Week 7 Immuno 1 Plfsom Jr

Front 1

Fever is caused by the systemic action of

Back 1

TNF-a and IL-1

Front 2

What is the main source of TNF-a and IL-1?

Back 2

macrophages

Front 3

Do activated T cells secrete any TNF-a?

Back 3

yes

Front 4

Nothing activates macrophages like _____!

Back 4

IFN-gamma

Front 5

Where is IFN-gamma produced?

Back 5

NK cells, CD4 T helper (main), CD8 T cells(minor)

Front 6

define cytokines

Back 6

polypeptides produced during immune response that mediate/regulate response

Front 7

cytokine method of action

Back 7

autocrine, paracrine, or endocrine(TNF-a and IL-1)

Front 8

Is cytokine release long/extended?

Back 8

no, it is brief, limited

Front 9

define pleiotropic

Back 9

one cytokine has multiple functions

Front 10

are cytokines pleiotropic?

Back 10

Yes

Front 11

Are cytokine redundant (multiple cytokines have similar functions)? Ex?

Back 11

Yes, Example TNF-a and IL-1

Front 12

Cytokines and feedback loops

Back 12

cytokines influence the secretion/action of other cytokines

Front 13

Where do T cells originate?

Back 13

bone marrow, mature in Thymus

Front 14

Where do B cells originate?

Back 14

Bone marrow

Front 15

Is the generation of T and B cells steady-state/random?

Back 15

yes

Front 16

Have Naïve cells yet encountered an antigen on their TCR or BCR they can bind?

Back 16

no

Front 17

What is the consequence of lymphocyes not finding an antigen to bind?

Back 17

death within a few weeks

Front 18

Which are harder to activate, naïve, effector, or memory cells?

Back 18

naïve

Front 19

What is the only location where lymphocytes are activated?

Back 19

in the peripheral lymphoid organs

Front 20

What makes dendritic cells the only cells able to active naïve t cells?

Back 20

they express enough MHC and costimulatory molecules and (IL-12) to activate a naïve T cell

Front 21

Naïve cells that bind antigen will become _____ or ______

Back 21

effector or memory cells

Front 22

what is the lifespan of effector cells?

Back 22

few days

Front 23

Generally in peripheral blood do we have more memory and effector or naïve cells?

Back 23

naïve

Front 24

B cell function

Back 24

make antibody

Front 25

T cell function

Back 25

migrate to tissues where CD4 make cytokines which activate other cells like macrophages or CD8s

Front 26

How long can memory cells be quiscent for?

Back 26

years

Front 27

how are memory cells reactivated?

Back 27

by seeing their specific antigen again.

Front 28

Are memory T cells heterologous?

Back 28

Yes (CD4+TH1, TH2, TH17; CD8+ CTL)

Front 29

Do we know much about memory B cells?

Back 29

No, most of what we know is about memory T cells

Front 30

Where are memory T cells found?

Back 30

everywhere

Front 31

Memory cells are dependent on what IL?

Back 31

IL-7

Front 32

What does IL7 do for memory cells?

Back 32

helps them survive and divide from time to time

Front 33

Are memory cells easier or harder to activate than naïve cells?

Back 33

easier

Front 34

Why is T cell reactivation easier than naïve cell activation?

Back 34

doesn’t need dendritic cells, can occur outside of the lymph nodes

Front 35

Some activated B cells (from T-dependent responses to protein antigens) differentiate into long-lived memory cells which are:

Back 35

heterologous (HC of BCR is isotype switched); found mostly in lymphoid organs; dormant unless reactivated; easier to activate than naïve cells)

Front 36

What are the 4 types of CD4 TH cells?

Back 36

TH1, TH17, TH2, Tregs

Front 37

What is the 5th type of T cell

Back 37

CD8+

Front 38

TH1

Back 38

stimulate phagocyte-mediated ingestion (opsonization) and killing of microbes

Front 39

TH17

Back 39

produce IL-17, mediate inflammation, powerful recruitment of neutrophils and monocytes

Front 40

TH2

Back 40

immunity to parasites (allergies too) mediated by eosinophils and mast cells. Alternatve macrophage activation, production of neutralizing vs opsonizing antibodies

Front 41

Tregs

Back 41

Regulatory T cells,

Front 42

CD8

Back 42

kill infected cells

Front 43

What 2 cytokines favor differentiation of naïve CD4 T cells into TH1 cells?

Back 43

IL-12 from DCs and macros, plus IFN-gamma from NK ells or TH1 cells

Front 44

What signaling pathway does IFN-y activate?

Back 44

STAT 1 signalling pathway

Front 45

STAT 1 induces expression of what?

Back 45

T-bet- don’t forget T-bet!!!

Front 46

Il-12 acivates what STAT signaling pathway

Back 46

STAT 4

Front 47

What is the one thing to remember about TH1 cells?

Back 47

They produce IFN-y

Front 48

Is IFN-y more or less potent than IFN-a and IFN-B?

Back 48

IFN-y is less potent

Front 49

IFN-y promotes__________.

