Immunopathology

Question 1

What are the two types of adaptive immune response?

Answer 1

Humoral and cellular

Question 2

Name 6 pattern recognition receptors (PRRs)

Answer 2

Toll-like receptors (TLRs), NOD-like receptors (NLRs), rigl-like receptors (RLRs), C-type lectins (CLRs), scavenger receptors

Question 3

Name the 5 major components of the innate immune system

Answer 3

pattern recognition receptors (PRRs), antimicrobial peptides, cells, complement components, cytokines

Question 4

What is meant by pattern recognition receptors?

Answer 4

inclusive term for antigen recognition receptors in innate immune system (initial alert to any sort of infection)

Question 5

What are the two groups of pattern recognition receptors?

Answer 5

1) cell-surface and intracellular receptors (TLRs, NLRs, RLRs, CLRs)
2) fluid-phase soluble molecules

Question 6

How do fluid-phase recognition molecules bind?

Answer 6

Via Carbohydrate-recognition domains (CRDs)

Question 7

What is the role of antimicrobial peptides?

Answer 7

These are in places like the saliva and they aim to destroy a pathogen before the immune system is even aware of it

Question 8

What are cytokines?

Answer 8

Chemical messengers of the innate immune system

Question 9

What are collectins?

Answer 9

A type of fluid-phase recognition molecule

Question 10

What are the main roles of colletcins?

Answer 10

role in neutralisation of pathogen and recruitment of adaptive response

Question 11

What are the major roles of marcophages in innate immunity?

Answer 11

phagocytose and kill bacteria, produce antimicrobial peptides, produce inflammatory cytokines

Question 12

What are the major roles of plasmacytoid dendritic cells in innate immunity?

Answer 12

produce large amounts of interferon

Question 13

What are the major roles of myeloid dendritic cells in innate immunity?

Answer 13

produce interleukin 12 and 10

Question 14

Where are denderitic cells found?

Answer 14

T cell zones of lymphoid organs (circulate in blood)

Question 15

What are the major roles of natural killer cells in innate immunity?

Answer 15

kill foreign and host cells with low levels of MHC+ self peptides

Question 16

What are the major roles of neutrophils in innate immunity?

Answer 16

phagocytose and kill bacteria, produce antimicrobial peptides

Question 17

What are the major roles of eosinophils in innate immunity?

Answer 17

kill invading parasites

Question 18

What are the major roles of mast cells and basophils in innate immunity?

Answer 18

release TNF, IL-6, IFN in response to a variety f bacterial PAMPs

Question 19

What are the major roles of epithelial cells in innate immunity?

Answer 19

produce antimicrobial peptides, produce mediators of local immunity

Question 20

Which mutate faster: the variable regions of pathogens or humans?

Answer 20

pathogens

Question 21

What is unique on each lymphocyte of the adaptive immune system?

Answer 21

antigen receptor

Question 22

What type of expansion do lymphocytes undergo in response to infection?

Answer 22

Clonal

Question 23

What are the primary lymphoid organs and what are their functions?

Answer 23

Bone marrow and thymus.

Site of lymphocyte development and selection

Question 24

What are the secondary lymphoid organs and what are their functions?

Answer 24

Spleen, lymph nodes, mucosal surfaces.

Immune response.

Question 25

How is the specificity of T and B cell antibody receptors achieved?

Answer 25

Each is made up of fragments to enable a magnitude of different variations

Question 26

Briefly describe the mechanism of antigen presentation

Answer 26

antigens internalised and broken down to peptides; peptides associate with newly synthesised calss 2 molecules and brought to cell surface; if foreign, they are recognised by Th cells which are then activated

Question 27

What are major histocompatability antigens?

Answer 27

Glycoproteins found on the surface of cells which make us unique

Question 28

How many classes of histocompatability antigen are there?

Answer 28

2

Question 29

What does HLA stand for?

Answer 29

Human leucocyte antigen

Question 30

Name the 3 class 1 histocompatability antigens

Answer 30

HLA-A, HLA-B, HLA-C

Question 31

Name the 3 class 2 histocompatability antigens

Answer 31

HLA-DP, HLA,DQ, HLA-DR

Question 32

What cells do MHC class 1 proteins present peptides to?

