Unit One Innate Immunity Flashcards
What is the immediate response to infection
Innate immunity
What are the physical nad chemical barriers
Skin and mucosal epithelium
Commensal microorganisms colonize what
Skin and mucosa
Do babies have commensal population
No not initially
The gut has what type of relationship for commensal
Symbiotic
Extracellular infections are subject to
Soluble secreted molecules of the immune system such as antibodies
Intracellular infections are fought off how
Infected cell has to be sacrificed
Where is compliment made
Liver
What is complement
Soluble proteins used as a defense mechanism
Complement is found where
In lymphatics and blood
How does complement work
Coats the surface of bacteria or virus to make easier to phagocytosis
Some complement proteins are what type of enzyme
Proteases
Compliment circulates in inactive forms called
Zymogen
What triggers compliment activation
Infection which causes a cascade of enzymatic reactions
The cascade of complement activates what
Proteases
When complement is activated what happens with C3
C3 is cleaved into C3a and C3b
What occurs during compliment fixation
C3b binds to pathogen surface
What occurs during complement organization
C3b organizes other complement proteins
What occurs during complement calling effector cells
C3a calls macrophages
When C3b is activated, what is exposed and is targeted by water to allow tight fixation to pathogen surface
Thioester bond
What are the three pathways of complement activation
Alternative pathway, lectin pathway, classical pathway
What complement pathway works at the start of an infection
Alternative
What complement pathway takes days and is induced by innate immunity
Lectin pathway
What complement pathway requires binding of antibody or a specialized protein to pathogen surface
Classical
What is complement pathway cleaves and activates Cb3
C3 convertases
C3b can also bind to what to cause cleavage by factor D
Factor B
What is the alternative C3 convertase
C3bBb
C3bBb creates more what
C3b and causes more activation
What are complement control proteins
Plasma proteins that interact with C3b on human and microbial cell surfaces that prevent complement fixation on human cells