Brainscape's Knowledge GenomeTM

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


See full index

Microbiology > Immunity > Flashcards

Immunity Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

What is CD?

A

Cluster differentiation - way of labelling

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

How do cells signal?

A

Signalling though surface molecules or signalling through secreted molecules

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

What is the dark side to the immune system?

A
  • Allergy (immunity to non harmful things)
  • Autoimmunity (immune system attacking the body)
  • Rejection of transplants
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the mechanisms of preventing infection?

A

Barriers. Innante immune system. Adaptive immune system.

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

How do barriers prevent infection?

A

Skin, respiratory and digestive tracts. Physical - epithelial. Chemical - saliva/mucus.

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

How does the innate immune system prevent infection?

A

Fast. Invariant receptors. Broad specificity, No memory. Eg neutrophils, macrophages, dendrite.

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

How does the adaptive immune system prevent infection?

A

Slow. Highly variant receptors. Highly specific. Generates memory. T cells and B cells.

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

Where are stem cells produced?

A

Bone marrow

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

Where do immune cells develop?

A

In primary lymphoid organs

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

How do immune cells travel through the body>

A

Migrate via lymph and blood to specialised lymphoid organs. From periphery to lymph nodes. Here response occurs.

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

What are secondary lymphoid organs?

A

Defined structure that promote adaptive immune response

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

What are the main stages of immunity?

A
  1. Recognition (innate then adaptive)
  2. Effector response (innate and adaptive)
  3. Memory (adaptive only)
  4. Immune turn off = immune regulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is recognition?

A

Immune cells distinguish Self (dont kill) and Non-Self (kill)

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

What are PAMPs?

A

Pathogen associated molecular patterns - pathogens have evolutionary conserved molecules

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

What are PRRs?

A

Patter recognition patter receptors to recognise PAMPs

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

Describe recognition in a gram -ve bacter.

A
  • LRS = PAMP
  • TLR4 = PRR
  • LPS binds to TLR4
  • Results in inactivation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What can innate immune cells do?

A

Express multiple PRR at the same time

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

Describe the activation of a macrophage?

A
  • Professional phagocyte
  • Kills bacteria
  • Recruits other immune cells = inflammation (neutrophils, cyotkines, chemokines)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Describe the activation of a dendritic cell.

A
  • Phagocytes
  • Antigen presenting cell = APC
  • Takes up pathogen proteins
  • Migrates to secondary lymphoid organs
  • ‘Presents’ fragments of pathogen proteins → sticks on surface
  • Activates T cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is an example of a primary lymphoid?

A

Thymus, bone marrow

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

What is an example of a secondary lymphoid?

A

Spleen, lymph node

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

Which two ways can antibodies protect against pathogens?

A
  1. Direct neutralisation of toxins
  2. Pathogen opsonisation and uptake by phagocyte
  3. Complement activation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How do epitopes recognised by T cells and B cells differ?

A

T cells can recognise only linear eptitopes. B cells can recognise both linear and conformational epitopes.

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

What are the main cells of the adaptive immune response?

A

Dendritic cells (activation of the adaptive immune system), T cells and B cells

25
Q

What are lymphocytes?

A

T cells and B cells

26
Q

What are CD4 Th cells?

A

Helpers

27
Q

What are CD8 Tc cells?

A

Cytotoxic cells - killers

28
Q

What are T and B cells activated through?

A

Surface receptors eg BCR and TCR

29
Q

Compare BCR and TCR

A

Made in a similar fashion but of completely different proteins

30
Q

Describe the BCR

A

Membrane bound antibody with the same specificity as secreted antibody

31
Q

What are antigens?

A

Pathogen molecules recognised by T or B cells

32
Q

What do T cells recognise?

A

Protein

33
Q

WHat do B cells recognise?

A

Proteins, sugars and lipids

34
Q

What is an epitope?

A

Specific part of the antigen that binds to the BCR or TCR

35
Q

What are the forms of epitopes?

A

Linear or conformational

36
Q

What does the B cell recognise?

A

Conformational and linear shapes

37
Q

What does the T cell recognise?

A

Linear

38
Q

What is a conformational epitope?

A

Parts of the amino acid only brought together when the protein folds

39
Q

WHat is the linear epitope?

