MIC finals Flashcards
(117 cards)
1
Q
fx of neutrophils
A
- usually 1st cell to respond
- ingest microbes via phagocytosis, discharge granules containing microbicidal substances
2
Q
fx of mast cells
A
- allergic responses
- parasites (worms)
- inflammation
- release histamine
3
Q
fx of basophils
A
- allergic responses
4
Q
fx of eosinophils
A
- allergic responses
- parasites (worms)
- asthma
5
Q
fx of NK cells
A
- do not attack microbes
- kill virally infected target cells and tumour cells
6
Q
fx of macrophages
A
- ingest via phagocytosis
- APC
7
Q
fx of dendritic cells
A
APC
8
Q
fx of T cells
A
helper and cytotoxic T cells
- T cell R on their surface recognises Ag
- some can kill infected cells and cancer cells
9
Q
fx of B cells
A
plasma cells secrete antibodies, which binds to Ag
10
Q
pri lymph organs
A
foetal liver, thymus, bone marrow
11
Q
sec lymph organs
A
lymph nodes, spleen
12
Q
organisation of lymph nodes
A
immune cells enter through afferent lymphatics and High Endothelial Venules (HEV)
immune cells exit via efferent lymphatics
13
Q
what is lymphadenopathy
A
enlargement of lymph nodes
14
Q
fx of spleen
A
- filters blood (remove old or damaged RBCs, foreign materials)
- contains red pulp (RBC destruction) and white pulp (B cells in white pulp produces antibodies)
15
Q
progression from stem cell to dendritic cell
A
stem cell - myeloid progenitor - granulocyte - monocyte - dendritic cell (/ macrophages)
16
Q
progression from stem cell to B cell
A
stem cell - lymphoid stem cell - lymphocyte - b cell progenitor - plasma cells/ memory cells
17
Q
progression from stem cell to NK cell
A
stem cell - lymphoid stem cell - lymphocyte - NK cell
18
Q
autocrine
A
cytokine producing the signal is also the cell that responds to it
19
Q
paracrine
A
cytokine produced signals that affects cells in the near vicinity
20
Q
endocrine
A
cytokine produce signals that affect cells that are far away
21
Q
what are Pathogen Associated Molecular Patterns (PAMPs)?
A
found only on pathogens, the “red flag” to be recognised by body’s cells
22
Q
what are Pattern Recognition Patterns (PRRs)?
A
found on body’s cells (either secreted, located on cell surface or intracellular); PAMPs bind to PRR
23
Q
what are the receptors req’d for phagocytosis?
A
- membrane receptors
- opsonin receptors
24
Q
what are 2 types of membrane receptors?
A
- mannose receptors: directly bind to polysaccharides
- schavenger receptors: directly recognise charged molecules in targets
25
which type of PRR is most associated w intracellular recognition of pathogens and can activate inflammatory responses?
nod-like R
26
intracellular PRRs pri fx to
respond to pathogens inside the cell
27
what happens when intracellular PRRs, such as nod-like R, detect a pathogen?
they trigger inflammatory responses, including cytokine release or apoptosis of infected cells
28
how do toll-like R contribute to the immune response?
by recognising PAMPs and triggering the production of cytokines and interferons
29
what is a potential result of a cell infected by a pathogen utilising intracellular PRRs?
release of chemokines and cytokines
30
what is a key role of secreted PRRs in the immune syst?
to induce the complement cascade by binding to pathogen surfaces
31
extracellular PRRs pri participate in
phagocytosing pathogens
32
what is the pri fx of mannose and scavenger R in the immune response?
to engulf and destroy pathogens through phagocytosis and release of lysosomal contents
33
which type of PRR on the cell surface is pri responsible for recognising pathogens associated molecular patterns and can activate the secretion of cytokines or interferons when a virus invades a cell?
toll-like R
34
what is the role of the complement cascade activated by secreted PRRs?
to opsonise pathogens for phagocytosis and induce cell lysis
35
what action is most closely associated w mannose R?
binding to carbohydrate structures on pathogens
36
which receptor class would pri be involved in recognising and responding to fungal cell wall components?
scavenger R
37
which receptor type is mainly secreted by the liver as a crucial part of the innate immune syst?
complement R
38
how do APCs present antigens onto MHC?
convert the antigen into peptides by proteolytic cleavage, binds to MHC which is then presented by APCs
39
what MHC class presents endogenous Ag?
MHC I to cytotoxic T cells
40
what MHC class presents exogenous Ag?
MHC II to helper T cells
41
what is opsonisation
when pathogen is coated w AB eg IgG via FAB region, which binds to Fc receptor of neutrophil
- helps facilitate and improve efficiency of phagocytosis
42
what are the receptors used for phagocytosis
1. membrane R (mannose for polysaccharides, scavenger for charged)
2. opsonin R (Fc to bind to antibodies, complement R to bind to complement-reacted target)
43
what is complement
a cascade of proteases, resulting in diff effector responses
44
fx of complement syst
1. opsonisation
2. inflammation
3. complement-mediated cyotoxicity - MAC (membrane-attack complex)
45
how does fever come about
cytokines eg TNF-alpha, IL-6 stimulating the thermoregulatory center of the brain
46
factors of T cell activation
1. MHC-Ag
2. cytokines
47
where can IgD be found
on the surface of immature B cells
48
what comprises of AB
1. FAB (fragment Ag binding)
2. Fc (fragment crystallisable)
49
role of IgA
mucosAl immunity eg tears, saliva, breast milk, bile by blocking adhesion, trapping microbes in mucus
- basis of protection by oral vaccines
50
role in IgE
against parasitic worms/ allergy rxns
51
examples of intracellular bacteria
TB, listeria monocytogenes
52
examples of extracellular bacteria
streptococcus pneumoniae, pseudomonas, vibrio cholera
53
examples of intracellular parasite
plasmodium (malaria), leishmania (sandflies)
54
examples of extracellular parasite
helminths (parasitic worms)
55
immune response to intracellular bacteria
cell-mediated immunity (T cells)
- promote granuloma formation (keep it in)
- TB reactivation common in pts w CD4 T cell def
56
immune response to extracellular bacteria
humoral immunity (B cell)
- AB binds to Ag
57
immune response to fungi
cell-med (T cells)
- Th1 (IL-2, IFN-gamma)
- Th17 (IL-17, IL-22)
- NOT Th2 (allergy)
58
immune response to helminth
Th2 cells - eosinophils kill IgE-coated parasites
59
immune response to leishmania
Th1-activated macrophages - phagocytosis & intracellular killing
60
immune response to plasmodium (liver)
CD8+ T cells - apoptosis of infected cell
61
natural passive immunity
transplacental IgG
62
artificial passive immunity
injection of preformed AB
63
natural active immunity
production of AB by the immune syst in response to the presence of an Ag of a clinical infection
64
artificial active immunity
production of AB by the immune syst in response to the presence of an Ag of a vaxx
65
disadvantage of passive immunity
- short period of protection
- potential allergic response if foreign AB are given
66
disadvantage of active immunity
takes some time to develop
67
what are toxoids
inactivated toxins from bacteria (no longer toxic but still antigenic)
- build immunity against the toxin and not the bacteria that produced the toxin
68
what are conjugated vaccines?
certain materials are not very immunogenic and req to be conjugated (combined) to a protein to be a good vaccine
- to induce stronger, long-lasting T cell dependent immunity
69
what are the 3 blood diagnostic tests
1. CBC
2. Fluorescence Flow Cytometry (FFC)
3. histological test (stain and visualise)
70
FFC procedure
1. blood sample diluted and labelled w fluorescence marker that binds specifically to nucleic acids
2. transported into the flow cell
- fwd-scatter light: indicates cell vol
- side scatter: internal cell struct & its contents eg nucleus
- side fluorescence: # of nucleic acids present
3. presented in a scatterplot, showing the percentage of each cell popn
71
what does fwd-scatter light do in Fluorescent Flow Cytometry
indicate cell vol
72
what does side-scattered light do in Fluorescence Flow Cytometry
provides info abt internal structure and its contents eg nucleus
73
what does side fluorescence light do in Fluorescence Flow Cytometry
of nucleic acids present in the cell
74
will being pregnant result in low or high WBC count
high WBC count due to the changes in the body to carry a fetus or stress caused by delivery (no treatment needed unless there is an infection)
75
will sepsis cause low or high WBC count
low since body might use it up faster than it can produce & it will suppress BM
76
what happens in type I hypersensitivity
Th2 promotes AB class swaitch to produce IgE. IgE produced binds to mast cells/ basophils w formation of crosslink of 2 adj IgE. when IgE on binds to antigen of allergen, releases histamine and activates inflammatory response
77
treatment for type I hypersensitivity
- adrenaline (epipen)
- mast cells stabiliser (cromolyn)
