Page 118 - MNU microbiology theoritical 2025

General Microbiology & Immunology (PM 401) Second level Semester 4 2024/2025

B) The Lectin Pathway

• Antibody-independent pathway

• Activated by mannose-binding lectin (MBL(to mannose residues on

foreign surface

• Binding activates MASP-1 and MASP-2 (MBL associated serine

proteases) that cleave and activate C4 and C2

• Cleaved C4 and C2 generate C3 convertases

• Converges with the classical pathway at activation of C3

General Microbiology & Immunology (PM 401) theoretical handbook Page 107