Muscle 5

Question 1

What are the features of adenovirus?

Answer 1

• Medium sized non-enveloped icosahedral virus
• Very large genome and carrying capacity
• Causes gastroentitis and conjunctivitis (mild diseases)
• Capable of transducing both proliferating and non-proliferating cells (low tropism for skeletal muscle)
• 35kb capacity

Question 2

What are the features of 1st gen adenovirus?

Answer 2

Generated by substitutions of E1 and/or E3 with an expression cassette – carrying capacity of 8kb and elicit a significant immune response in vivo (due to still producing viral genes) – successfully used to deliver a mini-dystrophin gene to mouse muscle

Question 3

What are the features of 2nd gen adenovirus?

Answer 3

Deletion of additional viral genes to result in carrying capcity of 10kb, elicited an immune response, both 1st and 2nd gens had leaky expression of viral genes leading to an immune response against the vector

Question 4

What are the features of 3rd gene adenovirus?

Answer 4

Gutted adenoviral vectors, lack all viral genes, reduced immunogenicity and carrying capacity of 30kb. Demonstrated to deliver full length dystrophin via injection leading to functional improvement (still need high doses for effect and these high doses cause immune response)

Question 5

What is the size, carrying capacity and disease cauding potential of lentivirus?

Answer 5

Meidum sized envelpoed retrovirus, 8kb capacity, can cause HIV

Question 6

What is lentivirus capable of?

Answer 6

Transducing proliferating and non-proliferationg cells and integrating into the genome of the host cells

Question 7

Does lentivirus work better in vitro or vivo?

Answer 7

In vitro - limited transduction in vivo

Question 8

What does lentivirus present a high risk of?

Answer 8

Insertional mutagenesis - limits further treatment, may turn on cancerous gene

Question 9

What delivery is not suitable for lentivirus and why?

Answer 9

Systemic - potential oncogenesis

Question 10

What is adeno associated virus?

Answer 10

Small ssDNA parovirus

Question 11

What % of the population has adeno associated virus infected?

Answer 11

80%

Question 12

What does adeno associated virus need to replicate?

Answer 12

Presence of a helper virus

Question 13

Why does adeno associated virus not cause disease in humans?

Answer 13

We are the natural host

Question 14

What is the carrying capacity of adeno associated virus?

Answer 14

5kb

Question 15

How is adeno associated virus generated?

Answer 15

Two-plasmid transfection system in the presence of viral helper genes

Question 16

How many adeno associated virus serotypes and which ones can transduce the heart and skeletal muscle?

Answer 16

9

1,6,8,9

Question 17

What is utrophin?

Answer 17

• Homologue of dystrophin and structurally similar (doesn’t have ABD2 region)
• Normally expressed at the NMJ and overexpressed on the sarcolemma in the mdx mouse, thought to be compensating for the loss of dystrophin

Question 18

What was the effect of AAV9?

Answer 18

Improved function in diaphragm but didn’t improve fibrosis