immunology of endocrinology

Question 1

define immunological tolerance?

Answer 1

unresponsiveness to an antigen that is induced by previous exposure to that antigen

Question 2

outcome of activated lymphocytes?

Answer 2

immune responses

Question 3

outcome of inactivated/ eliminated lymphocytes?

Answer 3

tolerance

Question 4

what is a tolerogen?

Answer 4

antigen that induces intolerance

Question 5

self-tolerance?

Answer 5

a fundamental property of the normal immune system - allows body’s cells to be identified as harmless

Question 6

failure of self-tolerance?

Answer 6

immune reactions against self antigens

Question 7

what happens to T and B cells to avoid autoimmune responses?

Answer 7

they must be eliminated or downregulated to promote tolerance to self antigens

Question 8

what is the cause of autoimmunity?

Answer 8

break down of immunological tolerance mechanisms involved in central and peripheral tolerance

Question 9

describe 2 things involved in central tolerance?

Answer 9

thymus - eliminates T cells with a high affinity for self antigens

bone marrow - important for B cell tolerance

Question 10

describe peripheral tolerance?

Answer 10

antigen recognition without co-stimulation

maintained by regulatory T cells (TRegs) - these actively suppress the activation of lymphocytes

Question 11

name 3 mechanisms involved in peripheral tolerance?

Answer 11

anergy
TReg suppression
deletion (cell death)

Question 12

anergy?

Answer 12

functional unresponsiveness?

Question 13

2 reasons peripheral tolerance can be overcome?

Answer 13

inappropriate access of self-antigens

inappropriate/ increased local expression of co-stimulatory molecules

Question 14

when is most likely case that peripheral tolerance can be overcome?

Answer 14

inflammation of tissue damage is present -

due to increased activity of proteolytic enzymes and high levels of peptides being presented to responsive T cells

Question 15

defective TSH receptor?

Answer 15

hyper/hypo-thyroidism

Question 16

defective insulin receptor?

Answer 16

hyper/hypo-glycaemia

Question 17

defective thyroid peroxidase?

Answer 17

thyroiditis/ hypothyroidism

Question 18

defective steroid 21-hydroxylase?

Answer 18

Addison disease

Question 19

defective HLA association: DR3 gene?

Answer 19

Addison disease

Hashimoto thyroiditis

Question 20

defective HLA association: DR4 gene?

Answer 20

insulin-dependent Diabetes Mellitus

Question 21

2 ways that infections can cause autoimmune disease?

Answer 21

molecular mimicry

up regulation of co-stimulation

Question 22

2 ways that drugs can cause autoimmune disease?

Answer 22

molecular mimicry

genetic variation in drugs metabolism

Question 23

2 ways that UV radiation can cause autoimmune disease?

Answer 23

skin inflammation

modification of self-antigen

Question 24

what is the name of the microbial agent that uses molecular mimicry in insulin-dependent diabetes mellitus?

Answer 24

Coxsackie B4 nuclear protein

mimics the pancreatic islet cell glutamate decarboxylase

Question 25

2 ways of treating autoimmune diseases?

Answer 25

suppression of damaging immune response

replacing function of damaged organ