Unit One Innate Immunity Flashcards Preview

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Flashcards in Unit One Innate Immunity Deck (73)
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1
Q

What is the immediate response to infection

A

Innate immunity

2
Q

What are the physical nad chemical barriers

A

Skin and mucosal epithelium

3
Q

Commensal microorganisms colonize what

A

Skin and mucosa

4
Q

Do babies have commensal population

A

No not initially

5
Q

The gut has what type of relationship for commensal

A

Symbiotic

6
Q

Extracellular infections are subject to

A

Soluble secreted molecules of the immune system such as antibodies

7
Q

Intracellular infections are fought off how

A

Infected cell has to be sacrificed

8
Q

Where is compliment made

A

Liver

9
Q

What is complement

A

Soluble proteins used as a defense mechanism

10
Q

Complement is found where

A

In lymphatics and blood

11
Q

How does complement work

A

Coats the surface of bacteria or virus to make easier to phagocytosis

12
Q

Some complement proteins are what type of enzyme

A

Proteases

13
Q

Compliment circulates in inactive forms called

A

Zymogen

14
Q

What triggers compliment activation

A

Infection which causes a cascade of enzymatic reactions

15
Q

The cascade of complement activates what

A

Proteases

16
Q

When complement is activated what happens with C3

A

C3 is cleaved into C3a and C3b

17
Q

What occurs during compliment fixation

A

C3b binds to pathogen surface

18
Q

What occurs during complement organization

A

C3b organizes other complement proteins

19
Q

What occurs during complement calling effector cells

A

C3a calls macrophages

20
Q

When C3b is activated, what is exposed and is targeted by water to allow tight fixation to pathogen surface

A

Thioester bond

21
Q

What are the three pathways of complement activation

A

Alternative pathway, lectin pathway, classical pathway

22
Q

What complement pathway works at the start of an infection

A

Alternative

23
Q

What complement pathway takes days and is induced by innate immunity

A

Lectin pathway

24
Q

What complement pathway requires binding of antibody or a specialized protein to pathogen surface

A

Classical

25
Q

What is complement pathway cleaves and activates Cb3

A

C3 convertases

26
Q

C3b can also bind to what to cause cleavage by factor D

A

Factor B

27
Q

What is the alternative C3 convertase

A

C3bBb

28
Q

C3bBb creates more what

A

C3b and causes more activation

29
Q

What are complement control proteins

A

Plasma proteins that interact with C3b on human and microbial cell surfaces that prevent complement fixation on human cells

30
Q

Examples of complement control proteins

A

Properdin (factor P), factor H and Factor I

31
Q

Aka of properdin

A

Factor P

32
Q

Function of properdin

A

Binds to C3bBb on microbial surfaces and prevents its degradation

33
Q

Properdin increases what of C3 convertase

A

Power, speed and efficiency

34
Q

What regulatory proteins shut down compliment pathway

A

Factor H and I

35
Q

Function of factor H

A

Binds to C3b and promotes cleavage of C3b by Factor I to become iC3b

36
Q

Function of factor I

A

Works with factor H to decrease C3 convertase molecules on the pathogen surface

37
Q

What happens in people who lack Factor I

A

C3bBb is unchecked, reservoir of C3 depletes, no C3 is left when a new pathogen is encountered

38
Q

What are the membrane proteins that interfere with complement activation at human cell surfaces

A

Decay accelerating factor (DAF) and membrane cofactor protein (MCP_

39
Q

DAF function

A

Binds to C3b and renders it inactive

40
Q

Function of MCP

A

Makes C3b more susceptible to cleavage and inactivation by factor I

41
Q

Macrophages are part of what immunity

A

Innate and adaptive

42
Q

Where are macrophages present

A

Mucosal surfaces and in the liver (kupffer cells)

43
Q

What on the surface of macrophages enhances phagocytosis

A

Complement receptor 1 (CR1)

44
Q

What on macrophages bind to iC3b on microbial surfaces to enhance phagocytosis

A

CR3 and CR4

45
Q

C5 convertase acts on

A

C5 component

46
Q

C5 convertase composed of

A

Bb and two C3b fragments

47
Q

Function of alternative C5 convertase

A

Splits

C5 into C5a and C5b

48
Q

C5b forms what

A

A membrane attack complex (MAC attack)

49
Q

MAC attack does what

A

Breaches pathogen membrane by making holes in the membrane

50
Q

C5b binds to what

A

C6 and C7

51
Q

Function of C6 and C7 after binding with C5b

A

Insert into lipid bilayer of pathogen

52
Q

Function of C8 after binding to C5b

A

Inserts into membrane to initiate polymerization of C9 to help form transmembrane pores

53
Q

What are some terminal complement components

A

C5, 6, 7, 8 and 9

54
Q

Terminal complement components are regulated by

A

Soluble and cell surface proteins

55
Q

What are some soluble proteins that prevent pores from forming in host cells by terminal complement components

A

S protein, clusterin and factor J

56
Q

What cell surface proteins help protect against terminal complement components

A

Homologous restriction factor (HRF) and CD59

57
Q

Function of CD59 cell surface protein

A

Prevents C9 from being called by C5b, C6, 7 and 8

58
Q

C3a and C5a causes

A

Inflammation by phagocytes, endothelial cells and mast cells

59
Q

What cells have receptors fo C5a and C3a triggering inflammation

A

Phagocytes, endothelial cells and mast cells

60
Q

What occurs during inflammation

A

Contraction of smooth muscle, degranulation of mast cells and basophils, release of histamine, capillary permeability

61
Q

Function of C5a during inflammation

A

Acts on neutrophils and monocytes to increase their adherence to blood vessel walls and acts a chemoattractant to call cells to site of inflammation

62
Q

Function of complement

A

Opsonization (C3b), inflammation (C3a and C5a) and MAC attack

63
Q

The coagulation system uses plasma enzymes that induce

A

Blood clotting

64
Q

Platelets release substances that causes

A

Inflammation and trigger wound healing

65
Q

What is the kinin system

A

Enzymatic cascade triggered by tissue damage to cause vasodilation

66
Q

Example of kinin system

A

Bradykinin

67
Q

Pathogens also create proteases that do what

A

Damage host tissue

68
Q

Alpha2-macroglobulins function

A

Lure pathogen proteases and trap them and deactivates them

69
Q

What in alpha2-macroglobulins lure pathogenic proteases

A

Thioactive region

70
Q

What are some antimicrobial peptides

A

Defensins and penetrations

71
Q

Function of defensins

A

Penetrate microbial membranes to disrupt the integrity of bacteria, enveloped viruses and fungi

72
Q

Defensins are produced by

A

Neutrophils

73
Q

Function of pentraxins

A

Assist with phagocytosis by binding bacterial membrane to phagocytic cells