Antigen Capture & Presentation

Question 1

These antigen presenting molecules are on all nucleated cells.

Answer 1

MHC I

***Also called HLA

Question 2

These antigen presenting molecules are on professional APCs (DCs, macrophages, B-cells).

Answer 2

MHC II

Question 3

T-lymphocytes DO NOT recognize antigens in free or soluble forms. They recognize portions of _______ antigens associated with HLA (MHC).

Answer 3

Protein

Question 4

The total set of MHC/HLA alleles are present on each chromosome. The set of alleles on each chromosome is called an MHC/HLA _________. Encode protein antigens central for immune system to discriminate between self and non-self.

Answer 4

Haplotype

Question 5

Most humans are heterozygous and have two MHC/HLA haplotypes, one from Mom and one from Dad. Both are expressed simultaneously exhibiting ________ (generates more diversity this way).

Answer 5

Co-dominance

Question 6

This class of MHC/HLA gene is encoded by three separate gene regions in the locus (HLA-A, HLA-B, HLA-C). They are membrane bound glycoproteins and are expressed on all nucleated cells.

Answer 6

MHC I

Question 7

What type of T-cells do MHC I bind to?

Answer 7

CD8+ cytotoxic T-lymphcytes (CTLs)

Question 8

What does MHC I inhibit?

Answer 8

NK cells

Question 9

(MHC I) Alpha-chain translated into _____ as glycoprotein. Alpha-chain interacts with Beta2 microglobulin. Complex transported to cell surface.

Answer 9

ER

Question 10

What region are class II MHC/HLA encoded by?

Answer 10

HLA-D (HLA-DP; HLA-DQ; HLA-DR)

Question 11

What type of T-cells do MHC II bind to?

Answer 11

CD4+ T-lymphocyte

Question 12

T/F. Only one peptide binds to a molecule of MHC/HLA at any one time, but the same molecule of MHC/HLA has the capacity to bind to multiple peptides.

Answer 12

True

Question 13

There are _______ in the floors of the peptide-binding clefts that the side chains of the amino acids on the antigen peptides fit into and anchor the peptides in the cleft.

Answer 13

Pockets

Question 14

These are antigens coded on Y chromosome. They’re associated with acute rejection of male grafts in female recipients.

Answer 14

H-Y

Question 15

Microbes that enter the body are either:

– Phagocytosed or pinocytosed by APCs in the tissues

– (Enter via the periphery) They are filtered by the lymph and lymphoid tissues

– (In the blood) Filtered by the ________

Answer 15

Spleen

Question 16

This type of APC can activate naive mature T cells and are in tissues or blood.

Answer 16

DCs

Question 17

Classical DCs are in all tissues, but __________ DCs are in the blood and tissues. These promote innate anti-viral state.

Answer 17

Plasmacytoid DCs (pDC)

Question 18

Which class of MHC work against intracellular pathogens and self?

Answer 18

MHC I

Question 19

What class of MHC work against extracellular pathogens?

Answer 19

MHC II

Question 20

T/F. Even in the absence of infection, protein degradation and peptide transport occur simultaneously. MHC/HLAs carry peptides derived from normal self-proteins, but normally these do not provoke immune responses.

Answer 20

True

***MHC I carry self proteins

Question 21

During this, DCs can ingest virally infected or transformed cells and display Ag to CTLs via MHC I.

Answer 21

Cross-Presentation

***Remember, MHC I is usually intracellular. DCs ingested virus from extracellular environment, and displayed to MHC I.

Question 22

A large number of autoimmune diseases and susceptibility to infectious agents are associated with particular ______ alleles.

Answer 22

HLA

Question 23

This HLA-associated disease exhibits inflammation of the spine, and is due to the expression of the HLA-B27 allele. This allele can not bind a critical antigenic peptide, allowing it to cause disease.

Answer 23

Ankylosing spondylitis

Question 24

This HLA-associated disease occurs as a result of Streptococcus pyogenes infection. There is a generation of Abs against the streptococci that cross react with cardiac tissue.

Answer 24

Rheumatic fever

Question 25

Patients who have the _______ allele are more prone to develop Rheumatic fever.

Answer 25

HLA-DR4

Question 26

This HLA-associated disease results in a defect in salivation and lacrimation. Associated with HLA-DR3.

Answer 26

Sjogren’s Syndrome

Question 27

This disease is associated with HLA-DQw8 and others.

Answer 27

Insulin-dependent diabetes mellitus

Question 28

This disease is associated with HLA-B3.

Answer 28

Psoriasis

Question 29

Class I Antigen-processing defects in renal cell carcinoma are due to a down-regulation of ______.

Answer 29

TAP

***Brings peptide (antigen) from cytosol into ER and makes MHC/Antigen complex

Question 30

In this rare disease, the TAP protein is nonfunctional, so no peptides can enter the ER. Since Class I molecules cannot leave the ER unless they have bound a peptide, cells cannot present antigens on their cell surface. Symptoms include chronic respiratory infections, and poor response to viruses.

Answer 30

Bare Lymphocyte Syndrome (Class I)

Question 31

This disease can be caused by an inherited defect in CIITA, leading to a deficiency in HLA class II expression on cells and non-functioning T-lymphocytes. HLA II genes are turned on by transcriptional activator CIITA, so without it HLA is not expressed. Patients have severe chronic infections.

Answer 31

Bare Lymphocyte Syndrome (Class II)

Question 32

What polypeptide chains make up MHC I?

Answer 32

Alpha

Beta2-Microglobulin

Question 33

What polypeptide chains make up MHC II?

Answer 33

Alpha

Beta

Question 34

What is the binding site on MHC I for T-cells?

Answer 34

Alpha-3 region binds CD8

Question 35

What is the binding site on MHC II for T-cells?

Answer 35

Beta-2 region binds CD4

Question 36

This inhibitor is on the surface of all cells, and protects against complement.

Answer 36

DAF