A

Stretches of amino acid that exist in the primary sequence

40
Q

Describe clonal selection of lymphocytes.

A
  1. Each lymphocyte has multiple copies of single antigen receptor
  2. Antigen binding causes cell activation and clonal expansion
  3. All daughter cells have the same antigen receptor specificity
41
Q

What happens in the secondary lymphoid organ?

A
  • Antigen can directly bind to BCR on surface of B cells

- T cells only binds to antigens that are present to them

42
Q

Describe the bind of BCR and antigen

A

BCR is a surface antibody
Antibody can bind directly to intact targets (antigens)
B cells can bind linear and conformational epitopes

43
Q

How are B cells activated?

A
  1. Lymphatic drains to lymph node
  2. Pathogens can migrate directly into lymph node
  3. Pathogen molecules interact with B cells
  4. Binds to BCR and activates it
  5. Get clonal expansion
  6. Secrete antibodies and bind to the pathogen molecules
44
Q

What are the specific zones of lymph nodes?

A

T zone and B zone

45
Q

WHat do antibodies do?

A
  • Antibody directly neutralises pathogen molecule eg toxin

- Antibody ‘opsonises’ pathogens increasing phagocytes

46
Q

What is meant by ‘opsonises’?

A

innate immune cells express Fc receptors = FcR, can then phagocytose the whole complex

47
Q

What is the structure of an antibody?

A 
variable = Fab portion → provides the specificity
non-variable= Fc portion
48
Q

How are T cells activated?

A
  1. TCR binds to an antigen binds to a peptide present by MHC proteins
  2. T cell receptor recognises the peptide and MHC molecule
  3. The peptide is the antigen for the T cell
  4. Activation
49
Q

What are the Differences in antigen presentation to CD8 Tc and CD4 Th cells?

A
  1. Type of cell that present antigenic peptide
  2. MHC molecule that present peptide (MHC I or MHC II)
  3. Where antigen comes from (cytosol vs extracellular)
  4. Consequences of T cell activation (kill or help)
50
Q

How are CD8 Tc Cells activated?

A
  • Destroy infected cells
  • Host and viral proteins degraded by proteases
  • host and viral peptides
  • viral peptide on MHC class I
  • recognised by CD8 Tc cell
  • interaction is stabilised by a co-receptor called the CD8 protein
  • results in activation
51
Q

What happens with MHC class I in normal cells?

A
  • All cells constantly display a sample of their proteins in the form of peptides which are always bound to MHC class I
  • Host proteins constantly being degraded by host proteases
  • Create host peptides and are displayed in MHC class I
52
Q

How are CD4 Th cells activated?

A
  • a dendritic cell → draining lymph node T zone and interacts with the CD4 Th cells
  • Dendritic cells forms a lot of contacts with the CD4 T cell which activates it
  • Dendritic cells present antigenic peptides on their surface using MHC class II
  • These peptides derive from extracellular pathogens
    CD4 protein is co-receptor for MHC II and stabilised and activates the T cells ‘helps’
53
Q

What does CD4 do?

A

‘help’ B cell antibody production

‘help’ macrophages kill pathogens

54
Q

How do CD4 cells ‘help’ B cell antibody production

A

through production of cytokines or surface molecules result in the B cell producing higher affinity antibodies and go through class switching

55
Q

How do CD4 cells ‘help’ macrophages kill pathogens?

A

activated, producing cytokines which increase production anti-microbial factors with better microbial killing

56
Q

What is the diversity problem?

A

Adaptive immune systems requires a lot of specific B and T cells for the endless number of pathogens. B and T cells need to be highly specific to avoid autoimmunity

57
Q

What is generation of diversity in TCR?

A

TCR → 2 long polypeptides with and alpha chain and a beta chain → within the chains there is a variable and a constant region
Gene rearrangement
Genes for TCR and BCR encoded in gene segments
Each segment of variable region has many different variants
Gene segments brought together through random gene rearrangement → random variant genes are brought together – alpha genes has 5000 variants, beta genes has 1000 variants
Any alpha chain can potentially combine with any beta chain

58
Q

How many receptors are there in the adaptive immune system?

A

10^18

Microbiology (8 decks)

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