Alternate and classical pathway components of complement in the normal cornea.

Area of Science:

• Immunology
• Ophthalmology
• Biochemistry

Background:

• Corneal inflammation may involve complement system activation via classical or alternate pathways.
• The presence of complement components in the healthy cornea is not fully understood.

Purpose of the Study:

• To investigate the presence of complement system components in the normal human cornea.
• To determine if the cornea contains elements for both classical and alternate complement pathway activation.

Main Methods:

• Direct immunofluorescence of human donor corneas using fluorescein-labeled antiserums.
• Elution of complement components from corneas using phosphate-buffered saline.
• Analysis of eluates using Ouchterlony plates and radial immunodiffusion.

Main Results:

• Complement component C1q was detected in the corneal periphery.
• Corneal eluates revealed the presence of C1q, C3, C4, C5, properdin, properdin factor B, and plasminogen.
• Concentrations of C3, C4, and C5 were estimated using radial immunodiffusion.

Conclusions:

• The normal human cornea possesses components necessary for both classical and alternate complement pathway activation.
• These findings suggest a potential role for complement in maintaining corneal homeostasis or mediating inflammatory responses.