Track: Formulation and Delivery - Biomolecular - Drug Delivery - On Body Delivery Systems (OBDS)
Category: Poster Abstract
High-Efficient Immune Cell Production of Extracellular Vesicles for Developing a Novel Nanodelivery Approach
Purpose: Emerging studies indicate that dendritic cells (DCs)-derived exosomes enclose numerous DC-originating membrane molecules and cytosolic components, which is critical in regulating immune system. However, obtaining DC-derived exosomes in high-efficient production for meeting clinical demands is extremely challenging, due to the limited cellular secretion rate, which substantially hindered the therapeutic potential of exosomes as either the delivery platform or therapeutic agents. In this paper, we will introduce a novel approach simply using a LED light with near UV irradiation for stimulating high-efficient cellular production of extracellular vesicles. Methods: Immature and mature JAWSII cells (100 ng/mL LPS-treated) were treated with different UV irradiance (0.8, 1.6, 2.4, 3.2 W/cm2) at 365 nm for different time intervals (5, 10, 15, 20, 30 min). The exosomes were isolated by serial centrifugation and suspended in PBS. The concentration and size were measured using nanoparticle tracking system (NTA). Immunofluorescence double-staining with MHC-I and CD86 was analyzed by flow cytometry. Exosomes were first lysed with RIPA buffer with proteinase inhibitor and the lysate was analyzed by TNF-α ELISA kit. Results: The concentration of exosomes isolated from either immature or mature JAWSII cells was increased 10-fold more than native cell secretion post-treatment of 3.2 W/cm2 UV irradiance for 30 min (Figure 1). The size of aforementioned exosomes was around 120 nm with uniform dispersion. After LPS+UV treatment, the percentage of MHC-I+CD86+ cells was increased to 14.2% compared to untreated cells (10.8%) (Figure 2). More importantly, TNF-α carried by each exosome derived from LPS+UV treated JAWSII cells was 1.3-fold than that carried by untreated exosome (Figure 3). Conclusion: We found that near UV irradiation substantially enhance the exosome secretion from JAWSII cells regardless of the immature or mature status, which may imply the low UV dose capable of predisposing immune cells to a stronger response used in phototherapy. The immunogenic function of such secreted exosomes is also enhanced by carrying more TNF-α. This research will open up a new avenue to explore therapeutic production of DCs-derived exosomes in high throughput, such as producing exosomes as the therapeutic agents to regulate immune system.