Lecture 5 - Large DNA Viruses Flashcards
Poxviruses do not translocate to the _____ because they bring with them their own _____. This is unlike Herpesviruses and the other small DNA viruses we’ve discussed.
Nucleus
Polymerase
Herpesviruses are large DNA viruses with ______ (the only one that has this among the DNA viruses we’ve discussed) and 2 lifestyles.
Envelopes
Herpesviruses have a characteristic _____ layer between the envelope and the capsid. It contains an important transcription factor for HSV-1 genes: _____.
Tegument
VP16
Alpha herpesviruses include herpes _____ 1+2 as well as ______-_____ (Human herpesvirus 3.) All three have relatively rapid _____ growth cylce and establish latent infections primarily in _____ ganglia.
Simplex
Varicella-Zoster
Cytocidal
Sensory ganglia
Beta herpes viruses include humanherpes virus 5 (aka ______), HHV-6, and HHV-7. The reproductive cycle for all three is long and ____, and grow _____ in culture. _____ establishes latency in monocytes while HHV-6 and HHV-7 establish latency in ___-cells.
Cytomegalovirus (CMV)
Slow
Slowly
CMV
T-cells
Gamma herepesviruses include HHV-4 (aka ______) and HHV-8 (aka ______ ______ associated herpesvirus.) These both establish latency in __-cells and can transform lymphoid cells, resulting in cancer.
Epstein Barr virus
Kaposi’s Sarcoma associated herpesvirus
B-cells
When herpesvirus DNA enters the host cell nucleus, it becomes ______ (remember it is double stranded and linear in the virus.)
Circular
Herpesvirus Immediate early (IE) genes are expressed as soon as the viral DNA enters the nucleus. To determine which genes these are, you can use _______ (a protein synthesis inhibitor) to prevent the expression of downstream genes (early and late) such that the only gene products will be Immediate early. Similarly, to distinguish Early from Late genes, you can use a ______ synthesis inhibitor, which will block the downstream expression of Late genes.
Cycloheximide
vDNA synthesis inhibitor
_____ for alpha herpesviruses and _____ for Beta herpesviruses are drugs that act as _____ analogs. They are administered in an inactive form, and are activated by virus-induced _____. This is what makes them non-harmful for the host cell. They work by terminating DNA _____ and selectively inhibit viral DNA _____.
Acyclovir (alpha)
Ganciclovir (Beta)
Guanosine
Kinases
viral DNA Polymerase
A good way to distinguish HSV-1 and HSV-2 is the region of the body they affect. _____ affects mostly oral and ocular areas while _____ affects genital and anal areas.
HSV-1 (oral/ocular)
HSV-2 (genital/anal)
HSV enters and replicates in the ____, but travels through _____ neurons to sensory ganglia, where it develops latent infection. The virus can be reactivated and travel back through the neurons to the _____.
Skin
Cutaneous
Skin
VZV (aka HHV-3) gives rise to two distinct clinical syndromes:
- _____ in children (initial infection)
- _____ in adults (reactivation after latency in ganglia.)
Chicken pox (Varicella)
Shingles (Zoster)
VZV initially enters through _____ surfaces. It is subsequently transmitted throughout the body via infected __-cells (representing the first viremia.) It is amplified in the internal organs, and then travels again through the blood (second viremia.) It can infect the skin causing chicken pox, or develop latency in _____ ganglia.
Mucosal
T-cells
Sensory ganglia
One of the key differences between reactivation in HSV and VZV is that _____ reactivation leads to shedding and infection of neighboring neurons, while _____ reactivation does not infect neighboring neurons; it just travels back to the skin.
VZV
HSV
CMV (aka HHV-5) reactivates during ______ or in immunocompromised individuals. In these individuals, infection can lead to severe disease of lung, ____, colon, ____, or brain.
Pregnancy
Lung, Liver, Colon, Eye, or Brain.
