A 7

Question 1

how does mycobacterium tuberculosis live within a phagocyte and not die?

Answer 1

it prevents the fusion of phagosome with the lysosome.

Question 2

many bacteria that can live within a phagocyte survive because they escape into the cytoplasm. Name 4 common bacteria that do this?

Answer 2

1) salmonella
2) legionella
3) Francisella
4) Listeria
(note: viruses can also do this)

Question 3

how does salmonella make you sick?

Answer 3

It gets phagocytosed but does not die because it escapes into the cytoplasm. It can live within all phagocytic cells and B cells.

Question 4

what is the difference between a NOD like receptor and a TOLL like receptor?

Answer 4

NOD receptors are free floating in the cytoplasm looking for foreign anigen.
TOLL receptors are looking for pathogen on the outside surface as well as inside vesicles.

Question 5

What do NOD’s detect?

Answer 5

NOD’s detect peptidoglycan (NAG and NAM) of bacterial cell walls.

Question 6

What does NOD1 do? Which bacteria would this include?

Answer 6

senses gamma glutamyl diamino group. (Bridge between NAM molecules)
salmonella and listeria.

Question 7

what does NOD2 do?

Answer 7

senses muramyl dipeptide (NAM)

Question 8

The LRR and CARD (Caspase attracting) domains make up which molecules?

Answer 8

NOD like receptors (which also have a NOD domain of course)

Question 9

Once NOD binds, it dimerizes and binds to _______This then leads to the activation of ______ which ultimately makes _________ for cytokine production?

Answer 9

1) RIP2K
2) TAK1
3) NFkB

Question 10

What is NLR-P3 (NALP3)?

Answer 10

It senses celluluar damage or stress.

Question 11

What forms when NALP3 is bound to the protease caspase1?

Answer 11

inflammasomes are released. Two mentioned were IL 1 and IL18

Question 12

what is the function of caspase 1?

Answer 12

cleaving of pro-inflammatory cytokines (activate)
DNA cleavage
Induce cell death.

Question 13

what happens during NALP3 (NLRP3) activation?

Answer 13

1) cell distress
2) NALP3 recruits PYCARD/Caspase complex
3) activation of caspase 1 through interaction.
4) Caspase 1 cleaves pro-inflammatory
5) release of inflammatory cytokines (including IL 1 and IL 18) to cell surface and cell death.

Question 14

What is pyroptosis?

Answer 14

inflammation and cell death.

Question 15

what is the purpose of MHC?

Answer 15

1) to determine self from non-self (type 1)

2) determines the strength of adaptive immune response. (type 2)

Question 16

What are the two groups of Human leukocyte antigen (HLA) called? What chromosome is HLA found on?

Answer 16

1) MHC1
2) MHC 2
- chromosome 6 and invariant region of MHC 1 is on chrom. 15

Question 17

what are the three subtypes of Class 2 MHC? Which one has 2 copies of its B subunit?

Answer 17

Dp, Dq, Dr (within each subtype there are many alleles)

-Dr has two copies of its B subunit while the rest only have one

Question 18

what are the three subtypes of Class 1 MHC?

Answer 18

A,B,C (within each subtype there are many alleles)

Question 19

What is B2 microglobulin?

Answer 19

The second part of MHC class 1 molecules. They help with surface expression and stability.

Question 20

How are class 1 and class 2 molecules expressed in human cells?

Answer 20

codominantly, with 6 (class 1) alleles, and up to 25 (class 2) alleles.

Question 21

Class 1 MHC determines?

Answer 21

You from not you

Question 22

Class 2 MHC determines?

Answer 22

the strength of an immune response.

Question 23

which types of cells express MHC type 2?

Answer 23

dendritic cells, macrophages, B- cells, or any cell that presents.

Question 24

Which cells target the foreign MHC class 2 molecules?

Answer 24

The T-cells with CD 4 receptors to initiate the adaptive immune response.

Question 25

which MHC class binds to self and non-self peptides that are generally 8-10 AA’s long?

Answer 25

Class 1 MHC

Question 26

which MHC class binds to self and non-self peptides that are generally 15 AA’s long?

Answer 26

class 2 MHC

Question 27

Which cells target the foreign MHC class 1 molecules?

Answer 27

CD 8 T-cells to attack things like intracellular pathogens and donor transplants.

Question 28

How does MHC 1 become expressed on the cell surface?

Answer 28

1) calnexin bound to pre-MHC1 in E.R.
2) calnexin releases Pre-MHC1 once it binds B-microglobulin.
3) MHC 1binds TAP
3) TAP transports random peptide fragments into ER to become part of MHC 1 complex active site.
4) MHC complex is sent to cell surface for Identification. (NOTE: samples endogenously)

Question 29

How does MHC 2 become expressed on the cell surface?

Answer 29

1) Stuck to ER membrane with active site blocked by invariant chain.
2) Invariant chain cleaved off in acid endosome except part in cleft which is called Clip.
3) Endocytosed peptides are broken down and placed in same vesicle.
4) HLA-DM binds to MHC 2 complex displacing Clip.
5) foreign peptide binds to MHC 2
6) MHC with foreign antigen placed on membrane.

Question 30

What are the primary lymphiod tissues?

Answer 30

Thymus and bone marrow

Question 31

What are some examples of secondary lymphoid tissues?

Answer 31

Lymph nodes, spleen, liver, and MALT/GALT/SALT

Question 32

What are the subunit sizes for MHC Class 1 and Class 2? (The alpha and beta subunits)

Answer 32

• 43 K and 12 K respectively a and b

- 28 K and 32 K