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Case 9 Flashcards

1
Q

What is a standard deviation and what does it mean if it is particularly large or small ?

A

Variation around the mean.
Small = data is closely grouped
Large = data is sparsely grouped

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2
Q

If the data peak was on the left of the data, with a long tail to the right, what type of skew would it be called ?

A

Positive skew. Most values are greater than the value at the peak.

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3
Q

What does a z score show and how is it calculated (might help realise what it shows)

A

How many SDs a value is above (or below) the mean. Shows the rarity or particular value.
z = (value - mean) / SD

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4
Q

What would a birth weight on the 10th centile mean in terms of relation to other children ?

A

Lighter than 90% of comparative children

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5
Q

What is the formula for BMI calculations ?

A

BMI = weight/height^2

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6
Q

What is another way of referring to +ve sense single stranded RNA ?

A

mRNA

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7
Q

A virion containing what type of nucleic acid would be least likely to have enzymes to make mRNA ?

A

+ve sense single stranded RNA, same base sequence as mRNA so wouldn’t need to replicate

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8
Q

What does the +ve/-ve sense of a nucleic acid refer to?

A

The 5’ or 3’ direction at which replication occurs.

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9
Q

What is a major property of an enveloped virus ?

A

Can utilise membranes of host cells and cause syncytia formation.

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10
Q

What is the envelope made of in enveloped viruses and what can it resist ?

A

Lipids (Fusogenic glycoproteins) so fragile and disintegrates quickly. Can still resist GI tract pH.

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11
Q

Why might visions not be able to be viewed using a regular light microscope ?

A

They are smaller than the wavelength of visible light

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12
Q

Why do DNA viruses mutate less frequently than RNA viruses ?

A

DNA polymerase gives a proof reading function whereas RNA doesn’t so more likely to mutate.

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13
Q

What drugs are likely to be involved in the treatment of Hep C ?

A

Sofosbuvir, Ledipasvir and Ribavirin

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14
Q

What are the general actions of Sofosbuvir, Ledipasvir and Ribavirin ?

A

Sofosbuvir, nucleotide analogue that inhibits RNA polymerase
Ledipasvir, inhibits viral replication
Ribavirin, Blocks RNA synthesis

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15
Q

What are the classic symptoms of Measles and what will develop within 2-5 days ?

A

4 day fever and cough. Red pharynx with white spots

Rash will develop in 2-5 days.

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16
Q

Why is a secondary bacterial infection common after an initial viral one ?

A

Immune system is temporarily exhausted/compromised

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17
Q

How would bacterial pneumonia present in a px ?

A

Almost like a secondary infection because bacterial one is delayed. Affected alveoli on X-ray.

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18
Q

What viral infection may lead to bronchiolitis and what would be seen on X-ray ?

A

RSV (respiratory syncytial virus) . Peribronchial thickening on X-ray.

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19
Q

What is the difference between antigenic shift and antigenic drift ?

A

Antigenic shift = pandemic by reassortment (worldwide, like the game)
Antigenic drift = epidemic

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20
Q

What prophylatic treatment is taken to prevent pandemics from occurring ?

A

Vaccination

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21
Q

What is the typical presentation of glandular fever (4) and what is a common viral cause ?

A

Sore throat, difficulty swallowing, enlarged cervical lymph nodes with splenomegaly.
Epstien-Barr virus.

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22
Q

What types of HPV can cause ; common warts, cervical cancers ?

A 
Warts = 6 and 11 
Cancers = 16 and 18
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23
Q

Which of the hepatitis viruses can be spread by contaminated food and water ?

A

Hep A and E

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24
Q

What type of infection does HPV cause ?

A

Local infection of specific host tissues

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25
Q

What does the Coxsackie A virus cause ?

A

Herpangia, hand foot and mouth disease

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26
Q

Which of the hepatitis viruses can you not be directly infected by ?

A

Hep D, must have had Hep B first

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27
Q

Which of the heps can you vaccinate against ?

