TCR and cell mediated immunity

Question 1

the part of a peptide antigen that is recognized by the T lymphocyte antigen receptors (TCR) aka the Antigenic Determinant

Answer 1

Epitope

Question 2

TCR and BCR have constant regions (genetically conserved) _ domain and variable regions (genetically diverse) _ recognition

Answer 2

receptor, antigen

Question 3

BCR or TCR? Recognizes linearized peptides derived from proteins

Answer 3

TCR

Question 4

BCR or TCR? Which is capable of recognizing numerous chemical structures?

proteins, lipids, lipoproteins

Answer 4

BCR

Question 5

BCR or TCR? Which are MHC restricted?

Answer 5

TCR

Question 6

Early lymphocyte development requires a commitment of progenitor cells. B cells: _ _ _ expression

T cells: _ _ _ expression

Answer 6

Heavy chain protein

TCR B chain protein expression

Question 7

Proliferation of precursor lymphocytes: _ produced by bone marrow stromal cells provides the mitogenic signal for developing lymphocytes to proliferate

Answer 7

IL7

Question 8

What are the checkpoints of lymphocyte maturation

Answer 8

1. Expression of Beta chain- has variable and constant region. Three segments- Variable (V) diversity (D) and joining (J)
2. Expression of alpha chain (variable and constant)

no d segment in alpha chain

Question 9

Each variable region of the TCRBeta and TCRalpha chain has 3 regions of hypervariability known as _

Answer 9

CDR (CDR 1, CDR2, CDR3)

Question 10

Antigenic diversity:

Combinatorial: variation amongst possible _ _ _ or _ _ exon combinations

Junctional: Removal of nucleotides, addition of nucleotides by _ enzyme

Answer 10

VDJ VJ

TdT (mutation in this leads to immunocompromised)

Question 11

Where do the induction and effector phases occur?

Answer 11

lymphatic tissue, peripheral tissue (site of infection)

Question 12

Naive T lymphocytes re-circulate through the body and are activated when _

Naive t cells possess machinery to recognize antigens but lack the _ functions to _ antigen

Answer 12

activated when they encounter microbial antigen in peripheral lymphoid organ

effector function, eliminate antigen

Question 13

Induction phase: what are the steps in t cell activation?

Answer 13

cytokines IL-2R, clonal expansion, differentiation (effector t cell, memory t cell)

Question 14

Step1 in antigen recognition and t cell activation

Answer 14

interact w/ APCs transiently, Recognition of antigen increases T cell integrin (LFA1) affinity

Question 15

CD4+ T cells function as _

CD8+ T cells function as _

Answer 15

cytokine producing helper cells

cytolytic T lymphocytes

Question 16

How many TCR coreceptors need to be engaged simultaneously in order to activate naive t cells?

Two families of TCR

• most common, abundant, recognize peptides: _
• prevalent in mucosal tissues, recognize lipids: _

Answer 16

two or more

alpha beta

gamma delta

Question 17

Step two in activation of Naive t lymphocytes (step 1 was antigen recognition)

Answer 17

T cell CD28 interaction with co-stimulatory molecule (B7?) on APC cell surface

Question 18

what is the purpose of each of these brackets on the left

Answer 18

signal transduction

antigen recognition

signal transduction

adhesion

Question 19

Naive t cells express these proteins on the surface. what are their functions?

CD3

CD4

CD8

CD28, ITAM

CTLA4, ITIM

LFA1

ICAM1

Answer 19

Question 20

Dendritic cells ingest antigen (something to do with PAMP) and then

Upregulate costimulatory molecules (_)

increase levels of _

Secrete _

Answer 20

b7

MHC

cytokines (e.g. IL12)

Question 21

cd28 on t cell recognizes _ on APC

Answer 21

B7

Question 22

three professional APCs- dendritic, B cell, and macrophages. B cell apc bind specific antigen via surface immunoglobulin. What happens next?

Answer 22

Endocytosis, degradation, then complex with MHC Class 2 surface

Question 23

IL-2 is produced by an activated _

it is a cytokine that stimulates proliferation 1-2 days after activation.

Answer 23

T Cell

Question 24

IL7

Answer 24

produced by bone marrow stromal cells, provides the mitogenic signal for developing lymphocytes to proliferate

Question 25

The variable region of the TCRβ chain is composed of three gene segments that recombine during cellular differentiation and maturation. These segments are:

Answer 25

V Variable D Diversity J Joining

Question 26

variations amongst possible V-D-J or V-J exon combinations is called _ antigenic diversity Removal of nucleotides, addition of nucleotides by _ enzyme, and strand repair during the recombination process is called _ antigenic diversity

Answer 26

**combinatorial** **antigenic (TdT enzyme)**

Question 27

Recognition of antigen increases T cell _ affinity so that the T cell:APC binding may remain in place for days as the naive T cell undergoes Activation, clonal expansion, and differentiation

Answer 27

T cell integrin LFA 1

Question 28

Naive t cells require 2 signals to become activated

Answer 28

1) TCR interaction with MHC antigen peptide complex 2) T cell cd28 interaction with co-stimulatory molecule on APC cell surface

Question 29

IL12 is secreted from _ and it's function is to \_

Answer 29

Cytokine secreted from an activated APC to cause differentiation of the T cell

Question 30

IL2

Answer 30

T cell proliferation cytokine produced by an activated T cell

Question 31

Role for IL-2 and the IL-2 receptors in T cell proliferation

Answer 31

T Cells upregulate **IL2Ra** chain to establish the high-affinity receptor

Question 32

What kind of cell would you get with each cytokine profile? IFNy, IL12 IL4 TGFβ, IL6, IL23

Answer 32

TH1 T cell TH2 T cell Th17 T cell

Question 33

T cell subset differentiation: Th1 cells are from _ cytokines? Th2...? Th17 ...?

