ches? ??? ??? ??? regulatory T cells (Treg) these T cells suppress the immune response in order to prevent overactivity; they may inhibit or destroy active lymphocytes ??? ??? ??? memory T cells these T cells remember an antigen & start a rapid response if that antigen is contacted again ??? ??? ??? antigen-presenting cells APC's most important of these cells are macrophages & dendritic cells deri