{
  "abstract": "Background Interleukin-2 (IL-2) is an important cytokine that plays a significant role in the stimulation and proliferation of various immune cell populations, including primary T lymphocytes. The involvement of IL-2 in stimulating the expansion of immune cells has led to the development of commercially available recombinant IL-2 as a therapeutic for several types of cancers. The availability of recombinant IL-2 has also enabled the development and manufacture of T lymphocyte-based adoptive cell therapies such as Chimeric Antigen Receptor (CAR)-T cell therapies, where it serves as a critical cell culture medium supplement, prolonging cell expansion and postponing cell cycle arrest. This study sought to assess the stability and utilization of IL-2 in culture medium with the aim of developing effective and efficient supplementation strategies in CAR-T therapy manufacturing.Methods Freshly activated primary T cells were expanded in batch culture with differing initial cell seeding densities and an initial IL-2 bolus to supplement the culture medium. Every 24-hours, cell counts were performed, and supernatant samples collected. Samples were analyzed by ELISA to quantify the concentration of IL-2 in culture medium throughout the culture duration.Results Available IL-2 rapidly declined in a mass-dependent manner with a half-life of 1-2 days for cell-free culture. With higher cell seeding densities, a more rapid decline was observed, but this contribution was secondary. Both bolus amount and frequency of IL-2 supplementation were assessed for impact on rate of cell proliferation. The best frequency for supplementation corresponded to the half-life of IL-2 in culture. The proliferation rate increased with increasing bolus amount but quickly became asymptotic.Conclusions The need for moderate, frequent IL-2 supplementation in cell cultures as opposed to large, infrequent boluses is consistent with the kinetics of IL-2 availability in culture. This supplementation strategy is more effective and efficient for manufacturing T-lymphocyte-based adoptive cell therapies.",
  "authors": [
    {
      "affiliations": [
        "AstrZeneca, Gaithersburg, MD, USA"
      ],
      "name": "Michael Degaga"
    }
  ],
  "title": "215 Evaluating the stability and utilization of inteleukin-2 in culture medium to inform supplementation strategies for T cell therapy manufacturing",
  "uid": "b6598261-c825-5ba0-b6df-88abf29c5184"
}