¦ ̷ ̷ ̷ ̷ ̷ ̷ ̷ ̷ ¦ ̷ ̷ ̷ ̷ - noun
: any of various cells (as a macrophage or a B cell) that take up and process an antigen into a form that when displayed at the cell surface in combination with a molecule of the major histocompatibility complex is recognized by and serves to activate a specific helper T cell