Characterization of structure and direct antigen presentation by dendritic/tumor-fused cells as cancer vaccines

Previous work has shown that fusion of dendritic cells (DCs) and tumor cells induces potent antitumor immune responses. However, little is known on whether fused cells directly present tumor-associated antigens (TAAs) through major histocompatibility complex (MHC) class I and II pathways in the context of co-stimulatory molecules.

Fusion cells were generated between DCs and MC38 carcinoma cells stably expressing mucin-1 (MUC1) by polyethylene glycol. The characterization of structure and antigen presentation by fused cells was examined by immunoelectron microscopic and flow cytometric analyses.

The cytoplasm from both cellular entities was integrated, while their nuclei were independently preserved. Short-term culture gave fused cells sufficient time to integrate and directly display MUC1 through MHC class I and II pathways in the context of co-stimulatory molecules.

DC-derived molecules and TAAs are presumably synthesized at separate sites of fused cells, to converge and complex with each other.