Immuno: Autoimmunity Breakdown Tolerance

Question 1

Definition of autoimmunity

Answer 1

B and T cells recognize own cells and it is a process of launching attack against their own cells

Question 2

Definition of immunity

Answer 2

The immune system protects the body by producing antibodies and white blood cells that attack germs like viruses and bacteria

Question 3

Definition of immunodeficiency

Answer 3

The immune system doesn’t respond properly to infections. Symptoms include slow healing, chronic fatigue, digestive issues, and allergies

Question 4

Definition of hypersensitivity

Answer 4

An immune system overreaction to an antigen, such as a food, medication, or chemical. Hypersensitivity can cause allergies and other immune diseases.

Question 5

Mechanism(s) of central tolerance

Answer 5

Clonal deletion

Question 6

Mechanism(s) of peripheral tolerance

Answer 6

Anergy
Deletion
Suppression

Question 7

Clonal deletion occurs during lymphocyte (t and B cells) maturation in the ______ ________ organs.

Answer 7

Primary lymphoid organs ( thymus and bone marrow)

Question 8

Clonal deletion: The body presents immature lymphocytes with self antigen. Lymphocytes which react with _____ affinity to this self antigen are deleted.

Answer 8

High

Question 9

Clonal deletion: Lymphocytes that are presented and react with low affinity to the self-antigen are ______ __ _____.

Answer 9

Selected to mature

Question 10

Peripheral tolerance takes place where in the body?

Answer 10

Everywhere but the thymus and bone marrow

Question 11

Peripheral tolerance: During maturation, lymphocytes _____ be presented with every self-antigen

Answer 11

Cannot

Question 12

Peripheral tolerance: Lymphocytes cannot be presented with every self-antigen for what two reasons

Answer 12

1. Some antigens are found in low concentrations in specific locations
2. New antigens are formed during life

Question 13

Anergy induction is the stage in which….

Answer 13

T cells become unresponsive to the antigen stimulation due to inadequate activation of T cells.

Question 14

What is another name for B7

Answer 14

CD80/CD86

Question 15

CTLA-4 binding B7 proteins transmits _______ signal that shuts down _____ activity

Answer 15

Inhibitory, T cell

Question 16

When CD28 binds to B7 it provides _______ signal for T cells recognize own activation

Answer 16

Costimulatory

Question 17

Deletion is the process

Answer 17

Of deleting or killing the autoreactive cells. It is also called apoptosis

Question 18

Suppression is when T regulatory cells found in thymus and peripheral tissues, inhibit the functions and activation of ______ T cells

Answer 18

effector

Question 19

Suppression:

Answer 19

prevents auto-reactive T cells from attacking self antigens

Question 20

What are the four causes for loss of self-tolerance

Answer 20

1. Exposure of normally inaccessible self-antigens
2. Self antigen modification
3. Molecular mimicry(cross reactions)
4. Chronic inflammation

Question 21

Exposure of normally inaccessible self-antigens: Physical trauma to one eye initiates _________ that can destroy vision in both eyes called ________ ______-

Answer 21

Autoimmunity, Sympathetic ophthalmia

Question 22

Self Antigen modification: normal self antigens may be modified by factors such as ______,_____,and _____ ______so they no longer recognized by the immune system as a self Ag

Answer 22

Viruses, drugs, and genetic mutations

Question 23

Molecular mimicry: infectious agents appear ______ to self-antigens

Answer 23

Similar

Question 24

examples of molecular mimicry:

Answer 24

Reaction between Streptococcal Ag and myocardium in rheumatic fever

Question 25

Chronic inflammation can cause significant ____ _____

Answer 25

Tissue damage

Question 26

tissue damage due to chronic inflammation exposes/releases ____ __

Answer 26

Self- Ag

Question 27

Chronic inflammation is linked to an increase in ___________

Answer 27

Autoimmunity

Question 28

Where does positive selection occur?

Answer 28

Cortex

Question 29

Thymus epithelial cells express _____

Answer 29

MHC

Question 30

If CD8 and CD4 (as one cell) bind WEAKLY to MHC 1 and 2, it causes cell death which is a from of ____________ selection

Answer 30

Positive

Question 31

In the medulla, CD8 and CD 4 _______ into two cells

Answer 31

Differentiate

Question 32

What form of selection takes place in the medulla?

Answer 32

Negative selection

Question 33

In the medulla, thymus epithelial cells and dendritic cells express______ __________.

Answer 33

Self antigens

Question 34

In the medulla, CD 8 and CD4 (separate cells) bind strongly to self antigens resulting in cell death. This is a form of ___ selection

Answer 34

Negative

Question 35

Maturing T cells in the medulla and cortex survive if the T cell receptor does what two things?

Answer 35

1. Binds with self MHC1 and MHC2 2. Does not bind with self antigens

Question 36

How does genetics contribute to autoimmunity:

Answer 36

-genetic defects can cause failure of intrinsic tolerance -Autoimmune conditions run in families

Question 37

What is Hashimoto’s thyroiditis disease?

Answer 37

Antibodies are produced against thyroglobulin and destruction to thyroid gland’s hormone secreting capacity

Question 38

Hashimoto’s thyroiditis causes

Answer 38

Hypothyroidism

Question 39

What is Grave’s disease?

Answer 39

Ab stimulates inappropriate function of TSH-R causing more thyroid hormone production than normal

Question 40

Grave’s disease causes

Answer 40

Hyperthyroidism