“…They can inhibit cell-mediated responses, including mitogen-induced [3, 5, 11, 17-19, 22, 23], antigen-induced [24] and al logeneic cell-induced [5,12,14,17,22,25,26] lym phoprolifération, and cell-mediated cytotoxicity [1,10,12,25]. They can inhibit humoral immune re sponses including immunoglobulin synthesis as mea sured by immunofluorescence [4,27,28], ELISA [16], direct plaque-forming cells [15,29,30] and reverse hemolytic plaque assay [21 ].…”