Objective To investigate the effect of calcineurin(CaN)on the superantigne activity of staphylococcal enterotoxin C2(SEC2).Methods Splenic lymphocytes of SD rats were stimulated with recombinant wild SEC2(rSEC2) and its enhanced mutant(mSEC2)(T20L / G22E / H118A / H122A),at various final concentrations(0.5,1,2,3 and 4 μg / ml),and determined for proliferation level by MTT assay.The changes of CaN activity in the course of induction of proliferation of rat lymphocytes with rSEC2 and mSEC2,at a final concentr...