MCM 2-19 Immunity to Microorganisms

Question 1

which organisms will be successful pathogens?

Answer 1

only those organisms that can successfully evade the immune response

Question 2

primary adaptive response to bacteria is…

the primary local immune response is

the serum antibody response is mostly

Answer 2

antibody response

an IgA response

IgG

Question 3

in most cases the microorganism is actually destroyed in a

Answer 3

phagolytic cell

Question 4

only infected host cells are killed by

Answer 4

CD8+ cells

Question 5

specific immunity acts to enhance the uptake of microorganisms by

Answer 5

phagocytotic cells or to enhance the activity of phagocytotic cells

Question 6

innate immunity protects us against..

Answer 6

99% of bacteria. only the smallest percentage get in and cause disease

Question 7

you can’t live without

Answer 7

phagocytes

you can live without B cells and T-cell

Question 8

Rule #1: most bacteria die within

Answer 8

a phagocyte

Question 9

how does complement recognize microbial surfaces?

Answer 9

complement doesnt specifically recognize microbial surfaces, its the fact that our own cells have inhibitors which are lacking on microbial surfaces

Question 10

spreading factors

Answer 10

enzymes on skin and tissue that break down collagen connection, let bacteria in

Question 11

what do most toxins do

Answer 11

most toxins (not including tetanus) kill immune cells. The hemolytic properties of bacteria are due to toxins that kill blood cells both red and white

Question 12

Protein A

Answer 12

found in staph aureus, binds to and blocks opsonization action of IgG

Question 13

M-protein

Answer 13

an antiphagocytotic factor

Question 14

epithelium attatchment

Answer 14

allows bacteria like cholera/mycobacteria not to get washed away

Question 15

activities of antibody

Answer 15

IgA prevents attatchment to epithelium, doesn’t allow bacteria to stick, gets washed away by mucus or in the digestive tract

triggers complement leading to increased opsonization/lysis

binding to antiphagocytotic Mpreoteins or capsules, preventing antiphagocytotitc activity and acting as an opsonin (for phag and NK cells)

opsonized bacteria are taken up better and killed faster

neutralize toxins before they can harm immune cells

neutralize spreading factors as tissue damaging enzymes

Question 16

2 main facultative intracellular parasites

Answer 16

mycobacterium tuberculosis (MTB)
listeria monocytogenes (LM)

Question 17

describe activity of listeria

Answer 17

gets inside phagosome, detects environment (slightly acidic) and produces 2 enzymes

1. listeria lysin-o
2. phospholipase C

these two enzymes destroy the phagosome, listeria gets into the cytoplasm of the cell. In cytoplasm, forms ACT-A that depolymerizes actin and can shoot itself into neighboring cells

Question 18

process of listeria immunity

Answer 18

developed listeria strain that would kill mice when high dose of bacteria injected

low dose will induce short-term growth but will give immunity

these mice will not be immune to high dose of listeria

Question 19

molecular level of listeria immunity

Answer 19

initially listeria phag but not killed
added antibody to listeria, phag faster but not killed

take macrophages from site of infection are able to kill - these are activated macrophages with heightened and new activities

could kill everything better, but the immunity was not humoral the immunity was cellular.

Question 20

describe activated macrophages

Answer 20

able to kill better, kill everything better. they were non-specific at killing just like regular macrophages are non specific

Question 21

what passed immunity from one mouse to the other?

Answer 21

CD4+ t-cells, not serum.

Question 22

live listeria vs dead listeria response

Answer 22

live - macrophages
dead- antibodies

it must be the presenting cells are making the distinction. the T-cells see antigen on surface of phagocyte. something about APC was detecting if the listeria was growing inside of it or not, causing a shift in influencing t-cells to become TH2 or TH1. The t-cell was making a choice based on how antigen was prseneted and what cofactors were being expressed.

Question 23

Two types of Helper T-cells

Answer 23

helper T-cells are CD4+

TH1 stimulate cell mediated immunity
TH2 stimulate antibody production

Question 24

Effect of TH1 vs TH2

Answer 24

TH1 - macrophage activation, some b-cell activation, production of IL2 and IFN gamma. production of opsonizing antibodies such as IgG1. TH1 will see macrophage and give signals (IFN-gamma and CD40 ligand) to macrophage to activate it

TH2 - b-cells will make lots of antibodies, produce IL4 and IL5

Question 25

dealing with infected macrophages

Answer 25

One of the things that happens when you have listeria infection, and the macrophage is filled
With listeria in its cytoplasm. You can activate the macrophage all you want, but the cytoplasm is not where bacteria gets killed. Cytoplasm is safe, phagosome is wehre bacteria get killed. Nothing about cytoplasm that is toxic. So what you have to do with infected cell is kill it to release bacteria so they can be taken up by a now healthy activated macrophage which can kill it.

Even cd8 cells killing infected macrophage is part of response to listeria.

Question 26

IL-2

Answer 26

t-cell proliferation, NK activation

Question 27

IL12

Answer 27

important in stimulating TH1 response

Question 28

IL10/IL4

Answer 28

important in stimulating TH2 Response

Question 29

necessary signals for TH_ cell to stimulate a b cell

Answer 29

TH2 stimulate B-cells

-IL4, 5,6 along with CD40

Question 30

____ are critical for immunity to parasites

Answer 30

T cells. Activation of macrophages, no direct killing

Question 31

two types of viruses

what do these require?

Answer 31

1. Get into cell, and within 24 hours lyses the cell to release
2. Virus gets in cell, over weeks and months the cell keeps pumping out virus, pushing It into cells near it

different types of immune response

Question 32

dealing with viruses that enter cells and constantly bud off

Answer 32

Need to get CD8 cells to recognize infected cells, can do this on their own, but works best when CD4 is nearby to help.

TH1 cytokines include IL2 - necessary for stimulating CD8 to kill better. One case where THelper cells actually help a CD8 in addition to macrophages

Question 33

describe the effects if IFN-1 (alpha and beta)

Answer 33

induces resistance to viral replication in all cells

increase MHCI expression and antigen presenttion in all cells

activate NK cells to kill virus-infected cells.