Effects of NOD1 and NOD2 agonists polymuramyl as well as NOD2 agonist glucosaminylmuramyldipeptide on phenotype of neutrophile granulocyte CD64-CD16+CD32+CD11b+, CD16+CD62L+CD63-, CD16+CD62L+CD63+ subsets

Abstract

Antimicrobial activity of neutrophilic granulocytes (NG) is based on effective recognition and elimination of microbial pathogens, as well as on complex intracellular signal transduction pathways interconnecting these processes. NG dysfunction leads to emergence of atypical infectious and inflammatory diseases recalcitrant to standard interventions, which requires new vector platforms aimed at restoring normal NG functioning and overcoming antibiotic resistance. Moreover, we emphasize about special interest paid to the NOD1 and NOD2 agonist polymuramyl and NOD2 agonist glucosaminylmuramyldipeptide. Objective of the study was to compare effects triggered by NOD1 and NOD2 agonist polymuramyl and NOD2 agonist glucosaminylmuramyldipeptide on phenotype of neutrophilic granulocyte subsets CD64- CD16+CD32+CD11b+, CD16+CD62L+CD63-, CD16+CD62L+CD63+ in the in vitro system. 64 samples of peripheral blood (PC) collected from 8 apparently healthy children (4 boys and 4 girls) aged 3 to 9 years were examined by flow cytometry (FC 500, Beckman Coulter, USA) assessing NG surface receptors CD64, CD16, CD32, CD11b, CD62L, CD63 with MonAb (Beckman Coulter International S. A., France) by analyzing NG number (%) expressing receptors examined, density of receptor expression measured as mean fluorescence intensity (MFI). For this, there were assessed intact peripheral blood NG from apparently healthy children (comparison group) as well as those exposed to polymuramyl (PM) (at concentration of 10-6 g/l) or glucosaminylmuramyl-dipeptide (GMDP) (at concentration of 10-6 g/l) for 60 minutes at 37 °С temperature. Comparative analysis of surface receptor expression was performed on CD64-CD16+CD32+CD11b+, CD16+CD62L+CD63- and CD16+CD62L+CD63+ NG subsets that suggested about positive transformation of activation parameters in circulating NG exposed to NOD1 and NOD2 agonist polymuramyl as well as NOD2 agonist glucosaminylmuramyldipeptide. At the same time, similar effects of varying intensity were revealed manifested as increased count of NG subsets CD16+CD62L+CD63+ bearing increased level of CD16 and reduced CD62L expression, as well as differences uncovered as significantly increased expression of surface membrane molecules CD16 and CD11b in CD64-CD16+CD32+CD11b+ NG subset from apparently healthy children exposed to polymuramyl as well as increased surface CD32 expression after incubation with GMDP.