Deck 16: Tolerance, Autoimmunity, and Transplantation

Question 1

Central tolerance

A)is the first step of tolerance mechanisms.
B)affects both T cells and B cells.
C)deletes cells that are autoreactive.
D)occurs in the bone marrow and thymus.
E)All of the answers are correct.

Answer 1

E

Question 2

Which of the following statements does NOT describe tolerogens accurately?

A)They can be the same molecules as immunogens.
B)They lead cells to become unresponsive.
C)They are part of peripheral tolerance.
D)They only affect B cells.
E)All of the answers describe tolerogens.

Answer 2

D

Question 3

The tolerogenic response

A)is not antigen specific.
B)leads to apoptosis but not anergy.
C)results in cells becoming nonresponsive.
D)depends on the presentation context.
E)affects T cells only.

Answer 3

C

Question 4

Tolerance is promoted by all of the following circumstances EXCEPT

A)high doses of antigen.
B)persistent antigen.
C)oral introduction of antigen.
D)presence of adjuvant.
E)low levels of costimulation.

Question 5

Tolerance is promoted by

A)induction of anergy.
B)induction of apoptosis.
C)regulation of activity of cells.
D)All of the answers are correct.
E)None of the answers are correct.

Question 6

Apoptosis is

A)similar to necrosis.
B)important in peripheral but not central tolerance.
C)important in central but not peripheral tolerance.
D)impaired in Fas-deficient systems.
E)None of the answers are correct.

Question 7

Maintaining immunologically protected sites, such as the eye,

A)allows sequestration of antigens.
B)reduces central tolerance.
C)can lead to autoreactivity secondary to injury.
D)can reduce background reactivity.
E)All of the answers are correct.

Question 8

Central tolerance employs all but which of the following mechanisms?

A)Apoptosis
B)Receptor editing
C)Positive selection
D)Negative selection
E)Clonal deletion

Question 9

Peripheral tolerance

A)is caused by costimulation without TcR-MHC₊ peptide interaction.
B)is caused by TcR-MHC₊ peptide interaction without costimulation.
C)leads to anergy.
D)both leads to anergy and is caused by costimulation without TcR-MHC₊ peptide interaction.
E)both leads to anergy and is caused by TcR-MHC₊ peptide interaction without costimulation.

Question 10

Which molecule is MOST closely associated with inhibitory responses to antigen?

A)TCR
B)MHCI
C)CTLA-4
D)CD80
E)All of the answers are equally associated with inhibitory responses to antigen.

Question 11

CD8⁺ T_REG cells can counteract autoimmune diseases in mice deficient in

A)AIRE.
B)CD4⁺ T_REGs.
C)IL-10.
D)plasma cells.
E)lymphocytes.

Question 12

Which of the following events PRIMARILY drives the need for tolerance?

A)Organ transplants
B)V(D)J recombination in lymphocyte development
C)HLA polymorphisms
D)All of the answers are correct.
E)None of the answers are correct.

Question 13

What are the three main methods through which our body prevents immune responses against itself?

Question 14

Speculate as to why regulatory T cells may have evolved, despite us having negative selection of lymphocytes during development.Explain your answer.

Question 15

What is the PRIMARY difference between how central and peripheral tolerance are developed?

Question 16

Autoimmune diseases

A)involve a failure of central tolerance.
B)involve a failure of peripheral tolerance.
C)lead to tissue destruction.
D)All of the answers are correct.
E)None of the answers are correct.

Question 17

Hashimoto's thyroiditis targets the thyroid and

A)is more common in men than in women.
B)shows juvenile onset.
C)is primarily T-cell mediated.
D)leads to hypothyroidism.
E)All of the answers are correct.

Question 18

Insulin-dependent diabetes

A)usually shows juvenile onset.
B)is more common in men that in women.
C)interferes with fat metabolism.
D)seems to be triggered by antibodies.
E)None of the answers are correct.

Question 19

Myasthenia gravis is an autoimmune disease that

A)is triggered by antibodies.
B)targets the neuromuscular junction.
C)leads to destruction of muscle cells.
D)All of the answers are correct.
E)None of the answers are correct.

Question 20

Systemic lupus erythematosus

A)is more common in women than in men.
B)is antibody mediated.
C)targets multiple organs.
D)All of the answers are correct.
E)None of the answers are correct.

Question 21

Multiple sclerosis

A)does not seem to have an environmental component.
B)seems to have some genetic component.
C)is more common in Europe than North America.
D)seems to be primarily mediated by antibodies.
E)All of the answers are correct.

Question 22

Rheumatoid arthritis

A)seems to be T-cell mediated, with cytotoxic T cells being primarily responsible.
B)is more common in men than in women.
C)targets the joint capsules.
D)is characterized by juvenile onset.
E)All of the answers are correct.

Question 23

Individuals who express HLA-B27 are 90 times more likely to develop the autoimmune disorder ankylosing spondylitis than individuals with a different HLA allele at this locus.This leads to the conclusion that

A)HLA-B27 causes ankylosing spondylitis.
B)individuals with HLA-B27 will develop ankylosing spondylitis.
C)autoimmune disorders must have genetic components.
D)patients with ankylosing spondylitis express HLA-B27.
E)None of the answers are correct.

