Brainscape's Knowledge GenomeTM

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


See full index

ESA2 - Infection > Adaptive Immunity > Flashcards

Adaptive Immunity Flashcards

1
Q

What are some examples of antigen presenting cells?

A

Macrophages, B cells, dendritic cells, Langerhans’ cells

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

What are some features of antigen presenting cells?

A

Strategically located (SALT, GALT, NALT, BALT, lymph nodes, spleen etc)

Pathogen capture (phagocytosis, macropinocytosis)

Diverse pathogen sensors (PRRS)

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

What are pathogen regonition receptors?

A

They are proteins expressed by cells of the innate immune system to identify two classes of molecules: pathogen-associated molecular patterns (PAMPs), which are associated with microbial pathogens, and damage-associated molecular patterns (DAMPs), which are associated with cell components that are released during cell damage or death.

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

Where are dendritic cells located?

A

Lymph nodes, mucous membranes, blood

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

What do dendritic cells present to?

A

Naive T cells

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

Where are Langerhans’ cells located?

A

Skin

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

What do Langerhans’ cells present to?

A

Naive T cells

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

Where are B cells located?

A

Lymphoid tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What do macrophages present to?

A

Effector T cells

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

What do B cells present to?

A

Both naive and effector T cells

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

What does MHC stand for?

A

Major Histocompatibility Complex

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

What are PAMPs?

A

Pathogen-associated molecular patterns are molecules associated with groups of pathogens, that are recognized by cells of the innate immune system

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

Where are class I molecules found?

A

On all nucleated cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the function of class I molecules?

A

To display peptide fragments of non-self proteins from within the cell to cytotoxic T cells; this will trigger an immediate response from the immune system against a particular non-self antigen displayed with the help of an MHC class I protein.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Where are class II molecules found?

A

On dendritic cells, macrophages, B cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the HLAs corresponding to class I molecules?

A

HLA-A, B, C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the HLAs corresponding to class II molecules?

A

HLA-DR, DQ, DP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Give a difference between class I and II molecules

A

The antigens presented by class II peptides are derived from extracellular proteins (not cytosolic as in MHC class I)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are some key features of MHC class I and II molecules

A

1) Co-dominant expression (greater number of different MHC molecules)
2) Polymorphic genes (presentation of different antigens/microbes)

3) Class I - present peptides from intracellular microbes
Class II - present peptides from extracellular microbes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

On which chromosome are the genes for MHC molecules coded?

A

6 (short arm)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the peptide binding cleft?

A

Variable region with highly polymorphic residues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Between which chains are the peptides presented in MHC class I molecules?

A

Between alpha 1 and 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the difference in the sizes of peptides that MHC class I and II can present?

A

Class I - between 9-10 amino acids

Class II - between 13-20 amino acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Where are the peptides presented in MHC class II molecules?

A

Between alpha 1 and beta 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

True or False:

An MHC molecule can only present one type of peptide

A

False

Many peptides can be presented by the same MHC molecule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What does MHC class I activate?

A

CD8+ T cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What does MHC class II activate?

A

CD4+ T cells

28
Q

True or False:

The viral proteins on the airway epithelial cells are presented by MHC molecules called HLA-DP, HLA-DQ, HLA-DR

A

False

These are class II molecules

Should be presented by class I - HLA-A, HLA-B, HLA-C

29
Q

True or False:

All peptides from the same microbe are presented by different MHC molecules

A

True

30
Q

Are both self and non-self peptides presented?

A

Yes

31
Q

What are long-tern nonprogressors?

A

Long-term nonprogressors (LTNPs), sometimes also called “elite controllers”, are individuals infected with HIV, who maintain a CD4 count greater than 500 without antiretroviral therapy with a detectable viral load.

32
Q

What can determine whether a HIV-infected individual is a slow progressor or rapid progressor?

A

Slow progressors [HLA-B27, HLA-B51, HLA-B57]
MHC molecules able to present key peptides for the survival of the virus (unmutated) so effective T cell response

Rapid progressors [HLA-B35]
MHC molecules present mutated peptides (less crucial peptides for the virus) - poor recognition by T cells, poor T cell response

33
Q

What are some clinical problems associated with MHC molecules?

