THE IMMUNOMODULATORY EFFECTS OF ANTIBIOTICS - IN-VITRO AND EX-VIVO INVESTIGATIONS OF 21 SUBSTANCES BY MEANS OF THE LYMPHOCYTE-TRANSFORMATION TEST

Besides their antimicrobial activity antibiotics can modulate immune r esponse. The paper provides original data about in vitro and in vivo i nfluence of antibiotics on lymphocyte transformation test (LTT) and gi ves a comprehensive overview of literature data. Tn the study presente d here the influence of several antimicrobial substances on unstimulat ed and PHA-stimulated lymphocyte transformation was investigated. The proliferative response was measured as (H-3) thymidine uptake by lymph ocytes. For initial screening the lymphocyte transformation test was p erformed on murine lymphocytes in vitro. As a whole 21 antimicrobial s ubstances were tested including representative substances of the most important main groups. As a second step experiments were done with sel ected substances on human lymphocytes that had shown a distinct influe nce on murine cells in vitro. At therapeutic concentrations a pronounc ed stimulation of murine lymphocyte transformation was caused by carba penems, aminothiazole cephalosporins and imidazoles. Purine analogs ha d only suppressive effects. However, the increased (H-3) thymidine upt ake in murine cells could not be regularly reproduced in human lymphoc ytes and in ex vivo experiments.