title: Clinical scale electroloading of mature dendritic cells with melanoma whole tumor cell lysate is superior to conventional lysate co-incubation in triggering robust in vitro expansion of functional antigen-specific CTL.
abstract: Recent commercial approval of cancer vaccine, demonstrating statistically significant improvement in overall survival of prostate cancer patients has spurred renewed interest in active immunotherapies; specifically, strategies that lead to enhanced biological activity and robust efficacy for dendritic cell vaccines. A simple, widely used approach to generating multivalent cancer vaccines is to load tumor whole cell lysates into dendritic cells (DCs). Current DC vaccine manufacturing processes require co-incubation of tumor lysate antigens with immature DCs and their subsequent maturation. We compared electroloading of tumor cell lysates directly into mature DCs with the traditional method of lysate co-incubation with immature DCs. Electroloaded mature DCs were more potent in vitro, as judged by their ability to elicit significantly (p < 0.05) greater expansion of peptide antigen-specific CD8(+) T cells, than either lysate-electroloaded immature DCs or lysate-co-incubated immature DCs, both of which must be subsequently matured. Expanded CD8(+) T cells were functional as judged by their ability to produce IFN-γ upon antigen-specific re-stimulation. The electroloading technology used herein is an automated, scalable, functionally closed cGMP-compliant manufacturing technology supported by a Master File at CBER, FDA and represents an opportunity for translation of enhanced potency DC vaccines at clinical/commercial scale.
authors.affiliation: MaxCyte, Inc., Gaithersburg, MD 20878, USA.
authors.forename: Lawrence A
authors.initials: LA
authors.lastname: Wolfraim
authors.forename: Masashi
authors.initials: M
authors.lastname: Takahara
authors.forename: Angelia M
authors.initials: AM
authors.lastname: Viley
authors.forename: Rama
authors.initials: R
authors.lastname: Shivakumar
authors.forename: Mie
authors.initials: M
authors.lastname: Nieda
authors.forename: Ryuji
authors.initials: R
authors.lastname: Maekawa
authors.forename: Linda N
authors.initials: LN
authors.lastname: Liu
authors.forename: Madhusudan V
authors.initials: MV
authors.lastname: Peshwa
mesh_terms: D017951:Antigen Presentation; D000951:Antigens, Neoplasm / Q000276:immunology; D016827:CD8 Antigens / Q000378:metabolism; D019496:Cancer Vaccines / Q000276:immunology*; D002454:Cell Differentiation; D049109:Cell Proliferation; D002478:Cells, Cultured; D018920:Coculture Techniques; D003713:Dendritic Cells / Q000166:cytology / Q000378:metabolism*; D018274:Electroporation / Q000379:methods*; D005240:Feasibility Studies; D006801:Humans; D016219:Immunotherapy, Adoptive / Q000379:methods*; D007371:Interferon-gamma / Q000378:metabolism; D008213:Lymphocyte Activation; D008545:Melanoma / Q000276:immunology* / Q000628:therapy; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
chemical_list: D000951:Antigens, Neoplasm; D016827:CD8 Antigens; D019496:Cancer Vaccines; D007371:Interferon-gamma