In-vitro effects of cilofungin (LY121019), amphotericin B and amphotericin B-deoxycholate on human polymorphonuclear leucocytes

Immunomodulating effects of antibiotics: literature review

Antibiotics can interact directly with the immune system. This is a review of the immunomodulating effects of antibiotics. The Medline database on CD-ROM was searched for the years 1987 to 1994 using the following search string: "thesaurus explode antibiotics/all AND (thesaurus explode immune-system/drug effects OR thesaurus immune-tolerance/drug effects)." Aspects of the immune system studied were aspects of phagocyte functions: phagocytosis and killing, and chemotaxis and aspects of lymphocyte functions: lymphocyte proliferation, cytokine production, antibody production, delayed hypersensitivity and natural killer-cell activity. In order to quantify and to compare immunomodulatory properties of antibiotics we calculated an "immune index," defined as: number of positive statements--number of negative statements/total number of statements. Concerning phagocytosis, positive effects were observed for cefodizime, imipenem, cefoxitin, amphotericin B and clindamycin and negative effects for erythromycin, roxithromycin, cefotaxime, tetracycline, ampicillin and gentamicin. Clindamycin, cefoxition and imipenem induce enhancement of chemotaxis, whereas cefotazime, rifampicin and teicoplanin decrease chemotaxis. Regarding lymphocyte proliferation, cefodizime has the strongest stimulating effect, whereas tetracycline has the strongest negative effect. Except for erythromycin and amphotericin B the number of statements reported is too small to be conclusive for the interpretation of effects on cytokine production. Erythromycin and amphotericin B appear to stimulate cytokine production. As to antibody production, cefodizime has the strongest positive effect, whereas josamycin, rifampicin and tetracycline have marked negative effects. For delayed hypersensitivity and the natural killer-cell activity the number of statements is too small for any single antibiotic to be conclusive. There are three markedly immuno-enhancing antibiotics (imipenem, cefodizime and clindamycin) and eight markedly immuno-depressing antibiotics (erythromycin, roxithromycin, cefotaxime, tetracycline, rifampicin, gentamicin, teicoplanin and ampicillin).

Effects of naftifine and terbinafine, two allylamine antifungal drugs, on selected functions of human polymorphonuclear leukocytes

Many antimycotic agents negatively affect the natural immune response. Typically, these drugs impair polymorphonuclear leukocyte (PMN) production of superoxide anion, chemotaxis, or the killing of pathogens. Allylamines are a new class of antimycotic compounds with a new mechanism of antifungal action, i.e., inhibition of the fungal squalene epoxidase. The trial that we describe aimed to evaluate the effects of two allylamines, terbinafine and naftifine, on selected functions of PMNs, i.e., superoxide anion production, chemotaxis, and killing of Candida albicans blastospores. Terbinafine and naftifine on their own did not affect superoxide anion production when they were added to PMNs. When PMNs were preincubated with allylamines and were then stimulated by N-formyl-Met-Leu-Phe or phorbol 12-myristate 13-acetate, superoxide anion production was increased (priming effect). Since intracellular free calcium (Ca2+i) is involved in the control of superoxide anion production, we evaluated the effects of the allylamines on the Ca2+i concentration ([Ca2+]i). In the presence of terbinafine or naftifine, the [Ca2+]i increased in a dose-dependent manner; the source of Ca2+i was not extracellular since it was not affected by extracellular calcium chelation with ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid. In the presence of terbinafine or naftifine, chemotaxis of PMNs was not impaired. Terbinafine and naftifine slightly but significantly increased the killing of C. albicans blastospores (P < 0.05 at 10 and 100 microM). In conclusion, in contrast to imidazole-like drugs, the allylamine antimycotic compounds terbinafine and naftifine enhance selected functions of PMNs.

Effect of several antimicrobial agents on ciprofloxacin uptake by human neutrophils

The effect of antimicrobial agent active against anaerobes, gram-positive cocci and fungi on the uptake of ciprofloxacin by human neutrophils (PMNs) was evaluated. In the presence of therapeutic extracellular concentrations of these agents, ciprofloxacin reached high intracellular concentrations [cellular-to-extracellular ratio (C/E) greater than or equal to 2.9], this value being higher in the presence of amphotericin B (C/E 6.3 +/- 0.9). The intracellular penetration of ciprofloxacin was higher when PMNs were stimulated with opsonized zymosan (C/E greater than or equal to 5.6). In summary, none of the antimicrobial agents tested significantly impaired the uptake of ciprofloxacin by human PMNs.

Activity of intracellular antibiotics

We have studied the intracellular bioactivity of several antimicrobial agents against two strains of Staphylococcus aureus, a pathogen sequestrated in phagolysosomes, using peripheral blood neutrophils from human volunteers. This was compared to the activity of cell-associated drugs also measured in vitro. Several discrepancies (high cellular association, low bioactivity) were observed (coumermycin, glycopeptides, erythromycin and clindamycin) which can be due to the binding of the drug to a particular cellular organelle, to intracellular metabolization or inactivation, to unfavourable conditions in the phagolysosome (pH drop), or to a toxic effect of the drug on the functions of the neutrophil. Addition of the antibiotic during ingestion was frequently associated with better neutrophil-dependent killing through several potential mechanisms: coingestion of the antibiotic with the inoculum, modification of opsonization, release of activating substances and fragilization of the microorganism to oxygen-dependent or -independent killing mechanisms.