Herpes Family Flashcards
What are the members of the Herpesviridae family?
Herpes Simplex, Varicella-Zoster, Epstein-Barr, and Cytomegalovirus
Describe Herpes virus structure.
Icosahedral capsid with envelope
How does Herpes enter the cell?
Nucleocapsid enters cytoplasm via fusion or receptor mediated endocytosis.
Where are nucleocapsids targeted to ?
Nuclear pores
Discuss Herpes virus gene expression.
- Gene expression using host RNA polymerase and transcription factors including its own VP16.
- IE gene producs activate early genes which code for enzymes needed for viral DNA replication
- Replication begins
- Late genes encode structural proteins of virus.
Where does herpes like to have latent infections?
Neurons
How is HSV-1 and HSV-2 transmitted?
HSV-1 is orally transmitted; HSV-2 is sexually transmitted
How is HSV diagnosed in the laboratory?
Ballooning of cells; Multinucleated giant cells
How is HSV treated?
Acyclovir is selective against HSV and VZV; Chain terminator
How is VZV spread?
Respiratory droplets or direct contact
Discuss the pathogenesis of VZV
- Enters and replicates in the respiratory tract.
- Spreads to lymphoid cells
- Causes skin rash
What are the complications of VZV
- Hemorrhagic Chickenpox
- Viral pneumonia
- Encephalitis
- Congenital varicella
Which cells are infected by Epstein-Barr virus?
B cells; Uses complement receptor CR2 and CD21
- Lytic and Latent in B cells.
- Lytic in epithelial cells
- Immortalization of B cells and stimulation of proliferation.
What is the role of the 3 Epstein Barr Nuclear Antigens?
EBNA 1: maintains presence of viral genome
EBNA 2: Stimulate B cell proliferation of genes.
EBNA 3: Inactivats Rb, stimulates cell gene expression
How is EBV diagnosed?
- CBC with differential
2. EBV specific antibodies
