electroporation were spun at 200g for 10 minutes and 2x107 cells were mixed with supercoiled DNA plasmids (5 µg SB11 transposase and 15 µg SB transposon) in Human T cell Nucleofector Solution (cat#VPA-1002, Lonza), added to a cuvette, and electroporated on the U-014 program of Amaxa Nucleofector II (Lonza). Electroporated cells were transferred to a 6-well plate containing phenol-free RPMI, 20% FBS, and 1x Glutamax-100. The following day, electroporated T cells were phenotyped and stimulated with AaPC clone#1 (irradiated using cesium source to 100 Gy) at 1:1 ratio of clone#1 to ROR1-specific CAR+ T cells Lonza Summary: The authors work showed that the SB transpotion method could be used to achieve stable CAR expression in T cells and has implications for the outgrowth of memory T cell populations with ROR-1 restricted anti-tumor activity.
Abstract
T cells modified with chimeric antigen receptors (CARs) targeting CD19 demonstrated clinical activity against some B-cell malignancies. However, this is often accompanied by a loss of normal CD19+ B cells and humoral immunity. Receptor tyrosine kinase-like orphan receptor-1 (ROR1) is expressed on sub-populations of B-cell malignancies and solid tumors, but not by healthy B cells or normal post-partum tissues. Thus, adoptive transfer of T cells specific for ROR1 has potential to eliminate tumor cells and spare healthy tissues. To test this hypothesis, we developed CARs targeting ROR1 in order to generate T cells specific for malignant cells. Two Sleeping Beauty transposons were constructed with 2nd generation ROR1-specific CARs signaling through CD3? and either CD28 (designated ROR1RCD28) or CD137 (designated ROR1RCD137) and were introduced into T cells. We selected for T cells expressing CAR through co-culture with ?-irradiated activating and propagating cells (AaPC), which co-expressed ROR1 and co-stimulatory molecules. Numeric expansion over one month of co-culture on AaPC in presence of soluble interleukin (IL)-2 and IL-21 occurred and resulted in a diverse memory phenotype of CAR+ T cells as measured by non-enzymatic digital array (NanoString) and multi-panel flow cytometry. Such T cells produced interferon-? and had specific cytotoxic activity against ROR1+ tumors. Moreover, such cells could eliminate ROR1+ tumor xenografts, especially T cells expressing ROR1RCD137. Clinical trials will investigate the ability of ROR1-specific CAR+ T cells to specifically eliminate tumor cells while maintaining normal B-cell repertoire.