Back 49

phagocytosis

Front 50

IFN-y promotes B cell isotype switch to

Back 50

IgG/IgG3 isotypes

Front 51

IgG1/IgG3 isotypes opsonize via ____ receptorson phagocytes

Back 51

Fc

Front 52

IgG1/IgG3 activate the ________ pathway and opsonize microbes via _______ on phagocytes

Back 52

Classical complement, complement receptors (CR1)

Front 53

IFN-y is a potent activator of macrophages- increases their production of

Back 53

NO, ROS, MHC2, B7 (costimulatory molecule)

Front 54

Steps to class switching of B cells in lymph node

Back 54

1- TCR binds MHC2 on B cell. 2- CD40L on T cell binds CD40 on B cell. 3- Multiple direct interactions cause secretion of IFN-y by the T cell. 4- Direct interactions and IFN-y causes B cell to class switch from IgM to IgG1 or IgG3

Front 55

B cells class switch from _______ to _________or ________ through TH1 cell binding

Back 55

IgM to IgG1 or IgG3

Front 56

Steps to activation of MACROPHAGES by TH1 cells

Back 56

1- TCRs on T cell bind to MHC2/peptide complex on macrophage 2- CD40L on T cell binds CD40 on macrophage 3- Direct interactions cause secretion of IFN-y by TH1 cell which activates macrophage.

Front 57

What does the secretion of IL-12 by macrophage do?

Back 57

amplifies the macrophage activation process

Front 58

IMPORTANT- Activated macrophages secrete what cytokines?

Back 58

TNF-a, IL-1, and IL-6

Front 59

Il-1 and TNF-a induce what?

Back 59

FEVER!!!!!!!!

Front 60

Can TH1 cells also make some TNF-a directly?

Back 60

Yes

Front 61

Do TH1 cells secrete IL-2?

Back 61

Yes

Front 62

What IL2 chain do TH1 cells EXPRESS?

Back 62

IL-2Ra chain (CD25)

Front 63

What does IL-2Ra convert?

Back 63

IL2-R from low to high affinity so they bind IL-2 better

Front 64

Which IL is a major autocrine/paracrine proliferator for T cells?

Back 64

IL-2

Front 65

IL-2 is a proliferation factor for what cells?

Back 65

T cells, NK cells, B cells, and Tregs

Front 66

IL2 and CD8 relation

Back 66

IL2 activates naïve CD8 cells

Front 67

What Interleukins to TH17 cells produce?

Back 67

IL-17 and IL-22

Front 68

What cytokines favor development of TH17?

Back 68

IL-6, IL-23 and TGF-B

Front 69

Do TH17 cells have a role against some bacterial/fungal infections?

Back 69

Yes

Front 70

What does IL-17 do?

Back 70

causes chemokine/cytokine production by various cells, strong recruitemnt of neutrophils/monocytes

Front 71

What does IL-22 do?

Back 71

maintain epithelial barrier

Front 72

Type 1 hypersensitivity

Back 72

Immediate, IgE mediated

Front 73

Type 2 hypersensitivity

Back 73

antibody mediated (not IgE) (

Front 74

Type 3 hypersensitivity

Back 74

immune complex mediated- "floated there and got stuck"

Front 75

Type 4 hypersensitivity

Back 75

cell-mediated

Front 76

Damage of Type 4 caused by:

Back 76

1- macrophages activated by IFN-y predominantly from TH1 cells (also called Delayed Type hypersensitivity). IMPORTANT 2- killing of infected cells by CD8s

Front 77

Define Hypersensitivity

Back 77

Damage caused due to an immune response

Front 78

Type 4 hypersensitvity is caused by __________

Back 78

adaptive cell-mediated immunity

Front 79

IFN-y from TH1 cells and some IFN-y from CD8 cells activate _______

Back 79

macrophages

Front 80

IL-17 from TH17 recruit_________.

Back 80

neutrophils

Front 81

Explain Delayed-Type Hypersensitivity in relation to TH1 CD4 cells

Back 81

"Some microbes have virulence factors that resist innate immune microbial killing functions of macrophage, Macrophage activation by IFN-g from TH1 cells shifts the battle in favor of the macrophage allowing it to become activated and kill the microbes. Products of activated macrophages (like ROS) are toxic to tissues, so prolonged macrophage activation injures tissues

Front 82

What types of intracellular microbes are eliminated by CD4 TH1 cells?

Back 82

phagocytosed mucrobes that survive within phagolysosomes, microbes that escape from phagolysosomes into cytoplasm. Ex: mycobacteria

Front 83

What intracellular microbes are killed by CD8 cells?

Back 83

microbes that infect nonphagocytic cells. Ex: all viruses

Front 84

Define immunologic synapse in terms of CD8 CTLs

Back 84

CTL adheres to target cell via adhesion molecules (integrins, LFA-1, ICAM-1) which forms the immunologic synapse

Front 85

What does CTL deliver into the synapse that the target cells uptake?

Back 85

granules containing perforin and granzymes, by receptor mediated endocytosis

Front 86

What do perforins (similar to C9) do?

Back 86

make "holes"

Front 87

What do granzymes do?

Back 87

go through the "holes" caused by perforins and activate caspase-3, which causes apoptosis.

Front 88

Which granzyme activates caspase-3?

Back 88

granzyme 3

Front 89

Can CTL kill after already having killed?

Back 89

Yes

Front 90

Are CTLs and NK cells similar in their mode of attack?

Back 90

Yes