Adenoviruses & Viral Gene Therapy Vectors Flashcards Preview

Infectious Disease: Unit 2 > Adenoviruses & Viral Gene Therapy Vectors > Flashcards

Flashcards in Adenoviruses & Viral Gene Therapy Vectors Deck (9)
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1
Q

General structure of the adenovirus virion

A
  • Adenovirus is a non-enveloped icosahdral linear dsDNA virus.
  • It is heat stabile and lacks lipids which confers a r_esistance to lipid solvents_, including bile salts.
  • Its structure permits survival in the lower GI tract, feces, and throat.
  • Has a fiber protein for attachment.
2
Q

Types of dz caused by adenovirus

A
  • Pharyngoconjunctival fever, conjunctivitis (via dissemination in swimming pools), epidemic keratoconjunctivitis
  • Diarrhea in children (via fecal-oral mode of transmission)
  • Respiratory illness
  • Ocular infections
  • CNS infection
  • Genitourinary tract infections
  • Obesity
  • HIV-infected patients
  • Disseminated or subclinical infections
3
Q

Types of respiratory illnesses caused by adenovirus

A
  • Acute, pneumonia
  • Middle upper respiratory tract infection
  • Sporadic/epidemic severe respiratory disease
  • Acute respiratory disease
  • Fatal nonbacterial pneumonia in infants
  • Recent severe pneumonia outbreaks
  • fatal pneumonia in military recruits (rare)
4
Q

Tyeps of genitourinary tract infections caused by adenovirus

A
  • Epidemic infantile gastroenteritis
  • Acute hemorrhagic cystitis
5
Q

Types of DNA Virus gene therapy vectors

A
  • Retroviruses
  • Adenoviruses
  • Adeno-associated virus (AAV)
6
Q

Retrovirus vectors: advantages & disadvantages

A
  • Adv.
    • 8 kb of foreign DNA can be used
    • Stable expression of the transduced gene because of proviral integration in host DNA
  • Disadv.
    • Relatively small amounts of virus obtained during growth
    • Virions are not very stable
    • Low efficiency of transduction of certain non-mitotic cells
7
Q

Adenovirus vectors: advantages

A
  • Very high titers can be obtained
  • Virions are stable
  • The viral chromosome does not normally integrate
  • Non-mitotic cells are efficiently transduced
  • 8-36 kb of foreign DNA can be inserted
  • Can be made to selectively replicate in, and kill, tumor cells
  • Inflammatory response is potential advantage when targeting tumor cells or when used as a vaccine agent
8
Q

Adenovirus vectors: disadvantages

A
  • Elicit a strong inflammatory response
    • almost all people have Ab titer against the adenoviruses most used as vectors ==> repeated use of this virus problematic
    • most adenovirus genes are conserved in the vector leading to inflammatory vector response
  • Expression of the transduced gene will be transient in mitotic cells
  • Death of patient in gene therapy trial
9
Q

Adeno-associated virus vectors: advantages & disadvantages

A
  • Adv.
    • High titers can be obtained
    • The virions are very stable
    • Approximately 5 kb of foreign DNA can be introduced
    • Hasn’t been shown to cause clinical sx
  • Disadv.
    • viral chromosome integrates into host DNA ==> potentially mutagenic event
    • Second strand DNA synthesis, gene expression, and integration are typically very slow in the absence of helper virus
    • The small size of the genome means that large genes cannot be introduced