Lecture 8.9: Viral Pathenogenesis 1

Question 1

True or false? Any sized virus can get into alveoli.

Answer 1

False, has to be below 5um.

Question 2

Explain the infection of measles.

Answer 2

Infects macrophages, lymphocytes, DC via receptors CD150, 46.

Enter circulation and amplifies in lymph. Returns to epithelial cells in lungs and mouth.

Question 3

What happens if a virus does not have receptor for epithelial cells? How does it infect?

Answer 3

Via a breach in the surface, such as an abrasion (HIV in rectum). The M cells ingest and deliver antigens to lymphoid tissues.

Question 4

Rotaviruses have tripled shelled capsids. What do they do?

Answer 4

They cannot be destroyed by bile or acid. And instead destroys epithelial cells and M cells, causing inflammation and diarrhoea.

Death is via dehydration.

Question 5

What is tropism and its determinants?

Answer 5

Tropism refers to the anatomical localisation of infection. Dependent on availability of receptors in optimum environment such as pH and temperature.

Ability to replicate in macrophages and lymphocytes.

Presence of activating enzymes such as those provided by cells in large airways for influenza virus.

Question 6

What is molecular mimicry? Give an example.

Answer 6

It is an example of autoimmunity, can be illustrated as with endocarditis due to Coxackie B4 virus.