Immunopathology (5 and 6)

Question 1

Innate immune system

Answer 1

Barrier and chemical mechanisms, PRR, cellular (phagocytes, natural killer cells)

Question 2

Adaptive immune system

Answer 2

Humoral or cellular

Question 3

Pattern recognition receptors

Answer 3

Antigen recognition receptor in the innate system

Question 4

What do pattern recognition receptors usually detect?

Answer 4

Pathogen-associated Molecular Patterns (PAMPs) but also Danger Associated Molecular Patterns (DAMP’s)

Question 5

2 Groups of PRR

Answer 5

1. Cell surface (transmembrane) and intracellular receptors -TLRs, NLRs, RLR’s and CLR’s
   - Fluid-phase soluble molecules

Question 6

Fluid-phase recognition molecules

Answer 6

C-type lectin family

• Collections - Mannan-binding Lectin/Surfactant protein A & D
• Recognition of microbal complex carbohydrates

Question 7

Fluid-phase recognition molecules role

Answer 7

Neutralisation of pathogen and recruitment of adaptive response

Question 8

What do fluid-phase recognition molecules bind via

Answer 8

Carbohydrate-Recognition Domains (CRDs)

Question 9

IL1

Answer 9

First cytokine in response to infection makes you feel ill

Question 10

Other important cytokines

Answer 10

TNF, IL6, IL23

Question 11

Plasmacytoid dendritic cells

Answer 11

Produce IFN (circulate in blood)

Question 12

Myeloid dendritic cells

Answer 12

Produce IL12 and IL10 (circulate in blood)

Question 13

Natural killer cells

Answer 13

Kill foreign and host cells that have low levels of MHC+ self peptides (self regulatory)

Question 14

NK-T cells

Answer 14

T cell and NK surface markers, kill host cells infected with intracellular bacteria

Question 15

Plasma cell

Answer 15

First thing engaged with macrophages if infection, informs adaptive immune system what to do, found everywhere

Question 16

Neutrophils

Answer 16

Phagocytose and kill bacterial (produce antimicrobial peptides)

Question 17

Eosinophils

Answer 17

Kill invading parasites

Question 18

Mast cells and basophils

Answer 18

Release TNF, IL-6, IFN in response to bacterial PAMPs

Question 19

Adaptive immune response

Answer 19

Unique antigen receptor found on each lymphocyte, in infection undergoes clinical expansion, high degree of specificity

Question 20

Primary lymphoid organ

Answer 20

Bone marrow and Thymus

Question 21

Secondary lymphoid organ

Answer 21

Spleen (white pulp), lymph node, mucosal surfaces

Question 22

Antigen presentation

Answer 22

Antigens are internalised and broken down to peptides, associate with newly synthesised class 2 molecules brought to cell surface

Question 23

Peptide are foreign

Answer 23

Recognised by helper T cells which are activated, produce cytokines need by B cells, T cells etc

Question 24

What are Histocompability Antigens/HLA?

Answer 24

Glycoproteins found on the surfaces of mammalian cells which make everyone unique

Question 25

Class 1

Answer 25

HLA-A, HLA-B, HLA-C

Question 26

Class 2

Answer 26

HLA-DP, HLA-DQ, HLA-DR

Question 27

Functions of class 1 and class 2 MHC proteins

Answer 27

T cells can only see antigen in associated with MHC proteins (can present many peptides with similar structure)

Question 28

MHC class 1 proteins present peptides to

Answer 28

Cytotoxic T cells

Question 29

MHC class 2 proteins present peptides to

Answer 29

Helper T cells

Question 30

B lymphocytes

Answer 30

Can secrete antibodies (humoral immunity)

Question 31

Killer/cytotoxic T cell

Answer 31

Can kill (cellular immunity)

Question 32

Helper T cell

Answer 32

Secrete growth factors (cytokines) which control immune response, help B and T cells

Question 33

Suppressor T lymphocytes

Answer 33

Dampen down immune response

Question 34

Which lymphocytes are the target of HIV?

Answer 34

Helper T lymphocytes

Question 35

Th1

Answer 35

Parasites/virsuses

Question 36

Th2

Answer 36

Allergies

Question 37

Th3

Answer 37

Produces IL-17, fungal defence

Question 38

Immunosuppression

Answer 38

A natural/artificial process which turns off immune response (partially/fully) (accidentally/on purpose)

Question 39

Immunodeficiency

Answer 39

Lack of an efficient immune system-susceptibility to infections

Question 40

Uses of immunosuppression

Answer 40

Transplant rejection, autoimmune disease and lymphoprolfierative diseases

Question 41

Hypersensitivity

Answer 41

Undesirable, damaging and sometime fatal reactions produced by normal immune system in a pre-sensitised host

Question 42

Allergy

Answer 42

Altered reactivity

Question 43

Hypersensitivity Type 1

Answer 43

IgE mediated

Question 44

Hypersensitivity Type 2

Answer 44

Cytotoxic

Question 45

Hypersensitivity Type 3

Answer 45

Immune complex reaction

Question 46

Hypersensitivity Type 4

Answer 46

Cell mediated reaction (DTH)

Question 47

Examples of allergic diseases

Answer 47

Asthma, rhinitis, dermatitis, food allergy

Question 48

Hypersensitivity Type 3 reaction

Answer 48

- IgG + Ag = AgAb complex - FcR in complex bind C1q - Complement activation leads to generation of activated complement fragments - C5a - attractant for neutrophils - C3b - opsonin - Attempted phagocytosis of complexes - release of enzymes, O2 radicals - Tissue damage

Question 49

Hypersensitivity Type 4 reaction

Answer 49

- Perivascular infiltration of lymphocytes and monocytes - Langherhan's cells present neo-antigen to T cells - Ag-specific T cells release cytokines - recruitment of macrophages (non Ag-specific) - Activated macrophages cause tissue damage - Requires previous exposure to antigen

Question 50

Contact dermatitis

Answer 50

Combination of DTH and cytotoxic reaction, antigen presentation by APC, Keratinocytes present to CTL precursors

Question 51

Examples of contact dermatitis

Answer 51

Posion ivy and Nickel (Nickel acts as hapten with epidermal proteins)

Question 52

What are granulomas?

Answer 52

Focal collections of inflammatory cells in tissues - macrophages, epitheloid cells, giant cells, lymphocytes

Question 53

T cell granulomas

Answer 53

Th1 type and secrete IL2 and IFNy

Question 54

What is released by macrophages to initiate granuloma formation?

Answer 54

IL-12

Question 55

Granulomatous diseases examples

Answer 55

- Mycobacterial (TB, atypical mycobacteria, leprosy) - Sarcoidosis - Wegener's Granulomatosis - Crohn's disease

Question 56

Tuberculoid Leprosy

Answer 56

Th1 protective

Question 57

Lepromatous Leprosy

Answer 57

Th2 non-protective