Beyond the Role of CD55 as a Complement Component

Area of Science:

• Immunology
• Molecular Biology
• Pathology

Background:

• The complement system is a vital part of innate immunity, traditionally viewed as a non-specific defense against pathogens.
• Decay-accelerating factor (DAF or CD55) is a key regulator of complement activation.
• Emerging evidence highlights CD55's involvement in diverse pathological conditions beyond its role in pathogen clearance.

Purpose of the Study:

• To review the current understanding of Decay-accelerating factor (DAF or CD55) and its multifaceted roles.
• To elucidate the specific involvement of CD55 in various human diseases.
• To provide insights into potential therapeutic strategies targeting CD55 for disease diagnosis and treatment.

Main Methods:

• Literature review of existing research on CD55.
• Analysis of studies investigating CD55's function in immune regulation.
• Examination of clinical data linking CD55 to disease pathogenesis.

Main Results:

• CD55 deficiency can cause protein-losing enteropathy, leading to complement hyperactivation, malabsorption, and thrombosis.
• CD55 serves as a critical host receptor for malaria parasite infection.
• CD55's interaction with CD97 and its presence on various cells link it to cancer, malaria, protein-losing enteropathy, paroxysmal nocturnal hemoglobinuria, and autoimmune diseases.

Conclusions:

• CD55 plays a significant, often overlooked, role in regulating immune responses and maintaining physiological homeostasis.
• Dysregulation of CD55 is implicated in the pathogenesis of numerous diseases, presenting therapeutic opportunities.
• Further research into CD55's functions may lead to novel diagnostic and therapeutic interventions for associated conditions.