Suppressive effects of B-lactam-antibiotics on in vitro generation of cytotoxic T-cells.

The in vitro effect of several compounds containing the B-lactam structure (including 6-aminopenicillanic acid, piperacillin, 7-aminocephalosporanic acid, ceftazidime and clavulanic acid) on the generation of cytotoxic lymphocytes was investigated in two different in vitro systems: (1) generation of virus specific cytotoxic T-cells and (2) proliferation of lymphocytes were assessed in secondary in vitro anti-viral immune responses. Both activities were suppressed by B-lactams in a dose-dependent manner. In these experiments, as found previously with human in vitro granulopoesis and proliferation of the human erythroleukaemic cell line K-562, cephalosporins and clavulanic acid were five to twenty times more suppressive than penicillins. Since concentrations that were effective in vitro are being achieved, particularly with cephalosporins, in the serum of patients, the possible clinical consequences of our findings may have to be taken into consideration.