ICS - Immunology Flashcards

1
Q

what is innnate imunity

A

instinctive, non specific does not depend on lymphocytes, it is presant from birth

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2
Q

what is adaptive immunity

A

specific and learned. it requires lymphocytes and antibodies
noth innate and adaptice immunity are made up of cells and soluble factros (humoral)

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3
Q

what is teh main purpose of eh immune system

A

to distuingish between self and non self

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4
Q

when you centrifuge a blood sample, what 3 layers are presant

A

plasma, tehn teh buffy coat of leukocytes, then teh lower layer of erthrocytes and platelets

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5
Q

what is serum

A

plasma witjout fibrinogen and other clotting factors

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6
Q

what are the three polymorphonucleur leukocytes

A

eosinophil. neutrophil, basophil

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7
Q

what are teh mononumcleur leukocytes

A

monocytes, t cells, b cells

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8
Q

what do monocytes turn into

A

macrophages whihc are static in tissues

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9
Q

what do b cells turn into

A

plasma cells

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10
Q

what do t cells turn into

A

t regulator, t helper, cytotoxic, th17

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11
Q

what are the three immune cells whihc are in a catogry by themselves

A

mast cells, natural killer cells, dendritic cels (macropgages in teh skin)

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12
Q

what are teh 4 soluble factors

A

complement, antibodies, cytokines and chemokines

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13
Q

what are complement factors

A

serum priotines secreted by the liver that need to be activated to be functional

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14
Q

what are teh modes of action for complement factors

A

direct lysis, attract more leukocytes, coat invading organism

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15
Q

how do antibodies work

A

bind to antigens, are soluble

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16
Q

what are teh 5 classes of imunoglobulins

A

GAMED

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17
Q

what is teh structure of an antibodies

A

it is Y shaped, with an Fc (commen end) and then FAB ends which are specific to teh antigens, it is made of a heavy chain and a light chain

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18
Q

what is teh most commen tyrp of antibody

A

IgG, it can go anywhere

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19
Q

infomation about IgM

A

it is a large molecuke and is resticted the blood

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20
Q

what is IgA

A

it is secreted in everything - saliva, breastmik, vaginalk fluids. It is important for killing things outsode of teh body

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21
Q

wha are teh functions of antibodies

A

act as opsiion
agglutination
anti toxin

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22
Q

what is a cytokine

A

protiens secreted by the immun and non immune cells

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23
Q

what are teh 5 groups of cytokines

A

interferons
interluikins
colony stimuluating factors
tumour nectosis factor
chemokines