- corticosteroid (dexamethasone, prednisolone, hydrocorticosone)
78
what happens in type II hypersensitivity
AB IgM/ G binds directly to own's cell surface or tissues eg RBC, kidney cells or basement membrane (instead of targeting foreign invaders), resulting in the destruction of cells via complement/ phagocytosis and inflammatory response
79
what happens in type III hypersensitivity
circulating AB-Ag complexes deposit on blood vessel walls, activating the complement syst. eventually, lymphocytes eg neutrophils will find to Fc R of these immune complexes, causing inflammatory response and cell/ tissue damage
80
what happens in type IV hypersensitivity
own T cells attack own tissues/ cells
81
what allergic rxn stage is swelling away from sting
stage II
82
what allergic rxn stage is difficulty breathing
stage III
83
what allergic rxn stage is incontinence
stage II
84
what allergic rxn stage is fall in BP
stage IV
85
what type of hypersensitivity is arthur rxn
type III
85
what type of hypersensitivity is pemphigus vulgaris
type II
86
what type of hypersensitivity is goodpasture's syndrome
type II
87
what type of hypersensitivity is SLE
type III
88
what type of hypersensitivity is myasthenia gravis
type II
89
what type of hypersensitivity is contact dermatitis
type IV
90
what type of hypersensitivity is Graves' disease
type II
91
what type of hypersensitivity is serum sickness
type III
92
what type of hypersensitivity is tuberculin rxn
type IV
93
what type of hypersensitivity is type I diabetes
type IV
94
what does ADA deficiency result in pri (congential) deficiency
- blocks purine metabolism
- buildup of deoxyadenosine (toxic to lymphocytes
- affects both T and B cells
95
what does PNP deficiency result in pri (congential) deficiency
- also blocks purine metabolism
- mainly affects T cells
96
what does Btk def result in pri (congential) deficiency
low production of B cells, plasma cells and thus AB
97
what disease does Btk def cause
X-linked agammaglobulinemia
98
what does RAG def result in pri (congential) deficiency
- critical in TCR & BCR formation
- NK cells are intact
99
what does gamma chain def result in pri (congential) deficiency
- low production of T cells & NK cells formation
- B cells present but non-fxal
100
which immune cell deficiency results in DiGeorge syndrome
T cell def
101
which immune cell def results in X-linked gammaglobulinemia
B cell def
102
signs/ symptoms of DiGeorge syndrome
- anatomical abnormalities (eg small jaw, upper lip, slanted eyes, low set ears, short stature)
- cardiac malfxs
- no T cells (CD4/ 8)
- recurrent infections
103
signs/ symptoms of SCID
- loss of T & B cells (maybe NK cells as well)
- increased susceptibility to infections w fungi
- live attenuated vaxx can be fatal
104
treatment of SCID
bone marrow transplant
105
treatment of X-linked gammaglobulinemia
- immunoglobulin replacement therapy
- prophylaxis
106
cause of X-linked hyper-IgM syndrome
defects in helper T cell-dependent B cell so T cells cannot activate B cells to undergo class switch, resulting in B cells only producing IgM so high # IgM, low IgG/ E/ A
107
what does defective class II MHC result in
low # of helper T cells (CD4), normal # of B cells but low # of AB
108
what does TAP deficiency/ bare lymphocyte syndrome result in
TAP - transporter associated w antigen processing
results in low # class I MHC expression so low # of cytotoxic T cells (CD8)
109
how does HIV (Human Immunodeficiency Virus) affect the immune syst
HIV infects CD4 T cells
- retrovirus that contains reverse transcriptase that allows the transcription of their RNA into host cell DNA
- synthesis of HIV proteins, new HIV virion synthesised (replication)
110
mode of transmission of HIV
- sexual activities
- from mother to baby
- blood-blood contact (sharing of needles, drug, blood tranfusion)
111
treatment of HIV
antiretroviral drugs eg abacavir, ganciclovir that inhibits viral replication
112
what is pos selection
tests if T cells can recognize self-MHC
113
what is neg selection
removes T cells that bind too strongly to self-peptides/ self- MHC
114
what does AIRE (autoimmune regulator) do
produce self-peptides during central tolerance - if T cells rxt strongly, they will be eliminated through neg selection
115
mechanisms of peripheral T cell tolerance
1. anergy (fxal inactivation)
- when a T cell binds to Ag but does not receive costimulatory signals
2. suppression by Tregs (secrete inhibitory cytokines)
3. deletion (by apoptosis)
4. ignorance
116
