Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BIOC 372: Immunology > L14: Cell Mediated Cytotoxic Responses > Flashcards

L14: Cell Mediated Cytotoxic Responses Flashcards

1
Q

the primary agents of cell-mediated (TH1)immunity are the____ cells

A

Tc and NK

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Lymphoid cells developing in the thymus ___rearrange TCR genes

A

DO rearrange

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Lymphoid cells developing in the bone marrow ____ rearrange TCR genes

A

DO NOT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Lymphoid cells that develop in the thymus:

A

TH

TC

γδ T cells

NKT cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Lymphoid cells that develop in the bone marrow:

A

B cells

NK cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

TH cells

A

TH- signal to tailor and coordinate responses.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

TC cells

A

TC– attack and kill cells displaying specific antigens by disrupting membrane andlysing cell.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

γδ T cells

A
  • patrol epithelia
  • attack and kill pathogens and rogue-self using same mechanisms as NK and TC cells
  • signal
  • Some authors refer to these as“primitive” because their function seems less specialized.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Two types of NKT cells

A
  • NKT
  • iNKT
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

iNKT cells (type 1)

A

respond to lipid antigens,especially those characteristic of bacteria.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

NKT cells (type 2)

A

recognize a wider array of lipids and have more variation in the receptor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

____ cells perform functions native to TH, TC, NK, Treg, and γδ T cells

A

iNKT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

B Cells

A
  • rearrange immunoglobulin genes, phagocytize, but do not seem to be aprimary killer of pathogens, and do not attack rogue self.
  • The antibodies that they produce are often important in directing attack by other cells.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

NK cells

A
  • do not rearrange any genes.
  • They attack and kill cells withsuspicious surface displays by disrupting their membranes and lysing the cells.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Myeloid cells

A
  • macrophages
  • neutrophils
  • eosinophils
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Macrophages

A

macrophages – phagocytize, present antigen

17
Q

neutrophils

A

neutrophils – phagocytize, do not present antigen

18
Q

Eosinophils

A

eosinophils – coordinate attack on eukaryotic parasites, do not present antigen,weakly phagocytic

19
Q

Steps for activating TC cells

A
  1. The TC cell binds a foreign antigen on MHC I (TC cells that bind self-antigen have been killed off during negative selection.)
  2. CD45R on TC and TH attaches to CD22 (sometimes called CD45L) on target cells.
  3. TH cell activates the cell, turning it into a CTL.
20
Q

____ speeds TC activation by making it easier for the Tc cells to encounter the foreign antigen.

A

Cross presentation

21
Q

Activation of TC cells leads to:

A

a. Cell division
b. Up-regulation of cell adhesion molecules
c. Synthesis of the complete IL-2 receptor

22
Q

CTL cell attached to target will up-regulate ____, forming

conjugate.

A

cell adhesion molecules

23
Q

Steps for CTL attack on target cell membrane:

A
  1. cytoskeleton rearranges, directing Golgi and storage granules (perforins and granzymes) to target cell
  2. granule contents released by exocytosis (Ca2+ dependent)
  3. Perforin monomers undergo conformational change and insert in the targetmembrane (sequence homology with C9 of the complement system).
  4. Granzymes (serine proteases) enter through pores and activate apoptosis.
24
Q

Alternatively, CTLs can induce apoptosis by ____

A

Fas ligand binding to target Fas receptor on the target cells

25
Q

Cells from mice that are both perforin knock-out AND Fas knock-out _____ be killed by cytotoxic T cells.

A

CANNOT

26
Q

CTL-dissociation

A
  • The integrin holding the cells together reverts to its less avid form after 5 to 10 minutes.
  • The CTL undocks and begins looking for another cell to hit.
27
Q

CTL destroyed cells are scavenged by __

A

macrophages or neutrophils

28
Q

Characteristics of NK cells

A
  • Large cells with lots of granular inclusions.
  • Lymphoid, sharing a common progenitor and surface markers with T cells,including the use of signaling peptides similar to those in the complete CD3complex
  • Develop in the bone marrow and do not rearrange genes
  • Also have TLRs and inflammatory cytokine receptors typical of those ofmacrophages and neutrophils
  • Do express the receptor of FC of IgG (CD 16) and the IL-2 receptor. This allowsthem to recognize and attack antibody-coated cells during ADCC
  • Have MHC I receptor, but it is inhibitory, and not used to recognize antigen, butrather viral down-regulation.
29
Q

NK mechanism of killing

A
  • Granules containing perforins and granzymes directionally released at target cell
  • Constitutively cytotoxic; do not require activation
  • Do not require antigen or MHC recognition
  • Adhesion to target triggers release
30
Q

However virus that down-regulate MHC I production may fool ___, but they will activate ___ cells.

A

fool TC cells, activate NK cells

31
Q

Stress receptors are possesed by ___ cells

A

NK cells

-There are a variety of stress indications displayed by sick cells,and a variety of receptors used by NK cells to sense them. The interaction promotes attack.

32
Q

______ not only lowers the cell’s MHC

production, it attempts to fool the NK cells by producing a fake MHC.

A

Cytomegalovirus

  • The viral genome codes for a proteinresembling MHC I.
  • This does not activate TC cells as it does not display foreign antigen.
  • However, it is recognized as MHC I by NK cells of susceptible mice.
  • The fake MHC binds to the same NK inhibitory receptor that real MHC binds to.
33
Q

How does Antibody Dependent Cell Mediated Cytotoxicity (ADCC) work?

A
  1. Targeting of cell harboring pathogens.
    1. The cells display abnormal antigen.
    2. B-cells produce antibodies to this antigen
    3. The antibodies attach so that their FC portion stick out from the cell.
34
Q

Which cells are capable of ADCC?

A

1) Cells with Antibody (FC) Receptors
a. NK
b. macrophages
c. neutrophils
d. eosinophils

35
Q

NK cells recognize ____, attacking ____, resulting in ____

A

IgG and IgM, rogue self, apoptosis

36
Q

Macrophages recognize ____, attacking ____, resulting in ____

A

IgG and IgM, pathogen, phagocytosis

37
Q

neutrophils recognize ____, attacking ____, resulting in ____

A

IgG and IgM, pathogen, phagocytosis

38
Q

Eosinophils recognize ____, attacking ____, resulting in ____

A

IgE, parasites, surface attack

39
Q

Graft vs Host disease

A
  • Supply immuno-incompetent individual with competent lymphocytes from another genetically different individual.
  • The Tc cells activate and begin to attack the host cells.
  • The B cells produce antibodies to the host cells surface antigen.
  • The patient experiences a cell-mediated attack from both NK and TC cells, withsome help from the macrophages, neutrophils and maybe even complement.
  • The cells under heaviest attack are GI epithelial (diarrhea), skin (which mayslough off in sheets), and spleen, (which may attack the red blood cells, resultingin jaundice). The whole response can kill a person.

BIOC 372: Immunology (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions