Immuno Cell Types

Question 1

natural killer cells

Answer 1

use perforin / granzymes –> apoptosis of viral / tumor cells.
only lymphocyte of innate immune system.

Question 2

cytokines increasing NK cells activity

Answer 2

IL2, IL12, IFNB, IFNa

Question 3

mechanism of NK cells killing

Answer 3

Antibody dependent cell mediated cytotoxicity.

Question 4

antibody dependent cell mediated cytotoxicity

Answer 4

CD16 binds Fc regions of bound Ig –> NK activation

Question 5

positive T cell selection

Answer 5

occurs i the thymic cortex. T cells expressing TCRs that can bind surface self MHC molecules survive

Question 6

negative T cell selection

Answer 6

occurs in medulla. T cells expressing TCRs with high affinity for self antigens undergo apoptosis

Question 7

2 signals required for T cell activation

Answer 7

1) MHC II cell presents antigen

2) costimulatory signal given by B7 / CD28

Question 8

2 signals required for B cell activation / class switching

Answer 8

1) helper T cell activated by MHC II antigen mediated activation
2) CD40 on B cell binds CD40 ligand on Th cell
3) Th cell secretes cytokines –> Ig class switching of B cell via affinity maturation + antibody production

Question 9

antigen presenting cells: 3 types

Answer 9

B cells
macrophages
dendritic cells

Question 10

Th1 cell secretes

Answer 10

IFN y

Question 11

Th2 cell secretes

Answer 11

Il4, IL5, Il6, IL13

Question 12

Th1 activates

Answer 12

macrophage + cytotoxic lymphocytes (CTLs). used for INTRACELLULAR organisms

Question 13

Th2 function

Answer 13

recruits eosinophils for parasite defense / promotes IgE production by B cells

Question 14

cytotoxic T cells

Answer 14

kill virus infected, neoplastic, donor graft cells via apoptosis induction

Question 15

cytotoxic T cell mechanism

Answer 15

release cytotoxic granules w/ perforin (deliver granules into target cell) + granzyme B (serine protease, which activates apoptosis inside target cell), granulysin (antimicrobial inducing apoptosis)

Question 16

regulatory T cells suppresses

Answer 16

CD4 / CD8 T cell effector n –> maintain specific immune tolerance.

Question 17

regulatory T cells expresses

Answer 17

CD3, CD4, CD25, transcription factor FOXP3

Question 18

Fab region on antibody

Answer 18

1) binds antigen

2) determines IDIOtype (unique antigen binding pocket)

Question 19

Fc region

Answer 19

1) constant
2) carboxy terminal
3) site of complement binding
4) carbohydrate side changes
5) determines ISOtype (IgM, IgD)

Question 20

how is antibody diversity generated

Answer 20

1) random VJ / V(D)J recombination
2) random heavy chain / light chain combos
3) somatic hypermutation after antigen stimulation
4) addition of nucleotides to DNA during recombination via terminal deoxynucleotidyl transferase

Question 21

thymus independent antigens

Answer 21

lacks a peptide component –> it cannot be presented by MHC to T cells.
weak / nonimmunogenic.

Question 22

ex. of a thymus independent antigen

Answer 22

lipoplysaccharides from gram-negative bacteria. vaccines made from this require a booster (i.e.: pneumococcal polysaccharide vaccine)

Question 23

thymus dependent antigen

Answer 23

antigens w/ protein component (class switching + immunologic memory via direct contact of B cells / Th Cd40 interaction)

Question 24

thymus dependent antigen vaccine example

Answer 24

diphtheria vaccine

Question 25

3 mechanisms for activation of complement

Answer 25

1) classical pathway: IgG / IgM
2) alternative: microbe surface molecules
3) lecithin pathway: mannose / other sugars on microbe surface

Question 26

functions of complement 3b

Answer 26

opsonization; binds BACTERIA

Question 27

function of C3a, 4a, 5a

Answer 27

anaphylaxis

Question 28

function of C5a

Answer 28

neutrophil chemotaxis

Question 29

function of C5b-9

Answer 29

cytolysis by MAC

Question 30

inhibitors of complement

Answer 30

1) DAF (decay accelerating factor / CD55)

2) C1 esterase inhibitor –> prevents complement activation on self-cells (RBC)

Question 31

TNFa function

Answer 31

1) SEPTIC SHOCK
2) activation of endothelium
3) leukocyte recruitment / vascular leakage

Question 32

Macrophage secretions

Answer 32

IL1, Il6, Il8, Il12, TNF-a

Question 33

Th1 secretion:

Answer 33

interferon y

Question 34

cytokines secreted by T cells

Answer 34

Il2 / Il3(bone marrow stem cells)

Question 35

effects of interferon a + b

Answer 35

innate host defense against viruses resulting in apoptosis and interrupting viral amplification

1) activation of RNAse L –> degradation of viral / host mRNA
2) protein kinase –> inhibition of viral / host protein synthesis

Question 36

T cell surface proteins

Answer 36

TCR (binds antigen-MHC complex)
CD3 (TCR + signal transduction)
CD28 (B7 on APC)

Question 37

Helper T cell surface proteins

Answer 37

CD4, CD40 ligand

Question 38

cytotoxic T cells surface markers

Answer 38

CD8

Question 39

B cell surface markers

Answer 39

CD19, 20, 21, CD40, MHC II / B7

Question 40

macrophages surface markers

Answer 40

CD14, CD40, MHC II, B7. Fc / C3b receptors, enhancing phagocytosis

Question 41

NK surface markers

Answer 41

Cd16 (binds Fc of IgG), Cd56 –> marker for NK

Question 42

macrophage surface receptor

Answer 42

CD14 (kupffer cells, mesangial, alveolar macrophages, microglia)