Naked DNA: Day 2

Question 1

What are the categories of naked viruses?

Answer 1

1. papovaviruses 2. adenoviruses 3. parvoviruses

Question 2

What are defining characteristics of papovaviruses? Shape, Nucleic acid, where they replicate?

Answer 2

isosahedral circular dsDNA nucleus

Question 3

What are two types of papovaviruses?

Answer 3

papillomaviruses (HPV) polyomaviruses (BK virus, JC virus)

Question 4

Answer 4

HPV

Naked capsid, double-stranded, circular DNA viruses

(this is an example of a papillomavirus, which is one of two types of papovaviruses.

Question 5

Name four genes involved with HPV. Which one does the vaccine target, and how does it do so? Which 2 are involved in dysregulating cell cycle, and how?

Answer 5

RNA polymerase

E6 and E7 dysregulate the cell cycle to increase cell division. E6 targets p53, and E7 targets pRb.

L1 and L2 form the caspid.

HPV L1 Virus-like Particles: it forms the structure of the virion without containing any HPV genetic material, creating anti L1 antibodies

Question 6

How is BK transmitted? What is its initial target, its primary viremia target, and its secondary viremia target?

Answer 6

Transmitted through aerosol. Initial target is respiratory tract, primary viremia in kidney, secondary viremia in urinary tract.

Question 7

What disease impact does BK have?

Answer 7

Trick q. Nothing if you’re immunocompoetent, but renal disease if you’re immunocompromised.

Question 8

How is JC virus transmitted? Initial target? Primary viremia target? Secondary viremia target?

Answer 8

transmitted through aerosol. Primary viremia target is in respiratory tract. Secondary viremia target is in CNS.

Question 9

What disease impact does JC have?

Answer 9

nothing if immunocompetent.

if immunocompromised:

Progressive Multifocal Leukoencephalopathy (PML): progressive brain disease, with death after months

Question 10

Adenoviruses: what is the caspid symmetry, nucleic acid, and site of replication?

Answer 10

isosahedral, linear ds DNA, nucleus

Question 11

How are adenoviruses transmitted? initial target? primary target? secondary target?

Answer 11

Spread by aerosol, close contact, or fecal-oral route

Virus infects first mucoepithelial cells causing direct cell damage

Virus persists in lymphoid tissue

Disease is determined by the tissue tropism of a virus

Question 12

Conjunctivitis (pink eye) is an example of what type of virus?

Answer 12

adenovirus

less pus than the bacterial counterpart

Question 13

Answer 13

Parvoviridae (parvus=small)

Question 14

Parvovirus: caspid symmetry, genome, replication?

Answer 14

Icosahedral

Genome: ss DNA

Replication: nucleus

Question 15

Parvovirus transmission, initial target, primary viremia target, secondary viremia target

Answer 15

transmisison: aerosol
initial: upper respiratory tract

primary target: erythroid precursor cells in bone marrow

seconday: n/a

Question 16

what virus causes this?

Answer 16

Aplastic crisis: B19 parvovirus can arrest red blood cell production. Esp. dangerous in patients with increased red blood cell turnover/chronic anemia (e.g. sickle cell anemia). Transfusion recommended.

Question 17

Answer 17

hydrops fetalis:

Human hydropic fetus and placenta after intrauterine parvovirus B19 infection

Fetal anemia leads to hydrops fetalis

Hydrops is an edema (swelling due to lymph fluid) in subcutaneous tissue

Question 18

What are the low risk forms of papilloma virus? What are they associated with?

Answer 18

HPV 6, 11, 42, 43 and 44, are considered “low risk” for cancer but often lead to the development of genital warts.

Question 19

What are the high risk papilloma viruses? What are they associated with?

Answer 19

• HPV 16,18, 31 and 45 are considered “high risk”

• Can lead to cervical cancer