<prompt> Which one of the following are most improtant antigen presenting cells in human-MacrophagesPlasma cellsLangerhans cellshistiocytesLymphocytes  <response>: Robbins and Cotran pathologic basis of disease South Asia edition. immature dendritic cells within the epidermis are called langerhans cells .dendritic cells are the most impoant antigen presenting cells for initiating T cell responses against protein antigen. 