Trans - Basic Concepts in Immunology Flashcards

1
Q

overall strategy of immune system

A

to recognize danger and avoid damage to self

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

danger - define

A

potentially harmful agent that may cause damage

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

damage - define

A

disruption of normal structure / function

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

disease - define

A

clinical manifestation of damage beyond some threshold

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

danger hypothesis / model theory

A

core function of the immune system is to perceive danger (rather than recognize nonself)

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

tolerance - define

A

unresponsiveness to self or nonself molecules (no immune response)

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

immunity - define

A

resistance to harmful effects of disease-causing agents

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

3 principles in disease-response framework

A
  1. host-pathogen interaction
  2. severity of disease
  3. host damage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

hypersensitivity - define

A

pathologically exaggerated immune reactions with features of inflammation

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

hypersensitivity - examples

A
  1. allergy - hypersensitivity to allergen

2. autoimmunity - hypersensitivity to self

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

hygiene hypothesis

A

insufficient exposure of host to pathogens of natural environment during development leads to increased risk of autoimmunity or allergy

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

hygiene hypothesis - examples

A
  1. C section babies - not exposed to vaginal microorganisms

2. overuse of antibiotics

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

old friends hypothesis

A
  1. old friends - microorganisms very closely associated with the host during evolution (e.g. gut flora)
  2. old friends train immune system to regulate against hypersensitivity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

humoral immunity - define

A

immunity mediated by soluble substances in body fluids (e.g. protein in plasma, serum)

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

cell mediated immunity - define

A

immunity mediated by specialized cells

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

innate immunity - define

A

immunity hardwired into genome, usually nonspecific

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

adapative immunity - define

A

learned immunity, response to exposure to specific antigens, usually specific

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

[T/F] innate and adaptive immunity are independent

A

F

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

[T/f] innate immunity is the first line of defense

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

antigen - define

A

substance with potential to be recognized by the immune system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

antibody - define

A

secreted or soluble form of immunoglobulin that can mediate recognition of antigen by the immune system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

antibody - structure

A
  1. Y-shaped molecule with two antigen-binding arms and 1 trunk
  2. 4 polypeptide chains - 2 light and 2 heavy linked by a disulfide bond
  3. antigen binding arm - 1 light chain+part of heavy chain
  4. Fc region - structure that can be recrystallized
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

how many chains are in an antibody?

A

4 polypeptide chains - 2 light, 2 heavy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what bond links the chains of an antibody

A

disulfide bond

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

antigen binding arm is composed of:

A

1 light chain + part of heavy chain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Fc region - define

A

structure in an antibody that can be recrystalized

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

variable region of antibodies is located in:

A

distal part of antigen-binding arm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

complementarity determining region - define

A

variable region of antibodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

IgM - special characteristics

A

1st to appear during exposure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

IgG - special characteristics

A

majority of circulating antibodies, can cross placental barrier

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

[T/F] the fact that IgG can cross the placental barrier is always a good thing.

A

F. If the mother is hypersensitive to the fetus, it may cause a detrimental immune reactions (e.g. erythroblastosis fetalis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

IgA - special characteristics

A

majority of secreted antibodies in mucosal secretions and colostrum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

IgE - special characteristics

A

responds against parasitic worms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

IgD

A

no biological effector function; major membrane bound antigen in B cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

IgG - % distribution

A

80

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

IgM - % distribution

A

5-10

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

IgA - % distribution

A

10-15 mostly in secretions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

epitope - define

A

antigen determinant; part of antigen actually recognized by immune system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

paratome - define

A

part of antibody in direct contact with antigen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

opsonization - define

A
  1. the process by which antibodies enhance or stimulate phagocytosis
  2. deposition of opsonin on an antigen, promoting stable adhesive contact with phagocyte
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

membrane attack complex - define

A

final result of the complement system, protein-lined transmembrane pore that causes lysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

3 pathways of the complement system

A
  1. classical pathway
  2. alternative pathway
  3. mannose-binding lectin pathway
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

complement system - classical pathway

A

activated by immune complexes of IgM and some subtypes of IgG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

complement system - alternative pathway

A

activated by cell-surface constituents foreign to the host, also activated by classical pathway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

complement system - mannose-binding lectin pathway

A

activated by mannose-bearing foreign substances (e.g. bacteria)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

minor source of antibody variation

A

multiple variant genes in the germline DNA sequence coding for natural antibodies –> pre-immune antibody reportoire

