Optimizing T Cell Expansion in a Hollow-Fiber Bioreactor

Abstract

Purpose of ReviewRecent developments in regenerative medicine have precipitated the need to expand gene-modified human T cells to numbers that exceed the capacity of well-plate-based, and flask-based processes. This review discusses the changes in process development that are needed to meet the cell expansion requirements by utilizing hollow-fiber bioreactors. Maintenance of cell proliferation over long periods can become limited by unfilled demands for nutrients and oxygen and by the accumulation of waste products in the local environment.Recent FindingsPerfusion feeding, improved gas exchange, and the efficient removal of lactate can increase the yield of T cells from an average of 10.8E +09 to more than 28E +09 in only 10 days.SummaryAggressively feeding cells and actively keeping cells in the bioreactor improves gas exchange and metabolite management over semi-static methods. The ability to remove the environmental constraints that can limit cell expansion by using a two-chamber hollow-fiber bioreactor will be discussed.

Large-scale expansion and characterization of CD3+ T-cells in the Quantum® Cell Expansion System

“…The Quantum system has previously been described as a robust platform for expanding adherent cells such as adult stem cells [4–8] and, more recently, preliminary results for expansion of non-gene-modified T-cells were reported [9]. We now show that the Quantum system supports consistent expansion of T-cells from apheresis collections from multiple healthy donors, yielding numbers of CD3 + T-cells in clinical dose ranges (approximately 13 × 10 9 to 25 × 10 9 T-cells per expansion run depending on numbers of cells seeded) in a short time frame of 8 to 9 days and with consistent viability, fold expansion and doubling times.…”

“…The day of seeding is referred to as Day 0 of the expansion. Cell expansion methods in the Quantum system were as described previously [9] with the following modifications.…”

“…Although the Quantum system was designed to grow both adherent and suspension cells, to date it has mainly been used for growth of adherent cells such as mesenchymal stromal cells [also known as mesenchymal stem cells (MSCs)] [4–6] and adipose-derived stem cells [7], and its advantages over manual processes for scale-up of MSCs in compliance with GMP have been highlighted [8]. More recently, the Quantum system has been used to grow T-cells derived from peripheral blood of healthy donors and process improvements were shown to support low seeding densities, more sustained log phase growth and high yields [9].…”

“…The operation of the Quantum system has been described in several previous publications [4–6, 9]. In brief, the system consists of a synthetic hollow-fiber bioreactor that is part of a sterile closed-loop circuit for media and gas exchange.…”

A Comparison of Automated Perfusion- and Manual Diffusion-Based Human Regulatory T Cell Expansion and Functionality Using a Soluble Activator Complex

“…Gas control is also managed using hollow-fiber technology in a gas transfer module with a surface area of 0.16 m 2 . In Quantum system culture, perfusion feeding, improved gas exchange, and efficient removal of lactate were previously shown to increase the yield of human peripheral blood mononuclear cell-derived T cells from an average of 10.8 × 10 9 to more than 28 × 10 9 in only 10 d 7 , 8 . In order to further evaluate the capability of the Quantum system, the current comparative study was designed to evaluate the growth of Tregs in the Quantum system two-compartment bioreactor versus the static conditions in tissue culture polystyrene T225 flasks.…”