A

Hep A and B

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28
Q

Which hep can exacerbate another type of Hep?

A

Hep A worsens Hep B

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29
Q

Which hep are hepatocarcinomas most likely to arise from?

A

Hep C

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30
Q

What is HIV made of and how does it replicate ?

A

Made of two copies of +ssRNA

Has to integrate into chromosome of cell in order to be reproduced

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31
Q

How might you monitor a px with Hep B ?

A

Blood plasma for quantitive PCR to determine viral load.

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32
Q

What further tests would be run on an HIV +ve px and why ?

A

Blood sample PCR and blood sample flow cytometry.

Want to see viral load to see if the CD4+ cell count is decreasing.

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33
Q

What virus is associated with hemorrhagic fever?

A

Dengue virus

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34
Q

What does the Ebola virus cause and what is its animal reservoir ?

A

Hemorrhagic disease with high pathogenicity

Fruit fly bats

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35
Q

What are the consequences of being infected once by dengue fever ?

A

Shouldn’t return to places where it’s present

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36
Q

What are the 9 protected characteristics as defined by the equality act ?

A

Age, Disability, gender reassignment, marriage and civil partnership, pregnancy and maternity, race, religious beliefs, sex, sexual orientation/attraction

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37
Q

When a bacteria enters through breach in perineal cavity what happens? (detection, activation, secretion)

A

Resident macrophages are activated through PRRs (pathogen recognition receptors). This leads to secretion of TNF-a, IL8 and IL-6

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38
Q

What are the general actions of TNF-a and IL-8 ?

A

TNF-a , makes the endothelium more permeable (leaky)

IL-8, initiates direct recruitment of neutrophils

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39
Q

Plasma enters through the endothelium and activates what pathways ?

A

Lectin and alternative

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40
Q

What is the function of cDCs and what happens when they mature ?

A

Phagocytosis and pinocytosis (ingestion of liquid into a cell by budding of small vesicles from the cell membrane)
Migrates to draining lymph nodes.

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41
Q

How is clonal expansion triggered in a T cell ?

A

Antigen presentation MHC 2 by cDCs to circulating naive T cells in draining LNs. Appropriate T cell with correct TCR then replicated.

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42
Q

When CD4 Th17 cells traffic to the site of infection they release… which acts to …. ?

A

IL-17 , increases neutrophil recruitment and production

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43
Q

What immunoglobulin do B cells secrete once they’re activated in draining LN ?

A

IgM

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44
Q

B cells initiate the endocytosis of surface antigens. They then do what with the fragments ?

A

Present to MHC 2 to cognate TFH cells. They then help more B cells to undergo somatic hypermutation and class switching

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45
Q

What occurs after a bacterial infection (e.g. E coli) has been cleared ?

A

Memory B and T cells are produced against E coli

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46
Q

Viral infections are presented to epithelium cells through what process ?

A

They adhere to the cells in the lungs by the mucous and cilia

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47
Q

What is the action of cilia against respiratory viruses ?

A

Sweep the virus to the upper respiratory tract for exhalation.

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48
Q

What is the action of a viral infection e.g. influenza A on respiratory cells ?

A

acute cell death of respiratory epithelium cells. Removes mucous secreting cells and blocks the function of mucociliary escalator

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49
Q

What do infected cells and plasma DCs produce that initiates an IFN response ?

A

Type 1 interferons (a and b). bind through auto and paracrine methods. Inhibits viral replication and protein synthesis.

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50
Q

IFN also induce proliferation/activation of NK cells which do what ?

A

Induce direct killing of viral cells

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51
Q

What is the function of IL-12 and what structures secrete it?

A

Activates NK cells to produce IFN-y which increases APCs antigen processing.
Produced by activated antigen presenting cells eg. macrophages and dendritic cells.

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52
Q

What class of MHC is presented to CD8 cells lymphocytes ?

