Key Summary of Pulmonary Surfactant Protein A (SP-A):

Molecular Structure

• Collectin protein family member
• Two gene variants (SP-AI and SP-A2)
• Octadecameric bouquet-like structure

Lung Surfactant Functions

• Reduces surface tension
• Prevents alveoli collapse
• Manages surfactant balance
• Supports air sac stability

Immunomodulatory Properties

• Recognizes pathogen-associated patterns
• Enhances pathogen clearance
• Regulates immune cell activities
• Controls inflammatory responses

Pathological Implications

• Critical in respiratory distress syndrome
• Impacts lung infection responses
• Associated with asthma and COPD
• Genetic variations linked to respiratory diseases

Biosynthesis

• Produced in alveolar type II and Club cells
• Regulated by developmental and inflammatory factors
• Involves post-translational modifications