Deck 2: Nature of Antigens and the Major Histocompatibility Complex

Question 1

Which of the following is a characteristic of MHC-DR,MHC-DP,and MHC-DQ molecules?

A) Antigen receptors on all lymphocytes
B) Antigen receptors on T lymphocytes
C) Surface alloantigens on liver and kidney cells
D) Expressed co-dominantly (maternal and paternal)

Answer 1

Expressed co-dominantly (maternal and paternal)

Question 2

Which of the following would be the most effective immunogen?

A) One that is genetically foreign and has a single epitope
B) One with a molecular weight of less than 10,000 Da
C) One with multiple epitopes with many specificities
D) One with multiple epitopes with a single repeated specificity

Answer 2

One with multiple epitopes with many specificities

Question 3

Antigens found in different species that trigger a similar antibody response are called:

A) heterophile antigens.
B) haptens.
C) alloantigens.
D) autoantigens.

Answer 3

heterophile antigens.

Question 4

A 50-kDa protein from a bacterial cell that has numerous different epitopes would be called:

A) a hapten but not an antigen.
B) a hapten and an antigen.
C) an antigen but not an immunogen.
D) an immunogen and an antigen.

Question 5

A processed antigen first encounters and binds to MHC class II molecules in the:

A) nucleus.
B) endoplasmic reticulum.
C) endosomal compartment.
D) membrane surface.

Question 6

Each class II MHC molecule has specificity for:

A) any endogenous peptide.
B) related peptides that share a similar peptide sequence.
C) one very specific peptide sequence.
D) native, conformational epitopes.

Question 7

A macromolecule that is capable of eliciting an immune response in an immunocompetent host is called:

A) an antigen.
B) an antibody.
C) a hapten.
D) an acute-phase reactant.

Question 8

Endogenous peptides binding to MHC-A,MHC-B,or MHC-C molecules on the surface of hepatocytes are critical for the response by:

A) B lymphocytes.
B) T helper cells.
C) cytotoxic T cells.
D) macrophages.

Question 9

Which of the following is likely to be the most immunogenic?

A) A lipid with a molecular weight of 50,000 Da
B) A polysaccharide with a molecular weight of 40,000 Da
C) A protein with a molecular weight of 45,000 Da
D) A nucleic acid with a molecular weight of 60,000 Da

Question 10

Class II molecules bind to what kind of peptides?

A) Native peptides
B) Processed exogenous
C) Processed endogenous
D) Any of the above

Question 11

Which of the following is NOT a characteristic shared by class I and class II MHC molecules?

A) Expressed co-dominantly
B) Involved in antigen recognition
C) Members of the immunoglobulin superfamily
D) Expressed constitutively on all nucleated cells

Question 12

A processed antigen first encounters and binds to class I MHC molecules in the:

A) nucleus.
B) endoplasmic reticulum.
C) endosomal compartment.
D) membrane surface.

Question 13

The purpose of the invariant chain is to block the peptide-binding site of:

A) antibody molecules.
B) class II MHC molecules.
C) class I MHC molecules.
D) T-cell receptors.

Question 14

An antigenic determinant is also called:

A) an immunogen.
B) an epitope.
C) an antibody.
D) a polysaccharide.

Question 15

Antigen recognition by CD4-positive T cells requires:

A) class I MHC molecules.
B) class II MHC molecules.
C) class III MHC molecules.
D) no MHC molecules.

Question 16

Which of the following molecules is the best immunogen?

A) Protein
B) Polysaccharide
C) Nucleic acid
D) Lipid

Question 17

MHC molecules containing beta-2-microglobulin:

A) contain alpha and beta transmembrane polypeptides.
B) participate in the activation of CD4 T cells.
C) are determined by MHC-A, MHC-B, and MHC-C genes.
D) are determined by MHC-DR genes.

Question 18

Which of the following is a low-molecular-weight molecule that has one binding site for an antibody?

A) Antigen
B) Hapten
C) Immunogen
D) Adjuvant

Question 19

The ability to respond to antigen depends on which of the following factors?

A) Age
B) Proper nutrition
C) Genetic predisposition
D) All of the above

Question 20

The term "human leukocyte antigen" is synonymous with:

A) allele.
B) haplotype.
C) major histocompatibility complex.
D) chromosome.

