Innate immune system

Question 1

4 “C” chemical components of the immune system

Answer 1

1. cytokines - proteins that affect other cells
2. Complement - set of plasma proteints that act in cascade to attack extracellular pathogens
3. chemokines - small proteins that cause leukocytes to migrate
4. coagulation - blood proteins that cause blood clotting

Question 2

2 functions of immune system

Answer 2

1. sentinal - recognize non-self

2. attack

Question 3

2 primary defence types against path.

Answer 3

1. physcial

2. chemical - pH, antimicrobials, ROS

Question 4

what recognizes bad pathogens

Answer 4

TLRs or PRRs (pattern recognition receptors)

Question 5

what do TLRs recognize

Answer 5

PAMP - pathogen assoc. molecular patterns

Question 6

2 places TLR are expressed

Answer 6

1. extra - for bact etc.

2. intracellular - for viruses

Question 7

general steps when TLR binds path.

Answer 7

1. send signal to adapter molecule in cell
2. kinases signal to nucleaus
3. nucleus transcribes genes to deal with danger signal

Question 8

what is an inflammasome

Answer 8

assembled intracellular complex of proteins that are signalled by phaged paths. and secrete IL-1 for inflammation

Question 9

what cells phag

Answer 9

neutro, macro, dendritic, B-cells

Question 10

4 main receptors on a macrophage

Answer 10

1. Fc
2. TLR
3. mannose
4. complement

Question 11

what does phagocytosis lead to (3)

Answer 11

1. initiation of bactericidal activities
2. antigen presentation for T-cells
3. induciton of pro-inflammatory cytokine reslease

Question 12

4 mechs. other than phag t deal with a path.

Answer 12

1. complement cascade
2. ADCC - antibody dep. cellular toxicity
3. defensins - anti-microbial peptides on mucous
4. pentraxins - bind path. and act as a signal

Question 13

3 different outcomes of completment activation

Answer 13

1. recruitment on inflamm. cells
2. opsinization
3. killing of paths

Question 14

what is ADCC - antibody dep. cellular toxicity

Answer 14

NK cells killing of paths. that have been opsinzed by surface bound antibodies

Question 15

what are 3 first innate cells that will deal with an infection

Answer 15

1. tissue sentinal cells - secrete cytokines
2. neutophils - short-lived dedicated killers
3. macrophages - supress neutophils and come in and clean up

Question 16

3 ways neutrophils kill

Answer 16

1. phag.
2. degranulate
3. netting

Question 17

3 main pathways of complement activation

Answer 17

1. classical - antibody depenedent
2. lectin - lectin binding to path surfaces
3. alternative - pathogen surfaces

Question 18

what is main complement of complement activation

Answer 18

C3 convertase to C3a and C3b

Question 19

what is function if C3a

Answer 19

small frag that cause increased vasc. permeability and inflammation

Question 20

what is funciton of C3b

Answer 20

tags bacteria for phag - opsinization

Question 21

what happens in C3 conversion

Answer 21

breaks into 2 peices (a and b)

Question 22

how does C3b opsinize

Answer 22

bound C3b frag is recognized on phag. cell

Question 23

what is early component of compliment system

Answer 23

C1 binding to antibodies

Question 24

what is late component of compliment system

Answer 24

1. C3 convertase > C5 convertase
2. leads to membrane attack complex (MAC attack)
3. pokes small pore in membrane and leads to explosion

Question 25

what else does complement do aside from recognize paths

Answer 25

recognizes damage host cells to elim. danger

Question 26

what happens if def. in early components

Answer 26

not severe - assoc. with lupus

Question 27

what happens if def. in late components

Answer 27

more nesseria infections

Question 28

what happens if def. in C3

Answer 28

recurrent pyogenic infections -M and M

Question 29

3 places where complement is regulated

Answer 29

1. at C1 conversion 2. C3 convertase 3. late phase

Question 30

what is hereditary angioneurotic edema

Answer 30

C1INH (inactivtate C1) deficiency leads to too much active C1 and get excessive response

Question 31

what is febrile neutropenia

Answer 31

severe lack of neutrophils and get infected easily