Following 4 h incubation at 37C, supernatants were harvested and radioactivity was counted in a microplate scintillation counter (Packard Instruments Co., Relebactam Meriden, CT). activity of 1928z+ T cells in SCID beige mice FOX CHASE C.B-17 (SCID-Beige) mice (Taconic, Germantown NY) inoculated intravenously by tail vein injection with 5 105 Raji cells develop hind-limb paralysis in 3 to 5 5 weeks after tumor cell injection, secondary to spinal cord compression from vertebral bone marrow tumor involvement.11 Mice bearing established Raji tumors, six days after intravenous injection, were treated with 107 1928zCD3+ transduced T cells from VR4 by tail-vein injections. validation runs using apheresis products from patients with CLL. Additionally, following expansion of the T cells, the diversity of the skewed V T cell receptor repertoire was significantly restored. This validated process will be used in phase I clinical trials in patients with chemo-refractory CLL and in patients with relapsed ALL. It can also be adapted for other clinical trials involving the expansion and transduction of patient or donor T cells using any chimeric antigen receptor or T cell receptor. and and eradicate systemic tumors in SCID-Beige mice that do not express costimulatory molecules in SCID-Beige mice. 12, 15 The method used for expanding T cells prior to infusion is an essential determinant of their efficacy. It has been previously exhibited that T cells derived from patients with various lymphoma and leukemias16-20, myeloma21, HIV22-24 or viral antigen-specific T cells25 can be expanded with anti-CD3 and anti-CD28 monoclonal antibodies covalently linked to magnetic beads and that these cells exhibit anti-tumor activity and and SCID-Beige mice 27 similarly to T cells activated with PHA and subsequently restimulated on artificial antigen presenting cells.11 To evaluate the safety and efficacy of autologous T cells genetically modified to express the 1928z CAR in human Phase I clinical trials in patients with CLL and ALL, we developed a manufacturing process based on T cell expansion with Dynabeads? CD3/CD28 for the activation, transduction and expansion of clinical relevant numbers of autologous 1928z+CD3+ T cells. This process allows us to generate clinical doses of biologically functional 1928z+ T cells in approximately 2 to 3 3 weeks in a large-scale semi-closed culture system using the Wave bioreactor. Materials and Methods Selection of a PG13-SFG-1928z clone A clinical grade high-titer PG13 clone expressing the 1928z chimeric antigen receptor (CAR) was generated by transiently transfecting Phoenix-eco cells with the plasmid encoding the gammaretroviral vector SFG-1928z12 and subsequently infecting PG13 cells with cell-free vector stocks from the transfected Phoenix-eco cells. The PG13-1928z cell population was subsequently subcloned by limiting dilution. Clones were isolated and titers were determined by infecting HeLa cells under standardized conditions. High titer clones were identified by fluorescence activated cell sorting (FACS) using the anti-1928z CAR hamster monoclonal antibody 19E3 that was generated in-house by the MSKCC monoclonal antibody core facility. The high titer PG13-1928z clone 34 was subjected to a second round of subcloning by limiting dilution. The subclone PG13-1928z cl.3 was demonstrated to express the 19-28zCAR and was selected for its ability to efficiently transduce peripheral blood mononuclear cells (PBMCs). Integrity of the retroviral vector construct was exhibited and a single copy of the integrated proviral vector was detected by Southern blot analysis in the genomic DNA extracted from PG13-1928z clone 3 (data not shown). The PG13-1928z clone 3 was expanded to generate a seed bank (SB) that was tested for absence of mycoplasm, replication qualified retrovirus (RCR), and for sterility. The SB exceeded all required assessments. Generation of a PG13-1928z Grasp Cell Bank A grasp cell bank Rabbit polyclonal to AdiponectinR1 (MCB) of 100 vials of the resulting PG13-1928z clone 3 was produced and tested according to FDA and NIH recommendations and guidelines (see Results section). The biosafety assessments for the MCB were performed by Charles River Laboratories (CRL, Malvern, PA) and the National Gene Vector Laboratory (NGVL, Indianapolis, IN). Manufacture of cGMP-like clinical grade vector stocks cGMP-like grade PG13-1928z vector stocks were prepared as previously described28. Briefly, cells were initially seeded using one Relebactam certified MCB cryovial made up of 107 cells and ultimately expanded into four 10-tray Cell Factories. Viral stocks were harvested from 4 Cell Factories in a 5 L sterile bioprocessing bag using a peristaltic pump on each of 3 consecutive days. Viral stocks were filtered, temporary stored at 4C, pooled on the third day and frozen at ?80C in cryobags. Cell expansion and viral Relebactam stocks production was performed in DMEM, 10% FBS. In order to release the vector stocks, biosafety testing was performed according to FDA and NIH guidelines and recommendations. The biosafety assessments were performed by.