Effects of Injectable Solutions on the Quality of Monocyte‐Derived Dendritic Cells for Immunotherapy

Abstract

Therapeutic vaccines based on monocyte‐derived dendritic cells have been shown to be promising strategies and may act as complementary treatments for viral infections, cancers, and, more recently, autoimmune diseases. Alpha‐type‐1‐polarized dendritic cells (aDC1s) have been shown to induce type‐1 immunity with a high capacity to produce interleukin‐12p70 (IL‐12p70). In the clinical use of cell‐based therapeutics, injectable solutions can affect the morphology, immunophenotypic profile, and viability of cells before delivery and their survival after injection. In this sense, preparing a cell suspension that maintains the quality of aDC1s is essential to ensure effective immunotherapy. In the present study, monocytes were differentiated into aDC1s in the presence of IL‐4 and GM‐CSF. On day 5, the cells were matured by the addition of a cytokine cocktail consisting of IFN‐α, IFN‐γ, IL‐1β, TNF‐α, and Poly I:C. After 48 hr, mature aDC1s were harvested and suspended in two different solutions: normal saline and Ringer’s lactate. The maintenance of cells in suspension was evaluated after 4, 6, and 8 hr of storage. Cell viability, immunophenotyping, and apoptosis analyses were performed by flow cytometry. Cellular morphology was observed by electron microscopy, and the production of IL‐12p70 by aDC1s was evaluated by ELISA. Compared with normal saline, Ringer’s lactate solution was more effective at maintaining DC viability for up to 8 hr of incubation at 4 or 22°C.