Brainscape's Knowledge GenomeTM

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


See full index

Principles > Immunology > Flashcards

Immunology Flashcards

1
Q

Significance of low oxygen tension on skin

A

Good against aerobic microbes

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

Main immunoglobin found in mucous

A

sIgA, prevent attachment and penetration of epithelial cells

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

Enzymes in mucous

A

Lysozyme, defensins, antimicrobial particles directly kill pathogens. Lactoferrin starve invading bacteria

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

What are bactericidins

A

Produced by commensal bacteria which can cause lysis of other bacteria

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

What is humoral immunity

A

Immunity mediated by soluble macro-molecules found in extracellular secretions and fluids such as antibodies, complement system proteins, cytokines

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

What are cytokines

A

Small proteins and peptides that modulate behaviour of cells and co-ordinate the immune system

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

Different long lived tissue macrophage

A

Kupffer cell - Liver
Alveolar macrophage - Lung
Mesangial cell - Kidney
Microglial cell - Nervous system

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

What are polymorphonuclear cells

A

Neutrophils

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

Main role of natural killer cells

A

Detect and kill tumour cells and virally infected cells

Also kill antibody-bound cells/pathogens

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

Main function dendritic cells

A

Phagocytose, process and present antigen on surface

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

What are primary lymphoid tissues

A

Sites of leukocyte development - Thymus and Bone Marrow

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

What cells do immune cells derive from

A

Hematopoietic stem cells

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

What are secondary lymphoid organs

A

Sites where T and B cell become activated by antigen

Adenoid, tonsil, lymph node, spleen, peyer’s patch in small intestine, large intestine

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

What comprises the adaptive immunity

A

B cells, T cells, antibodies

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

What cells acts as a link from innate to adaptive

A

Dendritic cells

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

Example of anti-viral cytokines

A

Interferon alpha, beta released by virally infected cells

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

How does recognition occur in innate immunity

A

Pathogen Associated Molecular Pattern on pathogens are recognised by Pattern Recognition Receptors on innate immune cells

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

PRR for lipopolysaccharide found on gram negative bacteria

A

Toll-like receptor 4

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

PRR for beta-glucans (Fungi)

A

Dectin - 1

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

PRR for ssRNA (Virus)

A

Toll-like receptor 7

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

Which cells are best at phagocytosis

A

Macrophage, Neutrophils and Dendritic cells

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

What cell release pro-inflammatory mediators

A

Natural killer cells release Interferon Gamma that activate macrophage

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

How is Natural Killer Cell response mediated

A

NK cells contain inhibitory receptor that doesn’t affect cells with normal MHC Class-1. Also activated by interferon alpha/gamma

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

How is phagocytic capacity of macrophage increased

A

By natural killer cells releasing Interferon gamma

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

What is a hallmark in inflammation

A

Neutrophillia

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

What are acute phase proteins

A

Proteins whose plasma concentration increase or decrease in response to inflammation, eg: C-reactive protein and complement proteins

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

What can increase C-reactive protein be indicative of

A

Marker for inflammation, production increased by the liver in infection/inflammation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What pro-inflammatory mediators increase vascular permeability and cause vasodilation

A

Nitric oxide, Prostaglandins, Leukotrienes, Histamines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Which vessels does margination occur in

A

Venules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Which has tighter bond, with Selectin or ICAM/VCAM

A

With Selectin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is Diapedesis

A

Neutrophils squeeze through endothelial cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Neutrophil killing mechanisms

A

Phagocytosis, degranulation, NETs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Mechanism of neutrophil phagocytosis

A

Anti-microbial proteins and enzymes, reactive oxygen species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is Neutrophil Extracellular Traps

A

Neutrophils release their intracellular structures and immobilize and phagocyte pathogens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Why is pus yellow-green in colour

A

Neutrophil release enzymes that require Iron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Pathways in complement system

A

Classical, mannose-binding lectin pathway, alternative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Initial step in complement cascade

A

C3 - C3b (Amplification loop) + C3a

38
Q

How does spontaneously broken down C3 stabilise

A

C3 breaks down into C3a and C3b. C3b produced near bacterial with carbohydrate or protein ligand get attached and stabilized. This C3b further amplifies the cascade

39
Q

Classical complement pathway

A

The classical complement pathway is initiated by antigen-antibody complexes with the antibody isotypesIgGandIgM. Following activation, a series of proteins are recruited to generateC3 convertasewhich cleaves theC3 protein. TheC3bcomponent of the cleaved C3 binds to C3 convertase (C4bC2a) to generateC5 convertase which cleaves theC5protein. The cleaved products attract phagocytes to the site of infection and tags target cells for elimination by phagocytosis. In addition, the C5 convertase initiates the terminal phase of the complement system, leading to the assembly of the membrane attack complex (MAC). The membrane attack complex creates a pore on the target cell’s membrane, inducing cell lysis and death

40
Q

What part of the immune system is important against encapsulated bacteria

A

Membrane attack complex, forms a pore and causes osmotic lysis of pathogen

41
Q

What is opsonisation

A

Coating of pathogens by humoral factors such as C3b, C-reactive protein, IgG/IgM to facilitate phagocytosis

42
Q

What part of complement system are anaphylatoxins

A

C3a and C5a

43
Q

CD4+ vs CD8+ T cells

A

CD4+ T cells - Regulate entire immune system

CD8+ T cells - Kill virally infected cells

44
Q

PAMPs vs Antigens

A

Limited number of PAMPS common to different pathogens

Antigens are unique to individual species

45
Q

Receptors in T cells

A

Membrane bound alpha-beta heterodimer

46
Q

Receptors in B cells

A

Membrane bound antibody (IgM or IgD)

47
Q

Structure of antibodies

A

Two Ig heavy and two Ig light polypeptide chains help by disulphide bond

48
Q

What forms antigen binding site

A

Hypervariable regions of heavy and light chains

49
Q

How does adaptive immune system recognise millions of different antigens

A

Antibody heavy and light chains are encoded by segmented genes in haematopoietic cells. Random arrangement of these gene segment occurs in development of B cells

50
Q

Where does adaptive immune response occur

A

In secondary lymphoid tissue

51
Q

How do naive B and T cells enter lymph nodes

A

Transendothelial migration from high endothelial venules

52
Q

Function of dendritic cells

A

Immature state in peripheral tissue
Phagocytose antigens partially
Travel to secondary lymph nodes
Antigen presentation to T cells here

53
Q

How do dendritic cells express co-stimulatory molecules

A

By inflammatory cytokines such as Tumour Necrosis Factor alpha

54
Q

Do dendritic cells have PRR or MHC

A

Both

55
Q

What gene complex encodes MHC

A

Human Leucocyte Antigen (HLA)

56
Q

MHC Class 1 vs 2

A

MHC Class 1 are expressed on all nucleated cells, present peptide antigen to CD8+ T cells
MHC Class 2 expressed on professional antigen presenting cell, present to CD4+ T cells

57
Q

How many signals do T cells need for activation

A

Two, one if antigen specific between TCR and MHC

Second is non-antigen specific between TCR and co-stimulatory molecules

58
Q

What trap opsonised antigens in lymph nodes

A

Stromal cells with opsonin receptors

59
Q

How many signals does B cell require

A

Two, BCR + antigen and T follicular helper cell or PRR + PAMP
Second, multiple BCR’s engaged

60
Q

What cells can B and T cells differentiate into

A

Effector or memory cells

61
Q

What are plasma cells

A

Fully differentiated B cells that secrete antibodies

62
Q

Possible B cell pathway after activation

A

Differentiate into short lived plasma cells that secret low affinity antibodies (or)
Cluster to form a germinal center and undergo clonal expansion to produce long lived plasma cells with high affinity antibodies and memory B cells

63
Q

What antibodies are found in humans

A

IgA, IgD, IgE, IgG and IgM

64
Q

Functions of IgM

A

B cell antigen receptor (activate B cell)
Agglutination (Immune complex formation)
Complement system activation