A

MHC class 1 (always add up to 8)

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53
Q

What is the action of B cells on viral infections ? (action, where, presentation, action)

A

Endocytose virus in draining LN and present on MHC 2 to CD4+. CD4 then stimulate specific B cells to undergo somatic hypermutation and class switching.

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54
Q

What is a common virus that can be transmitted across the placenta ?

A

Rubella

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55
Q

What are the 3 methods of non contact transmission ?

A

Airborne (aerosol) , vechile Bourne (Food e.g. salmonella) and vector Bourne (mosquitos)

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56
Q

What is the definition of isolation ?

A

When an individual is known to have a given infection they are removed from general population to prevent further spread of infection.

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57
Q

What is the definition of quarantine ?

A

A group of people who don’t have a given illness but may be incubating it from somebody else who had it. May show signs later and have been infecting others without knowing so kept away as a prevention incase.

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58
Q

What is an emerging infection ?

A

a new , re-emerging or drug resistant infection whose incidence in humans has increased in the last 20 years or is predicted to increase in the future.

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59
Q

List some causes of a new emerging infection ? (6)

A

change in environment, war, international traffic (traded goods) , new tech (food GM) , bioterrorism, eco changes (global warming)

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60
Q

What is a vital component of a pandemic virus ? (4)

A

Must be able to replicate in humans and cause serious illness that can spread effectively from person to person. Most of the population can’t be immune

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61
Q

Name two common antiviral drugs

A

Oseltamivir and zanamivir

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62
Q

What is the average weight, height and OFC of a newborn ?

A

Weight = 3.5 Kg
Height = 50cm
OFC (occipital frontal circumference) = 35cm

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63
Q

How much weight does a newborn lose on average in the 3-5 days after birth? when should they regain the weight by ?

A

5-10%

10th day

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64
Q

What are the 4 modalities of developmental milestones ?

A

Gross motor function, fine motor function, hearing/vision, communication/social

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65
Q

What is the formal assessment of growth ?

A

SOGS, schedule of growth skills. Refer to paediatrician if concerns arise.

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66
Q

What are the 4 common reflexes assessed in a newborn ?

A 
Tonic neck (looking in each direction)
Grasp reflex (grip fingers) 
Step reflex (walking)
Crawl reflex
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67
Q

What are the key developments after 3 months ?

A

turns head side to side. opens hands momentarily. brief hold gaze, particularly in mum. crying. recognise mum with a social smile

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68
Q

What are the key developments after 6 months ?

A

rolls prone to supine. holds objects briefly. follows moving objects across midline. holds bottle firmly. spontaneous smile. Gurgling

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69
Q

What are the key developments after 9 months ?

A

crawling. finger feeding. Tracks movements. pointing. recognises and responds to own name. waves and clasps objects

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70
Q

What are they key developments in a 1 year old ?

A

walk briefly, crawls up stairs. pinsor grip. eats with spoon. protective of toys, enjoys pictures and blocks

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71
Q

What are the key developments in a 2 year old ?

A

Run, start, stop, kicks. Hand preference starts to show. Recognises faces. Starts to self dress. Drinks from cup. 50 word vocal 2 word phrases.

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72
Q

What is the need for vaccination of mothers against the whooping cough ?

A

Can pass to infants and adolescents where the risk/prevalence is high. IgG from mum’s immunity goes to baby, gives protection for 2 months until they get vaccine.

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73
Q

What is the function of Th1 in bacterial infections ?

A

help macrophages kill intracellular bacteria and Ig class switch (want IgA)

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74
Q

What is the function of Al salts in the whooping cough whole cell vaccine ?

A

Acts as an adjuvant. holds antigen in place at the site of vaccination to give time for DC to come and sample the antigens

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75
Q

When do you give a pregnant women the whooping cough vaccination ?

A

28-32 weeks, enough time for immune response and transferal of IgG to take place

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76
Q

If the mother has had a previous child or been vaccinated against whooping cough in the past does she still need the vaccine ?

A

Yes, the immunity decreases over time so boosters are necessary.

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77
Q

What is the general function of adjuvants ?

