17/1 Adaptive immunology

Question 1

Adaptive immunology involves:

Answer 1

lymphocytes ( T & B Cells), highly specific antigen recognition, cytokines & collaboration with other cells

Question 2

All immune responses can be divided into:

Answer 2

cell mediated and humoral immunity

Question 3

cell mediated immunity

Answer 3

all responses in which antibodies play little/no part; involves T cells, macrophages, neutrophils, NKs

Question 4

Humoral immunity

Answer 4

antibody mediated ( B cells)

Question 5

define antigen

Answer 5

any substance that binds to specific receptors on lymphocytes i.e B cell/ T cell receptors

Question 6

antigen can be many forms. List some

Answer 6

• may be protein, lipid, carbohydrate or any combination
• may be foreign or altered self molecule
• may be soluble or particulate, simple or complex with many diff. antigenic determinants

Question 7

define antigenic determinant/ Epitope

Answer 7

part of antigen that binds to these receptors

Question 8

any molecules or group of molecules that induce an immune response

Answer 8

immunogen

Question 9

small molecule that can act as an epitope but not elicit an immune response

Answer 9

hapten

Question 10

non microbe derived antigens might include?

Answer 10

pollen, food & dust or ‘self’ antigens from dead/ senescent cells or altered self molecules

Question 11

non microbe derived antigens might include?

Answer 11

pollen, food & dust or ‘self’ antigens from dead/ senescent cells or altered self molecules

Question 12

antigens can enter the body by various methods. List some

Answer 12

Breaks in skin & mucous membranes
Direct injection e.g. bite/needle
Organ transplants & skin grafts
Microfold cells in the mucosal surfaces

Question 13

structure of antibody

Answer 13

Monomer: flexible Y-shaped molecule with 4 protein chain
Has variable region, constant regions, Fc region

Question 14

what is the 4 protein chain in antibody structure?

Answer 14

2 identical light chains
2 identical heavy chains

Question 15

Variable region in antibody structure

Answer 15

2 sections at the end of the Y arms
- contain antigen binding sites
- identical on the same antibody, but vary from one antibody to another- contains some hypervariable regions

Question 16

constant region in antibody structure

Answer 16

stem of monomer on lower part of Y’s arm

Question 17

Fc region on antibody structure

Answer 17

stem of monomer only

Question 18

why is the Fc region important?

Answer 18

because they can bind to complement or cells

Question 19

5 different classes of antibodies

Answer 19

IgG, IgM, IgA, IgE, IgD

Question 20

why is each B cell different?

Answer 20

to make unique receptors

Question 21

the class of antibody involved in immune response depends on:

Answer 21

type of foreign antigen, the portal of entry & the antibody function needed

Question 22

what class of antibody can join together to form a secretary dimer?

Answer 22

IgA

Question 23

what class of antibody has the lowest affinity for AB (antigen-binding)

Answer 23

IgM

Question 24

structure of IgM

Answer 24

pentemeric, largest, lowest affinity for AB, 10 binding sites

Question 25

structure of IgE

Answer 25

monomeric, highly glycosylated. Most associated with allergy

Question 26

the two heavy chains are linked by and each heavy chain linked to light chain by? antibody structure

Answer 26

disulfide bonds

Question 27

function for IgA

Answer 27

Aggulation and neutralisation

Question 28

where is IgA located?

Answer 28

muscous membrane secretions

Question 29

Location of IgE

Answer 29

Serum, mast cell surfaces

Question 30

location of IgG

Answer 30

Serum, intracellular fluid

Question 31

location of IgM

Answer 31

Serum

Question 32

function of IgE

Answer 32

Trigger release of histamines from basophils and mast cells

Question 33

function of IgG

Answer 33

Complement activation, aggulation, opsonisation and neutralisation, crosses placenta to protect placent

Question 34

Function of IgM

Answer 34

Complement activation, aggulation and neutralisation

Question 35

antibodies bind to antigens based on?

Answer 35

the 'complementarity' of the epitope on the antigen & the antigen- binding (AB) site of the antibody

Question 36

Approx. 10^13 different specificities can be generated of AB-AT interaction but actually more due to?

Answer 36

somatic hypermutation seen during immune response

Question 37

the strength of AB-AT interaction is referred to as?

Answer 37

the affinity of the antibody

Question 38

Which affinity (high/low) is more protective (AT-AT)?

Answer 38

High because it will bind antigens at lower concentrations

Question 39

Antibody-antigen interactions are non-covalent. list some interactions

Answer 39

H-bonds, ionic bonds, hydrophobic interactions, van der Waals interactions

Question 40

AB-AT interactions are reversible or irreversible

Answer 40

reversible

Question 41

1 epitope of antigent binds to what part of AB structure?

Answer 41

variable region of antibody hypervariable regions

Question 42

B cell stimulation requires what else?

Answer 42

cytokines from T helper cells Co- stimulatory molecules ( CD19 + others)

Question 43

1000-10,000x proliferation & differentiation of B cells into plasma cells packed with RER & highly metabolically active ... happens once?

Answer 43

Once AB/B cell receptor has bound AT & signalled through the Ig alpha & beta chain (CD79a)

Question 44

All immunogens are antigens but?

Answer 44

not all antigens are immunogens (not all antigens will produce an immune response)

Question 45

On first exposure, there is a delay before specific AB seen in serum why? what type of immunity is this?

Answer 45

because it takes a while for cells to differentiate - In humoral immunity kinetics

Question 46

what is produced by T cells to stimulate plasma cell maturation?

Answer 46

cytokines

Question 47

role of cytokines produced by T cells. Take how long?

Answer 47

to stimulate plasma cell maturation - approx. 1 week

Question 48

in humoral immunity what class of AB is poduced? then switches to ?

Answer 48

IgM, then switches to IgG , IgA or IgE