Lecture 4 part 2 -- herpes, etc

Question 1

explain the envelope, capsid, and genome of herpesviruses

Answer 1

envelope – has an envelope. RICH in glycoproteins
capsid – icosaDELTAhedral
genome – dsDNA virus with a linear genome

Question 2

what are the 3 subfamilies of the herpesviruses

Answer 2

-alpha
-beta
-gamma

Question 3

the 3 subfamilies of herpesviruses was determined based on….

Answer 3

their gene structure and site of latent infection

Question 4

where are herpesviruses replicated and assembled?

Answer 4

in the nucleus

Question 5

explain the symptoms usually exhibited in herpesviruses (be general)

Answer 5

herpes is a common infection.
usually, benign and asymptomatic but can be serious especially in immunocompromised ppl

Question 6

where in the body is there significant morbidity if herpesviruses get their

Answer 6

eye, brain, and disseminated infections (spread)

Question 7

true or false

some herpesviruses have highly specific tissue tropism

Answer 7

true

Question 8

how are herpes viruses released from the cell?

Answer 8

through lysis, exocytosis, or cell-cell bridges

Question 9

name the 3 viruses under alpha herpesvirus

Answer 9

HSV-1 (herpes simplex)
HSV-2
Varicella-Zoster virus (VZV) – HHV-3 (chicken pox)

Question 10

name the viruses under beta herpesvirus

Answer 10

CMV (cytomegalovirus) – HHV-5
Human Herpes virus 6 and 7

Question 11

name the viruses under gamma herpesvirus

Answer 11

EBV – epstein-barr virus – HHV-5
Kapsi’s Sarcoma-related virus (HHV-8)

Question 12

HHV3

Answer 12

varicella-zoster virus (chicken pox) (VZV)
ALPHA

Question 13

HHV 6 and 7

Answer 13

human herpes virus 6 and 7 (BETA)

Question 14

HHV-4

Answer 14

Epstein-barr virus (EBV)
GAMMA

Question 15

HHV-5

Answer 15

CMV (cytomegalovirus)
BETA

Question 16

HHV-8

Answer 16

kapsoi’s sarcoma related virus (gamma)

Question 17

explain the replication scheme for herpesviruses (how they make protein and more genome)

Answer 17

herpes genome: dsDNA

to make protein:
SAME WAY AS HOST – USES DNA DEPENDENT RNA POLYMERASE THAT IS MADE BY THE HOST to make (+)mRNA. this is then translated to protein on a host ribosome

to make genome: uses VIRAL DNA dependant DNA polymerase to replicate into more dsDNA

Question 18

which herpesvirus(es) cause mononucleosis

Answer 18

Epstein-barr virus (gamma) - HHV-5
cytomegalovirus (beta) - HHV-4

Question 19

which virus has a TEGUMENT and what is it

Answer 19

herpesviruses
cluster of proteins that surrounds the nucleocapsid

Question 20

what is one of the only viruses to use the rolling circle method of replication?

Answer 20

herpesviruses

Question 21

explain how herpesviruses replicate

Answer 21

their genome (dsDNA) circularizes in the nucleus. the transcription of immediate early genes begins.

alpha proteins are the products of immediate early genes. they stimulate the transcription of early genes.

beta proteins are the products of early genes. they function in DNA replication, yielding CONCATEMERIC DNA which is very long, linear, and multiple genomes.
late genes are transcribes

the product of late genes = gamma genes. they participate in virion assembly

to actually replicate, they use the ROLLING CIRCLE METHOD OF REPLICAITON

Question 22

Name the primary infection sites for HHV1-4

Answer 22

HHV-1: mucoepithelial cells
HHV-2: mucoepithelial cells
HHV-3: mucoepithelial cells
HHV-4: B cell, oral epithelium

Question 23

name the latent infection sites for HHV1-4

Answer 23

HHV-1: nerve ganglia
HHV-2: nerve ganglia
HHV-3: nerve ganglia
HHV-4: B lymphocytes

Question 24

HHV-4- —- HHV-8 are all latent in…..

Answer 24

IMMUNE CELLS

Question 25

which herpes virus has symptoms like genital and anal lesions, severe neonatal infections, and meningitis?

Answer 25

HHV-2

Question 26

which herpes virus has symptoms like oral and ocular legions and encephalitis? (inflammation of brain)

Answer 26

HHV-1

Question 27

Which herpes virus gives the chicken pox with primary infection and shingles virus with reactivation?

Answer 27

HHV-3 (varicella-zoster virus)

Question 28

which herpes virus gives tumors and some B cell lymphoma?

Answer 28

HHV-8 (kaposi sarcoma)

Question 29

which herpes virus gives roseola in infants and infections in allograft recipients ?

