TBL 1

Question 1

What does complement do?

Answer 1

Part of innate immune system
Opsonizes pathogen
Recruits phagocytes

Question 2

What are phagocytes?

Answer 2

Macrophages
PMNs (neutrophils)
Dendritic cells

Question 3

What do macrophages do?

Answer 3

They’re sentinels and refuse collectors

They seek and engulf

Question 4

What do neutrophils do?

Answer 4

Chemotax along gradients, engulf and kill
Major component of pus
Survive 6-12h

Question 5

How do macrophages/PMNs kill?

Answer 5

Complement opsonizes bacterium
Bacteria are phagocytosed
Macrophages membranes fuse to create vesicle and then phagosome
Lysosomes fuse with phagosome
Bacterium is degraded

Question 6

What do dendritic cells do?

Answer 6

Constant pinocytosis to sample surroundings
When it comes in contact with pathogen, migrates to local lymph node
Presents pathogen fragments to adaptive system
Bridge between innate and adaptive

Question 7

Define: cytokines

Answer 7

Secretory proteins that mediate immune cell development, maturation, level of activation, and life span

Bind to specific signal-receiving cells
Direct the lineage, localization, and effector functions on the recipient cell

Question 8

Define: interleukins

Answer 8

Subset of cytokines that generally function to communicate between leukocytes

Question 9

Define: chemokines

Answer 9

Small cytokines that function in leukocyte chemotaxis

Question 10

How are immunoglobulins arranged?

Answer 10

2 heavy chains (inside), 2 light chains
Variable end on tips where the antigen binding site is
Constant end determines Ig class (IgM, IgD, etc)

Question 11

What activates complement?

Answer 11

Antigen:antibody complexes
Lectin binding to pathogen surfaces

Collagen-like stalks serve as spring; serine professes activate when spring is deformed by lectin binding

Question 12

What is the “alternative” pathway for complement?

Answer 12

C3 convertase aqueous becomes c3 convertase cell-bound becomes c5 and then lyses

Question 13

What are the components of the “classical” pathway?
The lectin?
The alternative?

Answer 13

Classical: c1s, c4, c2
Lectin: MBL, MASP, C4, C2
Alternative: C3, B, D

Question 14

What are the steps of phagocytosis?

Answer 14

Pathogen enters clathrin coated pit
Clathrin is uncoated (ATP-dependent)
Lysosomes fuse
Pathogen is destroyed
Takes about 30 min to be destroyed

Question 15

What contributes to lysosomal killing mechanisms of phagocytes?

Answer 15

Acid hydrolases
Lysozyme (disrupts peptidoglycan)
Human beta defensins (cationically charged proteins that disrupt pathogen cell membranes)

Question 16

What are the reactive species in a macrophage?

Answer 16

Hypochlorite acid
NADH oxidase
reactive oxygen species

Question 17

What is chronic granulomatous disease?

Answer 17

Defect in NADPH oxidase

Leads to recurrent staph infections

Question 18

What are type I interferons?

Answer 18

Anti-viral cytokines
Activate NK cell killing
Increases MHC I
recruits other leukocytes
Resists viral replication

Question 19

What are toll-like receptors?

Answer 19

Sense bacteria, fungi, viruses, and Protozoa

Found on cell surface and endoscopes

Alert pro-Il, chemokines, interferons

Question 20

What is a NOD-like receptor?

Answer 20

Senses bacteria, viruses, and cell distress

Located in the cytoplasm

Pro il to il maturation

Activated by PAMPs and DAMPs

Question 21

What is a RIG-like receptor?

Answer 21

Senses viruses

Located in cytoplasm

Alarms interferons

Question 22

What does TLR-4 recognize?

Answer 22

LPS

Polymorphisms are related to link in risk of asthma, allergy, etc

Question 23

What do TLRs activate?

Answer 23

NFkB
MAPK
IRFs
These turn on interferons and pro inflammatory cytokines

Question 24

What are DAMPs?

Answer 24

Damage Associated Molecular Patterns

K+ efflux from the cell (necrosis)
Chromatin-associated proteins (outside of the nucleus)
Cellular DNA
Extracellular ATP

Question 25

How does the inflammasome work?

Answer 25

``` NLR recognizes PAMP/DAMP protein complex assembles Pro-Caspase-1 Caspase-1 ProIL1 IL1 ```

Question 26

What disease is NLR associated with?

Answer 26

Gout

Question 27

What is the common nexus in complement pathways?

Answer 27

C3

Question 28

What do NOD-1 and NOD-2 do?

Answer 28

Activate NFkB

Question 29

What is the structure of a t-cell receptor?

Answer 29

alpha chain and beta chain Variable region on top Constant region on bottom

Question 30

What holds the antigen-antibody complex together?

Answer 30

Electrostatic forces Hydrogen bonds Van der waals forces Hydrophobic forces

Question 31

When are IgM, G, D, A, E expressed?

Answer 31

``` G: antigen-activated B cells M: naive B cells D: naive B cells A: antigen-activated B cells E: antigen-activated B cells ```

Question 32

Define: affinity

Answer 32

Strength of binding at single site

Question 33

Define: avidity

Answer 33

Overall binding at multiple sites

Question 34

How do IgA combine?

Answer 34

Dimer

Question 35

How do IgM combine?

Answer 35

Pentameric

Question 36

What is ADCC?

Answer 36

Antibody dependent cell-mediated cytotoxicity Antibody binds antigen DC receptors on NK cells bind antibody Target cell is killed Cell apoptoses

Question 37

What does IgE do?

Answer 37

Sensitization of mast cells | Leads to rapid release of inflammatory mediators

Question 38

How does T cell gene rearrangement work?

Answer 38

V and J segments rearrange (variable gene segment and joining gene segment)

Question 39

What are the components of immunoglobulin loci?

Answer 39

Variable (V) Diversity (D) - found in heavy chain Joining (J) Constant (C) All are flanked by RSS (recombination signal sequences) - either 23 or 12 BP

Question 40

How many antibody specificities are there?

Answer 40

10^11

Question 41

Where do B cells develop?

Answer 41

``` Bone marrow (dev) Spleen and lymph nodes (maturation) ```

Question 42

How does the innate immune system recognize a pathogen?

Answer 42

It recognizes PAMPs (pathogen-associated molecular patterns)