A

Make the vaccine stronger. Modifies effects of other parts of the vaccine

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78
Q

What response do the adjuvants favour ?

A

Th2 > Th1

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79
Q

Th1; what cytokine does it release, what immune reactions does it trigger, what host defence does it control ?

A

IFN-y
Macrophage and B cell activation
Intracellular microbes

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80
Q

Th2; what cytokine does it release, what immune reactions does it trigger, what host defence does it control ?

A 
IL-4, 5 and 13 
Mast cell (eosinophil activation) IgE production 
Helminthic parasites
81
Q

Th17; what cytokine does it release, what immune reactions does it trigger, what host defence does it control ?

A

IL-17, 22
Neutrophil/monocyte activation for inflammation
Extracellular bacteria and fungi

82
Q

What is the difference between MHC 1 and 2 relative to antigen presentation ?

A

MHC 1 = presenting peptides from inside the cell

MHC 2 = presenting antigens from outside the cell

83
Q

Why do organ transplants have to be properly tested ?

A

Host T cells reject foreign MHC due to different structures so organ would fail and potentially damage other structures

84
Q

What is the critical vaccine coverage and what is its given formula ?

A

Proportion of immune individuals needed in a population to decrease the frequency of a disease.
1-(1/Ro) where Ro is number of 2ndry infections from first individual

85
Q

Would a highly infectious disease have a low or a high Ro?

A

Very high, for example measles.

86
Q

Bacteremia can be described as an opportunistic infection, what does this mean ?

A

Only becomes infectious if it enters the blood or the CSF

87
Q

What specific structures do T and B cells exclusively recognise ?

A

T cells = only proteins

B cells = only polysaccharides

88
Q

What is a conjugate ?

A

A protein has been added to a structure eg. a polysaccharide

89
Q

How would a polysaccharide conjugate be broken down and displayed ?

A

B cell endocytose the protein along with the pathogen and displayed to T cell to initiate a response to conjugate vaccine

90
Q

Where are T (fh) cells found and what is their function?

A

Subset of CD4 cells found in draining LNs. Activate induced cytokine deaminase. This allows B cell to undergo isotope class switching and somatic hypermutation

91
Q

What area of the immunoglobulin changes during somatic hypermutation ?

A

Changes in fingertip (variable regions) from random mutations

92
Q

What immunoglobulin will be produced in response to a polysaccharide vaccine ?

A

Just IgM as no class switching will occur. This is because T cells haven’t been stimulated because they only see proteins.

93
Q

What region changes during class switching ?

A

Constant region.

94
Q

What type of progenitor gives rise to NK, T, B and plasma cells ?

A

Common lymphoid progenitor

95
Q

What is the bacterial capsule made of ?

A

Layer of polysaccharide and glycoproteins outside the plasma membrane

96
Q

What is the function of the bacterial capsule ?

A

Prevents recognition of surface molecules, forces immune system to produce capsule specific antibody to allow phagocytosis of bacteria

97
Q

What are pili and what is their function ?

A

glycoprotein projections used for attachment to epithelia.

Promotes bacterial entry

98
Q

What is present in GRAM +ve bacteria which colour them to stain what colour ?

A

Peptidoglycan walls, stain purple Because it retains the crystal violet.

99
Q

What do the following shapes mean about the different bacteria ; cocci, bacilli, spirochaete, vibrio

A 
cocci = spheres 
Bacili = rods 
Spirochaete = spirals 
Vibrio = comma / curve shaped
100
Q

What is the alternative pathway and what type of reaction occurs ?

A

most used in absence of a specific antibody. C3b and C3 convertase at microbial surface activates CR1 on phagocyte granules -> opsonisation -> phagocytosis

101
Q

In the manose binding lectin pathway what two structures bind together to form manose ?

A

C2 and C4

102
Q

What is the action of C5a ?

A

Increases vessel permeability and is a chemotactic factor for neutrophils (increase in neutrophil number)

103
Q

What forms the membrane attack complex and how what is it’s action ?

A

C5b + C6-C9 .

Inserts into the bacterial membrane causing lysis

104
Q

What is anaphylaxis ?

A

Wide spread mast cell degranulation and basophil activation in response to allergens and IgE response.

105
Q

How are macrophages activated ?

A

PRRs (TLR is major group) binding to PAMPs

106
Q

What are the 4 major cytokines that macrophages release and what are their general actions ?

A

IL-1, acts on hypothalamus for fever
IL-6, goes to liver to form acute phase proteins
IL-8, endothelium to cause neutrophil chemotaxis
TNF-a, goes to endothelium to increase permeability and adhesion of certain molecules

107
Q

How are dead cells removed during apoptosis ?

A

Phagocytosed by macrophages using ATP in a non inflammatory response.

108
Q

How are dead cells removed during necrosis ?

A

Inflammatory response. production exceeds macrophage capacity. Pus and abscess form.

109
Q

What is chronic lymphocyte leukaemia ?

A

Uncontrolled proliferation of differentiated B cells. Overcrowds the bone marrow and invades other organs
Leads to hepato spleno megaly. Slow progress px may not realise they’re affected/won’t need treatment for years.

110
Q

What is the action of CD4 Th1 (what response, what does it activate, using which receptor, what does it secrete)

A

intracellular bacteria responses (macrophage activation using MHC 2).
Secretes IFN-y and TNF-a

111
Q

What is the action of CD4 Th2? (what response, what does it clear, what does it secrete)

A

Antibody (B cell) response, clearance of extracellular bacteria.
Secretes IL-4, 5, 13
IL-5 , responsbile for antibody formation.

112
Q

How does the cytokine environment affect the type of T cell that is formed ?

A

IL-12 = Th1

IL-2 and 4 = Th2

113
Q

Where is the MHC2 receptor synthesised and what is it’s pathway from there ?

A

Synthesised in the ER before it goes to the Golgi apparatus and binds to fragments

114
Q

How is the spleen divided ? (pulp)

A

Islands of white pulp (lymphatic component) interspersed through red pulp (chords of billroth)

115
Q

How does the antibodies in px show the type of infection present ?
IgM, IgM and IgG, IgG

A

IgM, acute infection
IgM and IgG, chronic active infection
IgG, previous exposure/immunisation

116
Q

What cytokine produced by macrophages helps to maintain the T cell ?

A

IL-12

117
Q

Which of the Hep viruses are acute, chronic or both ?

A

Hep a, e = acute
Hep b = both
Hep c = chronic
Hep d = only with hep B

118
Q

What is the direct action of IFN-y ?

A

Causes direct recruitment of inflammatory cells

119
Q

What are the actions of the enzymes perforin and granzyme ?

A

Perforin, causes pore formation in cell membrane
Granzyme, enters target cell and activates apoptosis
Releases IFN-y and IFN-a/b

120
Q

What is Epstein Barr virus ? (what does It cause, how does it present acute and chronically)

A

Herpes virus that causes latent infection (never cleared)
Acute = infection mononucleosis (common=glandular fever)
Chronic = increased risk of head and neck cancers

121
Q

What does normocytic anaemia indicate ?

A

normal RBC size. Can be a chronic disease that is characterised by bone marrow and renal failure. Can cause acute blood loss for example in pregnancy.

122
Q

What does microcytic anaemia indicate ?

A

iron deficiency due to small RBC for example in sickle cell anaemia.

123
Q

What does macrocytic anaemia indicate?

A

Large RBC, folate and B12 decrease. Haemolysis, hypothyroidism and liver disease are related.

124
Q

What is the cause of thalassemia? what does it result in?

A

Error in production of B chains in the bone marrow.

Chronic haemolytic due to unstable membranes

125
Q

What are the minor and major types of thalassemia ?

A 
Minor = 1 B chain allele affected so asymptomatic 
Major = both chains affected , transfusion dependant
126
Q

How do ferritin levels indicate IDA and inflammatory responses ?

A

Shows total body iron stores
Low = IDA (Iron def anaemia)
High = acute inflammatory response

127
Q

What is transferrin and what do high levels indicate ?

A

Iron transport protein, shows the total iron binding capacity.
High in IDA

128
Q

What does the transferrin saturation level show ?

A

% of transferrin that is bound to iron. Decreased in IDA

129
Q

When are the two MMR injections recommended ?

A

Within month of first bday

Booster between 3 and 5 years old.

130
Q

Why can some infections never be eliminated e.g. tetanus?

A

Always have non human sources eg. animal host, environmental reservoir.

131
Q

What is the problem with an attenuated vaccine ?

A

It is still live even through in a mild form so may cause the disease, especially in an immunocomprimsed px eg. MMR.

132
Q

What is the correlation between vaccine similarity to the disease and triggered immune response ?

A

The similar a vaccine is to the disease, the greater the immune response.

133
Q

How and when is the flu vaccine issued ?

A

Single IM dose of the new vaccine given each year between Sept-Dec.

134
Q

RSV and PIV are both common resp viral pathogens. Which part of the resp tract do they infect and what is their structure ?

A

Both single stranded -ve sense RNA.
RSV, paramoxivirus. severe lower resp tract eg. bronchitis. Mostly in kids >3 y/o
PIV, upper resp tract with fever, cough, rhinitis. Mostly in kids under 3 y/o

135
Q

The flu virus has segmented RNA packaged in nuclear protein which means that ….

A

RNA has multiple pieces spread across the genome

136
Q

The flu virus has a lipid envelope with two surface proteins. What are the names of these proteins ?

A

Hemagglutinin and neuraminidase

137
Q

What is genetic reassortment and what does it lead to ?

A

Shapes a gene segment so previous response is now useless. Leads to antigenic shift, pandemic is possible

138
Q

Why might birds being the major carrier of the flu virus lead to an increased chance of genetic reassortment ?

A

Birds spread the virus to other animals e.g. pigs. 2+ viruses reassort and produce a new virus that passes on to humans and causes infection.

139
Q

What is the action of neuraminidase during flu treatment?

A

Enables virus to be released from cell surface. viruses can’t escape cell so replicate and inhibit neuraminidase. Keeps virus away from lower resp tract and decreases aerosol load

140
Q

What is the action of aminitidine in flu treatment ?

A

Blocks M2 pore ion channel located with viral envelope, preventing replication.

141
Q

What is the proper name given to the red rash with white spots that is typical in measles infections ?

A

Enanthema with Koplik spots

142
Q

What is the chronic, incurable disease that arises if measles is not properly treated ?

A

Subacute sclerosis pan encephalitis

Delayed CNS disease, measles projects into brain tissue. CSF contains increased measles virus antibody.

143
Q

What is the incubation time of Hep C ?

A

2-26 weeks

144
Q

What is the function of the capsid ? what are the 3 types of capsid ?

A

Protects nucleic acid from virus, stops GM from drying out and degrading. Easy to dissemble therefore quickly active once inside the cell.
Helical (flu) , icosahedral (adenovirus) and complex (poxvirus)

145
Q

What are the 3 methods in which visions move to other cells ?

A

Cell free release, direct cell cell transfer , syncyntia

146
Q

What is syncsyntia ?

A

2 cells fuse with one large outer membrane allowing the virus to move across. New cells then fuse, virus moves further through enlarging multinucleate structure.

147
Q

What is the difference between localised and systemic infections ?

A

Localised, replication limited to region adjacent entry site. local damage against local immunity eg. flu. If immune response doesn’t occur it can develop into …
Systemic, infection spreads to other systems via lymph nodes eg. blood (Viraemia) and rest of body. Long incubation period

148
Q

What is the difference between horizontal and vertical spread ?

A

Horizontal, not related to infected. Passed through infected air, food, water etc
Vertical, related to infected. Passed through ovum, sperm, placenta or milk to next generation.

149
Q

What is the name of the virus that causes chickenpox? what is its reactivation called ? how is it prevented ?

A

Varicellular zosto virus
Shingles , possible to catch chickenpox from shingles
Antivirals can’t cure, live attenuated VZV vaccine used.

150
Q

What does Kaposi’s sarcoma virus cause and which px group does it most commonly effect?

A

Skin lesions

occurs in immunosuppressed px and genetically susceptible.

151
Q

Where does cytomegalovirus reside when latent ?

A

Bone marrow and circulating monocytes

152
Q

Which antivirals can be used to treat CMV?

A

Ganciclovir , fascornet and cidofovir

153
Q

What is the cause of 90% of anal cancers ?

A

Type 16 HPV

154
Q

What virus is commonly transmitted by mosquitos ?

A

Dengue fever

155
Q

What is the treatment for DHF ?

A

No effective antivirals or vaccine. Uses antibody enhancement (ADE)

156
Q

What are the stages of ADE ?

A

1st infection with subtype 1, antibody binds to virus preventing it from infecting cells. macrophages recruited and destroy virus
2nd infection with subtype 1, same response with pre existing antibodies
2nd infection with subtype 2, no neutralisation. Macrophages recruited by also become infected.

157
Q

How quickly is the immediate innate response initiated ?

A

0-4 hours

158
Q

List 3 preformed soluble effector molecules that are involved in the immediate innate response ?

A

Defensins, lactoferrin and lysozyme

159
Q

What does the cytolytic action of flu A cause ?

A

acute cell death of dilated resp cells. Removes mucous secreting cells, blocking the mucociliary escalator

160
Q

What two things do NK cells release to kill virally infected cells ?

A

Perforins and granzymes

161
Q

Where are immature dendritic cells and macrophages positioned ?

A

Areas vulnerable to microbes eg. skin and mucosal layers

Nasal passages, throat, intestines and genitals

162
Q

Name two endosomal location receptors and which structures they detect ?

A

TLR-7 , single stranded RNA

TLR-9, recognises herpes virus

163
Q

TLRs …. (4) are prototypic , involved in viral recognition and are primarily expressed on …. ?

A

3, 7, 8, 9

Immune cell endosomes

164
Q

What is the classical triad of triggering TLRs ?

A

Pyrexia, persistant parhyngitis and cervical lymphadenopathy

165
Q

What symptoms do IL-1 and 6 cause ?

A

Fever

166
Q

How is temperature changed to effect virus replication ?

A

Virus replication is temp sensitive, increasing temperature decreases replication

167
Q

Which cells can produce IFN-a+b , what is their surface effect on infection ?

A

All types of cells

Causes systemic symptoms associated with infection; malaise, myalgia etc.

168
Q

What is the effect of IFN when they’re bound to receptors ?

A

indices resistance to viral replication in all cells. ^ expression of ligands for receptors on NK cells. Activates NK cells to virally infected cells

169
Q

What is the action of IRFs ?

A

Interferon response factors

phosphorylated and enter nucleus to initiate interferon mRNA synthesis

170
Q

What is the action of ISGs ?

A

IFN stimulated genes

Suppress viral entry, viral replication and alter cellular metabolism

171
Q

How do IFNs produce an ‘antiviral state’ ?

A

bind to receptors on mast cells, trigger JAK/STAT activation and transcription of ISGs.
All genes involved in viral life cycle so perform variety of function to block replication.
Can pass to neighbouring cells to create ‘cellular firebreak’ to infection.

172
Q

Where are RLRs found and what can they induce ?

A

Found in mast cells

Produce type 1 IFNs against virus that uncoats at plasma membrane

173
Q

RLRs can detect abnormal RNA molecules and trigger a response. What RNAs would they consider ‘unusual’ ?

A

Double stranded RNA

RNA that lacks 5’ end cap of cellular mRNAs.

174
Q

What is significant about pDC secretion relative to other cells ?

A

pDCs can secrete 1000 x more type 1 IFNS. Extensive rough ER.

