23 exam 2

Question 1

which cells play an important role in pathogen clearance by activating other cells during an adaptive immune response?

Answer 1

T cells

Question 2

T cells that recognize antigen presented on MHC class 1 typically are

Answer 2

activated to fight off intracellular pathogens

Question 3

a T cell that has CD4 as a coreceptor is a(n) ____ cell

Answer 3

helper T

Question 4

all the alleles of every MHC class 1 and class 2 gene is an individual make up that person’s ____, which provides the overall MHC diversity

Answer 4

haplotype

Question 5

which of these is the major stimulatory signal molecule for naïve T-cells?

Answer 5

CD28

Question 6

what enzyme adds nucleotides to gene segments during recombination?

Answer 6

TdT

Question 7

which of these proteins includes beta2 microglobulin in its structure?

Answer 7

MHC class 1

Question 8

nearly all nucleated cells express which of these?

Answer 8

MHC class 1

Question 9

the invariant chain is important for which of these?

Answer 9

exogenous antigen presentation on MHC class 2

Question 10

which of these are effector B cells that secrete soluble immunoglobulins?

Answer 10

plasma cells

Question 11

which statement about B cells is true?

Answer 11

they are localized in the T-cell zone of a secondary lymphoid tissue and can activate naïve T-cells if they recognize the same antigen

Question 12

interaction between the T-cell receptor and an MHC-peptide complex, coupled with the proper costimulatory signaling, promotes the formation of a(n)

Answer 12

immunological synapse between the T cell and an APC

Question 13

the most important type of cells in T-cell activation are ____

Answer 13

dendritic cells

Question 14

following activation, naïve T-cells differentiate into what?

Answer 14

effector cells

Question 15

what happens when dendritic cells secrete the chemokine CCL18?

Answer 15

T-cells migrate to lymph nodes

Question 16

which of these is not a common antigen presenting cell for T-cell activation?

Answer 16

hepatocyte

Question 17

which of these is an important chemokine receptor found on T-cells?

Answer 17

CCR7

Question 18

ZAP-70 is involved in activating what type of cells?

Answer 18

T-cells

Question 19

which of these migrate from the bone marrow to the spleen?

Answer 19

transitional B cells

Question 20

during the development of B cells, successful recombination of what leads to creation of a B-cell receptor?

Answer 20

the successful recombination of a heavy chain locus

Question 21

rearrangement of the heavy chain loci is tested through the use of a surrogate light chain during the ____

Answer 21

early pre-B cell stage

Question 22

hematopoietic stem cells (HSCs) must be able to interact with and receive signals from specialized cells in the bone marrow known as what?

Answer 22

stromal cells

Question 23

where do B-cell first form during embryogenesis?

Answer 23

yolk sac

Question 24

which of these has low amount of IgM and high amounts of IgD on their cell surface?

Answer 24

B-2 B cells

Question 25

which population of B-cells seem to be self-renewing?

Answer 25

B-1 B cells

Question 26

where do most immature B-cells head to when first formed?

Answer 26

spleen

Question 27

What is a T1 cell?

Answer 27

a transitional stage of a B-cell

Question 28

immunoglobulin structure consists of which of these?

Answer 28

two heavy and two light polypeptide chains

Question 29

immunoglobulin molecules____

Answer 29

are expressed as membrane-bound or secreted soluble molecules

Question 30

B-cell activation requires interaction of specific cell-surface proteins associated with immunoglobulins known as what?

Answer 30

Ig-alpha and Ig-beta chains

Question 31

the ___ region of an antibody plays an important role in binding to receptors of certain immune system cells, including macrophages, dendritic cells, and granulocytes such as mast cells

Answer 31

Fc

Question 32

which isotype of antibody is most important for mucosal immunity

Answer 32

IgA

Question 33

what term refers to where an antibody bind on an antigen?

Answer 33

epitope

Question 34

which group of macromolecules are the most antigenic?

