Chapter 5 - T cell (Exam 3)

Question 1

similarities of antibodies to TCR

Answer 1

both have 2 chains
1 constant region
gene rearrangment

Question 2

differences of antibodies to TCR

Answer 2

Ab is wide range, TCR is peptides only
no further change in TCR after Ag stimulation
Ab has 2 binding sites, TCR has 1
TCR is membrane bound only

Question 3

unlike antibodies, TCR is membrane bound only. This means its function is to only _____________ and it has no ____________

Answer 3

recognize the antigen

no effector function

Question 4

TCR resembles _______ of an antibody

Answer 4

Fab

Question 5

somatic recombination in TCR

Answer 5

rearrange the beta chain
only 1 Ca gene segment

Question 6

RAG proteins are essential for

Answer 6

adaptive immunity

Question 7

omenn syndrome

Answer 7

partial loss of RAG protein activity
fatal

Question 8

treatment for SCID and Omenn syndrome

Answer 8

bone marrow transplant at birth

Question 9

MHC heterozygosity delays

Answer 9

AIDS progression

Question 10

populations maintain a _________ of HLA Class I and II ______________

Answer 10

diversity

allotypes

Question 11

gamma chain delta chain T cell receptor

Answer 11

1-5% of T cells
function is less defined
can bind peptide without MHC

Question 12

the delta chain has more ___________ than the beta chain

Answer 12

junctional diversity

Question 13

the delta chain locus is located between

Answer 13

V, J of alpha chain locus

Question 14

TCR has more ___________ than Ig in somatic recombination due to _____________

Answer 14

diversity

J segment

Question 15

antigen processing

Answer 15

degrading of pathogen derived proteins into peptides

Question 16

antigen presentation

Answer 16

binding of peptide by MHC and display at cell surface

Question 17

MHC class I targets ____________ by binding ____________

Answer 17

intracellular pathogens

cytotoxic T cells

Question 18

MHC class II targets ______________ by binding _______________

Answer 18

extracellular pathogens

helper T cells

Question 19

professional APCs

Answer 19

they have the highest expression on MHC class I and II
can present the best to T cells

Question 20

which types of cells are professional APCs

Answer 20

B cells
Macrophages
Dendritic Cells

Question 21

class I MHC is on

Answer 21

almost every cell

Question 22

2 effector functions of T cells

Answer 22

kills infected cells (CD8)
helps other cells (inc microbicidal activity of macrophages or B cell differentiation)

Question 23

MHC II also known as the

Answer 23

vesicular system

Question 24

MHC II is continuous with

Answer 24

the extracellular fluid

Question 25

MHC I is in the

Answer 25

cytosol

Question 26

MHC is ___________ because it can bind

Answer 26

promiscuous many different peptides

Question 27

Do MHC I and MHC II bind the same peptides?

Answer 27

NO! they bind different types

Question 28

immunoproteasome

Answer 28

modified subunits and cap proteins makes peptides with hydrophobic or basic terminus

Question 29

For MHC I, the __________ degrades cytoplasmic proteins into ___________ to present to _________ T cells

Answer 29

proteasome peptides CD8

Question 30

TAP

Answer 30

transporter associated with antigen processing transports peptides into ER so it can bind MHC I

Question 31

bare lymphocyte syndrome

Answer 31

TAP nonfunctional, no peptides enter ER very few MHC I on surface

Question 32

In MHC II, the ___________ pathogen peptide is generated in _________________

Answer 32

external endocytic vesicle

Question 33

how does proteases to degrade pathogen proteins into peptides?

Answer 33

the phagosome fuses with lysosome

Question 34

Even without infection, MHC I and II are constantly presenting ___________ that should not be recognized by TCR

Answer 34

self peptides

Question 35

2 stages of antigen presentation

Answer 35

T cell is primed by dendritic cell T cell performs effector function

Question 36

priming of T cell by dendritic cell occurs in

Answer 36

secondary lymphoid tissue

Question 37

T cell modification of other cells occurs at

Answer 37

site of infection, secondary lymphoid tissue, periphery

Question 38

CTL response (MHC I)

Answer 38

virus infects dendritic cell priming of naive CTL -> effector effector CTL migrates to infection site and kills

Question 39

Helper response: MO activation

Answer 39

dendritic cell phagocytoses pathogen migrates to lymph node and activates naive helper T cell effector T cell migrates to infection site and helps MO there

Question 40

Helper response: B cell activation

Answer 40

same steps as MO activation except effector T cell helps B cell in lymph

Question 41

Cross presentation

Answer 41

APC captures virus by extracellular pathway then prevents complex to CTL of intracellular pathway intracellular pathogen degraded by extracellular response

Question 42

can pathogens prevent processing and presentation?

Answer 42

YES!

Question 43

MHC has

Answer 43

inherited diversity

Question 44

very different _______ molecules are usually expressed on APCs from ______________

Answer 44

MHC different people

Question 45

2 sources of inherited diversity of MHC

Answer 45

different gene families genetic polymorphism

Question 46

different gene families

Answer 46

each person has multiple genes for MHC Ia chain and HC II a and b chains

Question 47

isotopes are different

Answer 47

proteins in a gene family

Question 48

genetic polymorphisms

Answer 48

multiple forms of these genes in one person vs another

Question 49

allotypes

Answer 49

different proteins encoded by different alleles

Question 50

types of genetic polymorphisms

Answer 50

highly polymorphic oligomorphic monomorphic

Question 51

MHC Class I isotypes

Answer 51

HLA-A HLA-B HLA-C

Question 52

MHC class II isotypes

Answer 52

HLA-DP HLA-DQ HLA-DR

Question 53

polymorphism in MHC alleles is

Answer 53

uniquely large

Question 54

differences in MHC are usually in the

Answer 54

peptide binding groove

Question 55

there is ______ polymorphism in MHC allotypes

Answer 55

high

Question 56

in class II MHC, each alpha and beta chain are encoded by

Answer 56

separate genes

Question 57

in class I MHC, each alpha chain is encoded by

Answer 57

a separate gene (A,B,C)

Question 58

MHC alleles are

Answer 58

codominant

Question 59

specific allotropes expressed are determined by

Answer 59

polymorphisms a person has

Question 60

HLA haplotype

Answer 60

particular combination of HLA alleles found on chromosome 6 in a single human

Question 61

is it likely that 2 people will share the same HLA haplotype?

Answer 61

VERY UNLIKELY

Question 62

minimum HLA isoforms

Answer 62

in homozygote 3 class I, 3 class II

Question 63

maximum HLA isoforms

Answer 63

in heterozygotę 6 class I, 12 class II

Question 64

having multiple different HLA alleles

Answer 64

improves immune response

Question 65

amino acid differences in MHC occur

Answer 65

at sites that contact peptide or TCR

Question 66

MHC restriction

Answer 66

each T cell receptor recognizes a unique peptide:MHC combination

Question 67

the specificity of T cells is dictated by

Answer 67

the distinct MHC molecules

Question 68

heterozygotę advantage

Answer 68

covers more types of peptides to present

Question 69

alloreactive T cells

Answer 69

attack a transplanted organ

Question 70

alloreactive antibodies

Answer 70

produced by mother during pregnancy react to HLA molecules in fetus specific to father can also attack a transplanted organ