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Flashcards in Week 4 Deck (63):
1

INF gamma and MHC

Signal causes proteosome to switch to an immunoproteosome which leads to proper size, charge for MHC presentation

2

TAP Protein

Tap 1 and TAP 2 are transport proteins which spans across the RER membrane. Affinity for proteins 8-16AA long.

3

ERAAP

ER amino peptidase. breaks up peptides down to 9 AA long. Anything smaller is further broken down to AAs.

4

20S proteosome

Is present in virally infected cells. Induced by INFy and TNFa. degrades and presents viral proteins via MHC class1

5

MHC class II Structure

Trimer made of Alpha, beta and invariant chains. The invariant chain assists in foldin of a and b chains, binds to the peptide presenting site of the class II molecules and assists in transport from MHC class II from the golgi to the cytoplasmic vesicles. Invariant chain is cleaved to CLIP before being exchanged for antigenic peptide and presentation.

6

Familial ALS

has a mutationin superoxide dismutase

7

Glutathione

enzyme which absorbs free radicles from lipid peroxides, needs selenium.

8

Vitamin E

alpha tocopherol. Most widely distributed antioxidant in nature. Protects against lipid peroxidation in membranes. Can donate a first e- and be stabilized by resonance, Second electron stabilized by oxidized Vit E.

9

Vitamin E deficiency

found in corn, nuts, olives, green vegetables, egg yolks. deficiency is uncommon. See hemolytic anemia, myopathy, and neurological defects

10

Ascorbic Acid

can donate 1e- to vitamin E for conversion back to reduced state. Important in collagen synthesis.

11

Ascorbic Acid deficiency

-citrus fruits, peppers, strawberries. Scurvey: impaired wound healing, bleeding eccymoses, swollen gums, anemia, lethargy, depression, corkscrew hairs.

12

Caratinoids

Vitamin A, beta carotene. antioxidant .... quench singlet oxygen.

13

Vitamin A deficiency

number 1 cause of accidental blindness in the world, night blindness, follicular hyperkaratosis, xeropthalmia.

14

Flavinoids

chelate Fe and prevent the fenton reaction. Donate electrons to superoxide or lipid peroxy radicles or complex them to stabilize them.

15

B cell Maturation

occurs in the marrow, does not require contact with antigen

16

TdT

expressed by pro and pre B cells. It adds random nucleotides for somatic mutations.

17

B cell staging

Stem cell, Pro, pre, Immature, mature, activated, memory B cell, Plasma cell.

18

CD34

present in stem and pro B cells, allowing attachment to their bone marrow receptor to allow for differentiation and growth.

19

Pre B cell

large and small (dividing status). As they become small pre-B cells, they begin to upregulate RAG1 and 2. They also express IL-7R and are stimulated to divide using IL7

20

Immature B cell

final stage of development in the marrow. Express IgM and later IgD. RAG1 and 2 downregulated. able to leave marrow and migrate.

21

IL7

Promotes B cell lineage development.

22

B- lymphocyte stimulator

Signals through BR3 for the survival of pre-immature B cell stages from transition stage onward.

23

IL4, IL3

are important in initiating B cell differentiation leading to division

24

Bruton's Tyrosine Kinase

Is a key enzyme involved in signal transduction downstream of the pre-BCR and BCR. defects lead to immunodeficiency XLA. patients have few circulating B cells and very low Ig. (agammaglobinemia).

25

TI 1

T Independant antigen 1. Can activate B cells without MHC class II T-help. TI-1 are predominantly bacterial cell wall components, mostly LPS. Stimulate via TLR 4, only IgM is produced. produce poor memory.

26

TI-2

predominantly large polysaccharide molecules with repeating antigenic determinants. ex. flagellin, ficoll. Can only stimulate B cells through the Bcell receptor. produce poor memory.

27

IL 2

from Th1 leads to B cell division.

28

Th2

releases IL 4 5 6 10 13 for B cell differentiation.

29

Th1

Releases INF y for B cell differentiation.

30

T cell induction of B cells

produces better memory and involves cytokine release.

31

Antigen presenting cell

releases IL1 for B cell activation.

32

T-cell maturation

originate in the marrow, migrate to thymus T cell precursor DN1-4(double -), double positive cell (cd4 and cd8) then CD4 or CD8 positive and negative selection, migation to body

33

Clonal anergy

if a T cell comes across an APC, CD28 looks for B7 on the APC. if cannot find it it is anergy and T cell can no longer become activated, will die shorly.

34

Super antigens

Recognize proteins outside the TCR and couples TCR, CD28 and MHC not needing B7 for activation. Nonspecific activation and cytokine storm.

35

CD 117

is Ckit. present in immature T cells D1 and 2 and less in D3 and low in D4

36

CD 44

Present In Immature T cells D 1 and D2, absent in D3 and D4

37

CD 25

Present in D2 and D3 absent in D1 and D4

38

CD 3

Is the T cell receptor

39

CD 4

Found on CD4 + T cells, after double positive stage

40

CD 8

Found on CD8 + T cells, after double positive stage

41

DN1

Ckit (CD117)++, Cd44+, CD 25-

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DN2

Ckit (CD117)++, Cd44+, CD 25+

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DN3

Ckit (CD117)+, Cd44-, CD 25+

44

DN 4

Ckit (CD117)low, Cd44-, CD 25-

45

MHC Class I

is the inhibatory signal for NK cells, activates CD8+ cells

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CD8+

Activated By MHC class1, costimulated by CD 28, B7 (from APC) interaction

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CTL (P)

naive T cells (precursor) CD8

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Naive CTL P

does not express IL2 or IL2 P Expresses CD45RA, no cytotoxic activity.

49

Mature CTL

High affinity for IL-2R, requires high levels of ILR to proliferate expresses CD45RO. Expresses high levels of the adhesion molecules CD2 and LFA-1. is cytotoxic

50

LFA-1

is part of CD8+ T cell receptor, increases and decreases its affinity to facillitate binding of the MHC class I.

51

CD8 killing

perforinmolecules form a pore on target cell membranes. Granzyme molecules activate apoptosis by cleavage of caspases

52

Fas ligand

binds to Fas on the membrane of target cells and initiates killing. activates apoptosis by cleavage of caspaces

53

TNF

is also secreted by CTLs leading to caspace impact and apoptosis.

54

NK cells

do not need antigen to work, no mhc. produce INF y which tilts immune response toward TH1 cells and M1 macrophages. Kills via Fas, perforin and granzyme. TNF expression.

55

NK cell stimulation

Stimulated by IFNa, IFN B, IFN y, TNFa, and IL 15

56

NK cell receptors

have both activation and inhibition receptors

57

Lectin like receptors (NK)

Bind proteins rather than polysaccharides mostly activating

58

Immunoglobulin like receptors (NK)

killer cell immunoglobulin like receptors. Bind most MHC class I molecules. mostly inhibatory

59

LILR

broad MHC-I inhibatory

60

NCRs

activating

61

NK killing

inhibatory signal(MHC I) trumps activating signal. kill with binding, perforins and granzymes

62

NKT cells

Little known about them. They express TCR, but different from CTLs. Mature in Thymus. Do not recognize MHC bound molecule.

63

Cytotoxic cells

Can bind to and kill anything connected to antibody. Bind to Fc region.