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Flashcards in lecture 19 - immunology Deck (29):
1

innate immunity =

recognition of obvious traits shared by a broad range of pathogens. very rapid response, however, if it is new and changing bacteria, you will not be able to identify it. e.g. neutrophils and macrophages

2

adaptive immunity =

recognition of specific pathogen traits, using a vast array of receptors. slower response and only occurs in vertebrates. Includes both humoral response and cell-mediated response.

3

humoral response

antibodies defend against infection in body fluids

4

how many lymphocytes renewed each day?

10^9

5

lymph nodes

mosaics of B-cell and t-cell clones. Lymph travels through them before re-entering the blood

6

5 steps to immune response

1. immediate inflammatory response
2. specific t-helper activation
3. specific b-cell activation
4. b-cell clonal expansion
5. memory update

7

trigger and cause of localised swelling at infection site (step 1)

triggered by tissue damage, caused by opening of capillary walls.

8

mast cells

move to infection site, release histamine, which in turn attracts neutrophils.

9

phagocytic cells involved in the immediate response

neutrophils (not an APC)
then, macrophages/dentritic cells (APC), B-cell (APC),

10

how do leukocytes move out of blood vessels (not including arteries)?

cytokines released at site of inflammation, increase permeability to WBCs

11

How leukocytes move through vessels

surface proteins called selectins form weak bonds with carbohydrates on the outside of the WBCs, which allow them to stick and roll slowly through.

12

Antigen presenting cells (APC)

- phagocytosis of pathogen
- digestion of antigen to peptide fragments
- vesicle with fragments fuse to vesicle with MHC class 2 molecules
- fragments form complex with MHC class 2
- vesicle undergoes exocytosis and complex binds to membrane

13

aproximate length of peptide antigen fragments

~10 amino acids

14

alarm #1

dendritic/macrophage cells carry antigen peptides (on membrane) to the lymph nodes, and bind the T-cell clones with the specific TCR - stimulating them to divide.

15

alarm #2

antigen presenting B-cells arrive at the lymph nodes. Activated T-cells bind to antigen and release interleukin 2 and cytokines, helping the B-cell differentiate. Activated B-cell clones produce huge number of antibodies.

16

clonal expansion

process where lymphocyte clones divide

17

auto-immune disease

antibodies bind to your own proteins

18

T-helper cells function?

assist other cells produce more anti-bodies, OR stimulate formation of cells which can specifically destroy foreign or infected cells

19

T-cell clones divide into...

memory T-helper cells (long lived) and T-helper clones

20

B-cell clones divide into

plasma cells (antibody production) and memory B-cells (long lived)

21

key features of B-cell clonal expansion

- delayed 1-2 weeks
- more effective and specific
- lymph nodes swollen
- huge antibody production
- t-cells still stimulating b-cell production

22

what eventually happens by the end of the immune response

all bacteria are eventually tagged and killed by macrophages or b-cells

23

first to develop a vaccine? for which disease?

Jenner. Vaccine for smallpox

24

second infection features and reasons

rapid response, may not even be noticed that you were ever infected. This is due to increased antibody level in blood and there are now large clones of specific B and T cells in the lymph nodes.

25

which cells have CD4 proteins?

macrophages and T-cells

26

what do antibodies do?

tag pathogens for destruction

27

chemicals released by T-helper cells, encouraging B-cell differentiation

interleukin 2 and cytokines

28

allergies

Inappropriate or excessive immune responses to antigens

29

cell-mediated response

Cytotoxic cells defend against infection in body cells.