05b: Viral Pathogenesis/Lab

Question 1

Viral “factories”, aka (X), can accumulate in cell cytoplasm/nucleus and cause host cell lysis.

Answer 1

X = inclusion bodies

Question 2

List some examples of cytopathic effects (CPE) of virus infection.

Answer 2

1. Inhibition of host cell DNA/RNA/protein synthesis
2. Inclusion body accumulation
3. Immune-mediated cytolysis
4. Apoptosis
5. Syncytia formation

Question 3

A “transforming” viral infection refers to:

Answer 3

Immortalization of host cell by oncogenic virus

Question 4

List the sites of viral entry into host body.

Answer 4

1. Skin
2. Resp tract mucosa
3. GI tract mucosa
4. GU tract mucosa
5. Conjunctiva

Question 5

List some protective mechanisms in resp tract that virus has to evade to enter.

Answer 5

1. Mucous/ciliated cells (clear foreign material)
2. IgA, IgE, macrophages
3. Cool T (URT) inhibits viral replication

Question 6

List some protective mechanisms in GI tract that virus has to evade to enter.

Answer 6

1. Harsh environment (pH, proteases, bile salts)

2. IgA and other nonspecific inhibitors of viral replication

Question 7

Some viruses cross intestinal mucosal layer by crossing through (X) cells.

Answer 7

X = M

Question 8

Primary replication occurs at (X). If virus stays put, (Y) infections are produced.

Answer 8

X = site of infection;
Y = localized

Question 9

List the three methods viruses use to spread from site of entry to target tissues.

Answer 9

1. On epithelial surfaces
2. Sub-epithelial invasion and lymphatic spread
3. Bloodstream
4. Peripheral nerves

Question 10

Virus that invades (X) via (Y) mechanism usually produces a generalized rash.

Answer 10

X = skin
Y = bloodstream

Question 11

Virus can invade CNS via which 3 mechanisms/routes?

Answer 11

1. Bloodstream (hematogenous)
2. CSF/meninges
3. Peripheral/sensory nerves

Question 12

Aside from killing infected cells, what are the mechanisms by which viruses cause disease?

Answer 12

1. Impair functions of host

2. Immunopathogenesis (elicit immune response)