Herpesvirus Biology

Question 1

what are the 3 alpha herpes viruses

Answer 1

latent cell = NEURONS
1. herpes simplex type 1 (HSV1)
2. herpes simplex type 2 (HSV2)
3. varicella-zoster virus (VZV)

Question 2

what are the 3 beta herpes viruses

Answer 2

latent cell = LYMPHOCYTES
1. cytomegalovirus (CMV)
2. human herpesvirus 6
3. human herpesvirus 7

Question 3

what are the 2 gamma herpes viruses

Answer 3

*cause CANCER
1. epstein-barre virus
2. Kaposi’s sarcoma (associated with HHV-8)

Question 4

herpesvirus structure - capsid

Answer 4

icosahedral + envelope

Question 5

important enzyme made by herpes viruses

Answer 5

thymidine kinase (they make their own)

Question 6

ALL herpes viruses establish what kind of infections?

Answer 6

lytic AND latent

Question 7

what is responsible for maintaining latency of herpes viruses

Answer 7

cellular immunity (T cells)

Question 8

what are the latent cells for HSV 1/2 ?

Answer 8

SENSORY neurons

Question 9

what are the latent cells for varicella-zoster virus (VZV / HHV-3) ?

Answer 9

dorsal root ganglia of sensory nerves

Question 10

what are factors that govern reactivation of latent alpha herpes virus infections

Answer 10

*IMMUNE SUPPRESSION
-UV-B radiation
-hyperthermia
-emotional stress
-physical stress
-menstruation

Question 11

transmission of HSV 1/2

Answer 11

-close personal contact (kissing, sexual contact)
-vertical (TORCH infection)

Question 12

clinical course of HSV 1

Answer 12

gingivostomatitis/cold sores
**latent in TRIGEMINAL ganglion
*can also cause encephalitis with focal TEMPORAL lesions

Question 13

clinical course of HSV 2

Answer 13

painful genital vesicles with fever/malaise
**latent in SACRAL nerve ganglia
*can also cause encephalitis with focal TEMPORAL lesions

Question 14

testing for HSV 1/2

Answer 14

*genital/skin lesions: immunofluorescent staining or PCR (Tzanck smear of vesicle)
*encephalitis: PCR of CSF

Question 15

treatment for HSV 1/2

Answer 15

ACYCLOVIR (oral prodrug = valacyclovir)

Question 16

how does acyclovir work to treat HSV 1/2

Answer 16

*in the virally infected cells, the VIRAL thymidine kinase converts acyclovir into a “false nucleotide” to BLOCK DNA synthesis (inducing chain termination)
*cellular thymidine kinase won’t do this

Question 17

which nucleoside is acyclovir an analog for

Answer 17

guanosine

Question 18

transmission of VZV (varicella-zoster virus)

Answer 18

*respiratory droplets from patients with chicken pox
*contact with lesions from patients with shingles

Question 19

clinical course of VZV: chicken pox

Answer 19

*ASYNCHRONOUS vesicular rash (lesions in different stages)
*fever
*pharyngitis
*malaise
*rhinitis

Question 20

clinical course of VZV: shingles

Answer 20

*REACTIVATION of latent VZV
*pain/vesicles in a DERMATOMAL DISTRIBUTION

Question 21

treatment for VZV

Answer 21

ACYLOVIR (oral drug = valacyclovir)

Question 22

vaccine for VZV (for children)

Answer 22

Varivax: LIVE ATTENUATED VACCINE

Question 23

vaccine for VZV (for adults 50+)

Answer 23

Shingrix: SUBUNIT VACCINE

Question 24

cytomegalovirus (CMV) appearance upon biopsy

Answer 24

“owl eye” inclusions in infected cells

Question 25

latent cells for cytomegalovirus (CMV / HHV-5)

Answer 25

mononuclear cells

Question 26

cytomegalovirus (CMV) transmission

Answer 26

-saliva, sexual, parenteral -in utero (vertical transmission)

Question 27

what cells are infected by CMV

Answer 27

salivary gland epithelial cells (LATENT in mononuclear cells though)

Question 28

clinical course of cytomegalovirus (CMV)

Answer 28

*mononucleosis but heterophile (monospot) negative *"blueberry muffin" babies if congenital *in immunocompromised pts, can cause retinitis, interstitial pneumonitis, GI disease

Question 29

testing for CMV

Answer 29

PCR of blood urine test in babies

Question 30

treatment for CMV

Answer 30

GANCYCLOVIR (oral prodrug = valgancyclovir)

Question 31

latent cells for HHV 6/7

Answer 31

mononuclear cells

Question 32

clinical course for HHV 6/7

Answer 32

ROSEOLA: fever for 5 days FOLLOWED BY lacy body rash *high fever can cause seizures (febrile seizures)

Question 33

treatment for HHV 6/7 (roseola)

Answer 33

supportive care only

Question 34

entry for Epstein-Barr Virus (EBV)

Answer 34

binds receptor CD21 (complement receptor 2)

Question 35

latent cells for Epstein-Barr Virus (EBV)

Answer 35

B cells

Question 36

transmission of Epstein-Barr Virus (EBV)

Answer 36

respiratory secretions and saliva ("kissing disease")

Question 37

clinical course for Epstein-Barr Virus (EBV) (immune COMPETENT patient)

Answer 37

mononucleosis (heterophile test +): -fatigue -fever -sore throat -lymphadenopathy -splenomegaly

Question 38

clinical course for Epstein-Barr Virus (EBV) (reactivation / cancer)

Answer 38

-lymphoma (endemic Burkitt) -nasopharyngeal carcinoma (Asian adults especially)

Question 39

Epstein-Barr Virus (EBV) testing

Answer 39

*antibody test or serology is best *monospot (heterophile) test is easiest *EBV blood PCR

Question 40

Kaposi sarcoma-associated herpesvirus (HHV-8) latent cells

Answer 40

B cells and glandular epithelial cells

Question 41

Kaposi sarcoma clinical course

Answer 41

-neoplasm of endothelial cells -seen in HIV/AIDS and transplant patients -dark/violaceous plaques or nodules

Question 42

herpesvirus structure - nucleic acid

Answer 42

dsDNA