Antigen/Antibody Reactions Flashcards Preview

MSS-IHL Final Exam > Antigen/Antibody Reactions > Flashcards

Flashcards in Antigen/Antibody Reactions Deck (60):
0

Ag vs Ab?

antigen - Ag

antibody - Ab

1

5 classes of antibodies in mammals?

IgG, IgM, IgA, IgE, IgD

2

class of antibody determined by what?

the heavy chain constant region

3

Fab

antibody portion that is variable region on heavy and light chain

4

Fc

constant region of the heavy and light chain

5

hypervariable regions

in the light and heavy variable regions of antibody

involved with the antigen binding that is complementary to epitope

6

CDR

hypervariable regions also known as the complementarity determining region
-location of junctional diversity

6 CDRs per antibody and TCR
3 light chain and 3 heavy chain

each antibody has 2 binding sites

7

CDR3

has the most variability

8

idiotope

CDR hypervariable regions of the antibody

9

isotype

class of the antibody

determined by the C region of the heavy chain

differ in size, charge, sequence, and carbohydrate content

9 isotypes in humans with functional differences
-all the basic Y structure

10

allotype

allelic differences in the heavy chain
-we all have suttle differences in our genetics

11

idiotype

antigenic differences in the V regions
-we all see an antigen differently
-this is our idiotypic antigen

12

what isotype is not bifunctional?

IgD

13

bifunctionality of antibody?

antibody binds antigen and mediates effector function

14

IgM

5-10% of total serum

in a pentamer form held by disulfide bonds
has a J chain - in the mucosa; immunity

10 binding sites for antigens

first antibody produced in a primary response
also, first produced by neonates
**bc first one in line of C regions on gene**

can be membrane bound or secreted (mIgM - membrane bound)

15

what antibody for primary response?

IgM

16

IgG

80%

primary antibody of secondary immune response

four classes:
IgG1, 2, 3, 4
all four can cross placenta
IgG 1 and 3 - bind Fc on phagocytes
IgG 3 - activator of complement
IgG 2 - relative restricted to carbohydrate antigens
IgG 4 - intermediate affinity for phagocytes

17

IgG four classes?

1, 2, 3, 4

all cross placenta

18

IgG 1

high affinity to Fc receptors on phagocytes

19

IgG 2

relatively restricted to carbohydrate antigens

20

IgG 3

efficient activator of complement

21

IgG 4

intermediate affinity for Fc receptors on phagocytes

22

CD markers

Fc receptors for IgG

23

CD 16

NK cells, monocytes, macrophages, and granulocytes

Fc receptor for IgG

24

CD32

on B cells, monocytes/macrophages, and granulocytes

Fc receptor for IgG

25

CD64

on monocytes/macrophages

Fc receptor for IgG

26

IgA

constituent of the secondary immune response

10-15% total antibody
can be a polymer with J piece (promotes secretory peptide)

secretory - colostrum, saliva, tears, GU tract, digestive

concentrated along mucous membrane surfaces

27

IgE

low concentration in serum

high affinity for basophils and mast cells

CD23a and CD23b

powerful pharmacologic reactions
-asthma, hay fever, peanut butters
-helminth infections

**important in worm defense

28

IgD

less than 1% of serum

monomeric form on the membrane of B cells

no function in serum

have both IgM and IgD on membrane with same antigen specificity

29

antigen

foreign molecule that binds to an antibody

**whether or not they induce an immune response

30

immunogens

antigen that causes an immune response

31

epitope

specific part of antigen that contacts the antibody binding site

epitope binds the idiotope

32

pathogen

organism that causes disease

33

hapten

small molecules that bind antibody but won't cause immune response unless bound to carrier macromolecule

**used in vaccinations

**also leads to penicillin allergy

34

endogenous antigens

body's own cellular components or intracellular pathogens

classified as:
-autoantigens
-alloantigens
-intracellular pathogens

35

autoantigen

type of endogenous antigens

self-antigen
-ex autoimmune disease

36

alloantigens

type of endogenous antigen

tissue specific antigen
ex/ABO or HLA

37

exogenous antigens

antigens enter body or freely circulate the body fluids and are trapped by APCs

classified as allergens, latrogenic, or microbial

**latrogenic - doctor induced

38

factors influencing immunogenecity

molecular mass (smaller less likely to provoke immunity)
**why happens need large molecule to bind to

foreignness (won't respond to self)

chemical composition (more complex molecule more immunogenic)

physical form (particulate more immunogenic than soluble)

degradability (easily phagocytosed are more immunogenic)

genetic factors (differences in individual immune repertoire)

age (older has weaker immune response)

39

why subQ administration better?

phagocyte activation further increases the immune response

40

adjuvants

substances that can enhance the immune response

can have undesirable side effects such as fever and inflammation

41

immunological priming

at slightly lower dose

atopic disease and hypersensitivity

42

immunogen dose that is higher than optimal dose

annergy - cells cannot respond

method of peripheral tolerance

43

vast majority of immunogens are?

proteins

44

nucleic acids immunogenecity?

poor

although, they are good if single stranded

45

epitopes recognized by B cells?

determined by the size of the antigen binding site of antibody

can bind soluble molecules

can bind proteins, polysaccharides, and lipids

46

epitopes of T cells?

only see a sequence of amino acids in protein

does not see thing in 3D

8-15 AAs in a row

free peptides are not recognized
-need to be bound to HLA (MHC)

cannot bind soluble antigens

47

T dependent antigens

require both T helper cells and B cells

**all T-dependent antigens are proteins

involved in class switching and affinity maturation

48

T-independent antigens

non-protein

can stimulate antibody response without help

usually multiple identical epitopes that can cross-link BCR

49

mitogens

cause cell to undergo division

LPS is an activator of B cells in humans

50

superantigens

activate a large number of T cells

*look into this more

51

antigen/antibody bonds?

non-covalent

hydrogen, electrostatic, van der waals, hydrophobic

all together gives a high affinity bond

52

affinity

strength between antibody and its antigens

53

avidity

strength of interaction between multivalent antigen and multivalent antibody


**avidity dependent on multiple affinities

54

hapten-carrier effect

basis of many drug allergies

55

monoclonal antibodies

mAB or moAb

immune cells are clones of a single parent cell

56

first melanoma drug?

monoclonal antibody for CTLA-4

Yervoy = Ipilimumab

57

ELISA

utilize monoclonal antibodies

ex/ pregnancy test

58

flow cytometry

monoclonal antibodies

looking for fluorescently marked antibodies

59

immunohistochemistry

??