175
Q

Why couldn’t the 3 MMR injections be given as single injections within a week of each other ?

A

IFN response to vaccine 1 would suppress vaccine 2 therefore immune response would be weakened and cover may not be given.

176
Q

What is the minimum recommended time between live attenuated vaccines in order to avoid overlapping IFN responses ?

A

30 days

177
Q

Why is the buttocks a poor location for vaccine administration

A

bad blood supply, poorly vascularised with a lower number of cDCs

178
Q

How does the IM injection into the deltoid/quads affect the type of response ?

A

activation of cDCs in axillary and linguinal LNs respectively favours IgG. Less protection than IgA, only protects disease from developing.

179
Q

What does TLR signalling do ?

A

Induces CCR7 and enhances processing of pathogen derived antigens.

180
Q

What is the function of CCR7?

A

directs migration to lymphoid tissues and augments expression of costimulatory/MHC molecules.

181
Q

What ‘trial’ do DCs follow in order to reach nearest draining LN?

A

Chemokine CCL21

182
Q

What is the passage of lymph from all tissues through host structures and back into circulation ?

A

Lymph -> all tissues, R lymphatic duct (upper body) , thoracic duct (lower body) , R/L subclavian veins , circulation

183
Q

Why is the spleen able to filter BBVs ?

A

Blood borne viruses

No lymph drainage to spleen so lymphocytes required to directly enter spleen from blood.

184
Q

If a vaccine is intended to activate T cells what must it contain ?

A

Proteins

185
Q

What is cross presentation ?

A

CD8 response generated without the virus. endocytose material goes into cytoplasm and presented by MHC1 so cDCs don’t need direct viral infection in oder to present viral antigens with MHC1.

186
Q

Which TLRs are specifically directed to the endoscope following synthesis in ER ?

A

3,7,8,9

187
Q

What do naive T cells require to become fully activated ?

A

Costimulation from B7 and CD28 along with signal through TCR to become fully activated by cDC

188
Q

Which type of CD4 is specific to viruses ?

A

Th1 , leave LN traffic to infection site and assist/stimulate macrophages

189
Q

What happens when B cells interact with CD4 T(fh) cells at border T+B cell areas of LN?

A

class switching, allows for somatic hypermutation in immunoglobulin gene.

190
Q

.How does a B cell bind to a virus ?

A

Through a viral coat protein. Virus then internalised and degraded.

191
Q

How do T and B cells interact in conjugate vaccines ?

A

CD40 (T) and CD40L (B). peptides from internal proteins of virus present to T cell, activates B cell produces antibody against viral coat protein.

192
Q

Which two types of HPV cause genital warts and cervical cancer ?

A

Genital warts = 6 and 11

Cervical cancer = 16 and 18

193
Q

What is unique about the HPV vaccine ?

A

Normally strength of immune response is wild > live attenuated > inactivated > subunits. In HPV the vaccine is the strongest response.

194
Q

What happens when a B cell receptor isn’t cross linked ?

A

low affinity surface Ig.

B cell receptor isn’t cross linked and centrocyte cannot present antigen to T cell so enterocyte dies by apoptosis

195
Q

What happens when a B cell is cross linked ?

A

High affinity surface Ig. B cell receptor cross linked antigen presented to T helper cell. Centroyte recipes help survives and divides

196
Q

Why are booster vaccinations given ?

A

every time you vaccinate it increases the chance of generating an ^ affinity for antibody

197
Q

What type of immunoglobulins are present in Anti A and B abs and anti Rh-d ?

A

Anti a and b = IgM

anti Rh-d = IgG

198
Q

What is the significance between ABO and Rhesus antigens ?

A

ABO antigens are carbs so no T cell response. Rhesus antigens are protein so T cell involved, B cells can undergo class switching

199
Q

Why is the presence of B7 important in autoimmunity ?

A

Only present in infection so limits autoimmunity because naive CD8 require it to become fully activated

test (14 decks)

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