In the context of complement activation, which pathway is activated by mannose-binding lectin (MBL) binding to microbial carbohydrate patterns?
- A Classical pathway
- B Lectin (MBL) pathway ✓
- C Alternative pathway
- D Terminal lytic pathway (MAC formation only)
Explanation
The lectin pathway (also called the MBL pathway) is activated when mannose-binding lectin or ficolins bind carbohydrate patterns (mannose, N-acetylglucosamine) on microbial surfaces, subsequently activating MASP-1 and MASP-2 serine proteases that cleave C4 and C2, generating the same C3 convertase as the classical pathway. It is distinct from both classical (activated by IgM/IgG-antigen complexes via C1q) and alternative pathways (spontaneous C3 hydrolysis, amplified by microbial surfaces). MBL deficiency increases susceptibility to recurrent infections in early childhood.
Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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