Time course of chemotaxis and chemokinesis of neutrophils following stimulation with IL-8 or FMLP

Abstract

Polymorphonuclear cells (PMNs) attend to inflammatory sites by chemotactic movement, caused by chemoattractants (CAs) like n-formyl-l-methionyl-l-leucyl-l-phenylalanine (FMLP) and interleukin-8 (IL-8). However, distinct but applicable assays for investigations of PMNs’ migration limit in vitro examination. We integrated CD15-bead-based isolation of PMNs with analysing their chemotaxis in a novel 3D-µ-Slide migration chamber. The PMNs were exposed to different concentrations of FMLP and IL-8 (1, 10 and 100 nM) and observed for 180 min in cell-physiological environment conditions. Moving PMNs’ percentage (median and interquartile range) decreased from 62% (27%) to 36% (31%) without CA, from 88% (30%) to 22% (26%) for 1 nM IL-8, from 70% (22%) to 28% (13%) for 100 nM IL-8, from 30% (23%) to 18% (46%) for 1 nM FMLP and from 76% (20%) to 28% (13%) for 100 nM FMLP. Centres of cell movement turned towards the CAs (negative values) within a single 30-min observation period: 5.37 µm (16.82 µm) without CA, −181.37 µm (132.18 µm) with 10 nM and −239.34 µm (152.19 µm) with 100 nM IL-8; −116.2 µm (69.07 µm) with 10 nM and −71.59 µm (98.58 µm) with 100 nM FMLP. FMLP and IL-8 ensure chemotaxis without increase of chemokinesis. 3D-µ-Slide chemotaxis chambers facilitate time course analyses of PMNs’ migration in stable conditions over a long time with concise distinction of chemotaxis and chemokinesis.