Sepsis-induced impairment of neutrophil chemotaxis on a microfluidic chip

• Neutrophil chemotaxis could be used as a diagnostic index of septic severity and an effective means for septic treatment and prognosis.
• Neutrophil chemotaxis in sepsis was significantly reduced as compared to healthy individuals.
• We speculated that impaired neutrophil chemotaxis in sepsis was probably mediated by the TLR2-CXCR2 pathway.

This study aimed to design a microfluidic chip to measure neutrophil chemotaxis, which is a convenient assay to assess the severity and prognosis of sepsis, and to study the mechanisms involved in the variation of neutrophil chemotaxis. Neutrophil chemotaxis was investigated in this microfluidic device by measuring the migration speed of neutrophils following the LPS concentration gradient stimulus. Neutrophils of 32 sepsis patients were divided into three groups according to the seriousness of physician-diagnosed sepsis, and 12 healthy individuals served as controls. Statistical significance was set at an alpha value of P < 0.05. Neutrophil chemotaxis was significantly decreased following the seriousness of sepsis. By contrast, in septic neutrophils, the expression of TLR2 was significantly increased, whereas the expression of CXCR2 was significantly decreased. Neutrophil chemotaxis in sepsis was significantly reduced as compared to healthy individuals. We speculated that impaired neutrophil chemotaxis in sepsis was probably mediated by the TLR2-CXCR2 pathway.