L3 & L4 Antigens and Major Histocompatibility Complex

c

Which of the following best describes an immunogen?

• a) Any substance capable of binding specifically with an antibody.

• b) A low molecular weight non-protein molecule.

• c) A macromolecule capable of triggering an adaptive immune response.

• d) A cross-reacting antigen that reacts with unrelated antibodies.

b

The capacity of an antigen to react specifically with the generated antibodies or sensitized T-cell receptors is known as:

• a) Immunogenicity

• b) Antigenicity

• c) Foreignness

• d) Degradability

c

3. What is the "Core Rule" regarding antigens and immunogens?

• a) All antigens are immunogens, but not all immunogens are antigens.

• b) All haptens are immunogens, but not all immunogens are haptens.

• c) All immunogens are antigens, but not all antigens are immunogens.

• d) Antigens and immunogens are entirely interchangeable terms.

b

A tiny molecule that cannot trigger an immune response on its own but becomes visible to the immune system when bound to a larger carrier protein is called a:

• a) Paratope

• b) Hapten

• c) Epitope

• d) Adjuvant

c

Which routes of administration are most effective for soluble antigens?

• a) Intravenous (IV) only

• b) Subcutaneous (SC) and Intravenous (IV)

• c) Subcutaneous (SC) and Intramuscular (IM)

• d) Intramuscular (IM) and Intravenous (IV)

d

According to the physical characteristics of immunogens, molecules generally become most effective at triggering a response when they reach what molecular weight?

• a) 1,000 Daltons

• b) 10,000 Daltons

• c) 50,000 Daltons

• d) 100,000 Daltons

b

Which of the following is considered an exception as a molecule that is small but still immunogenic?

• a) Carbon particles

• b) Insulin

• c) Growth Hormone (GH)

• d) Glycoproteins

c

Which chemical composition makes for the most immunogenic biomolecules due to high molecular weight and a large array of building blocks?

• a) Carbohydrates

• b) Lipids

• c) Proteins

• d) Nucleic Acids

b

Blood group antigens (ABO and Rh) induce an immune response primarily via their carbohydrate epitope. To which chemical class do they belong?

• a) Polysaccharides

• b) Glycoproteins

• c) Small Polypeptides

• d) Nucleic Acids

b

The basic surface recognition unit on an antigen that binds to an antibody or T-cell receptor is called the:

• a) Paratope

• b) Epitope

• c) Carrier

• d) Adjuvant

c

What type of epitope is formed when the folding of a polypeptide chain brings amino acid residues from different linear segments into close spatial proximity?

• a) Linear Epitope

• b) Sequential Epitope

• c) Conformational Epitope

• d) Accessible Epitope

a

The specific antigen-binding site on an antibody molecule that combines with an epitope is referred to as the:

• a) Paratope

• b) Hinge region

• c) Hapten

• d) Macrophage

c

A substance co-administered with an immunogen to enhance the overall immune response by increasing its effective size and prolonging its presence is a(n):

• a) Carrier

• b) Allergen

• c) Adjuvant

b

Antigens derived from genetically dissimilar members of the same species (e.g., in a kidney transplant) are called:

• a) Autoantigens

• b) Alloantigens

• c) Heteroantigens

• d) Heterophile Antigens

b

What term describes cross-reacting antigens that react with antibodies generated by an apparently unrelated antigen species?

• a) Heteroantigens

• b) Heterophile Antigens

• c) Autoantigens

• d) Complete Antigens

c

Soluble antigens that react with soluble antibodies to produce a visible precipitate are known as:

• a) Hemagglutinogens

• b) Agglutinogens

• c) Precipitinogens

• d) Anaphylactogens

b

On which chromosome are the genes coding for Major Histocompatibility Complex (MHC) molecules located?

• a) Chromosome 4

• b) Chromosome 6

• c) Chromosome 8

• d) Chromosome 12

b

Which of the following is NOT a component of the MHC Class I polypeptide structure?

• a) Heavy alpha chain

• b) Beta chain (28,000 Da)

• c) β2-microglobulin

c

Which domain of the MHC Class I molecule specifically reacts with and binds the CD8 co-receptor of cytotoxic T cells?

• a) a1 domain

• b) a2 domain

• c) a3 domain

• d) β2-microglobulin

b

Why is HLA typing generally NOT required for liver transplants?

• a) The liver relies strictly on innate immunity.

• b) MHC Class I expression is extremely low on liver hepatocytes.

• c) MHC Class II molecules are hyper-expressed on liver cells.

• d) The liver rapidly degrades heterophile antigens.

b

Which MHC class is structured as a heterodimer of an Alpha chain (33,000 Da) and a Beta chain (28,000 Da)?

• a) MHC Class I

• b) MHC Class II

• c) MHC Class III

• d) HLA-A and HLA-B loci

c

Which cell type is NOT categorized as a primary Antigen-Presenting Cell (APC) expressing MHC Class II?

• a) B cells

• b) Dendritic cells

• c) Neural cells

• d) Macrophages

c

Which MHC region contains genes for secreted soluble proteins such as classical complement pathway components (C2, C4a, C4b) and TNF-alpha?

• a) MHC Class I

• b) MHC Class II

• c) MHC Class III

• d) HLA-DR locus

c

In the Endogenous Pathway (MHC Class I), what structure is responsible for transporting peptides into the endoplasmic reticulum?

• a) Proteasome

• b) Endosome

• c) TAP (Transporter associated with Antigen Processing) channel

• d) Invariant chain

b

The Exogenous / Endocytic Pathway processes foreign materials utilizing which MHC class for presentation to CD4+ helper T cells?

• a) MHC Class I

• b) MHC Class II

• c) MHC Class III

• d) HLA-C locus

c

A set of MHC/HLA alleles located contiguously on a single chromosome that are inherited together from one parent is called a:

• a) Paratope

• b) Genotype

• c) Haplotype

• d) Codominant locus

d

If a father's HLA haplotypes are (a, b) and a mother's are (c, d), which of the following is a possible haplotype combination for their offspring?

• a) ab

• b) cd

• c) bc

• d) bd

a

Which HLA allele carries a high relative risk (up to 100x) for Ankylosing Spondylitis and is associated with Reiter's Syndrome?

• a) HLA-B27

• b) HLA-DR2

• c) HLA-DR3

• d) HLA-B8

c

Goodpasture's Syndrome and Multiple Sclerosis are primarily linked to which HLA allele?

• a) HLA-B5 (Bw51)

• b) HLA-Cw6

• c) HLA-DR2

• d) HLA-DR4

b

HLA-DR3 and HLA-DR4 are major genetic predisposition factors for which of the following conditions?

• a) Psoriasis Vulgaris

• b) Insulin-Dependent Diabetes Mellitus (Type 1)

• c) Behçet's Disease

• d) Anterior Uveitis