Lymphocyte expansion in bioreactors: upgrading adoptive cell therapy

Abstract

Bioreactors are essential tools for the development of efficient and high-quality cell therapy products. However, their application is far from full potential, holding several challenges when reconciling the complex biology of the cells to be expanded with the need for a manufacturing process that is able to control cell growth and functionality towards therapy affordability and opportunity. In this review, we discuss and compare current bioreactor technologies by performing a systematic analysis of the published data on automated lymphocyte expansion for adoptive cell therapy. We propose a set of requirements for bioreactor design and identify trends on the applicability of these technologies, highlighting the specific challenges and major advancements for each one of the current approaches of expansion along with the opportunities that lie in process intensification. We conclude on the necessity to develop targeted solutions specially tailored for the specific stimulation, supplementation and micro-environmental needs of lymphocytes’ cultures, and the benefit of applying knowledge-based tools for process control and predictability.

Natural killer cells in clinical development as non-engineered, engineered, and combination therapies

“…Adoptive cell therapy-suitable bioreactors provide controlled culture conditions favoring continuous nutrient supply and waste product removal, as well as physiological cues to guide cell growth [ 113 , 114 ]. Static bioreactors facilitate three-dimensional cell culture, although medium renewal cycles cause frequent nutrient and metabolite fluctuations that may trigger high phenotypical variability [ 114 ] and limit cell growth.…”

“…Adoptive cell therapy-suitable bioreactors provide controlled culture conditions favoring continuous nutrient supply and waste product removal, as well as physiological cues to guide cell growth [ 113 , 114 ]. Static bioreactors facilitate three-dimensional cell culture, although medium renewal cycles cause frequent nutrient and metabolite fluctuations that may trigger high phenotypical variability [ 114 ] and limit cell growth. The most used static platform is the Wilson Wolf Gas Permeable Rapid Expansion Platform, known as G-Rex®, consisting of a gas permeable membrane surface of different sizes which allows optimal gas exchange.…”

Influence of Culture Conditions on Ex Vivo Expansion of T Lymphocytes and Their Function for Therapy: Current Insights and Open Questions

“…These flasks can be incubated in usual cell culture incubators. It is considered a practical and cost-effective way to scale up the CAR T cell cultures as it does not require additional specialized equipment or sensors ( Baudequin et al, 2021 ; Garcia-Aponte et al, 2021 ; Westin et al, 2021 ). This system can be optimized to obtain a single therapeutic dose of CAR T cells per closed system.…”

“…The G-Rex vessels are available with different surface areas ranging from 5 to 500 cm 2 with a capacity of up to 4,500 ml. As this is a semi-automated technology, the cells are disturbed during sampling, which affects the cell expansion kinetics ( Bajgain et al, 2014 ; Wang and Rivière, 2016 ; Ludwig et al, 2020 ; Baudequin et al, 2021 ; Garcia-Aponte et al, 2021 ).…”

“…This system performs cell separation, activation, lentiviral transduction, and expansion automatically in the single-use closed tubing system. The gas and media exchange and gentle mixing of cells are also automated with sensors and controllers ( Apel et al, 2013 ; Mock et al, 2016 ; Baudequin et al, 2021 ; Garcia-Aponte et al, 2021 ). The CliniMACS Prodigy systems have been used for manufacturing CAR T cells as a substitute for the currently available technologies in clinical operation ( Mock et al, 2016 ).…”