Antigen Receptors: Lymphocytes - Bowden Flashcards Preview

HDM - Midterm > Antigen Receptors: Lymphocytes - Bowden > Flashcards

Flashcards in Antigen Receptors: Lymphocytes - Bowden Deck (73):
1

Where is LFA found?

On the surface of a neutrophil

2

Where is ICAM found?

On the surface of the endothelium

3

What adhesion molecule contained within LFA?

The adhesion molecule is an integrin CD11/CD18

4

What is the associated disease or infection with Leukocyte adhesion deficiency? 40

widespread pyogenic bacterial infections

5

Through what medium does the innate immune system recognize pathogens? 5

Toll-like Receptors (TLR)

6

What is an example of a soluble receptor? 6

Antibodies

7

What is similar about the immunoglobulin superfamily? 7

They all have the similar domain function, evolution, and function

8

Differentiate an immunogen vs tolerogen? 9

Immunogen--> an Ag that evokes a specific immune response

Tolerate not --> an Ag that induces immunologic tolerance

9

What are three types of intracellular pathogens? 10

Viruses

Intracellular bacteria

Parasites

10

What is an alloantigen? 10

A tissue specific Ag that is present in one species but not another

Ex. ABO and HLA

11

What are exogenous Ags? 10

Ag from outside the body that are trapped by APCs

12

What is a Hapten? Can we say that they're immunogens? 11

Small molecule or Ag that cannot induce an immune response on its own

Requires a carrier protein

They're NOT immunogens

13

What are two clinically important examples of Haptens? 11

Drug allergies

Vaccine design

14

What is the composition of a surface bound B-cell immunoglobulin (aka BCR)? What is the BCR important for? 13

Two chains --> Igα and Igβ

Contains an ITAM on each chain on the intracellular side

Important in signal transduction

15

What is the difference between secreted IgG and membrane IgG? 14

Secreted IgG = Antibody

Membrane IgG = B lymphocyte receptor

Membrane IgG is a secreted IgG with a transmembrane region and a cytoplasmic tail

16

How many polypeptide chains make up an Ab? 15

2 heavy chains (inside)

2 light chains (outside)

17

How does papain digest a B cell receptor? 16

Produces:
(2) monomers of Fab
(1) Fc region



18

How does pepsin digest a B cell receptor? 16

Produces:
(1) Bivalent Fab region w/ bivalent binding capability

Constant region completely degrades

19

What allows for Abs specificity? 17

Their hypervariable regions (3 per variable region)

20

What allows for an Ab to bind both widely spaced cell surface determinants or closely spaced cell surface determinants? 18

The hinge

21

How many isotypes of Ig do humans have? 19

9 isotypes

22

What determines the isotype of an IG? 19

The constant region of the heavy chain

23

What is an allotype determinant? 20

Alleluia differences in the H - Heavy chain

24

What is an idiotype determinant? 20

Antigenic determinants on the V region

The idea that our Ab all see Ag a little differently and bind to different locations and amounts of Ag

25

Which immunoglobulin isotypes have J chains? 21

Iga

IgM

26

What is the structure of IgA? 21

A dimer held together by a j chain

27

What is the structure of IgM? 21

A pentamer held together by disulfide bonds and secured by a J chain

28

What is the predominant antibody produced in a primary response? 22

IgM

29

How many binding sites does IgM have? 22

10 Ag binding sites - because it is a pentamer with bivalent binding sites

30

What is the first Ab produced by neonates? 22

IgM

31

What does IgM bind well? 22

RBCs

Viruses

32

How is IgM expressed on B cells? 22

As a monomer, a BCR

33

Why is IgM able to bind to secretory cells and cross the mucosa? 22

Because of its J chain

34

What is the most abundant Ab?

IgG - 80% of total serum Ab

35

What Ab is able to pass the placental barrier? 23

IgG

36

What is the predominant class of Ab found in secretions or mucosal surface? 24

IgA

37

What are examples of where IgA can be found? 24

Vagina

Breast milk

38

What Ab is in lowest concentration in the serum? 25

IgE

39

What cell types does IgE bind with high affinity? 25

Basophils

Mast Cells

40

What clinical situations is IgE involved in? 25

Asthma

Allergies

Helminth Infections

41

What is the Fc receptor for IgE

CD23a and CD23b

Mast Cells --> CD23

42

What type of bonding occurs between an Ag and Ab? 28

Non-covalent - Meaning it's reversible!

