Lec. 11 Immunity

Question 1

How can an organ like the human gut that is only a ~20 feet long have a surface the size of a tennis court?

Answer 1

The fold and villi massively increase the surface area.

Question 2

What is horror autotoxicus?

Answer 2

The horror of having one’s own immune system unleashed against oneself.

Question 3

What is autophagy? (ah-ta-fuh-gee)

Answer 3

In my own words: Process where cells can eat structures within the cell by sequestering them inside an autophogosome and digesting them.

Question 4

What is mucus?

Answer 4

A biogel, of highly hydrated mix of water and glycoproteins secreted (produced) by cells

Question 5

What is the first line of defense of your gut from foreign invaders?

Answer 5

The Mucus layer.

Question 6

What is the origin of most immune cells?

Answer 6

The bone marrow

Question 7

What kind of information does the immune system process?

Answer 7

Molecular information about self and non-self, consisting of composition and shape of molecules and the patterns they form.

Question 8

How can the cells lining the gut detect microbes that can form a threat of infection?

Answer 8

By expressing innate receptors that specifically detect bacterial molecular patterns.

Question 9

What is the complement system?

Answer 9

A part of the innate immune systems that relies on numerous secreted proteins that can distinguish self from non-self

and form a powerful membrane attack system as well as amplify the effect of antibodies and other molecular beacons that recognize non-self or “altered self”.

Question 10

Do soluble innate immune proteins in the blood tag for destruction or tag for
Protection?

Answer 10

Both.

Question 11

What happens to B-cell that make antibodies specific for self molecules?

Answer 11

They are forced to undergo suicide.

Question 12

How can the same gene give rise to different proteins?

Answer 12

Alternative splicing,

or different post-translational modifications, or somatic recombination.

Question 13

What is the difference between an antigen and an antibody?

Answer 13

Antigens are molecules that can be recognized by the immune system, antibodies are molecular probes that recognize antigens.

Question 14

Mention a key difference between innate and adaptive immunity.

Answer 14

Innate immunity acts rapidly, adaptive immunity can learn to detect new patterns and form memories.

Question 15

What do the acronyms PAMP, DAMP and SAMP refer to in the context of immunity?

Answer 15

Pathogen-associated, Damage-associated and Self-associated molecular patterns.

Question 16

What is the difference between HLA and MHC?

Answer 16

They are the same, HLA is also the other name for human MHC.

Question 17

How can the immune system detect the presence of a virus that has already infected a cell?

Answer 17

The HLA molecules of the cell will present cellular content on the outside of the cell allowing the immune system to detect viral debris, intra-cellular parasites or cancer.

Question 18

What is the name of the gut immune tissue”

Answer 18

GALT.

Question 19

What are the lymphoid organs around the gut called?

Answer 19

Peyer’s patches.

Question 20

What are mesenteric lymph nodes?

Answer 20

the tissue connecting the gut to the rest of the body.

Question 21

What do the life threatening consequences of gut puncture wounds highlight about the gut microbiome?

Answer 21

That the gut bacteria are extremely dangerous if they invade our bodies.

Question 22

Give two examples of external influence on gut immunity.

Answer 22

Breast feeding, nutrition, history of infection, antibiotics treatments.

Question 23

What is Anaphylaxis?

Answer 23

A potentially life threatening, all-out immune response.

Question 24

Do most people in the USA who avoid gluten have antibodies against gluten?

Answer 24

No, only a minority does.

Question 25

Why do patients with true celiac disease have immune
reactions that attack their own guts?

Answer 25

Because they trigger an immune reaction against gliadin in complex with a “self” enzyme (tissue Transglutaminase).

Question 26

How could the microbiome of a person influence their immune reaction after consuming an edible vaccine?

Answer 26

Persons with more diverse microbiota have better responsiveness of the gut-associated immune system.