Question 21

The inheritance of certain MHC antigens can result in which of the following?

A) Increased resistance to certain infectious organisms
B) Predisposition to particular autoimmune diseases
C) Diminished immune responses to particular antigens
D) All of the above

Question 22

Which option best describes a finding of Landsteiner's study of haptens?

A) Similar haptens trigger the same antibody response.
B) Spatial configuration is recognized by antibody.
C) Small chemical changes to a hapten do not affect antibody response.
D) A hapten can react with many different antibodies.

Question 23

Characteristics of heterophile antigens include which of the following?

A) Found in unrelated plants or animals but cross-react with the same antibody
B) One's own self-antigens
C) Any antigens used for immunization
D) All of the above

Question 24

The antigens that bind MHC class II antigens are first "processed" by:

A) the proteasome.
B) the endoplasmic reticulum.
C) transporters associated with antigen processing.
D) enzymes in the endosome.

Question 25

Characteristics of MHC class II molecules include which of the following?

A) Interact with CD8+ T cells
B) Have an alpha chain and beta-2 microglobulin
C) Have alpha and beta chains of approximately equal size
D) Combine with antigen made inside the cell

Question 26

A substance that is too small to stimulate antibody production by itself unless it is attached to a larger carrier molecule is called:

A) an autoantigen.
B) a cross-reacting antigen.
C) a hapten.
D) an alloantigen.

Question 27

If a mother is MHC A3A14/B5B15/Cw3Cw4 and her child is A3A9/B5B27/Cw4Cw7,which of the following men is the most likely candidate for the father?

A) A5A9/B5B27/Cw3Cw7
B) A9A11/B15B21/Cw1Cw4
C) A4A15/B2B27/Cw1Cw5
D) A5A9/B17B27/Cw3Cw5

Question 28

T cells are capable of recognizing:

A) conformational epitopes.
B) native (nondegraded) peptides.
C) degraded peptides.
D) haptens.

Question 29

MHC class I protein is found on:

A) red blood cells.
B) all nucleated cells.
C) B cells and macrophages only.
D) stem cells only.

Question 30

Which of the following must be matched between donor and recipient as closely as possible to avoid rejection of a tissue transplant?

A) Haptens
B) MHC molecules
C) Transporters associated with antigen processing
D) Beta-2 microglobulins

Question 31

Which option best describes MHC class I antigens?

A) They are recognized by helper T cells.
B) They are found on all nucleated cells.
C) They combine with exogenous antigen.
D) They are coded for on chromosome 9.

Question 32

A bacterial antigen to which the human immune system responds would be classified as:

A) an autoantigen.
B) an alloantigen.
C) a heteroantigen.
D) a holoantigen.

Question 33

Aluminum salt in the hepatitis vaccine functions as:

A) a hapten.
B) an adjuvant.
C) an immunogen.
D) a carrier.

Question 34

MHC class I antigens are recognized by which of the following cells?

A) CD4+ T cells
B) CD8+ T cells
C) B cells
D) Macrophages

Question 35

Naturally occurring anti-A and anti-B antibodies are thought to be the result of exposure to which of the following?

A) Heterophile antigens
B) Haptens
C) Alloantigens
D) Autoantigens

Question 36

A determinant site on an antigen that is produced by the folding of the primary chain is known as a:

A) conformational epitope.
B) linear epitope.
C) hapten.
D) monovalent epitope.

Question 37

A substance used to enhance antibody formation is called:

A) a hapten.
B) an adjuvant.
C) an immunogen.
D) a carrier.

Question 38

If a person has a reaction to poison ivy,this is caused by:

A) a hapten complexing with a tissue protein.
B) a heterophile antigen.
C) a T-independent antigen.
D) exposure to an adjuvant.

Question 39

All of the following are characteristics of a strong immunogen EXCEPT:

A) it is a large molecule.
B) it is foreign to the host.
C) it is a repeating polymer.
D) it is protein in nature.

Question 40

In antigen processing,the function of transporters associated with antigen-processing proteins is to:

A) help digest large proteins.
B) bind to MHC class II molecules in the endoplasmic reticulum.
C) transport digested proteins to MHC class I molecules.
D) recognize and digest exogenous protein.