65
Q

First antibody produced in immune response

A

IgM, pentamer in plasma and secretory fluids

66
Q

What is agglutination

A

Action of antibody cross-linking multiple antigens producing clumps of antigens. By IgM and IgG
Increases efficacy of microbial elimination

67
Q

Functions of complement system activation

A

Pathogen killing
Pathogen opsonisation
Leukocyte recruitment and inflammation
Removal of immune complexes

68
Q

How do antibodies cause complement system activation

A

Antigen binding to IgM and IgG causes a conformational change, Planar to Staple form of IgM
This exposes multiple binding sites for C1, first component of classical activation pathway

69
Q

Most abundant antibody in the body

A

IgG

70
Q

Functions of IgG

A 
Agglutination
Complement system activation
Foetal immune protection
Neutralisation
Opsonisation
NK cells activation
71
Q

What antibody provides foetal immune protection

A

IgG antibody

72
Q

How do antibodies neutralise pathogens

A

Binding prevents pathogens from infecting host and prevent microbial toxins from disrupting normal function

73
Q

How does opsonisation work

A

Cells such as neutrophils and macrophage contain Fc receptors that bind to IgG antibodies bound to antigen

74
Q

How does IgG activate NK cells

A

IgG opsonise the pathogen. NK cells have CD16 Fc receptors and degranulate upon cross linking with the IgG

75
Q

Function of IgD

A

B cell activation in monomeric membrane bound

76
Q

Second most abundant antibody

A

IgA

77
Q

Functions of IgA antibody

A

Monomeric form in serum-B cell activation
Secretory dimeric form in secretory fluids -
Neonatal defence and neutralisation (mucus)

78
Q

What antibody is found in colostrum

A

IgA

79
Q

Functions of IgE

A

Allergic response - Degranulation of mast cells through Fc receptor binding to IgE
Large intracellular pathogens - Parasites

80
Q

How are antibodies of same specificity but different Ig classes produced

A

B cells can switch Ig heavy chain constant region gene segment but retain Ig heavy and light chain gene hypervariable segment

81
Q

What cell secrete cytokines to cause T cell differentiate

A

Dendritic cells secrete cytokines

82
Q

Does dendritic cells have MHC Class 1 or 2

A

Both

83
Q

How do effector T cells help T cells respond

A

T helped cells secrete IL-2 to drive further proliferation and differentiation of helper T cells. IL-2 also drives differentiation of CD8+ T cells into cytotoxic T cells

84
Q

How do T helper 1 cells help macrophage

A

Th1 cells leave lymph node, travel to infected tissue site
Here, they are activated by macrophages in antigen specific manner. Th1 cells then release INF gamma to hyper activate macrophages

85
Q

How do effector Tfh cells help B cells

A

Effector Tfh cells are re-stimulated by co-stimulatory molecules. These cause B cells to clonally proliferate. Tfh secrete cytokines that stimulate germinal centre response

86
Q

Imporant of germinal centre response in B cells

A

Differentiation into antibody secreting plasma cells and memory cells
High affinity antibodies generated
Ig heavy chain switching

87
Q

What do CD8+ T cells differentiate into

A

Cytotoxic T cells, kill infected host cells

88
Q

How do cytotoxic T cells kill infected cells

A

By recognising and inducing apoptosis

89
Q

How does restoration after immune response occur

A

Macrophage release anti-inflammatory cytokines such as IL-10 that induce tissue repair and revert to a anti-infammatory state

90
Q

Main coreceptor used by HIV virus

A

CCR5 usually on CD4 T cells

91
Q

What causes immune suppression by HIV infection

A

HIV affects CD4+ cells which get overwhelmed eventually, leading to immune depression

92
Q

What is pyroptosis

A

A highly inflammatory form of programmed cell death that occurs during infection with intracellular pathogen like HIV. Infected cells recognize danger signs, release pro-inflammatory cytokines, swell, burst and die

Principles (14 decks)

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