Answer 29

HHV-6

Question 30

Which herpes virus gives some cases of roseola?

Answer 30

HHV-7

Question 31

The genomes of HSV-1 and HSV-2 encode around how many proteins? explain

Answer 31

~80 proteins divided in 2 groups: -viral replication --viral DNA polymerase --scavenging enzymes that create deoxyribonucleotides used for synthesis of new viruses -other proteins --attachment glycoproteins --immune escape proteins

Question 32

are HSV infections lytic or not lytic?

Answer 32

lytic

Question 33

HSV infections lyse what 2 types of cells?

Answer 33

epithelial cells and fibroblasts

Question 34

where are HSV infections latent?

Answer 34

in non-dividing cells. ie: neurons

Question 35

in latent HSV infections, are early and late genes being expressed?

Answer 35

no--- being suppressed by: -LATs (latency-associated transcripts) -micro RNAs inhibit gene expression

Question 36

HSV viruses persist in _____ neurons explain what is happening

Answer 36

sensory neurons ie: trigeminal nerve these viruses avoid the host immune response and the person is asymptomatic. TAP is blocked, and they express Fc and complement receptors reactivation of the herpes virus can occur with systematic infection, fever, stress, or sun exposure

Question 37

which HHV can affect neonates and is often fatal

Answer 37

HSV-2 cell mediated immunity of the neonates is not fully developed

Question 38

what are the symptoms of HSV-1

Answer 38

mucocutaneous lesions --- cold sores pharyngitis eczema encephalitis

Question 39

what are the symptoms of HSV-2

Answer 39

genital herpes -- affects sacral ganglion neonatal HSV

Question 40

chickenpox affects what 3 cells?

Answer 40

epithelial cells, fibroblasts, and T cells

Question 41

where does HHV-3 (VZV) go latent?

Answer 41

in neurons -- dorsal root or cranial root ganglia

Question 42

what is the primary route of transmission for VSV

Answer 42

inhalation

Question 43

where does VZV replicate

Answer 43

in mucosal epithelium. cell-cell spread (synctium)

Question 44

how is HHV-3 spread

Answer 44

by viremia to skin producing regions

Question 45

what are 3 potential outcomes of HHV-4

Answer 45

epsteinn barr virus 1. primary infection -- productive and lytic 2. latent infection in memory B cells -- recurrence when the B cell is activated 3. immortalization of B cells--lymphomas

Question 46

3 fates of the epsteinn-barr virus are: primary infection, latent infection in memory B cells, and immortalization of B cells explain how each is accomplished

Answer 46

primary infection -- lytic and productive. virus binds CR2 receptor on selected epithelial cells and B cells. early and late genes are transcribed and translated latent infection in memory B cells --- recurrence can occur once the B cell is activated. NO EARLY OR LATE GENE EXPRESSION immortalization of B cells --- B cell lymphomas and nasopharyngeal carcinomas

Question 47

how is HHV-4 transmitted

Answer 47

through shedding virus (saliva)

Question 48

what component of our immune system is critical for controlling HHV-4

Answer 48

T CELLS the massive activation of T cells by the proliferation of B cells contributes to symptoms of mono (infectious mononucleosis)

Question 49

name 3 symptoms of epsteinn barr virus that occur as a result of T cell mediated immunity to control the infection

Answer 49

lymphocytosis -- increase in cells with 1 nucleus swelling of lymph tissue malaise -- general discomfort

Question 50

what does EBV produce that inhibits the TH1 immune response?

Answer 50

an analog to IL-10 cytokine (a virokine)

Question 51

which HHV is a dsDNA virus but harbors mRNA transcripts in its capsid?

Answer 51

HHV-5 (cytomegalovirus)

Question 52

what are the permissive and non permissive cells for HHV 5

Answer 52

permissive -- fibroblasts, epithelial cells, granulocytes, macrophages nonpermissive -- lymphocytes, stromal cells, monocytes

Question 53

HHV-5 favors ___ infections. why?

Answer 53

latent because there is slow replication --reactivated in immunocompromised individuals

Question 54

which virus has asymptomatic shedding of the virus in bodily fluids?

Answer 54

HHV-5 cytomegalovirus

Question 55

for which herpes virus is nearly everyone seropositive in adulthood? name other characteristics of this virus

Answer 55

HHV-6 -- Roseola replicates in SALIVARY GLANDS high fever followed by neck and trunk rash

Question 56

where does HHV-6 go latent?

Answer 56

in CD4 cells and monocytes --productive infection when T cells are activated

Question 57

which herpes virus is opportunistic in AIDS patients

Answer 57

HHV-8 Kaposi sarcoma RARE