C3b and factor H: key components of the complement system.

Area of Science:

• Immunology
• Molecular Biology
• Genetics

Background:

• The complement system, particularly C3 and factor H, plays a vital role in immune responses and self-tissue protection.
• C3 cleavage generates C3b, a key opsonin and central component for complement cascade amplification.
• Factor H regulates C3b activity to prevent damage to host cells and uncontrolled complement consumption.

Purpose of the Study:

• To elucidate the critical roles of C3 and factor H in complement pathways.
• To explore the consequences of defects in C3 and factor H on human health.
• To highlight the association of factor H dysfunction with specific diseases.

Main Methods:

• Review of complement pathway mechanisms.
• Analysis of clinical implications of C3 and factor H defects.
• Examination of genetic polymorphisms and disease associations.

Main Results:

• C3 defects impair microbial defense and increase autoimmune susceptibility.
• Factor H deficiency or N-terminal defects cause glomerulonephritis and complement depletion.
• Factor H C-terminal defects are linked to atypical hemolytic uremic syndrome.
• Factor H Y402H polymorphism is a major risk factor for age-related macular degeneration.

Conclusions:

• Dysregulation of the complement system, specifically C3 and factor H, underlies various pathologies.
• Understanding these defects is crucial for diagnosing complement-related diseases.
• Factor H-related diseases present new therapeutic targets for conditions like AMD and kidney diseases.