CIS: Immunizations And Complement Flashcards Preview

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Flashcards in CIS: Immunizations And Complement Deck (68):
1

An immunization (vaccination) mimics a natural infection. A normal immune response is invoked to destroy and clear the components of the vaccine.

The primary immune response that results in immunological memory is called __________.

Each subsequent immunization results in increased __________ and __________ of response.

______________ is when repetitive challenge with antigen achieves a heightened state of immunity.

Priming

Intensity; magnitude

Hyperimmunization

2

_________ immunity is acquired when a critical number of individuals in a population are vaccinated which results in the reduction in the transmission of disease which effectively protects unimmunized individuals

Herd

3

Why can't all individuals in a population be vaccinated?

Certain individuals within a population will be immunocompromised or immunosuppressed

Vaccination would be potentially harmful or ineffective in this portion of the population

4

__________ immunization gives immediate but transient immunity, and uses preformed antibodies

Passive

5

What type of immunization might be used to prevent disease after a known exposure or ameliorate symptoms of an ongoing disease?

Passive

6

What kind of immunization protects immunosuppressd patients and blocks the action of bacterial toxins and prevent diseases they cause?

Passive

7

What are some examples of passive immunization?

Snake bite antivenom

Passive transfer of Ig from mother to child

8

_________ immunizations provide delayed immunity but more permanent, and produce immunological memory

Active

9

What are some examples of active immunization?

Natural exposure to pathogens

Vaccines

10

What type of immunization was designed to give both immediate, transient protection as well as slowly developing durable protection?

Combined passive-active immunization

11

What are some examples of combined passive-active immunization?

Tetanus

Rabies

12

Considerations to make in the development of an immunization schedule include:

Timing of likely __________

Immunological _________ of the child

Passively transferred Abs may interfere with the immune response to a vaccine

Interference

Exposure

Maturity

13

After birth, the mother is no longer capable of supplying the baby with _____, so the remaining maternally derived ____ is broken down.

Eventually, the infant will begin to produce its own antibody.

_______ is produced around birth, _____ and _____ lag 6-12 months, leaving a vulnerable period when a baby is not immunocompetent.

IgG; IgG

IgM; IgG, IgA

14

What are the 2 types of live vaccines?

Live viruses from a different species

Live, attenuated viruses

15

What are the 4 types of inactivated vaccines?

Killed
Subunit/component
Toxoid
Conjugate

16

What are the 2 types of experimental vaccines?

DNA
Recombinant vector

17

What are some potential problems with vaccines?

Clinically important epitopes may not be intact in vaccine

Individual genetics may effect efficacy

Some individuals may be genetically predisposed to adverse events

Often work poorly in very young infants or the elderly

Many do not induce CMI; Ab may not be sufficient

Allergies to vaccine components

18

___________ are used to heighten the effectiveness of a vaccination

Adjuvants

19

Adjuvants are normally composed of __________ components or other substances suspended in a medium such as ______

Bacterial
Oil

20

What is the benefit to using oil as an adjuvant

Prolongs dispersal in tissues

21

Adjuvants invoke a mild inflammation that attracts ___________ and accelerates _____ activation and antigen presentation to T cells

Phagocytes; APC

22

_________ vaccines utilize capsular polysaccharides from pathogenic bacteria that elicit TI responses


They do this via linkage of a polysaccharide to either an antigen or ______, forming an _______________

This stimulates a _____ T cell response

Conjugate

Toxoid; immunogen

CD4+

[TI responses are weak in children under the age of 18 months and in the elderly]

23

___________ ___________ refers to the unresponsiveness of adaptive immune system to antigens as a result of inactivation or death of antigen-specific lymphocytes, induced by exposure to the antigens

Immunological tolerance

24

_________ is a collection of circulating and cell membrane proteins that play important roles in host defense

It does this through a coordinated, sequential, proteolytic cleavage of C' proteins aka _______

Complement

Zymogens

25

C' functions to:

Trigger and amplify __________ reactions.

Attraction of ___________ by chemotaxis.

Clearance of immune __________.

Cellular activation and direct microbial _______

Development of _________ responses

Inflammation
Phagocytes
Complexes
Killing
Humoral

26

When a convertase cleaves a complement component, which fragment is larger?

Larger fragment is "b"

Smaller fragment is "a"

27

Which fragment of the complement system is the active component?

"b" fragment which binds to the target near the site of activation

28

Which complement fragment is the anaphylatoxin?

The "a" fragment, which diffuses from the site and plays a role in localized inflammatory response

29

How is the classical complement pathway activated?

IgM (or IgG) binds Ag (functions in adaptive immunity)

30

Which complement pathway is always on guard due to constant trickle of an activated component?

Alternative

31

Which complement pathway is activated by binding of a serum mannose binding protein to bacteria initiating the cascade?

Lectin

32

What are the serine proteases associated with each complement pathway?

