Intro to Innate

Question 1

Innate Immunity

Answer 1

Protection against infections that relies on mechanisms that exist before infection, are capable of rapid responses to microbes, and react in essentially the same way to repeat infections

Question 2

Characteristics

Answer 2

Respond rapidly to the presence of microorganisms or foreign antigen

Not Ag specific, limited diversity

No immunologic memory

Stimulates the adaptive immune system

Question 3

Receptors of the Innate immune system

Answer 3

Toll-Like receptors
Mannose Receptors
NOD-like receptor

Question 4

Mechanical barriers of innate

Answer 4

Epithelial cells joined by tight junctions (skin, gut, lungs, eyes/nose/oral cavity)
Longitudinal flow of air or fluid, movement of mucus by cilia, tears, nasal cilia

Question 5

Chemical barriers of innate

Answer 5

Skin: FA, B defensins,lemellar bodies, cathelicidin
Gut: Low pH, enzymes (pepsidin) alpha defensins, regIII, Cathelicidin
Lungs: pulmonary surfactant, alpha defensins, cathelicidin
Eyes/Nose/Oral cavity: histatins, Beta defensins, enzymes in tears and saliva (lysozyme)

Question 6

Granulocytes

Answer 6

Eosinophils (1-3%)
Basophils (<1%) 
Mast cells 
=== release pharmacological mediators 
responsible for combating multi-cellular parasites 
play a major role in atopic disease

Question 7

Natural killer cells provide immunity against

Answer 7

intracellular infections, especially viral ones and cancer

Perforins and granzymes induce apoptosis in target cell
express variable combinations of activating and inhibiting receptors

Question 8

Neutrophils

Answer 8

migrate 7-10 hours in bode then home to tissue where they have 3d lifespan
neutrophils are released in response to infection from bone marrow in greater numbers == neutrophil leukocytosis

FIRST at site of inflammation

component of pus/abcess (pyogenic)

CD15+ CD16b+

Question 9

Neutrophils activated by

Answer 9

IL-1, TNF-alpha, IL-8

endothelial cells near infection site express selectin proteins that home neutrophils

Question 10

functions of macrophages

Answer 10

garbage collectors
Ag presenting cells
vicious killers

Question 11

Cell surface marker of monocytes/macrophages

Answer 11

`CD14 (TLR4) - recognizes and binds LPS

Question 12

Classical macrophages

Answer 12

induced by innate immunity and play a role in inflammation

TLR-Ligands, IFN-gamma

secrete ROS, NO, lysosomal enzymes to kill bacteria
secrete IL-1, IL-12, IL-23, chemokines to induce inflammation

Question 13

Alternative macrophages

Answer 13

induced by IL-4, IL-13 and play a role in tissue repair and control of inflammation
Secrete IL-10, TGF-Beta

Question 14

Activated macrophages have

Answer 14

increased phagocytic activity
increased ability to activate Th cells
higher levels of class II mHC/HLA on the cell surface

Question 15

Dendritic cells

Answer 15

professional APC
express high levels of Class II HLA/MHC and CD80
after capturing Ag in the tissues, migrate into blood or lymph and circulate to various lymphoid organs where they present Ag to T cells

Bridge innate and adaptive

Question 16

PAMPs

Answer 16

pattern associated molecular patterns - molecules/structures that are shared by various classes of microbes but are not present of self
recognize structures of microbes that are essential for survival and infectivity

LPS - Mannose residues, dsRNA

Question 17

DAMPs

Answer 17

damage associated molecular patterns
molecules released by stressed cells undergoing necrosis that act as endogenous danger signals to promote and exacerbate the inflammatory response

Question 18

Binding of PAMP ligands to ____ induces

Answer 18

PRRs induces intracellular signaling in the phagocytes leading to their activation

Question 19

toll-like receptors

Answer 19

several receptors specific for different microbial products

respond to exogenous and endogenous Ag

Question 20

TLR-1, -2 -6

Answer 20

Bacterial lipopeptides
(TLR-2 also specifically recognizes peptidoglycan)
EC

Question 21

TLR-4

Answer 21

LPS, EC

Question 22

TLR-5

Answer 22

Flagellin, EC

Question 23

TLR-3

Answer 23

dsRNA IC

Question 24

TLR-7. -8

Answer 24

ssRNA IC

Question 25

TLR-9

Answer 25

CpG DNA IC

Question 26

Binding of ligand to TLRs results in

Answer 26

phagocytosis and secretion of cytokines, increased ROS, increased cytoskeletal changes

Question 27

Chediak-Higashi syndrome

Answer 27

autosomal recessive - LYST gene defect
microtubule defect inhibits fusion
recurrent pyogenic infections - presence of giant granules in leukocytes

Question 28

Chronic granulomatous disease

Answer 28

inherited deficiency in NADPH oxidase
decreased production of ROS
chronic, recurrent infections with CATALASE-POSITIVE MICROORGANISMS
chronic inflammatory symptoms like gingivitis, enlarged lymph glands, tumor-like granuloma masses

Question 29

Type I IFN

Answer 29

directly inhibit viral replication
(alpha from leukocytes, beta from fibroblasts)
degrade mRNA = inhibition of protein synthesis
shuts down cellular protein synthesis

Question 30

Functions off IFN

Answer 30

Induce resistance to viral replication in all cells
Increase MHC class I expression and Ag presentation in all cells
Activate NK cells to kill virus infected cells

Question 31

NK functions

Answer 31

destroy bacteria, parasites, fungi, tumor cells, and virus infected cells

force cells to commit suicide
perforin proteins deliver granzyme B into target cell

fas ligand expressed on cell surface induces apoptosis in cells containing FAS receptor

provide cytokine support for macrophages