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24
Q

what is an interferon

A

a cytokine whihc induces a state of antiviral resistance in uninfected cells

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25
what are interleukins
produced by many cells, can be proinflamitory causes cells to divide, differentiate and relaese factrs
26
what are colony stimulating facros
involved in teh division and differentiation of bone amarrow stem cells and are precurosrs to leukocytes
27
what is tumour necrosis factor
medicate the inflamitory response - are pro inflamitry and cytotoxic reactions
28
what are chemokines
leykocyte chemoattractants
29
what is innate immunity composed of 3 main parts
physical and chemicla barries phagocytic cells (neutrophilss and macrophages) blood protiens ( complement and acute ohase)
30
what are physical and chemicla barriers
lysozomes in tears skin as a physical barrier mucus n lungs acid in gut low vaginal ph
31
wha is teh bodys response to a cut
Stop bleeding (coagulation) Acute inflammation (leukocyte recruitment) Kill pathogens, neutralise toxins, limit pathogen spread Clear pathogens/dead cells (phagocytosis) Proliferation of cells to repair damage Remove blood clot – remodel extracellular matrix Re-establish normal structure/function of tissue
32
what are teh three steps of inflamaiton
Increased blood supply Increased vascular permeability Increased leukocyte transendothelial migration ‘extravasation’
33
which cells sense micorbes in the blood
monocytes and neutrophills
34
whihc cells sense microbes in teh tissues
macrophages, dendritic cells
35
what does PRR and PAMP stand for
PRR – Pattern Recognition Receptors (on cells) PAMP – Pathogen-Associated Molecular Patterns (on microbe)
36
what do tehe complement facotrs do
lyse microbes directly, chemotaxes, opsoniation
37
what is teh process of extraavasion
(diapadesis) endothelial cell becomes sticky, teh neutrophills strat to rolll instead of flowinf past they begin to get fully stuck they tehn squeeze though teh gaps and move to teh sight of infection
38
what is MHC
major histocompatibility complex
39
what are antigen presenting cells
macrophages, dendritic cells, b cells
40
how do t cells work
respond to presented antigens t cell receptor recognises forign antigens in association with major histocompatibility complex
41
how are t cells made in childood
in the feotus, teh t cells kill all of the self recognising t cells
42
what are intrinsic antigens
- are for viruses and kill teh cell infected by the pathogen, this is down by teh t killer cells
43
what are extrinsic antigens
MHC class 2, they t helper cells help teh b cells make extrcellular pathogen and can help to kill it directly
44
what are teh tyes of t cells
naive, undifferentiaeted CD8 - T killer cell CD4 - (teh precursor one that divides itno TH1 and TH2) TH1 - helps to kill intracellular pathpgens TH2 - T helper cell antibody production helper
45
what is humoral immunity
b cell based, this is teh antibodies
46
what are the three t cells taht do the work
TH1 - macrophage activation TH2 - b cell activation CTL - cytotoxicity
47
what are teh primary lymphoid organs
bone marrow - all immune cell origins and teh B cell maturation site thymus - t cell maturation sight
48
what is seconday lymphoid organs
They provide a space for teh forign antigens to inteact with the lymphocytes lymph nodes - site of DC, B and T cell interactions spleen - removal of RBC and Ab coated bacteria there are alos muscosal associated lymphoid tissues in teh gut such as peyers patches in teh gut
49
what is teh tertiary lymphoid organs
transiet formation of genminal centres, usulaly pathplogy related they form ectopicallt at sights of chronic inflamation such as in multiple sclarosis there are TLOs in teh brain whihc stop teh mylenation.
50
what are the two pulps of teh spleen
red pulp - miltratio of RBC white pulp - active immune response trhough humoral and cell mediated immunity. rich in t cells and teh lymphoid follicules are rich in b cells
51
what is teh storage function of teh spleen
stored 25% of lymphocytes and 30% of red blood cells, it can also store platelets it also produces red blood cells
52
what is teh initial blood cell called
heamocytoblast
53
how do neutrophills kill the pathogens though phagocytosis
contian 2 granule types containg enzyme and lowerd pH but this onyl kills 2% of pathogens they take loads of pathogens into the cell they then do teh respiritory burst whihc kills teh pathogens and also teh neutrophills tehmelsves, it is a suicide bomber!!
54
what is teh respitiory burst
teh releae of free radicals in neutrophils using the free radicas superoixede nd hydrogen peroxide teh enzyme myloperoxidase is used to produce CL.
55
what is teh role of dendritic cells
they are antigen presenting cells that take teh antigen to teh lymph node, where it can select teh correct T cell, thsi is caled T cell priming T cells can only recognise antigens presented on MHC
56
Whats do natural killer cells do
kill cells infected with viruses r cancer by injecting toxins or causing apoptosis
57
What is teh B cells role with antigens
They can react to both presented and non presented antigens tehy can also phagocytoese and present themsleves onto MCH2
58
How does a B cell react to being shown an antigen
phagocytose it if its a pathogen and become antigen presenting by putting it on the MHC2 Become activated whihc helps it turn into a mast cellk mast cells release antibodyes (whihc are really just the antigens on teh B cell but floating free)
59
Whast are teh two types of T cell
CD4 - the T helper cells which secrete cytokines to help teh cells coordinate via chemotaxis, They can only see antigens on MCH2 CD8 - these are teh cytotoxic t killer cells, very similar to teh natural killer cells but only see antgens presented on the MCH1 complex not all of them
60
what are the two types of receptors found on the T cells
phagocytotic - allow it to bind and then phagocytose, thsi allows for teh investigation of teh pathogens Signalling - toll like receptors which are all teh complicated (or not so much hahaha) T thingys whihc are inside and out side of teh cell
61
what re teh two gruanel tyes found inside of the ohagolysosome
specific - protease and hydrolse enzyme whihc are activated at a neutral ph (so first) nect teh ph is lowerd thsi causes teh azurophilic granusls to be reale whihc are hydrolases and oxidative eenzymes
62
describe the different signalling PRRs
TLR = toll like receptor TLR 1 2 4 5 6 - work extracellularly and respond to PAMPs such as peptidoglycan and lipolysaccorise and teh flagella protines TLR 3 7 8 9 - on teh inside of teh cell and respond to virus RNA, work intrinsically, cause a release of proinflamitory cytokines, whihc cass vasodilation, fever and increased leukocyte prescne it will also produce interferon alpha a and b whihc stop teh virus from replicating in other cells
63
which receptors are cytolysic
NOD-Like Receptors and RIG-Like receptors are cytosolic
64
what us pyroptosis
Pyroptosis is an inflammatory programmed cell death in response to bacterial infection.
65
what attracts neutrophills to teh sight of infection
chemokine IL-8 (CXCL8)
66
how do neutriphills get teh teh infected tissues
1. E-selectin (an adhesion molecule on the capillary endothelium), is activated by IL-1 and TNF-α from damaged cells and binds to the glycoprotein CD15 on neutrophils in blood. 2. This causes neutrophils in the blood to slow down and roll along the endothelium lining. 3. ICAM-1 on endothelium (induced by LPS, IL-1, TNF-α) binds to integrin on neutrophil; the neutrophil stops. 4. Diapedesis: neutrophil squeezes through endothelium (holes caused by C3a, C5a, chemokines, histamines, prostaglandins, leukotrienes (causing smooth muscle contractions in the bronchioles))
67
what are eosinophills important for
Important cells in dealing with parasitic infections. Release cationic granules such as major basic protein. Release ROS, eicosanoids, leukotrienes, elastase among other molecules.
68
whay are basophills importnat for
Can be thought of as circulating mast cells that release histamine upon IgE crosslinking Fcε receptors. They also secrete serotonin and heparin Important in asthma, anaphylaxis, atopic dermatitis, and hay fever. Key point; They do not egress into tissues and become mast cells .
69
what are yeh three granulomacytes (polymorphonuclar cells and whta does this mean)
BEN; Basophil, Eosinophil, and Neutrophil. pmn cells - tehy have multiple nucelues
70
what are mast cells important for
Important in parasitic infection and allergic reactions. At mucosal surfaces. Stem cell factor is essential for development. Main source of histamine. Activated by immune complex IgE crosslinking FcεR1
71
What are teh 5 antobodies for
G - teh main antibody, can cross teh placenta, beinds to phagocytes A - secretes into mucous saliva teads, tags pathogens for destruction M - fixes complement, main antibody of primary response, B cell recepor and important for the immune memnorry E - bainds to mast cells and basophil allergy and hypersensitivity D - b cell receptor, stimulates release of IgM
72
how do natural killer cells work
ADCC is an independent mechanism that does not require complement and uses only one cell type. It is classically NK cells that do this. Typically IgG will bind surface antigens on the pathogen-infected or cancer cell. NK have Fc receptors (CD16) that recognise the antibody Fc region. This cross-linking triggers degranulation and cell apoptosis. Viral proteins are expressed on the surface of cells during viral replication can become antibody targets.
73
whihc cells can present MCH1 and whihc can present MCH2
MCH1 - all nucleated cells - this means red vblood cells dont!! MCH2 - macrophages, B cells, dendritic cells
74
what has to happen between a dendritic cella and t cell for a response to occur
When immune cells come together they form what is know as an immune synapse. For a response to occur 3 things are essential 1. Binding of primary receptors e.g. TCR to MHC II. 2. Binding of co-stimulatory molecules e.g. CD28/CTLA4 to CD80/CD86. 3. A robust release of the appropriate cytokines. MHC binding without other stimulation leads to anergy (lack of response as a form of peripheral tolerance).
75
what are teh markers on T cells
Naïve T cells are identified by being CD45RA+ whereas memory T cells are identified by being CD45RO+. The general marker for T cell activation is CD25 expression.
76
what are the t types of T helper cells
Th1 - cell mediated immunir=ty regulation, regulation of monocytes and macrophages Th2 - hummoral immunity, regulators of eosinophil, basophils and mast cells
77
what are the 4 hypersensitivty reactions
Type I (allergy) Primarily IgE dependent Type II Primarily IgG-dependent cytotoxicity Type III IgG/IgM-dependent immune complex formation Type IV (delayed type hypersensitivity, DTH) Cell dependent (Th1/cytotoxic T cells/macrophages)
78
which antibodies corspond to whihc reaction
1= IgE - Eleanor is having an allergic reaction 2 = IgM and IgG - myself im attacking 3 = IgG - gathering of antibodies 4 = T cells - go cray cray but it’s a bit delayed
79
what are the 7 allergic diseases
Anaphylaxis Allergic asthma Allergic rhinitis (hay fever) Atopic dermatitis Allergic conjunctivitis Oral allergy syndrome (food allergy) Angioedema (not idiopathic)
80
what cells are invoved in allergic reactions
eosinophills, mast cells and basophills
81
defien atopy
Atopy = a hereditary predisposition to the development of immediate hypersensitivity reactions against common environmental antigens.
82
what are teh CD4+ cells for tolerance and inflammation
TREG - T regulation causes tolerance - IL10 cytokine has mass antiinflamitory actions Th17 - importnat in muclsal mucosal membranes it promtes inflamation, teh princilple cytokine is IL17!
83
where does B cell regulation take place
secondary lympohid organs (lymph nodes)
84
what is teh structure of an antibody
FAB regrion - antigen binding fragment binds to e antigen and are the effector regtions Fc region - constant regeon
85
what are teh functions of antibodies
Neutralisation of toxins, agglutination, precipitation, opsonisation of pathogens, complement activation via the classical pathway 🡪 cell lysis and chemoattraction.
86
what are teh 4 hypersensitivoty reactions (PTS defornitions)
Type 1 is a fast reaction occurring in minutes. Cross-linking of antigen to IgE on mast cells and basophils causes massive degranulation and therefore massive release of histamine. Type 2 IgM or IgG binds to self antigen leading to cell destruction by the membrane attack complex and cellular mechanisms. Type 3 IgG binds soluble antigen forming a circulating immune complex. These deposit in vessel walls especially in the kidneys. Here they kick off an inflammatory response causing complement deposition, opsonisation, phagocytosis etc. RBCs carrying the complement receptor 1 bind complement coated immune complexes and transport them to the liver and spleen for phagocytosis. Type 4; This is helper T cell mediated. Specifically Th1. Th1 are activated by antigen presenting cells. Memory T cells are formed. When the memory T cells encounter the antigen again, they will activate macrophages leading to tissue damage.
87
what is teh diffecne between immune tolerance and autoimmunity
Immune tolerance refers to the unresponsiveness of the immune system to self-antigens. This is crucial in order to avoid inflammatory reactions against healthy tissue. Autoimmunity arises when there is a breakdown of immune tolerance.
88
what are teh features of autoimmunity
Often relapsing-remitting Organ-specific vs Systemic Damage to or destruction of tissues Altered organ growth/function Generation of autoantibodies
89
what is a primary and secondary immunodeficancy
Primary Immunodeficiency Those born with intrinsic defects in their immune system. Rare and mostly genetic disorders E.g. SCID Secondary Immunodeficiency These are acquired and are referred to generally as immunosuppression Drug induced e.g. Steroids, azathioprine, chemotherapy. Cancers of the bone marrow and blood cells AIDS.
90
what is tumour necrosis factor
release by macrophages it induces fever and acts as a neutrophil chemotaxis
91
what are 4 immuno surpressive drugs
glucocorticoids Ciclosporin, tacrolimus and rapamycin Purine analogues. Alkylating agents.
92
what is a pyogenic infection and what cell is most liekly to be raised
Pyogenic infections are characterized by local inflammation of skin, soft tissue and bodily parts which are mainly caused by invasion and multiplication of pathogenic microorganism Neutrophil!
93
what is teh difference between MC2 and MHC 1
MHC1 - its is shown on all cells and shows endogenous antigens to show that it is part of self MHC2 - shown on antigen presentic cells such as b ells, macrophages and dendritic cells, its shows exogenous antigens such as from pathogens
94
what are toll like recepros
they are signalling PRRs cause a cascade of signals to be released Single polypeptide chain found on all leukocytes, epithelial cells ad endothelial cells as well
95
what are the two catogries of TRRs
* TLR 1 2 4 5 6 * Are on the cell surface and bind to extracellular PAMPs such as peptoglycan, lipopolysaccoride and flagella * TLR 3 7 8 9 * Are in the cell, bind to intracellular PAMPS such as viral RNA * These activate transcription factor NF-kb * Casing a proinflamitory cytokine secretion * This causes vasodilation, fever and increase leukocyte prescence * If it’s a virus the cell will also produce interferon alpha and beta which stops the virus from replicaitng in other cells
96
what does TLR 2 3 4 respong to
2- gram positive and TB 3- intracellular stuff 4- LPS (lipopolysaccoride on gram negative)
97
what do TLR 5 7 8 9 respong to
5 - flagella 7 - single strnad RNA 8 - intracellular 9 - non methylated DNA
98
what is teh comminication of a dendritic cell and t helper cell called
dendritic synapse
99
what receptors do cd4 and cd8 respond too
cd4 respond to mhc2 cd8 respond to mhc1 the way to remeber tis is that 8x1 is 8 and 2 x 4 is also 8
100
what is thymic selection and how does it happen
it is when teh thymus gets rid of teh t cells that are self recognising and would causse an autoimmune disease if it is positivly slected, it responds to mhc1 and 2 and doesnt cause an immune response
100
what is thymic selection and how does it happen
it is when teh thymus gets rid of teh t cells that are self recognising and would causse an autoimmune disease if it is positivly slected, it responds to mhc1 and 2 and doesnt cause an immune response if it is negativly selected it will recognise teh anitbodies but will still cuase an immune reponse
101
what do interlukins do t helper cells produce
T helper cells release interlukin 4 and 5 * Interlukin 4 incduces clonal expansion of b cells * Interlukin 5 induces b cell differentiation into a plasma cell to produce antibodies
102
define somatic mutation and class switching
* Somatic hypermutation - point mutation in Ig as evolutionary measyre * Class switching - change one Ig into anotehr type