Classical: C1r and C1s

Lectin: MASPs

Alternative: Bb

33

What is the enzymatically active complex that begins the complement cascade in the classical pathway?

C1qrs

34

Which complement component is responsible for the distinction between self and nonself?

C3

35

What is the main amplification step of the complement cascade?

Cleavage of C3

36

Which complement component forms the pore of the MAC?

C9

37

What component of complement acts as an antibody independent surveillance system by identifying and binding to non-self membranes?

Alternative pathway

38

Self membranes have ______ levels of sialic acid, which rapidly ____________ bound C3b molecules on host cells

High; inactivates

39

Non-self membranes have _____ levels of sialic acid, so bound C3b will remain active longer

Low

40

MBL is a member of the _________ family

Collectin

41

______ deficiencies lead to life-threatening problems associated with severe, recurrent infections that begin soon after birth due to the central role that ____ plays in opsonin.

C3; C3b

42

Deficiencies in ________ and ________ mimic C3 deficiencies as unregulated C3b generation completely exhausts C3 from the serum

Factor H; Factor I

43

Those with _______ deficiencies are generally healthy other than an increase in infection by Neisseria gonorrhoeae and meningitidis.

MAC

44

What is the most commonly identified form of complement deficiency?

C2 deficiency

45

A _______ deficiency results in a high degree of systemic lupus erythematosus and may arise from failure to efficiently clear circulating immune complexes (which deposit in blood vessel walls and tissues, activating the alternative complement cascade)

C2

[may lead to autoimmunity]

46

What are the primary mechanisms of regulation of the complement system?

Regulation occurs primarily during activation, amplification, and membrane attack.

The two main functions are binding with dissociation and proteolytic digestion

47

What is the first level of control of convertases?

Decay acceleration

48

Generation of _____ is a major amplification step in the complement cascade; rapid hydrolysis limits deposition on nearby cells, limiting formation of the _____ convertase


The same mechanism is used by C4b to regulate formation of the _____ convertase; the majority of C4b formed reacts with water and is inactivated

C3b; C5

C3

49

What is the effect of C1 inhibitors on complement regulation?

Binds C1r and C1s and dissociates them from C1q

Removes MASP enzymes from MBL complex

[Control of classical and lectin events]

50

What type of complement deficiency results in hereditary angioneurotic edema?

C1inh deficiency

51

With C1inh deficiency, C1 is not regulated properly, leading to chronically low levels of ____ and ____

C4; C2

52

Treatment with _________ has caused some patients to produce near normal levels of C1inh

Androgens

53

_________ is also known as a C3b inactivator due to its ability to cleave C4b or C3b; requires presence of a cofactor and prevents formation of convertases

Factor I

54

______ promotes dissociation of the C3 convertase, affecting the classical and alternative pathways

DAF (decay-accelerating factor)

55

What is the acquired hemolytic disorder with spontaneous episodes of RBC lysis, and patient presentation includes morning hematuria?

Paroxysmal nocturnal hemoglobinuria

56

What is the treatment for paroxysmal nocturnal hemoglobinuria?

Erythropoietin

57

_________ regulates the MAC by blocking C9 binding to C5bC678 complex on the cell surface

CD59

58

____________ regulates the MAC by binding to the fluid phase form of C5b67, preventing its ability to bind membranes but does not prevent association with C8 and 9 proteins

Vitronectin (S protein)

[since it is not in the membrane the MAC has no effect, although it still fully forms]

59

______ is the major opsonin in the complement system

C3b; C4b can also function as an opsonin

60

Opsonins such as C4b and C3b bind complement receptors on phagocytic cells like ----?

CR1, CR2, CR3, etc.

61

How does C5a act to increase inflammatory response?

As an anaphylatoxin, it increases the numbers of complement receptors on the cell surface and greatly facilitates their phagocytosis of C3b-coated antigen

62

How are immune complexes with bound C3b removed from tissues and circulation?

Monocytes and other phagocytes
Erythrocytes

Usually transported to spleen and liver

63

Immune complexes normally bind complement and are removed by the liver and spleen after binding CR1 on RBCs. What pathologic condition is characterized by an issue in this process, leading to increases in blood pressure, vascular turbulence, and complex deposition?

Type III Hypersensitivity

64

How many MACs are required to lyse an RBC?

One

65

What type of cells are most resistant to complement mediated lysis?

Nucleated cells

66

What are the primary functions of anaphylatoxins?

Bind receptors on mast cells and blood basophils --> induce degranulation with release of histamine and othe active mediators

Induce smooth muscle contraction

Induce monocytes and neutrophils to adhere to vascular endothelial cells

67

Which complement fragment is cleaved by plasmin to yield kinin, which results in edema?

C2b: Prokinin

68

Normal complement components can enhance infectivity of what viruses?

EBV - uses CR2 as a receptor for attachment

Measles uses MCP as a receptor

West Nile gains entry via CR3 receptor