C1, MBL, Ficolin Flashcards
What do these molecules have in common?
Three homologous Hexameric proteins that can all initiate complement activation
C1q binds
to Fc regions of IgM
MBL binds to
mannose or fucose on the surface of microbes and activates MASP-1 and MASP-2 asspcoated with mannose binding lectin
Ficolin binds to
N-acetylglucosamine on mircobes, activates MASP-1 and MASP-2
Ficolins are
plasma proteins; structurally similar to collectins, but possess a fibrinogen carb-recognition domain
humoral molecules of the innate system
initiate the lectin PW
Ficolins ligands
n-acetylglucosamine and lipoteichoic acid
Collectins
trimeric proteins with lectin head
soluble effector molecules in innate immunity: MBL and pulmonary surfacants SP-A and SP-D
MBL and SP-A and SP-D
Collectins
MBL binds carbs (terminal mannose, fucose) and enhance phagocytosis
SPA and SPD have lipophilic properties: main function is maintain lungs ability to expand and mediate innate immune response: initiate alveolar macrophages; directly inhibit bacterial growth; activate macs
SPA and SPD (From memory)
surfacant proteins
possess lipophilic abilities, main function is lung function, opsonize, attract macs, directly inhibit bacterial growth
MBL
MBL binds carbs (terminal mannose, fucose) and enhance phagocytosis
Explain “ficolins” are the humoral molecules of the innate system
- involved in opsonin-dependent phagocytosis: involved in limiting infection, and concurrently helping to initiate clonal expansion of the adaptive immune system
SP-A and SP-D
collectins with lipophilic properties
main function is lung function, but can act as opsonins and facilitate phagocytosis by alveolar macs
can also directly inhibit bacterial growth, or directly activate macrs
MBL binds to ___ and initiates ____ pathway
Ficolin binds to ___ and initiates _____ pathway
MBL binds to fucose or mannose and initiates the lectin PW through MASPs
Ficolin binds to n-acetylglucosamine and lipotechoic acid and initiates the lectin PW through MASPs
