Ovalbumin specific type 1 regulatory T- cells (Ovasave®) (TxCell)

Peripheral blood mononuclear cells (PBMCs) are isolated by Ficoll gradient centrifugation from 250 mL blood withdrawn from each patient. To expand ova-specific T cells, PBMCs are cultured at 37°C and 5% CO₂ in the presence of ovalbumin in X-Vivo15 supplemented with cytokine-enriched Drosophilafeeder cell supernatants. The supernatant is derived from Drosophila Schneider 2 (S2) feeder cells stably transfected with a transmembrane form of murine anti-human CD3 antibody, human CD80, human CD58, and human IL-2 and IL-4. After 7 days of culture, T cells are cloned by limiting dilution and cultured in the presence of S2 feeder cells. Ova-Treg clones are selected based on their ovalbumin-specific IL-10 and type 1 Treg lymphocyte cytokine production profiles. Ova-Tregs are maintained frozen in vapor-phase nitrogen.