Question 24

Many autoimmune disorders are treated with immunosuppressive drugs, which produce other problems.Antigen-specific immunotherapy would be much better because

A)they would target only the autoreactive cells.
B)they would not induce general suppression of the immune system.
C)they would produce a general reduction in inflammation.
D)they would both target only the autoreactive cells and not induce general suppression of the immune system.
E)they would target only the autoreactive cells and produce a general reduction in inflammation.

Question 25

Autografts will be rejected only rarely because of all but which of the following?

A)They are from the same individual.
B)They are MHC matched.
C)They do not trigger an immune response.
D)They have T_H17 cells.
E)All of the answers are correct.

Question 26

Isografts are NOT usually rejected because

A)they are between genetically identical individuals.
B)they are MHC matched.
C)they do not trigger an immune response.
D)they are syngeneic.
E)All of the answers are correct.

Question 27

Rejection of allografts

A)does not depend on MHC mismatching.
B)demonstrates immunological specificity.
C)demonstrates immunological memory.
D)both demonstrates immunological specificity and does not depend on MHC mismatching.
E)both demonstrates immunological specificity and immunological memory.

Question 28

Because T cells are essential in graft rejection, nude mice, which lack a thymus

A)will reject grafts the same as wild-type mice.
B)will reject grafts more vigorously than wild-type mice.
C)will not reject grafts as they lack T cells.
D)will not reject grafts as they lack B cells.
E)will not reject grafts because of peripheral tolerance.

Question 29

Kidney transplant infiltrates show both CD4⁺ and CD8⁺ T cells.This suggests that to reduce graft rejection

A)CD4⁺ T cells should be depleted.
B)CD8⁺ T cells should be depleted.
C)Both CD4⁺ and CD8⁺ cells should be depleted.
D)Inflammatory cells should be depleted.
E)None of the answers are viable treatments.

Question 30

Although MHC matching is important for transplantation, ABO blood group matching is also critical because

A)ABO antigens are expressed on nervous tissue.
B)ABO antigens are expressed on muscle cells.
C)complement will cause rapid lysis of ABO mismatched cells.
D)All of the answers are correct.
E)None of the answers are correct.

Question 31

Minor histocompatibility locus genes can cause tissue rejection

A)only if major histocompatibility genes also cause rejection.
B)even if major histocompatibility genes match properly.
C)more quickly than MHC-mediated rejection.
D)at the same rate as MHC rejection.
E)None of the answers are correct.

Question 32

Allografts can be accepted without use of immunosuppressive drugs if

A)they lack alloantigens, such as cartilage.
B)cells are grafted to a site that is immunologically privileged.
C)tolerance has been induced previously, such as nonidentical twins.
D)All of the answers are correct.
E)None of the answers are correct.

Question 33

Graft rejection consists of

A)sensitization, when T cells are stimulated, and effector, when they attack the graft.
B)sensitization, when B cells are stimulated, and effector, when they attack the graft.
C)recognition, when T cells are stimulated, and effector, when they attack the graft.
D)recognition, when B cells are stimulated, and effector, when they attack the graft.
E)None of the answers are correct.

Question 34

Transplantation of organs and tissues is challenging (even between relatives) for all of the following reasons EXCEPT

A)HLA alleles must be completely nonoverlapping.
B)HLA alleles must be all or nearly matched.
C)ABO blood groups must be matched.
D)Immunosuppression is needed.
E)All of the answers are correct.

Question 35

In transplantation, CsA, rapamycin, and FK506 are all used to

A)decrease the odds of rejection.
B)inhibit the activation of resting T cells.
C)improve the survival odds for the patient.
D)All of the answers are correct.
E)None of the answers are correct.

Question 36

What is the MOST important gene (or group of genes) for the development of autoimmunity? Explain.

Question 37

What causes the diseases APS-1 and IPEX? Explain why the conditions are grouped together despite being caused by different mutations.

Question 38

In immunotherapy, there has been a great deal of success through the use of tailored approaches and gene therapy - for example, engineering T cells that target a patient's unique cancer cells.With this in mind, what might a similar approach look like for autoimmune diseases?

Question 39

Small animal models (for example, drosophila) have afforded profound insights into both biology and genetics.Your classmate wants to propose an inexpensive lab studying autoimmunity by using this insect.Predict what will happen next.Will the funding be received?

Question 40

Why is type 1 diabetes considered an autoimmune disorder despite being caused by a lack of insulin in the body? Explain.

Question 41

What are three different ways to prevent rejection following organ transplantation?

Question 42

A transplantation doctor is observing her notes for an upcoming surgery.She sees the following information about the donor and recipient of a heart transplantation:
HLA: 11/12 [genes matched]
Donor blood type: A+
Recipient blood type: B-
What are the chances of success for this operation? Provide your prognosis.