Mycobacteria

Question 1

What are the general features of Mtb

Answer 1

Mycolic acids, lipoarabinomanin (LAM)– similar to LPS. They have a high amount of lipid in their cell wall, making it hydrophobic and hardy.

Question 2

What cell targets Mtb?

Answer 2

Macrophages.

Question 3

What types of disease are caused by Mtb?

Answer 3

Delayed type hypersensitivity. Macrophages aren’t killing Mtb. Proteins produced by Mtb eventually lead to the death of the non activated macrophage.

Question 4

How many people a week die due to Mtb?

Answer 4

30,000. There are 165,000 new cases a week. Only 10% of people actually get disease though.

Question 5

What is one of the first things that our body does to Mtb?

Answer 5

It coats it in complement so it can be phagocytozed by a macrophage.

Question 6

What can Mtb do so it doesn’t get killed by a macrophage?

Answer 6

Prevent the acidification of the endolysosome.

Question 7

What does DTH cause?

Answer 7

They cause macrophages to bust open, releasing their enzymes to the environment. This causes necrosis.

Question 8

How does Mtb prevent itself from being recognized by the adaptive immune system?

Answer 8

It secretes immunological decoys during early infection. It also inhibits MHC II presentation. It can also manipulate DC maturation

Question 9

How is Mtb diagnosed?

Answer 9

Tuberculin test. Uses purified protein to measure if the host is has delayed type hypersensitivity.