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
What is a hallmark in inflammation
Neutrophillia
26
What are acute phase proteins
Proteins whose plasma concentration increase or decrease in response to inflammation, eg: C-reactive protein and complement proteins
27
What can increase C-reactive protein be indicative of
Marker for inflammation, production increased by the liver in infection/inflammation
28
What pro-inflammatory mediators increase vascular permeability and cause vasodilation
Nitric oxide, Prostaglandins, Leukotrienes, Histamines
29
Which vessels does margination occur in
Venules
30
Which has tighter bond, with Selectin or ICAM/VCAM
With Selectin
31
What is Diapedesis
Neutrophils squeeze through endothelial cells
32
Neutrophil killing mechanisms
Phagocytosis, degranulation, NETs
33
Mechanism of neutrophil phagocytosis
Anti-microbial proteins and enzymes, reactive oxygen species
34
What is Neutrophil Extracellular Traps
Neutrophils release their intracellular structures and immobilize and phagocyte pathogens
35
Why is pus yellow-green in colour
Neutrophil release enzymes that require Iron
36
Pathways in complement system
Classical, mannose-binding lectin pathway, alternative
37
Initial step in complement cascade
C3 - C3b (Amplification loop) + C3a
38
How does spontaneously broken down C3 stabilise
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
Classical complement pathway
The classical complement pathway is initiated by antigen-antibody complexes with the antibody isotypes IgG and IgM. Following activation, a series of proteins are recruited to generate C3 convertase which cleaves the C3 protein. The C3b component of the cleaved C3 binds to C3 convertase (C4bC2a) to generate C5 convertase which cleaves the C5 protein. 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
What part of the immune system is important against encapsulated bacteria
Membrane attack complex, forms a pore and causes osmotic lysis of pathogen
41
What is opsonisation
Coating of pathogens by humoral factors such as C3b, C-reactive protein, IgG/IgM to facilitate phagocytosis
42
What part of complement system are anaphylatoxins
C3a and C5a
43
CD4+ vs CD8+ T cells
CD4+ T cells - Regulate entire immune system | CD8+ T cells - Kill virally infected cells
44
PAMPs vs Antigens
Limited number of PAMPS common to different pathogens | Antigens are unique to individual species
45
Receptors in T cells
Membrane bound alpha-beta heterodimer
46
Receptors in B cells
Membrane bound antibody (IgM or IgD)
47
Structure of antibodies
Two Ig heavy and two Ig light polypeptide chains help by disulphide bond
48
What forms antigen binding site
Hypervariable regions of heavy and light chains
49
How does adaptive immune system recognise millions of different antigens
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
Where does adaptive immune response occur
In secondary lymphoid tissue
51
How do naive B and T cells enter lymph nodes
Transendothelial migration from high endothelial venules
52
Function of dendritic cells
Immature state in peripheral tissue Phagocytose antigens partially Travel to secondary lymph nodes Antigen presentation to T cells here
53
How do dendritic cells express co-stimulatory molecules
By inflammatory cytokines such as Tumour Necrosis Factor alpha
54
Do dendritic cells have PRR or MHC
Both
55
What gene complex encodes MHC
Human Leucocyte Antigen (HLA)
56
MHC Class 1 vs 2
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
How many signals do T cells need for activation
Two, one if antigen specific between TCR and MHC | Second is non-antigen specific between TCR and co-stimulatory molecules
58
What trap opsonised antigens in lymph nodes
Stromal cells with opsonin receptors
59
How many signals does B cell require
Two, BCR + antigen and T follicular helper cell or PRR + PAMP Second, multiple BCR's engaged
60
What cells can B and T cells differentiate into
Effector or memory cells
61
What are plasma cells
Fully differentiated B cells that secrete antibodies
62
Possible B cell pathway after activation
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
What antibodies are found in humans
IgA, IgD, IgE, IgG and IgM
64
Functions of IgM
B cell antigen receptor (activate B cell) Agglutination (Immune complex formation) Complement system activation
65
First antibody produced in immune response
IgM, pentamer in plasma and secretory fluids
66
What is agglutination
Action of antibody cross-linking multiple antigens producing clumps of antigens. By IgM and IgG Increases efficacy of microbial elimination
67
Functions of complement system activation
Pathogen killing Pathogen opsonisation Leukocyte recruitment and inflammation Removal of immune complexes
68
How do antibodies cause complement system activation
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
Most abundant antibody in the body
IgG
70
Functions of IgG
``` Agglutination Complement system activation Foetal immune protection Neutralisation Opsonisation NK cells activation ```
71
What antibody provides foetal immune protection
IgG antibody
72
How do antibodies neutralise pathogens
Binding prevents pathogens from infecting host and prevent microbial toxins from disrupting normal function
73
How does opsonisation work
Cells such as neutrophils and macrophage contain Fc receptors that bind to IgG antibodies bound to antigen
74
How does IgG activate NK cells
IgG opsonise the pathogen. NK cells have CD16 Fc receptors and degranulate upon cross linking with the IgG
75
Function of IgD
B cell activation in monomeric membrane bound
76
Second most abundant antibody
IgA
77
Functions of IgA antibody
Monomeric form in serum-B cell activation Secretory dimeric form in secretory fluids - Neonatal defence and neutralisation (mucus)
78
What antibody is found in colostrum
IgA
79
Functions of IgE
Allergic response - Degranulation of mast cells through Fc receptor binding to IgE Large intracellular pathogens - Parasites
80
How are antibodies of same specificity but different Ig classes produced
B cells can switch Ig heavy chain constant region gene segment but retain Ig heavy and light chain gene hypervariable segment
81
What cell secrete cytokines to cause T cell differentiate
Dendritic cells secrete cytokines
82
Does dendritic cells have MHC Class 1 or 2
Both
83
How do effector T cells help T cells respond
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
How do T helper 1 cells help macrophage
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
How do effector Tfh cells help B cells
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
Imporant of germinal centre response in B cells
Differentiation into antibody secreting plasma cells and memory cells High affinity antibodies generated Ig heavy chain switching
87
What do CD8+ T cells differentiate into
Cytotoxic T cells, kill infected host cells
88
How do cytotoxic T cells kill infected cells
By recognising and inducing apoptosis
89
How does restoration after immune response occur
Macrophage release anti-inflammatory cytokines such as IL-10 that induce tissue repair and revert to a anti-infammatory state
90
Main coreceptor used by HIV virus
CCR5 usually on CD4 T cells
91
What causes immune suppression by HIV infection
HIV affects CD4+ cells which get overwhelmed eventually, leading to immune depression
92
What is pyroptosis
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.
© 2025 Bold Learning Solutions. Terms and Conditions