Innate Immunity

Question 0

What are biochemical components of system?

Answer 0

Complement

Type 1 interferons (alpha and beta)

Question 1

What are cellular components of system?

Answer 1

Neutrophils
Macs
Nk cells
Eosinophils
Basophils 
Mast cells

Question 2

What activates TLR 1 2 or 6?

Answer 2

Bacterial peptideglycan
Lipoprotein
Lipotechnoic acid

Question 3

What activates TLR4?

Answer 3

Gram neg bacteria Lps
Fungal mannans
Viral envelop proteins

Question 4

What activates TLR5?

Answer 4

Bacterial flagellin

Question 5

What are the downstream effects of TLR activation?

Answer 5

Activates adaptor proteins and protein kinases
Then act. Transcription factors - nfkb or irf3
Then leads to gene transcription
Which expresses inflammatory cytokines (Tnf, IL-1 and 12)
Chemokines (IL8 MCP-1 RANTES)
E selection which is endothelial adhesion molecule
Costim molecule CD80/86
Antiviral cytokines IFN-a/b

Question 6

Describe alternative pathway of complement

Answer 6

Activated by c3 binding to PAMP

Question 7

Describe classical pathway of complement

Answer 7

IgM or IgG bins to antigen

Question 8

What occurs upon initiation of complement system?

Answer 8

C3 cleaves to c3a and c3b

C3a responsible for inflammation also leads to mast cell degranulation
C3b responsible for opsonization and phagocytosis and leads to cleavage of c5

Question 9

Describe the lectin pathway of complement

Answer 9

Mannose binding lectin (soluble PRR) in serum binds to mannose residues on microbes

Question 10

What does mast cell degranulation achieve?

Answer 10

Releases histamine which increase vascular permeability and vasodilates.

Question 11

What occurs upon cleavage of c5?

Answer 11

C5 cleaves to c5a and c5b

C5a leads to mast cell degranulation and attracts neutrophils (acts as chemokine)
C5b activates c6-9 to create MAC (membrane attack complex) leading to cell lysis
c9 creates the pore that lyses the cell

Question 12

what is C3b?

Answer 12

an opsonin

Question 13

what is C3a?

Answer 13

induces inflammation by inducing mast cell degranulation

Question 14

What does C5b do?

Answer 14

binds to microbe membranes inducing c6-9 to bind and create a pore

Question 15

What is the function of c5a?

Answer 15

induce degranulation of mast cells to cause inflammation

chemotatic for neutrophils

Question 16

What is MAC?

Answer 16

membrane attack complex

its c6-9

Question 17

What is interferon?

Answer 17

cytokine (in this case alpha or beta)
produced due to intracellular PRRs and travels to neighboring cells
stimulates neighboring cells to turn on genes for antiviral proteins for cell to make changes to protect itself

Question 18

What enhances phagocytosis?

Answer 18

opsonins - c3b

IgG binds to Fc receptors on phagocytes

Question 19

What enzymes are on the membrane of phagolysosome?

Answer 19

iNOS
Phagocyte (NADPH) oxidase

these make NO and ROS (OH-, peroxide)

Question 20

What else do Macrophages do other then phagocytosis?

Answer 20

release cytokines for inflammation and to enhance adaptive immunity - cytokines
participate in wounding healing and tissue remodeling- FGF, angiogenic factors

Question 21

What are the functions of NK cells?

Answer 21

recognize infected cells
releases Perforin and grazymes if cell does not have MHC I (which all normal cells have)
if cell does not have MHC I, then killing is not inhibited and the NK releases its cytolytic mediators

Question 22

What stimulates endothelial cells to put up stop signs for neutrophils to infiltrate tissues?

Answer 22

Mast cell stimulate endothelial to put up stop signs