PGE2 Is Crucial for the Generation of FAST Whole- Tumor-Antigens Loaded Dendritic Cells Suitable for Immunotherapy in Glioblastoma

Abstract

Dendritic cells (DC) are the most potent antigen-presenting cells, strongly inducers of T cell-mediated immune responses and, as such, broadly used as vaccine adjuvant in experimental clinical settings. DC are widely generated from human monocytes following in vitro protocols which require 5–7 days of differentiation with GM-CSF and IL-4 followed by 2–3 days of activation/maturation. In attempts to shorten the vaccine’s production, Fast-DC protocols have been developed. Here we reported a Fast-DC method in compliance with good manufacturing practices for the production of autologous mature dendritic cells loaded with antigens derived from whole tumor lysate, suitable for the immunotherapy in glioblastoma patients. The feasibility of generating Fast-DC pulsed with whole tumor lysate was assessed using a series of small-scale cultures performed in parallel with clinical grade large scale standard method preparations. Our results demonstrate that this Fast protocol is effective only in the presence of PGE2 in the maturation cocktail to guarantee that Fast-DC cells exhibit a mature phenotype and fulfill all requirements for in vivo use in immunotherapy approaches. Fast-DC generated following this protocol were equally potent to standard DC in inducing Ag-specific T cell proliferation in vitro. Generation of Fast-DC not only reduces labor, cost, and time required for in vitro clinical grade DC development, but can also minimizes inter-preparations variability and the risk of contamination.

Dendritic Cells and Cancer Immunotherapy: The Adjuvant Effect

“…In a good manufacturing practice (GMP)-compliant context, this promotes increased costs in terms of consumables, as well as operator activity in a clean room. Some groups have demonstrated that it is possible to obtain DCs with the safety and efficacy requested by regulatory agencies using short culture protocols in three to five days [35,36].…”

In vivo targeting of a tumor-antigen encoded DNA vaccine to dendritic cells in combination with tumor-selective chemotherapy eradicates established mouse melanoma

“…The distinguishing abilities of DCs in capturing and processing tumor antigens and in presenting the processed antigenic fragments to the T cells in tumor-draining lymph nodes result in the generation of tumor-specific Cytotoxic T Lymphocytes (CTLs) that kill tumor cells. [2][3][4][5][6] DCs are capable not only of presenting extracellular antigen fragments in complexation with the major histocompatibility complex (MHC) class II molecules to CD4+ T helper (TH) cells but also of cross-presenting the antigen fragments on MHC class I molecules to CD8+ T cells. 7 Such cross-presentation capability of DCs is crucial in mounting anti-tumor immune responses.…”