Immunopathology (week 3)

Question 1

What are pattern recognition receptors? Give some examples

Answer 1

Antigen recognition receptors in innate immune system. Recognise 2 classes of molecules:
1) Pathogen associated - from microbial pathogens,
2) Damage associated - from cell components released in cell damage
Examples:
TLRs (toll-like), CLRs (C-type lectin), Scavenger receptors

Question 2

What is the effect of IL-1 cytokine release?

Answer 2

Stimulation of coagulation and inflammation

Question 3

What is the effect of TNF cytokine release?

Answer 3

Coagulation
Inflammation
Neutrophil activation

Question 4

What is the effect of IL-6 cytokine release?

Answer 4

B Cell Proliferation

Question 5

What is the role of macrophages?

Answer 5

Phagocytose bacteria
Produce antimicrobial peptides
Bind LPS
Produce cytokines

Question 6

What is the role of dendritic cells?

Answer 6

antigen presenting cells - process antigen material and present it to T cells

Question 7

What is the role of NK cells?

Answer 7

Kill cells that are missing MHC-1 (self-marker)

Question 8

Natural killer T cell

Answer 8

Kill infected cells

Produce interferon gamma, IL-4, TNF

Question 9

Neutophils

Answer 9

Phagocytes

Produce antimicrobial peptides

Question 10

Eosinophils

Answer 10

Kill invading parasites

Question 11

Basophils

Answer 11

Can cause allergic reactions - produce histamine

Phagocytosis

Question 12

Which type of cell recongnises MHC-I

Answer 12

cytotoxic T

Question 13

Which type of cell recognises MHC-II

Answer 13

helper T

Question 14

What is the role of B lymphocytes?

Answer 14

Secrete antibodies, form memory cells

Question 15

What is the role of helper T cells?

Answer 15

Secrete cytokines, help B cells

Question 16

What mediates a type I hypersensitivity reaction?

Answer 16

IgE

Question 17

What diseases are associated with type I hypersensitivity?

Answer 17

Asthma

Hayfever

Question 18

What is the role of histamine?

Answer 18

Stimulates irritant nerve receptors
Causes smooth muscle contraction
Increases vascular permeability

Question 19

What is the role of kallikrein?

Answer 19

Activates bradykinin

Question 20

What mediates type II hypersensitivity reactions?

Answer 20

Antibodies produced by immune response bind own cells. Can be self or extrinsic antigens.

Question 21

What type of cells do type II hypersensitivity reactions usually affect? Give some examples of reactions.

Answer 21

Haematopoietic cells
blood group incompatibility
autoimmune haemolytic anaemia

Question 22

What mediates type III hypersensitivity reactions?

Answer 22

Accumulation of antigen-antibody complexes that have not been adequately cleared by immune system. Involves soluble antigens that are not bound to cell surfaces. Complexes insert into small blood vessels, joints, glomeruli etc.

Question 23

What mediates type IV hypersensitivity reactions?

Answer 23

Delayed, cell-mediated response. CD4+ helper T cells recognise antigens with MHC-II on surface of antigen presenting cells. These can be macrophages which then stimulate further helper T cells. Examples: allergic contact dermatitis, type 1 diabetes