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Flashcards in Antigen Receptors: lymphocytes Deck (61):
1

What do helper T cells do?

Make cytokines

2

What do CTL do?

Kill infected cells

3

What is class 1 HLA/MHC found on?

All nucleated cells

4

What is class 2 MHC/HLA found on?

Professional APCs (macro, dendritic, b cells, some thymocytes)

5

What does HLA stand for?

Human leukocyte antigen

6

What is an antigen?

Part of a molecule that is recognized by the immune system

7

What is an immunogen?

An antigen that that evokes a specific immune response

8

What is a tolerogen?

An antigen that induces immunologic tolerance

9

What is an endogenous antigen?

The body’s own cellular components or intracellular pathogens

10

What are self-antigens?

Autoantigens

11

What are tissue specific antigens called?

Alloantigens

12

What are viruses, intracellular bacteria, and parasites called?

Intracellular pathogens

13

____________ antigens are those that enter the body from outside

Exogenous

14

__________ are small molecules that cannot induce an immune response alone but they can when coupled with a carrier protein

Hapten

15

Haptens are clinically important in what 2 processes?

Drug allergies and vaccine design

16

BCR are made of two ________ chains (Ig__ and Ig___). Does this molecule participate in signaling?

Invariate, alpha, beta, yes

17

Antibodies in circulation are what?

Surface immunoglobins in which the cytoplasmic and TM domain are removed and replaced with a tail piece

18

The EC tips of Ab are variable or non-variable?

Variable

19

What chain is the longest portion of the antibody?

Heavy chain

20

What type of bonds keeps antibodies together?

Disulfide

21

What does digestion of Ab with papain do?

It breaks off the two branch regions above the hinge

22

What does pepsin do to Ab?

Cleaves below the hinge and leaves the binding domains all connected

23

When an antibody is digested by either papain or pepsin does it retain function?

No, need the whole thing to be able to have the immune system recognize it

24

How many hypervariable domains are on each v domain

3, they are flanked on all sides by framework regions (total of 4)

25

What allows flexibility of Ab?

There are hinges below the branch which allow 2 and 3D flexibility

26

What distinguishes the _____ different isotopes of Ig?

5; charge, size, AA sequence, carb content

27

Subclasses of Ig are defined by what?

Constant region of heavy chain

28

How many classes and subclasses are in humans of Ig?

9

29

Allotype is determined by _____________ differences on the _____ chains

Allelic, heavy

30

Idiotype of Ig is determined by __________ ___________ on the ______ region

Antigenic determinants, variable

31

What is the first Ig produced in response to an antigen? What does it look like?

IgM, pentamer

32

What antibody is produced by neonates?

IgM

33

What is the purpose of the J chain in Ig?

Binds to secretory cells of the mucosa

34

What is the predominant Ab of secondary immune responses?

IgG

35

What is the most abundant Ab?

IgG, it makes up 80% of total serum Ab

36

How many different types of IgG are there? Where are the differences found?>

4, differences are on the H chain

37

What subclass of IgG are most abundant?

IgG1 then 2 then 3 then 4

38

What activates the classical complement pathway?

IgG

39

IgA can be found as what two forms?

Monomer or dimer, but it is predominantly a monomer

40

What does IgA primarily function in?

Mucosal immunity

41

Where is IgA found?

Breast milk (protects new borns), saliva, tears, mucus

42

What is the function of IgE?

Binds to blood basophils and tissue mast cells with high affinity (CD23a and CD23b)

Reacts in asthma, allergies, and helminth infections

43

What Ig has no know function? Where is it found in the body?

IgD; mature B cells have a receptor for it but it doesn’t activate B cells

44

What kind of bond do Ab form with their Ag?

Non-covalent and these are reversible

45

What is the strength that an Ab bonds to Ag called? What is the overall strength of Ab binding to Ag while factoring in number of binding domains?

Affinity, avidity

46

What are Ag that require both Th and B cells to stimulate an Ab response called?

T-dependent Ags, they are proteins

47

What are polysaccharides and lipids that can stimulate Ab responses without T help called?

T-independent Ags

48

On TCR what are the different chains?

Beta and alpha chains
(The more distal ends of both are variable)
(The beta chain has a larger bump out near the TM domain)

49

What is the the order of the hypervariable loops on TCR from lateral to medial?

213 312

50

What type of T cells express gamma/delta chains?

Epithelial/mucosal

51

What is the most variable region on TCR?

3, the innermost portion

52

What CD do all T cells express?

CD3

53

What does the CD3 complex ensure?

Cell surface expression of TCR and is involved in signal transduction

54

CD4 T cells are know as what? What do they bind to? What do they do?

Helper T cells, MHC/HLA 2, they activate macrophages and secrete cytokines and stimulate B cells to produce Ab

55

What are CD8 T cells called? What do they bind to? What do they do?

CTL (cytotoxic t lymphocytes), MHC/HLA1 , they kill intercellular pathogens

56

What do gamma/delta T cells do?

Recognize lipid Ags, can recognize DAMPs, don’t seem to be restricted to a MHC/HLA

57

What are not processed but bind directly to HLA class 2? What are some associated conditions

Super antigens; staph entero toxins (food poisoning), staph toxic shock syndrome, staph exfoliating toxins (scalded skin syndrome), step pyrogenic exotoxins, H1N1, SARS, Ebola

58

What are monoclonal Ab?

They are antibodies which recognize on epitope that originated from one cell

59

Antibodies targeting IL1 are important in the treatment of what disease?

RA

60

Ab targeting VEGF-A are important in targeting what?

Metastatic cancer

61

Ab targeting TNF-alpha are important in treating what?

Crohn’s disease