L3- Innate Immunity

Question 1

What is the innate system?

Answer 1

Non-adaptive host defense against pathogens

Question 2

What are phagocytes?

Answer 2

Leukocytes that recognize, ingest, and kill invaders

Question 3

Which cell si normally the first cell to encounter a pathogen?

Answer 3

MAcrophage

Question 4

What is the most abundant WBC in circulation?

Answer 4

NEutrophils

Question 5

Are macrophages or neutrophils uusally found in normal tissues?

Answer 5

macrophages

Question 6

Which is longer lived, macrophages or neutrophils?

Answer 6

Macrophages

Question 7

What is opsonization?

Answer 7

coating particles with molecules to enhance recognition by phagocytes

Question 8

How can the adaptive and innate immune systems opsonize pathogens?

Answer 8

Adaptive: antibodies
Innate: complement

Question 9

What are used by phagocytes to detect cells for phagocytosis?

Answer 9

PRRs to detect PAMPs on pathogens (TLRs, CLR, RLRs, NLRs,)

Question 10

What are the 3 key events in inflammation?

Answer 10

Altered blood flow
Inc vascular permeability
Infiltration of white blood cells into affected area

Question 11

What are the hallmarks of inflammation?

Answer 11

redness, swelling heat, pain

rubor, dolor, calor, tumor

Question 12

In what order do the following arive to an affected area for inflammation?
macrophages
neutrophils
lymphocytes

Answer 12

neutrophils, then macrophages, then lymphocytes

Question 13

What does the recognition of PAMPs/DAMPs lead to?

Answer 13

increased secretion of proinflammatory cytokines and antimicrobial proteins

Question 14

What does the recognition of PAMPs/DAMPs lead to?

Answer 14

increased secretion of proinflammatory cytokines and antimicrobial proteins

Question 15

What are some typical PAMPs?

Answer 15

Mannose containing structures
Lipids in lipopolysaccharids
Viral/Bacterial nucleic acids

Question 16

What kind of pathogens do each PRRs act towards?

Answer 16

TLR: EC pathogen (bacterial)
CLR: sugar molecules not seen in host (fungi, bacterial)
NLR: conserve molecules of virus/bacteria in cells
RLR: recognize RNR molecules (viral)

Question 17

What is the most important cell in the immune ssytem? why?

Answer 17

DCs. They act as gateway from innate to adaptive response

Question 18

What kind of ligand does TLR-4 bind?

Answer 18

LPS

Question 19

What is the common path for pro-inflammatory activation in TLR activation?

Answer 19

NK-kB -> leads to activation of genes encoding proinflammatory cytokines

Question 20

What happens when the TLR is missing or incorrrectly activated?

Answer 20

Pathogen not sense and get uncontrolled replication of pathogen (no innate imunity )

Question 21

What do deficiencies in MyD88/IRAK4 lead to?

Answer 21

Pts are more prone to bacterial infections

More severe than defective TLR-4 persay since this is downstream of all TLRs -> make them all useless

Question 22

What are natural killer cells?

Answer 22

Small porption of lymphocytes that circulate in blood to destroy virally infected cells and cancer cells

Question 23

What are NKT cells?

Answer 23

Subset of T cells that are part of innate immun system. Has TCRs that target glycolipid antigens

Question 24

What do NKT cells do?

Answer 24

Provide immediate help for adaptive immune system via cytokines

Question 25

What do NKT cells recognize lipids in context of with their TCRs?

Answer 25

Recoginze in context of CD1 molecules | INNATE IMMUNE CELL

Question 26

How do NK cells kill their targets?

Answer 26

Direct killing of infected cells OR ADCC (Antibody dependent cytotoxicity): interface with adaptive via Fc receptors recognizing constant regions of immunoglobulins to destroy the virally infected cell coated with antibody)

Question 27

What are γδ lymphocytes?

Answer 27

REcognize small molecule phosphoantigens not seen in mammals. Similar to CD4+ T cells

Question 28

Where do you find γδ lymphocytes?

Answer 28

host-environmental interfaces (respiratory, GI submucosa)

Question 29

What makes up the primary lymphoid tissue?

Answer 29

Bone marrow and thymus

Question 30

What makes up the secondary lymphoid tissue?

Answer 30

Lymph nodes, spleen

Question 31

What are regional/specialized lymphoid tissue?

Answer 31

Submucosal lymphoid tissue (respiratory and GI)

Question 32

How is innate memory or trained memory established?

Answer 32

No gene rearrangements or somatic hypermutations. EPIGENETIC!

Question 33

Give a sequential overview of dealing with infection from innate to immune

Answer 33

Bacteria invade -> phagocytosis by Macrophage via PRRs -> increase chemokine & cytokine -> increase neutrophils and other innate cells to area -> DCs come and uptake bacteria -> mature DCs via PRRS -> go to lymph node --> present to T/Bcells -> increase T cell differentiation and production of antibodies -> leave lymph node to site of infection-> clear infection