Hydrogen bonds, electrostatic bonds, van der Waals forces, hydrophobic forces

43

What is the definition of Ab affinity? 29

The non-covalent bond between an Ab and a Ag

44

What is the definition of Ab avidity? 29

Has to do with valency

Avidity increases with valency (binding sites)

45

What are T-dependent Ags? 31

Protein Ags (T cell only recognize proteins)

Both a B cell and T helper cell is required to stimulate Ab response

46

What are T-Independent Ags? 31

Non-protein Ags:
-polysaccharides
-lipids

can simulate Ab responses w/o T cell help

47

What is the structure of the TCR? 32

2 chains (β and α(on right))

No signaling capabilities!

2 Ig domains (loops) on each chain

48

What is the identity of the majority of T lymphocyte chains? 33

α and β

49

What makes up the TCR complex? 34

TCR (2 chains)

Zeta Chain (2 chains)

(2) CD3 (2 chains each = total 4 chains)

50

Which molecules of the TCR complex have ITAMs? 34

(2) CD3 molecules (4 total chains)

Zeta chain (2 chains)

51

What part of the TCR complex is mainly responsible for signal transduction? 34

The dimer of ζ chains (3 ITAMs each)

52

What is the structure of CD3? 34

One ε chain
One γ chain

Each has one loop or Ig domain

53

What are the two major roles of CD4 T cells? 35

activate macrophages for phagocytosis

secretion of cytokines to stimulate Ab production in B cells

54

What is required for binding of a T cell receptor to bind a HLA (MHC) 36

an Ag peptide

T cells can only recognize peptides

55

What are superantigens? 38

They're not processed, they bind directly to the HLA and the β chain of the TCR (make sure to note that it's the β chain!)

No Ag recognition required

56

Where are the majority of super antigens derived from? 38

bacterial superantigens

(viruses also have been associated with super antigens)

57

What does Superantigens do to the immune system? 38

Amps it up by making it super active

58

What are some examples of superantigen caused diseases? 38

Pyrogens exotoxins (Shock)

Staphylococcal enterotoxins (food poisoning)

59

What are monoclonal Abs? 40

Identical Abs that are produced to an Ag

Clone immune cells from a single parent

MAb or moAb

60

What are increasingly being used as a clinical diagnostic and therapeutic reagents? 41

Recombinant Abs

61

What is the monoclonal Ab Canakinumab used for and what's its target? 42

Target --> IL-1

Use --> RA

62

What Ags can B cells recognize? 43

protein, polysaccharid, and lipids

63

What is the associated disease or infection with Chronic Granulomatus Disease? 40

IC and EC infection or granulomas

64

What is the associated disease or infection with G6PD deficiency? 40

Defective respiratory burst and chronic infection

65

What is the associated disease or infection with Myeloperoxidase deficiency? 40

Defective intracellular killing and chronic infection

66

What is the associated disease or infection with Chediak-Higashi syndrome? 40

IC and EC infection or granulomas

67

What is the structure of IgG? 7

2 heavy chains (1 V Ig domain | 3 C Ig domains)
2 light chains (1 V Ig domain | 1 C Ig domains)

68

What is the structure of Class I MHC? 7

1 α chain with one binding region (for bacterial peptide) and 1 C Ig domain

1 β chain with one Ig domain

69

What conformations can Abs recognize Ags? 30

3D conformations and/or its denatured conformation

linear conformations

conformation after proteolytic cleavage

70

What identity of T lymphocyte chain exists in epithelial and mucosal compartments? 33

γ and δ

71

What is the structure of CD4? 35

a single chain of 4 Ig domains

72

What is the structure of CD8? 35

an α and β chain each with one Ig domain

73

What's unique about γδ TCRs?

They can recognize lipid and glycolipid Ags and are not HLA (MHC) restricted