Answer 34

polypeptides

Question 35

alternative mRNA splicing is involved in _____ in the heavy chain

Answer 35

VDJ-C joining (D-J and V-DJ were ruled out and hypermutation doesn't make sense)

Question 36

the action of AID causes cytosines to be converted to what?

Answer 36

uracil

Question 37

cross-presentation of antigens can occur through a process called what?

Answer 37

cytosolic diversion

Question 38

what is the function of TAP in antigen presentation?

Answer 38

transport of peptides into the ER

Question 39

MHC class I molecules are found on what cells?

Answer 39

all somatic cells

Question 40

which subunit of the IL-2 receptor converts it from low affinity to high affinity?

Answer 40

alpha

Question 41

which of these are most important for stimulating macrophage activity?

Answer 41

Th1

Question 42

which signaling pathway in B- and T-cells most involves the action of calcium?

Answer 42

IP3 pathway

Question 43

what enzyme is responsible for forming IP3 and DAG during cell signaling?

Answer 43

phospholipase c (PLC)

Question 44

at what location does most somatic hypermutation occur?

Answer 44

germinal centers

Question 45

which of these antibodies is not formed as a result of isotype switching?

Answer 45

IgD

Question 46

which of these antibodies in not released into the serum in appreciable amounts?

Answer 46

IgD

Question 47

which effector cytokine is most important for developing helper T-cells?

Answer 47

IL-4

Question 48

activation of Fas via its ligand leads to what process?

Answer 48

apoptosis

Question 49

what is the "second key" to activate and arm a naïve B-cell?

Answer 49

CD40 ligand

Question 50

what kind of b-cells are mostly found in the peritoneum?

Answer 50

B-1 B-cells

Question 51

which immune organ is most responsible for dealing with blood-borne pathogens?

Answer 51

spleen

Question 52

which of the following is not a direct function of antibodies?

Answer 52

cell lysis

Question 53

how many protein chains make up an antibody?

Answer 53

four

Question 54

what hold the chains of an antibody molecule together?

Answer 54

disulfide bonds

Question 55

which of these pairs is representative of endogenous antigen presentation?

Answer 55

MHC class I interacting with CD8

Question 56

____ T-cells activate other immune system cells

Answer 56

effector

Question 57

CTLA4 ___ regulates T-cell activity

Answer 57

down

Question 58

the most common type of T-cell receptor in the adult human body is ____

Answer 58

alpha/beta

Question 59

MHC class II presents ___ peptides than does MHC class I

Answer 59

longer

Question 60

class I MHC molecules are loaded with antigen in the _____

Answer 60

ER

Question 61

CCL19 is produced in the ____ to attract naïve T-cells

Answer 61

lymph nodes

Question 62

_____ is the main signal that allows T-cells to reenter circulation

Answer 62

sphingosine-1-phosphate

Question 63

signaling between a T-cell and a dendritic cell occurs in the immunological _____

Answer 63

synapse

Question 64

MAP kinases are mostly activated by ____-dependent mechanisms

Answer 64

DAG

Question 65

Th17 cells mostly stimulate _____

Answer 65

neutrophils

Question 66

_____ are the most common kind of B cells in our body

Answer 66

B-2 B

Question 67

stem cell factor is found on the surface of ____ cells in the bone marrow

Answer 67

stromal

Question 68

the cytokine ___ drives lymphocytes toward becoming B cells

Answer 68

IL-7

Question 69

in B-cell receptor formation, the ___ chain is made first

Answer 69

heavy

Question 70

a total of ___ chromosomes contain antibody protein genes

Answer 70

three

Question 71

the first structure of antibodies was worked out by ____

Answer 71

Ehrlich

Question 72

antibodies gain additional specificity through a process called ______

Answer 72

affinity maturation

Question 73

coating of a pathogen with antibodies is called ____

Answer 73

opsonization

Question 74

____ is the isotype of antibody formed in the primary immune response

Answer 74

IgM

Question 75

IgE binds to ____ and is associated with allergies

Answer 75

mast cells