Immunomodulatory gene expression analysis in LPS-stimulated human polymorphonuclear leukocytes treated with antibiotics commonly used for multidrug-resistant strains.

Conventional antibiotics used for the treatment of severe infections such as sepsis and septic shock confer immunomodulatory benefits. However, the growing problem of multidrug resistant infections has led to an increase in the administration of non-conventional last-resort antibiotics, including quinolones, aminoglycosides, and polypeptides, and the effects of these drugs on immunomodulatory gene expression in activated human polymorphonuclear leukocytes (PMNs) have not been reported. In this study, lipopolysaccharide-stimulated PMNs were incubated with piperacillin, rifampicin, fosfomycin (FOM), levofloxacin (LVFX), minocycline (MINO), colistin, tigecycline, or amikacin, and the mRNA expression levels of pattern recognition receptors (TLR2, TLR4, and CD14), inflammatory cytokines (TNFα and IL6), and chemokine receptors (IL8Rs and ITGAM) in these cells were quantitated using real-time qPCR. Many of the tested antibiotics altered the expression of the investigated cytokines. Notably, FOM, LVFX, and MINO significantly downregulated the expression of IL6, which is associated with pro- and anti-inflammatory defense mechanisms. Treatment of FOM and LVFX reduced IL-6 production as well as observed for IL6 gene expression. These findings indicated transcription and translation cooperation under the used experimental conditions. Therefore, our findings suggest that administration of these antibiotics suppresses the host anti-inflammatory response.