Introduction To Virology Ii

Front 1

Virus Key Fact

Back 1

Viruses must make mRNA that can be read by host ribosome and so genomes must provide mechanism for synthesis

Front 2

Baltimore System: Types of Viral Genome

Back 2

I. dsDNA
II. ssDNA+ to dsDNA
III. dsRNA
IV. ssRNA+ to ssRNA-
V. ssRNA-
VI. ssRNA+ to ssDNA-
VII. Gapped dsDNA

Front 3

Baltimore System Definitions/Important Facts

Back 3

mRNA is + strand ready, but not all +RNA is mRNA
DNA+ is equivalent polarity of mRNA

Front 4

What information is encoded in a viral genome?

Back 4

Replication of genome
Packaging genome
Regulate replication cycle
Modulate host defenses
Spread to other cells

Front 5

What information is not encoded in viral genomes?

Back 5

No genes encoding complete protein synthesis machinery
No energy or membrane production
No telomeres and centromeres

Front 6

dsDNA genomes

Back 6

Adeno (B), Hepadna, Herpes, Papillo (A), Polyoma (A), Pox

A. DNA is copies by host DNA polymerase
B. Genome encodes DNA polymerase

DNA is copied and also transcribed to make assembly proteins.

Front 7

Gapped dsDNA genomes

Back 7

Hepadna, Hepatitis B

Converted to dsDNA, then transcribed and either used to produce viral proteins or turned into DNA- and then gapped dsDNA

Front 8

ssDNA genomes

Back 8

Circo (TT), Parvo (Fifth)

DNA+ converted to dsDNA to mRNA for packaging proteins or converted to ssDNA to be packaged

Front 9

RNA genomes

Back 9

Most abundant
Encode RNA polymerase producing RNA and mRNA

Front 10

dsRNA genomes

Back 10

Seven viral families, segmented genomes

Reo (rota 10-12 segs), Birna (2 segs)

Front 11

ssRNA +

Back 11

Eight families

Picorna (polio, rhino), calici/Astro (gastroenteritis), Cororna (SARS), Arteri, Flavi (yellow fever, west nile, Hep C), Retro (HIV) and Toga (Rubella, Equine)

Front 12

ssRNA+ with DNA Intermediate genome

Back 12

Retro (HIV and HTL)
Reverse Transcriptase converts the ssRNA+ to DNA- to dsDNA which is read as mRNA and either sued to make packaging proteins or to make new ssRNA+ genome

Front 13

ssRNA- genome

Back 13

Paramyxo (measels, mumps, rubella), RHabdo (Rabies), Borna, Filo (Ebola, Marburg) Orthomyxo (Influenza) and Arena (lassa).

Segmented or non-segmented

always use a RNA-polymerase found in cpasid

Front 14

Segmented Genome can Lead to?

Back 14

Reassortment

Front 15

Designer Viruses

Back 15

Infectious DNA clones, cloned in bacterial vectors

Front 16

Why use virus vectors

Back 16

Gene therapy, deliver genes to patient, infect cells n culture and infuse back in patient
TO deliver Vaccines
Research

Front 17

Clinical Benefit of Lentiviral Gene Therapy in Rare Neurological Disease

Back 17

X linked ALD defect in ABCD1, hematopoietic stem cells infected with lentiviral vector containing correct gene, reinfused into patient leading to improvement

Front 18

Where do viral infections usually begin?

Back 18

Exposed epithelial surfaces, apical, basal, lateral, virus bind cell receptors on epithelial cells for attachment (CD155 for poliovirus)

Front 19

Attachment of Viruses

Back 19

Enveloped viruses attachment mediated by surface glycoprotein

Sialic Acid is receptor for Influenza hemagglutinin

Front 20

Potential unCoating Strategies

Back 20

Uncoating at Plasma Membrane
Uncoating within endosomes (influenza)
Uncoating at Nuclear Membrane

Front 21

Uncoating as Antiviral Target

Back 21

Amantadine and Rimantadine

Front 22

Strategies for Genome Entry into Nucleus

Back 22

through channel from cytoplasm
Injected into nucleus

Front 23

How are viruses assembled?

Back 23

Sequential (with scaffolding proteins)
Concerted

Front 24

Viral Release from Cells?

Back 24

Budding or Lysis
Cell-cell spread

or Both

Front 25

Influenza Neuraminidase

Back 25

Neuraminiadase is a protein used to cleave the bonds between heamglutinin and sialic acid important for budding off. Neuramioniadase inhibitors Tamiflu and relenza work by preventing release and spread.