Answer 33

IFNy, IL12 IL4 TGFβ, IL6 and IL23

Question 34

CD4+ t cells recognize MHC class 2 antigens and then differentiate into 3 types of t cells, what are their names and functions?

Answer 34

Th1- activate macrophage-\> kill intracellular bacteria Th2: activate B cells-\> secrete antibodies to parasites/ allergens Th17: activate PMNs-\> kill bacteria and fungi involved, in autoimmune response

Question 35

CD8+ t cells recognize antigen displayed by MHC class 1 and then differentiate into:

Answer 35

Cytotoxic t cells (**CTL**)

Question 36

TNF and IL-1 activation of endothelial cells and elevated production of chemokines occurs as a function of innate immunity.

Answer 36

Just so ya know.

Question 37

Those effector T cells that recognize specific antigens become further activated, increasing expression and affinity of _ integrins, allowing those cells to firmly adhere to the _ on endothelial cells and matrix at the site of infection

Answer 37

VLA4, VCAM1

Question 38

What does CCR7 do? L selectin? What does CXCR10 do? E or P selectin?

Answer 38

CCR7 and L selectin- traffic to lymphatic tissues CXCR10 and E or P selectin- traffic to peripheral/ regional tissues

Question 39

fill in the blanks

Answer 39

Question 40

fill in blanks

Answer 40

Question 41

CD40L and IFN- γ from _ bind receptors on _ to \_ Name 3 parts of the macrophage response and their role in cell-mediated immunity

Answer 41

CD4+ T cells, macrophages, enhance killing

Question 42

IL-12 fom macrophage function IFN γ from Effector T cell (Th1) function

Answer 42

IL-12 differentiation of naive CD4+ T cells into Th1 effector T cells IFN γ: increase antimicrobial killing in macrophages at the site of infection Positive feedback loop

Question 43

fill in

Answer 43

Question 44

CD4+ Th2 produce _ \_ and \_ and stimulate _ infammation and neutralizing \_

Answer 44

IL4, IL10, and IL13 eosinophilic inflammation neutralizing antibody

Question 45

which helper t cell inhibits microbicidal activity of macrophages?

Answer 45

Th2 cell via IL-4, -10, -13

Question 46

flil in the blanks about th17 cells

Answer 46

Question 47

TH17 cells

Answer 47

Question 48

CD8+ Cytolytic T lymphocytes (CTLs) are _ restricted secrete two proteins _ and \_ Express _ which can induce apoptosis by binding _ on target cells

Answer 48

MHC Class 1 Perforins, Granzymes Fas ligand, fas receptor

Question 49

Define superantigen, how does it work

Answer 49

massive and unregulated cytokine production triggered by activation of T cells by superantigen cross-links many different clones of T cells with class-II expressing APCs

Question 50

superantigen cytokines

Answer 50

IL1 and TNF changes in liver function, acute phase protein release change in vascular permeability hypotension IL2 (T cell proliferation) IFNy (isotype switching)

Question 51

Which cytokines are associated w/ superantigen

Answer 51

Question 52

Answer 52

Question 53

Answer 53

Question 54

Answer 54

Question 55

T cells develop in the _ and \_

Answer 55

bone marrow and thymus

Question 56

Expression of the _ chain is the first checkpoint in T cell development

Answer 56

TCRβ

Question 57

Expression of the _ a and β dimeric protein is the second checkpoint

Answer 57

TCTa and β

Question 58

T cell immune response is a sequential series: induction phase- TCR recognizes peptide antigens displayed with _ on \_

Answer 58

MHC, APC

Question 59

T cell immune response is a sequential series: induction phase- after TCR recognizes MHC on APC, T cell undergoes _ and \_

Answer 59

clonal expansion and differentiation

Question 60

T cell immune response is a sequential series: before t cell undergoes differentiation after TCR and MHC/antigen recognition, two signals are required:

Answer 60

signal 1: mhc-peptide recognition and binding by tcr signal 2: costimulatory molecule (b7/cd80)- recognition and binding by CD28 Cytokine environment dictates differentiation into T cell subsets

Question 61

CD4+ Th1: important in _ response Produces _ and \_ \_ activation Induce opsonizing antibody productoin (\_)

Answer 61

inflammatory response, IFNy and IL2, macrophage activation, IgG

Question 62

CD8+ \_ T lymphocytes

Answer 62

cytotoxic