10th Page

Question 1

What is an immunogen?

Answer 1

A substance capable of triggering an adaptive immune response by inducing formation of antibodies or sensitized T cells.

Immunogens are typically proteins with a molecular weight (MW) that is immunogenic.

Question 2

What is an antigen?

Answer 2

A substance that can combine with an antibody but may or may not invoke an immune response.

Antigens can be non-protein and are classified as antigenic.

Question 3

Increase MW, protein, immunogenic

Answer 3

Immunogen

Question 4

Decrease MW, protein, immunogenic

Answer 4

Antigen

Question 5

Relationship of host to immunogenic

Answer 5

The more different an antigen is from the host, the more immunogenic it is.

Question 6

What are the categories of antigens in relation to the host?

Answer 6

1. Autoantigen:
2. Alloantigen
3. Heterologous antigen
4. Heterophile antigen

Question 7

Autoantigen

Answer 7

same individual

Question 8

different individual, same species

Answer 8

Alloantigen

Question 9

Relationship of size to immunogenic

Answer 9

The greater the size, the more immunogenic.

Question 9

Ag in unrelated plants/animals but cross-reacting with other Abs

Answer 9

Heterophile antigen

Question 9

different individual, different species

Answer 9

Heterologous antigen

Question 10

Size requirement for immunogenicity?

Answer 10

The molecular weight (MW) should be at least 10,000 daltons

Question 11

second most immunogenic (less immunogenic than proteins)

Answer 11

Carbohydrates

Question 12

least or non-immunogenic alone

Answer 12

Lipids and nucleic acids

Question 13

What is an epitope?

Answer 13

An epitope is a specific part of an antigen that is recognized by the immune system.

Question 14

What is an epitope?

Answer 14

Part of an antigen/immunogen that binds to the paratope of the antibody.

Question 15

What is a paratope?

Answer 15

Part of an antibody that binds to the antigenic determinant site

Question 16

What are the types of epitopes?

Answer 16

The types of epitopes are linear and conformational.

Question 17

What is a linear epitope?

Answer 17

consists of sequential amino acids on a single polypeptide chain.

Question 18

What is a conformational epitope?

Answer 18

result from folding a polypeptide chain or chains, bringing non-sequential amino acids into close proximity.

Question 19

What is a hapten?

Answer 19

A hapten is a nonimmunogenic material that, when combined with a carrier, creates new antigenic determinants.

Question 20

What are adjuvants?

Answer 20

Adjuvants are substances added to vaccines to enhance immune adherence.

Question 21

Major Histocompatibility Complex (MHC)?

Answer 21

A tightly linked cluster of genes whose products play an important role in intercellular recognition and in discrimination between self and non-self.

Question 22

MHC is originally referred as

Answer 22

MHA / HLA.

Question 23

Where are the genes coding for MHC molecules found in humans?

Answer 23

On the short arm of chromosome 6 at band 21.

Question 24

What is the function of T MHC?

Answer 24

To bring or present antigens in the body to the surface cells for recognition of T cells.

Question 25

Where are MHC molecules synthesized/produced?

Answer 25

In the rough endoplasmic reticulum.

Question 26

What are the genetic loci for MHC Class I?

Answer 26

HLA - A, B, C.

Question 27

What are the genetic loci for MHC Class II?

Answer 27

HLA - DP, DQ, DP.

Question 28

What is the cell distribution for MHC Class I?

Answer 28

Found in all nucleated cells.

Question 29

What is the cell distribution for MHC Class II?

Answer 29

Limited to antigen-presenting cells (APCs).

Question 30

What is the chain structure of MHC Class I?

Answer 30

Contains an alpha chain (2) and a beta microglobulin (1).

Question 31

What is the chain structure of MHC Class II?

Answer 31

Contains two beta chains (2). Alpha and Beta

Question 32

What is the size of peptides bound by MHC Class I?

Answer 32

8 to 11 amino acids.

Question 33

What is the size of peptides bound by MHC Class II?

Answer 33

13 to 18 amino acids.

Question 34

What is the nature of the peptide binding cleft for MHC Class I?

Answer 34

Closed at both ends.

Question 35

What is the nature of the peptide binding cleft for MHC Class II?

Answer 35

Open at both ends.

Question 36

To whom does MHC Class I present antigens?

Answer 36

CD8

Question 37

To whom does MHC Class II present antigens?

Answer 37

CD4

Question 38

What type of antigen presentation does MHC Class I use?

Answer 38

Endogenous pathway.

Question 39

What type of antigen presentation does MHC Class II use?

Answer 39

Exogenous pathway.

Question 40

What degrades endogenous antigen within the cytosol?

Answer 40

proteasome

Question 41

How are peptides transported into the endoplasmic reticulum?

Answer 41

TAP (transporter associated with antigen processing).

Question 42

What does the alpha chain of class I MHC bind to?

Answer 42

beta microglobulin.

Question 43

What does the alpha chain of class I MHC bind?

Answer 43

peptide

Question 44

Where is the peptide-class I MHC transported?

Answer 44

Golgi complex and then to the cell surface.

Question 45

To which T cell does class I MHC peptide bind?

Answer 45

CD8+ T cell.

Question 46

What does class II MHC bind to block endogenous antigen binding?

Answer 46

invariant chain

Question 47

What happens to the MHC complex after binding the invariant chain?

Answer 47

goes through the Golgi complex.

Question 48

What is left after the invariant chain is degraded?

Answer 48

CLIP (class II invariant chain peptide) fragment.

Question 49

How is exogenous antigen processed?

Answer 49

taken in, degraded, and routed to intracellular vesicle.

Question 50

What replaces the CLIP fragment?

Answer 50

antigenic peptide.

Question 51

Where is the class II MHC antigenic peptide transported?

Answer 51

cell surface.

Question 52

To which T cell does class II MHC peptide complex bind?

Answer 52

CD4+ T cell.