2.3

Question 1

Binding of an protein antigen by an antibody. This
model of a protein antigen bound to an antibody molecule shows
how the antigen-binding site can accommodate

Answer 1

soluble

macromolecules in their native (folded) conformation.

Question 2

Antibodies can also recognize (3)

Answer 2

lipids, nucleic acids,

and other types of molecules

Question 3

Small molecules like — are

antigenic for antibody recognition

Answer 3

digoxigenin

Question 4

dendritic cell response after antigen presentation

Answer 4

naive T cell activation: clonal expansion and differentiation into effector T cells

Question 5

macrophage response after antigen presentation

Answer 5

effector T cell activation: activation of macrophages (cell-mediated immunity)

Question 6

B cell response after antigen presentation

Answer 6

effector T cell activation: B cell activation and antibody production (humoral immunity)

Question 7

infected cell with microbes in cytoplasm:

Answer 7

killing of infected cells

Question 8

Role of Dendritic cells in antigen capture and presentation (2)

Answer 8

lymph node collects antigen from tissue

blood-borne antigens are captured by antigen presenting cells in the spleen

Question 9

feature: surface markers
classical dendritic cells: (2)
plasmacytoid dendritic cells: (3)

Answer 9

CD11c high
CD11b high

CD11c low
CD11b negative
B220 high

Question 10

feature: major location
classical dendritic cells:
plasmacytoid dendritic cells:

Answer 10

tissues

blood and tissues

Question 11

feature: expression of toll-like receptors
classical dendritic cells: (3)
plasmacytoid dendritic cells: (2)

Answer 11

TLRs 4, 5, 8 high

TLRs 7, 9 high

Question 12

feature: major cytokines produced
classical dendritic cells: (3)
plasmacytoid dendritic cells: (1)

Answer 12

TNF, IL6, IL12

type 1 interferons

Question 13

feature: postulated major functions
classical dendritic cells:
plasmacytoid dendritic cells:

Answer 13

introduction of T cell responses against most antigens

antiviral innate immunity and induction of T cell responses against viruses

Question 14

cell type: dendritic cells
expression of Class2 MHC:
ecpression of costimulators:
principal function:

Answer 14

constitutive, increases with maturation, increased by INFgamma

constitutive, increases with maturation, increased by TLR ligands, INFgamma, and T cells (CD40-CD40L interactions)

antigen presentation to naive T cells in the initiation of T cell responses to protein antigens (priming)

Question 15

naive T cell activation:

Answer 15

clonal expansion and differentiation into effector T cells

Question 16

Costimulators are important for antigen

presentation to by

Answer 16

dendritic cells

activate naïve T cells.

Question 17

Macrophages and B lymphocytes are also important —-

Answer 17

APCs

Question 18

class 1 MHC 
Polymorphic	regions:	 (2)

Answer 18

a1 and a2

Question 19

class 1 MHC:
Peptide-binding	cleft	for	
peptides	---	aa	long

Answer 19

8-9

Question 20

class 1 MHC:
---	binds	CD8	T	cell	co-receptor

Answer 20

a3

Question 21

---- T cells can only respond to antigen presented
by MHC class I molecules

Answer 21

CD8+

Question 22

class 2 MHC
Polymorphic	regions:	 (2)

Answer 22

a1 and b1

Question 23

class 2 MHC

Question 24

class 2 MHC:
(2) binds CD4 T cell
co-receptor

Answer 24

a2 and b2

Question 25

``` class 2 MHC: Peptide-binding cleft for peptides --- aa long ```

Answer 25

10-30

Question 26

``` --- T cells can only respond to antigen presented by MHC class II molecules ```

Answer 26

CD4+

Question 27

Class I and class II MHC genes are the most --- genes in the genome.

Answer 27

polymorphic

Question 28

``` The total number of HLA alleles in the human population is estimated to be about --- class I alleles and --- class II alleles. ```

Answer 28

10,000 | 3,000

Question 29

--- expression of alleles inherited from parents

Answer 29

Codominant

Question 30

feature: polymorphic genes: many different alleles are present in the population significance:

Answer 30

different individuals are able to present and respond to different microbial peptides ``` 10,000 class 1 alleles 3,000 class 2 alleles ```

Question 31

feature: codominant expression: both parental alleles of each MHC gene are expressed significance:

Answer 31

increases number of different MHC molecules that can present peptides to T cells

Question 32

``` feature: MHC expressing cell types: class 2 (dendritic cells, macrophages, B cells) significance: ```

Answer 32

CD4+ helper T lymphocytes interact with dendritic cells, B lymphocytes

Question 33

``` feature: MHC expressing cell types: class 1 (all nucleated cells) significance: ```

Answer 33

CD8+ CTLs can kill any type of virus infected cell

Question 34

feature: broad specificity significance:

Answer 34

many different peptides can bind to the same MHC molecule

Question 35

feature: each MHC molecule displays one peptide at a time significance:

Answer 35

each T cell responds to a single peptide bound to an MHC molecule

Question 36

feature: MHC molecules bind only peptides significance:

Answer 36

MHC restricted T cells respond mainly to protein antigens

Question 37

feature: peptides are acquired during intracellular assembly significance:

Answer 37

class 1 and class 2 MHC molecules display peptides from different cellular compartments

Question 38

feature: style surface expression of MHC molecule requires bound peptide significance:

Answer 38

only peptide loaded mhc molecules are expressed on the cell surface for recognition by T cells

Question 39

feature: very slow off rate significance:

Answer 39

mhc molecule displays bound peptide for long enough to be located by t cell

Question 40

CD8+ Cytotoxic T cells (CTLs) recognize

Answer 40

``` endogenous (cytosolic) antigen presented by MHC class I molecules on an infected cell ```

Question 41

Class I MHC pathway of processing of cytosolic antigens (5 steps)

Answer 41

production of proteins in the cytosol proteolytic degradation of proteins transport of peptides from cytosol to ER assembly of peptide class 1 complexes in ER surface expression of peptide class 1 complexes

Question 42

CD4+ Helper T cells recognize

Answer 42

``` exogenous antigen presented by MHC class II molecules on a professional antigen presenting cell (APC) ```

Question 43

Class II MHC pathway of processing internalized vesicular antigens (5 steps)

Answer 43

``` uptake of extracellular proteins into vesicular compartments of APC processing of internalized proteins in endosomal/ lysosomal vesicles biosynthesis and transport of class 2 mhc molecules to endosomes association of processed peptides with class 2 MHC molecules in vesicles expression of peptide mhc complexes on cell surfaces ```

Question 44

Class I MHC-restricted cross-presentation of microbial antigens from infected cells by dendritic cells (3)

Answer 44

antigen capture cross presentation T cell response

Question 45

T cell dependent effector functions (3)

Answer 45

macrophage activation: killing of phagocytosed microbe b cell antibody secretion: antibody binding to antigen killing of antigen expressing target cell