A

Organ transplant rejection, Graft-Versus-Host reaction, association with autoimmune disease

34
Q

What is the association between HLA molecules and autoimmune disease?

A

Ankylosing spondylitis -> HLA-B27 in 90% of patients

Insulin dependent diabetes mellitus -> HLADQ2 in 50-75% of patients

35
Q

Summarise how extracellular microbes are processed and presented

A

Sensed by APC via the exogenous pathway (inside vesicles)
Presented by MHC class II
Activates CD4+ T cells
Activates humoral response (antibodies, complement)

36
Q

Summarise how intracellular microbes are processed and presented

A

Sensed by APC via the exogenous AND endogenous pathway (in cytoplasmic compartment)
Presented by MHC class II and MHC class I (cross presentation)
Activates CD8+ and CD4+ T cells (need CD4+ to become cytotoxic T cell)
Cell-mediated response and cytotoxic T cells activated

37
Q

Why is cross presentation required?

A

Need to activate CD4+ as well as CD8+ in order to get cytotoxic T cells (need the T helper cells too)

38
Q

Where do T cells mature?

A

Thymus

39
Q

What is the antigen receptor on the T cell called?

A

T cell receptor (TCR)

40
Q

How is TCR diversity generated?

A

Gene rearrangement

41
Q

Which kind of T cells are CD4+?

A

Helper

42
Q

Which kind of T cells are CD8+?

A

Cytotoxic

43
Q

What cytokines are produced by TH1 cells?

A

TNFalpha, IFNgamma

44
Q

What cytokines are produced by TH2 cells?

A

IL-4, IL-5, IL-10

45
Q

What cytokines are produced by TH17 cells?

A

IL-17

46
Q

What cytokines are produced by Treg cells?

A

IL-10, IL-35, TGFb

47
Q

How many signals do T cells require to become fully activated?

A

2 (costimulation)

48
Q

What are the signals required to fully activate a T cell?

A

A first signal, which is antigen-specific, is provided through the TCR which interacts with peptide-MHC molecules on the membrane of APCs. A second signal, the co-stimulatory signal, is antigen nonspecific and is provided by the interaction between co-stimulatory molecules expressed on the membrane of APC and the T cell.

49
Q

What is an example of a costimulatory molecule?

A

CD28

50
Q

Which T helper cells are activated in response to extracellular microbes?

A

TH2, TH17

51
Q

Which T helper cells are activated in response to intracellular microbes?

A

TH1

52
Q

What is the action of TH1?

A

Activate CD8+ cytotoxic T cells

Produce IFNg which activates B cells (IgG) and macrophages

53
Q

How do cytotoxic T cells kill cells?

A

Perforin makes holes in cell membrane

Granzyme enters through holes and initiates apoptotic processs

54
Q

What is the main antibody that regulates allergies?

A

IgE

55
Q

What is the first antibody to appear in response to initial exposure to an antigen?

A

IgM

56
Q

Which pathway of the complement system does IgG activate?

A

Classical

57
Q

Describe the ratio of IgM to IgG upon first encounter of an antigen

A

High ratio

58
Q

What is the main antibody produced upon second encounter of an antigen?

A

IgG

59
Q

What is isotype switching?

A

Biological mechanism that changes a B cell’s production of immunoglobulin (antibodies) from one type to another, such as from the isotype IgM to the isotype IgG

60
Q

What are the immune functions of IgG?

A

Enhanced phagocytosis, complement activation, neonatal immunity, toxin/virus neutralisation

61
Q

What is the main antibody found in breast milk?

A

IgA

62
Q

What is the function of IgA?

A

Mucosal immunity

63
Q

What are the functions of IgE?

A

Immunity against helminths

Mast cell degranulation (allergies)

64
Q

What is the function of IgM?

A

Complement activation

65
Q

In a case of chicken pox, which MHC molecules are expressing the viral peptides? Which cells?

A

MHC class I - all infected cells including APC

66
Q

In a case of chicken pox, which factors from the adaptive immunity will be used against the virus?

A

Antibodies, TH1, Cytotoxic T lymphocytes (NK cells used in innate immunity)

67
Q

How could you tell whether someone has had chickenpox before?

A

Blood test to look for VZV IgG (+/ IgM)

ESA2 - Infection (12 decks)

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