Severe sepsis cytomix elicits inflammation in cerebrovascular endothelial cells and polymorphonuclear (PMN) leukocytes in vitro.

Abstract

The mechanisms of severe sepsis induced activation/dysfunction of the cerebrovascular endothelium are poorly understood. Our findings indicate that severe sepsis in humans results in up‐regulation of 8 (p<0.01; out of 41 measured) inflammation‐relevant analytes in the blood plasma. We employed Severe sepsis Cytomix (SS‐CM) consisting of 8 cytokines/chemokines (at the levels detected in Severe sepsis‐plasma) to assess activation/dysfunction of human‐derived cerebrovascular endothelial cells (hCMEC/D3; provided by Dr. P.O. Couraud, INSERM) and neutrophilic leukocytes (PMN). Various inflammation‐relevant endpoints were assessed. The obtained results indicate that stimulation of hCMEC/D3 with SS‐CM failed to induce ROS production, activation of NF‐κB, and increase in hCMEC/D3 permeability; however ICAM‐1 gene expression was up‐regulated in hCMEC/D3. The latter was accompanied by increased PMN adhesion to hCMEC/D3 under conditions of “flow” (0.7 dyn/cm2 shear stress). The most potent increase in PMN adhesion, however, occurred when both PMN and hCMEC/D3 were stimulated with SS‐CM. PMN adhesions was prevented by interfering (neutralizing MAb) with β‐2‐integrin function. Taken together our findings indicate that increased adhesive interaction between circulating PMN and cerebrovascular endothelium may contribute to BBB dysfunction in severe sepsis via β‐2‐integrin. HSFO NA‐6914, PSI 11–01)