Neutrophil recruitment in skin window chambers--activation by complement

Area of Science:

• Immunology
• Inflammation research

Background:

• Neutrophil recruitment is crucial in acute aseptic inflammation.
• The complement system's role in neutrophil migration requires further in vivo validation.

Purpose of the Study:

• To investigate the effect of activated complement on neutrophil accumulation in a human skin inflammation model.
• To correlate complement activation with chemotactic activity.

Main Methods:

• Utilized skin window chambers in 15 healthy volunteers to model neutrophil recruitment.
• Employed autologous plasma activated via the alternative pathway as an attractant.
• Assessed complement component C3 consumption and chemotactic activity using Boyden chambers.

Main Results:

• Activated complement significantly enhanced neutrophil accumulation in skin window chambers over 24 hours.
• Control chambers with balanced salt solution or non-activated plasma showed minimal cell counts.
• Complement activation led to C3 consumption and generated significant chemotactic activity.
• A strong positive correlation was observed between skin chamber responses and Boyden assay results.

Conclusions:

• The complement system, particularly C3 activation, stimulates neutrophil migration in simulated in vivo conditions.
• Findings validate complement's role in neutrophil recruitment during acute inflammation.
• This study extends previous animal model observations to humans.