In vitro interaction of hormone-conditioned neutrophils with commensal and uropathogenic <i>Escherichia coli biofilms</i>

Abstract

The aim of the work was to examine an interaction between neutrophils conditioned with chorionic gonadotropin, estriol, kisspeptin, leptin, ghrelin and commensal and uropathogenic Escherichia coli biofilms. Peripheral blood neutrophils isolated from healthy non-pregnant women in the first phase of the menstrual cycle (n = 8) were cultured in vitro for 1 hour together with hormones at concentration corresp onding to their level in the first and third trimester of pregnancy. An interaction of neutrophils with commensal E. coli TG1 and uropathogenic E. coli DL82 (UPEC) biofilms was assessed 1 hour later. The biofilm biomass, activity of myeloperoxidase and cathepsin G was measured spectrophotometrically on a microplate reader Synergy H1 (BioTec, USA). Neutrophils conditioned with chorionic gonadotropin (10; 100 IU/ml), estriol (2; 20 ng/ml) and leptin (10 ng/ml) were found to enhance their potential to destroy solely opsonized commensal E. coli biofilm, without affecting the UPEC biofilm. The biomass of non-opsonized biofilm of commensal E. coli TG1 decreased after interaction with neutrophils conditioned with estriol (2 ng/ml), kisspeptin (9.6 pM) and ghrelin (0.83 ng/ml). In contrast, non-opsonized UPEC biofilm was more destroyed by neutrophils exposed to low- vs. high-dose chorionic gonadotropin (10 IU/ml and 100 IU/ml, respectively) or control group. Myeloperoxidase secretion increased when UPEC interacted with neutrophils conditioned with estriol at concentration of 2 ng/ml. Comparing the two E. coli strains allowed to find that chorionic gonadotropin (10 IU/ml) and estriol (20 ng/ml) enhanced activity of neutrophil myeloperoxidase after interaction with UPEC biofilms to a greater extent than with E. coli TG1 biofilms. Estriol (20 ng/ml) and kisspeptin (9 pM) reduced activity of neutrophil cathepsin G after interaction with UPEC biofilms.