Induction of a T helper cell response against the tumor-associated antigen HER2 using monocyte-derived dendritic cells.

Tumor-reactive CD4(+) T helper (Th) cells play a criticalrole in antitumor immunity, due to their ability to induceCD8(+) T cell-mediated cytotoxic activity and humoralresponse. This study focuses on the in vitro generationand expansion of Th cells specific for the tumor-associatedantigen ;human epidermal growth factor receptor-2' (HER2). Aprotocol for efficient HER2 presentation was developed usingautologous monocyte-derived dendritic cells (DC) as antigenpresenting cells (APC) and purified HER2 protein as antigensource. Our data suggest that DC pulsed with recombinantprotein of the extracellular domain (ECD) of HER2 (ECD/HER2)induce an ECD/HER2-specific Th cell response. This finding mayfacilitate the development of immunotherapy regimens withoutrequiring defined immunogenic epitopes of the antigen.