[Are antibiotics immunomodulators?].

Abstract

This review of the literature, although non complete, involving different observations, experiments and documented demonstrations, suggest the real importance of the interrelations existing between, the pathogenic bacteria, the specific and non specific reactions of the normal or infected host and the antibiotics. The bacterial infections are potent immunomodulators by causing significant alterations in one or more mediators of homeostasis (coagulation, complement, inflammation), inducing cellular and tissular alterations more or less dramatic depending upon the number, the virulence of the bacteria and the immune status of the host. Antibiotics in reducing the number of the infecting pathologic bacteria, in modifying their pathologic and virulence factors might them be considered as immunorestoring molecules. On the other hand, when large numbers of bacteria are killed rapidly by bactericidal antibiotics, their cytoplasmic enzymes or bacterial cell wall structures, are rapidly released locally and are able to amplify the various systems involved in the deleterious inflammatory reaction. Thus depending on their dose and their mode of action, antibiotics could be considered as immunomodulators, albeit indirectly in modifying the pathophysiology of the host, in inhibiting or enhancing the release of immunoreactive bacterial molecules. Moreover antibiotics have been shown to interfere directly on the non specific and specific defenses mechanisms. Until the recent years, only the immunotoxicological aspect has been evaluated, involving mostly the immunopharmacologic screening of the antibiotics effects on phagocytic cells or on the effectors of the immune responses. Several recent examples are given that illustrate a new approach looking at the molecular level of the cellular action of antibiotics.(ABSTRACT TRUNCATED AT 250 WORDS)