Answer 32

cytotoxic T cells

Question 33

What cells do MHC class 2 proteins present peptides to?

Answer 33

helper T cells

Question 34

What must antigens be associated with in order for T cells to 'see' them?

Answer 34

MHC proteins

Question 35

What is the function of B lymphocytes?

Answer 35

develop potential to secrete antibodies (humoral immunity)

Question 36

What is the function of cytotoxic T lymphocytes?

Answer 36

kill pathogens (cellular immunity)

Question 37

What is the function of helper T lymphocytes?

Answer 37

secrete growth factors (cytokines) to control immune response

Question 38

What is the function of suppressor T lymphocytes?

Answer 38

damp down the immune response

Question 39

Define immunosuppression

Answer 39

a natural or artifical process which turns off the immune response, partially or fully, accidentally of on purpose

Question 40

Define immunodeficiency

Answer 40

the lack of an efficient immune system - susceptibility to infections

Question 41

Define hypersensitivity

Answer 41

undesirable, damaging, discomfort-producing and sometimes fatal reactions produced by the normal immune system in a pre-sensitised host

Question 42

Name the 4 types of hypersensitivity

Answer 42

I - IgE mediated II - cytotoxic III - immune complex IV - cell mediated

Question 43

Which type of hypersensitivity is anaphylactic?

Answer 43

Type I (IgE mediated reaction)

Question 44

What are the clinical features of type I hypersensitivity?

Answer 44

fast onset (15-30 mins), weal and flare, can have 2nd phase response

Question 45

What is the immunopathogenesis of type I hypersensitivity?

Answer 45

IgE Ab mediated mast cell and basophil degrannulation - release of performed and de novo synthesised inflammatory mediators

Question 46

What do mast cells induce in early phase response of type I hypersensitivity?

Answer 46

degranulation and synthesis of lipid mediators

Question 47

What is the role of kallikrein in type I hypersensitivity?

Answer 47

activates bradykinin

Question 48

What is the role of histamine in type I hypersensitivity?

Answer 48

stimulation of irritant nerve receptors, smooth muscle contraction, increase in vascular permeability

Question 49

What are lipid mediators derivatives of?

Answer 49

arachidonic acids

Question 50

What is the role of eosinipohils in late phase response of type I hypersensitivity?

Answer 50

Granules containing cytotoxic proteins are attracted to site where contents released causing major tissue damage

Question 51

Cytokine-driven activity is the major source of what in allergic responses?

Answer 51

pathogenesis

Question 52

In type II hypersensitivity, what does binding of antibody to antigen result in?

Answer 52

Activation of complement cascade adn aggregation of Fc portions of immunoglobulins

Question 53

Which type of immunoglobulin inniates type II hypersensitivity?

Answer 53

IgM or complement-binding IgG (IgM>>IgG1&IgG3)

Question 54

What type of cells are usually affected by type Ii hypersensitivity?

Answer 54

haematopoietic

Question 55

Name 2 examples of type II hypersensitivity reactions?

Answer 55

blood group incompatability, autoimmune haemolytic anaemia

Question 56

What is the 6 stage process of type III hypersensitivity?

Answer 56

1) IgG + Ag = AgAb complex 2) FcR in complex bind C1q 3) complement activation leads to generation of activated complement fragments 4) C5a attracts neutrophils and C3b initiates opsonisation 5) attempted phagocytosis of complexes 6) tissue damage

Question 57

How is type IV hypersensitivity mediated?

Answer 57

T cell mediated - CD4+ helper T cells recognize antigen in a complex with Class II major histocompatibility complex

Question 58

What type of reaction is contact dermitis?

Answer 58

combination of DTH and cytotoxic reaction

Question 59

What is a granuloma?

Answer 59

A focal collection of inflammatory cells in tissues

Question 60

What must be released to initiate a granulomatous reaction?

Answer 60

IL-12 (released by macrophages)

Question 61

Name 3 infectious granulomatous diseases

Answer 61

tuberculosis, atypical mycobacteria, leprosy