Etc. HDM Exam #1

Question 1

Anatomy of BCR

Answer 1

Like an Ab, including the Iga and Igb for signaling.

Question 2

Antomy of TCR

Answer 2

Two loops on each side. Ca, Cb, Va, Vb.

Includes CD3 and zetas for signaling.

Question 3

Papain cleavage gives:

Answer 3

3 total products. 2 Fabs and 1 Fc.

Question 4

Pepsin cleavage gives:

Answer 4

Fabs still conected by Fc degraded.

Question 5

CD28 function

Answer 5

Costimulation of T cells.

Question 6

Difference in secreted Ig and membrane bound Ig:

Answer 6

Secreted Ig is missing CH4 and has a secretory tail piece.

Question 7

The hinge is located between:

Answer 7

CH1 and CH2 domains

Question 8

IgA

Answer 8

Mucosal immunity.

Question 9

IgD

Answer 9

Naive B cell Ag receptor.

Question 10

IgE

Answer 10

Allergies, hypersensitivity.

Question 11

IgG

Answer 11

Opsonization, complement, crosses placenta.

Question 12

IgM

Answer 12

Naive B cell antigen receptor. 1st Ig produced by fetus. Largest. Complement activation.

Question 13

Avidity is:

And is dependent upon:

Answer 13

Strength of the Ag-Ab complex.

Affinity and valence of both Ag and Ab.

Question 14

What does CD8 bind to on the MHC I molecule:

Answer 14

B2 microglobin.

Question 15

CD8 is composed of:

Answer 15

One CD8a and one CD8b

Question 16

Ig expression in B cell development:

Answer 16

Pre-B cell: m heavy chain and surrogate light chain.
Immature B cell: membrane IgM
Mature B cell: Membrane IgM and IgD.

Question 17

BCR genes:

Answer 17

Ig H chain: 14
k chain: 2
lambda: 22

Question 18

TCR genes:

Answer 18

alpha chain: 14

beta chain: 7

Question 19

RAG1 and RAG 2 function

Answer 19

Introduce double stranded DNA breaks during somatic recombination.

Question 20

Overview of VDJ recombination:

Answer 20

Begins with H chain.
D, J segments chosen first.
V chosen next.
C last.
Ab tested for productive arrangement.
If arrangement is productive, maternal and paternal chain genes fight it out.

Question 21

Heavy chain in BCR is homologous to:

Answer 21

beta chain in TCR.

Question 22

There is no D gene in:

Answer 22

BOTH light chain Ab and alpha chain TCR.

Question 23

Junctional diversity

Answer 23

A way to further increase diversity in TCR/BCR.

Done via tDT.

Question 24

Pre-BCRs have:

Pre-TCRs have:

Answer 24

m heavy chains.

beta chains.

Question 25

Development and properties of B-1 cells

Answer 25

Fetal-liver derived.
Limited diversity as tDT is not expressed in the liver.
These cells are more innate-like than others.
Secrete IgM.

Question 26

Development and properties of B-2 cells:

Answer 26

Bone marrow derived, but relocate to the spleen.

Immature B-2 cells differentiate to FO B-2 cells and MZ B-2 cells.

Question 27

FO B-2 cells are:

Answer 27

Circulating B cells.

Question 28

MZ B-2 cells are:

Answer 28

Found in the spleen and lymph nodes.
Mostly localize to splenic marginal zone and respond to blood-borne Ags.
Similar to B-1 cells.

Question 29

Isotype switching

Answer 29

Occurs in B cells. Switching IgM to IgD, etc.

Question 30

CD3 complex is composed of:

Answer 30

One gamma, one delta, two epsilon, two zeta.

Question 31

Function of IFN-gamma

Answer 31

Produced by NK cells, NOT macrophages.
Stimulates MHC I/II and CD4/8.
Stimulates macrophages.
Called IFN-II.

Question 32

MHC I receptor anatomy

Answer 32

3 alpha and 1 B2 microglobin.

Question 33

MHC II receptor anatomy

Answer 33

2 alpha, 2 beta

Question 34

Anchor residues

Answer 34

Residues in the peptide that bind to the MHC

Question 35

Which MHC accomodate longer peptides?

Answer 35

MHC II due to the open binding cleft.

Question 36

Invariant chain, CLIP, and HLA-DM

Answer 36

Invariant chain blocks the MHC from binding a molecule. CLIP replaces the invariant chain. HLA-DM replaces CLIP with the Ag. This is in MHC II.

Question 37

HLA-DM

Answer 37

Replaces CLIP, stabilizes binding site, facilitates binding of Ag to the MHC II.

Question 38

TAP 1 and 2

Answer 38

Transports peptides to the ER from the cytosol.

Question 39

Cross presentation

Answer 39

Allows DCs to present Ags via the MHC I pathway.

Question 40

Immunodominant peptides

Answer 40

The peptide that binds to the MHC.

Dictated by the fact that humans have only 6 HLA genes.

Question 41

Polymorphism of the MHC

Answer 41

Some peoplee may not express MHC capable of binding any peptide derived from an Ag.

Question 42

gamma-delta T cells

Answer 42

Not well understood, but believed to have greater binding ability of things like phospholipids and HSPs.