Virus entry attatchment

Question 1

Examples of virus attatchment factors:

Answer 1

Glycoaminoglycans
Linear polysaccharides
Linked or unliked cell surface proteins. often negatively charged

Question 2

Is Human rhinovirus enveloped or non enveloped?

Answer 2

Non enveloped

Question 3

What is the receptor for HRV14/16 (major)?

Answer 3

ICAM-1

Question 4

What is the receptor for HRV2 (minor)?

Answer 4

Low density lipoprotein receptor (LDLR)

Question 5

What is the normal function of ICAM-1

Answer 5

Intracellular adhesion

Question 6

What is the normal function of LDLR?

Answer 6

Uptake of lipids

Question 7

Where is the picornavirus receptor binding site?

Answer 7

Base of canyon

Question 8

What is at the base of the canyon?

Answer 8

A pocket occupied by a pocket factor, a lipid.

Question 9

Primary receptor of HIV

Answer 9

CD4

Question 10

What is the normal function of CD4?

Answer 10

Binding tp Class II MHC on APC, also binds IL16.

Question 11

What chemokine receptors does HIV also bind to?

Answer 11

CCR5 and CxCR4

Question 12

What gps multimerise to form spikes on HIV?

Answer 12

Gp41 and gp120 –> trimers.

Question 13

What loop is there on the gp120 HIV protein?

Answer 13

V3 loop

Question 14

What does V3 loop bind to prior to CD4/CCR5?

Answer 14

GAGs

Question 15

Timeline of cell tropism in HIV

Answer 15

Early HIV infection in macrophages expressing CCR5
V3 loop mutation, acidic to basic amino acids
Later, HIV infects T-cells expressing CxCR4.

Question 16

What drug is a CCR5 antagonist?

Answer 16

Maraviroc

Question 17

Is influenza A, enveloped?

Answer 17

Yes

Question 18

What are the two influenza A surface glycoproteins

Answer 18

Hemagglutinin (HA)
Neuraminidase (NA)

Question 19

What determined flu host range?

Answer 19

Sialic acid linkage

Question 20

What does avain HA sialic acid bind to

Answer 20

2,3-linkage to galactose

Question 21

What does human HA sialic acid bind to

Answer 21

2,6-linkage to galactose

Question 22

What is the trimer glycoprotein of SARS-CoV-2?

Answer 22

Spike glycoprotein S.

Question 23

Is SARS-CoV-2 enveloped?

Answer 23

Yes

Question 24

What is S cleaved into (covid)

Answer 24

S1 and S2

Question 25

What does S1 contain (covid)

Answer 25

Receptor binding domain

Question 26

What is the SARS-CoV-2 primary receptor?

Answer 26

Angiotensin converting enzyme 2 (ACE-2)

Question 27

Normal function of ACE-2

Answer 27

Cleaves angiotensin into Ang1-9, role in blood pressure and inflammation

Question 28

What is the additional receptor of SARS-CoV-2?

Answer 28

Transmembrane protease serine 2 (TMPRSS2)

Question 29

What does TMPRSS2 do to S?

Answer 29

Cleaves into S1 and S2

Question 30

What is TMPRSS2 cleavage of S dependent on?

Answer 30

pH.

Question 31

How does clathrin mediated endocytosis work?

Answer 31

Clathrin cage causes membrane to curve. Pinches off to form vesicle, targeted to endosome.

Question 32

How does non clathrin dependent endocytosis work?

Answer 32

Caveolae form from cholesterol rich lipid rafts. Targeted to ER/late endosomes

Question 33

What viruses use non clathrin dependent endocytosis

Answer 33

Polyomaviruses and bunyaviruses

Question 34

How does macropintoctosis work?

Answer 34

Membrane ruffling large vesicles, targeted to late endosome

Question 35

What viruses use macopinoctosis?

Answer 35

Large viruses e.g herpes, pox and ebola

Question 36

What is phagocytosis activity based on?

Answer 36

Actin and surface receptors

Question 37

What type of endocytosis occurs in macrophages?

Answer 37

Phagocytosis

Question 38

What type of endocyotsis does the mimivirus use?

Answer 38

Endocytosis

Question 39

How do enveloped viruses penetrate?

Answer 39

Receptor binding Endocytosis Endosome under acidic pH Fusion of biral and endosomal membranes lead to release of capsid into cytoplasm

Question 40

What drives the conformational change in the influenza virus HA.

Answer 40

Low pH

Question 41

How does HIV penentrate?

Answer 41

Receptor binding Fusion of viral and plasma membranes cause release of capsid into cytoplasm

Question 42

Where are fusion peptides found?

Answer 42

In viral glycoproteins

Question 43

What is a fusion peptide

Answer 43

Short hydrophobic amino acid sequences that are able to fuse the viral and cellular membranes.

Question 44

Penetration of non-enveloped virus (1)

Answer 44

Receptor binding Endocytosis Held in an endosome, acidic pH Three options: Uncoating before or after endosome distruption or pore formation

Question 45

Penetration of poliovirus (acid stable)

Answer 45

Receptor binds, memnbrane disruption and uncoating and pore formation