Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Immunology > chapter 5 > Flashcards

chapter 5 Flashcards

1
Q

A group of serum and cell membrane proteins that interact with one another and with other molecules of innate and adaptive immunity to carry out key effector functions leading to pathogen recognition and elimination

A

complement system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are examples of anatomical and physiological barriers?

A

skin, ciliary clearance, low stomach pH, and lysozymes in tears and saliva

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the letters for small and large fragments?

A

a and b

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What symbol distinguishes enzymatic complexes?

A

a bar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Once the complement system is activated, what are some possible outcomes?

A

-target cell membrane lysis
-chemotaxis
-opsonization to enhance phagocytosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

-complement pathway
-antigen-antibody immune complexes

A

classical pathway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

-complement pathway
-PAMP recognition by lectins (carbohydrate)

A

Lectin pathway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

-complement pathway
-spontaneous hydrolysis

A

alternative pathway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the 3 steps of the complement activation pathways?

A

initiation, amplification, termination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

describe the classical pathway:

A

-initiated by antibody binding
-IgM or IgG binds to a multivalent antigen
-this allows the binding of C1q, beginning the process of complement deposition
-C1 binds Fc on adjacent igG molecules or on IgM bound to anitgen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what initiated the lectin pathway?

A

when soluble proteins recognize microbial antigens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What do lectins bind to?

A

microbial surfaces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Lectins can serve as docking sites for __________________

A

MBL-associated serine proteases (MASPs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

MASPs cleave C4 and C2 to form the ______ convertase

A

C3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

-alternative pathway
-Small amounts of C3 are always being cleaved
-Usually quickly inactivated if nothing is around for it to bind to
-Activated C3b binds to membrane of target cell

A

alternative tickover pathway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

-alternative pathway
-Properdin can directly bind to a surface
-this can then recruit C3b and Factor B

A

alternative properdin-activated pathway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

-alternative pathway
-Initiation of clotting cascades has also been shown to stimulate cleavage of complement proteins
-Thrombin cleaves C3 and C5 in vitro
-Platelet activation releases ATP, calcium ions, and serine/threonine kinases that could stabilize C3b in fluid phase

A

alternative protease-activated pathway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

The three complement pathways converge at the formation of the _________________

A

C5 convertase

19
Q

C5 initiates the generation of the__________________

A

Membrane Attack Complex (MAC)

20
Q

is the result of deposition of C5b, C6, C7, C8, and C9 in target cell membranes

A

membrane attack complex

21
Q

what is disrupted by MAC?

A

the pore structure disrupts osmotic integrity, resulting in cell death

22
Q

What are the 3 main classes of complement activity in the service of host defense?

A

-innate defense against infection
-interface between innate and adaptive immunity
-complement in the contraction phase of the immune response

23
Q

What do complement receptors connect?

A

complement-tagged pathogens to effector cells

24
Q

On erythrocytes, CR1 helps to bring immune complexes to the liver for ______________

A

clearance by phaocytes

25
Q

On phagocytes, CR1 helps bind to complement-coated bacteria to enhance ingestion and destruction which is called _______________

A

opsonization

26
Q

On B cells, CR1 helps bind to complement-coated antigens, enhancing ingestion for ____________________________

A

processing and presentation to helper T cells

27
Q

CR2 on B cells binds to C3b on opsonized bacteria/antigens to help_______________

A

provide secondary signals to B cells through BCR complex for more efficient activation

28
Q

How does C3aR/C5aR affect granulocytes?

A

Stimulates release of proinflammatory cytokines and granule components from basophils, eosinophils, neutrophils

29
Q

how does complement enhance host defense against infection?

A

-MAC-induced cell death
-promotion of inflammation
-promotion of opsonization

30
Q

how does complement mediate interface between innate and adaptive immunities?

A
  1. Enhances antigen uptake of antigen by APCs
  2. Enhances B-cell response by an increasing avidity of B-cell binding to complement-bound antigen
  3. Lyse immature T cells
  4. Facilitates mature T cells growth, differentiation, and survival
31
Q

As lymphocytes are no longer required, complement aids in disposal of _________________________

A

apoptotic cells and bodies

32
Q

Complement also aids in removal/disposal of ___________________________ formed during responses

A

immune complexes

33
Q

the contraction phase of the immune response helps avoid______________

A

damaging inflammation induction in the absence of antigens following clearance of an infection

34
Q

Complement activity is passively regulated by _________________________

A

protein stability and cell-surface composition

35
Q

C3 convertase has a short half-life unless stabilized by ___________

A

properdin

36
Q

self-cells possess different carbohydrate structures that are more effectively bound by____________________________

A

fluid-phase proteases

37
Q

The C1 inhibitor, C1INH, promotes _____________________

A

dissociation of C1 components

38
Q

Work to accelerate the decay of C4b2a (C3 convertase) on the
surface of host cells

A

Decay accelerating factors

39
Q

Cleaves membrane-associated C3b and C4b into inactive fragments

A

Factor I

40
Q

-inhibits the MAC attack
-Binds C5b678 complexes deposited on host cells

A

Protectin (CD59)

41
Q

soluble complement S protein binds fluid phase
C5b67 to prevent insertion into host cell plasma membranes

A

vitronectin

42
Q

Patients with any C1q, C1r, C1s, C4, or C2 deficiency often present with immune complex disorders due to inadequate_______________

A

clearance

43
Q

Some with MBL deficiency may exhibit greater frequency of infections by _________________ due to inefficient opsonization and phagocytosis

A

encapsulated bacteria

44
Q

What are the different microbial complement evasion strategies

A
  • Some interfere with the first step of Ig-mediated complement
    activation
  • Microbial proteins may bind and inactivate complement proteins
  • Microbial proteases destroy complement proteins
  • Some microbes mimic or bind complement regulatory proteins

Immunology (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions