Updated Technology to Produce Highly Immunogenic Dendritic Cell-derived Exosomes of Clinical Grade

Abstract

Dendritic cell-derived exosomes (Dex) are nanovesicles bearing major histocompatibility complexes promoting T-cell-dependent antitumor effects in mice. Two phase I clinical trials aimed at vaccinating cancer patients with peptide-pulsed Dex have shown the feasibility and safety of inoculating clinical-grade Dex, but have failed to show their immunizing capacity. These low immunogenic capacities have led us to develop second-generation Dex with enhanced immunostimulatory properties. Here, we show that interferon-γ is a key cytokine conditioning the dendritic cell to induce the expression of CD40, CD80, CD86, and CD54 on Dex, endowing them with direct and potent peptide-dependent CD8(+) T-cell-triggering potential in vitro and in vivo. In this study, we describe the clinical grade process to manufacture large-scale interferon-γ-Dex vaccines and their quality control parameters currently used in a phase II trial.

Dendritic cell-derived exosomes for cancer immunotherapy: hope and challenges

“…Compared to the first-generation INF-γ-free Dex for phase I trial (12), INF-γ-Dex prepared from peptideloaded mature DCs exhibited a mature phenotype with upregulated expression MHC class II molecules, tetraspanins, CD40, CD86 and ICAM-1/CD54. These data suggest that INF-γ treatment has the potential to improve the capacity of Dex for antigen presentation and T cell activation, as previously reported (11).…”

“…In this study, they prepared second-generation Dex by differentiating patient's monocytes into immature DCs with GM-CSF and IL-4, followed by induction of mature DCs with INF-γ and loading of tumor-associated antigenic peptides. IFN-γ was reported to induce the expression of costimulatory molecules and ICAMs in DCs (11). Compared to the first-generation INF-γ-free Dex for phase I trial (12), INF-γ-Dex prepared from peptideloaded mature DCs exhibited a mature phenotype with upregulated expression MHC class II molecules, tetraspanins, CD40, CD86 and ICAM-1/CD54.…”

Therapeutic and diagnostic applications of extracellular vesicles

“…polyinosinic-polycytidylic acid (poly(I:C)) and cyclophosphamide [192] and Gehrmann et al associated -galactosylceramide (a iNKT stimulatory factor) to antigen-loaded DC-derived EVs, which induced a potent NK,  T-cell innate immune response and enabled proliferation of antigen-specific T and B cells [193]. Currently, a phase II clinical trial in NSCLC patients is evaluating the combination of cyclophosphamide with DC-derived EVs (pulsed with a range of antigens and INF-) that showed an improved immune stimulatory capacity in preclinical studies [194] (NCT01159288).…”

Dendritic Cell–Derived Exosomes as Immunotherapies in the Fight against Cancer

“…The use of exosomes derived from LPS-or IFN-g-matured DCs (mDex) has been an important advance in this field, following discoveries that such Dex induce greater T cell stimulation compared with those from immature DCs (24,39,40). This is likely due to the observation that mDex possess more surface MHC class II, ICAM1, and costimulatory molecules (39)(40)(41). Also, it was recently found that Dex should be engineered toward stimulating B cell responses, in addition to T cell stimulation, for optimal immunogenicity (42,43).…”