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

major source of antibody variation

A

modification of germline DNA sequences to yield multiple variant antibody genes for both heavy and light chains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

anatomic barriers in innate immunity

A

skin, mucous membrane

49
Q

physiologic barriers in innate immunity

A
  1. temperature
  2. pH
  3. chemical mediators
50
Q

responsible for digesting bacterial cell walls

A

lysozyme

51
Q

toll-like receptors - define

A

membrane-bound receptors that recognize commonly encountered pathogen-associated molecular patterns (PAMPs) leading to secretion of cytokines and chemokines

52
Q

TLR3 - function

A

recognizes double stranded RNA (e,g, virus)

53
Q

TLR4 - function

A

recognizes lipopolysaccharides (e.g. gram negative bacteria cell walls)

54
Q

cytokines - define

A

non antibody molecules that regulate immune function as paracrine or autocrine signals

55
Q

interferon - function

A

cytokines released from infected cells that induces antiviral state in neighboring cells

56
Q

chemokines - define

A

specialized cytokines that attract leukocytes and promote their adhesion to the endothelium

57
Q

endocytosis - define

A

internalization of molecules by various cell types through invagination of plasma membrane

58
Q

phagocytosis - define

A

endocytosis of particulate matter by specialized cells known as phagocytes

59
Q

5 cardinal signs of inflammation

A
  1. tumor
  2. rubor
  3. calor
  4. dolor
  5. loss of function
60
Q

tumor (inflammation) - define

A

swelling due to increased vascular permeability

61
Q

rubor - define

A

redness due to increased blood flow

62
Q

calor - define

A

heat due to increased blood flow

63
Q

dolor - define

A

pain due to release of pain mediators by inflammatory response cells

64
Q

clonal selection - define

A

means to obtain certain lymphocyte populations

65
Q

negative selection - define

A

selection before lymphocytes mature - elimination of cells that recognize self, to prevent autoimmunity

66
Q

positive selection - define

A

selection after lymphocytes mature - elimination of cells that fail to bind to MHC

67
Q

cell-mediated immunity involves which two groups of cells?

A
  1. lymphocytes

2. antigen-presenting cells

68
Q

B cells - where do they develop?

A

bone marrow

69
Q

B cells - function

A

upon activation, differentiate into plasma cells or memory B cells

70
Q

memory B cells - function

A

long-term immunologic memory (faster 2nd response)

71
Q

plasma cells - function

A

secrete antibodies

72
Q

T cells - where do they mature

A

thymus

73
Q

classification of antigens according to T cell activation

A
  1. thymus independent

2. thymus dependent

74
Q

thymus independent antigens - define

A

antigens that activate B cells without helper T cell

75
Q

TI-1 - define

A

polyclonal B cell activators, mitogens that nonselectively induce proliferation of B cells

76
Q

TI-2 - define

A

highly repetitious molecules, selectively activate mature B cells bearing antigen specific BCR

77
Q

TI-2 - mechanism of action

A

activate mature B cells through extensive cross linking of BCRs by antigen

78
Q

thymus dependent antigens - define

A

antigens that require helper T cells to activate BCR

79
Q

thymus independent antigens - type of immune response

A
  1. only IgM produced
  2. limited immune response
  3. no immunologic memory
80
Q

thymus dependent antigens - type of immune response

A
  1. class switching (IgM to other classes)
  2. affinity maturation (stronger affinity of antigen)
  3. with immunologic memory (generation of memory B cells)
81
Q

mast cell degranulation - define

A

acute reaction to antigen due to cross linking of receptor bound IgE on mast cell plasma membranes –> release of histamine

82
Q

what is the term for systemic mast cell degranulation

A

anaphylaxis

83
Q

antibody dependent cell mediated cytotoxicity - define

A

mediated by nonspecific cells with Fc receptors (e.g. NK cells and monocytes)

84
Q

antibody dependent enhancement of infection - define

A

improper or incomplete opsonization may allow pathogens easier access to cells (esp. phagocytic cells)

85
Q

how do T cells recognize antigens?

A

through T cell receptor

86
Q

two types of T cells

A
  1. effector (helper T, killer T)

2. regulatory (Treg cells)

87
Q

helper T cell - function

A

coordinate immune response to pathogens, activate other cells in immune system

88
Q

cytotoxic T cell - function

A

recognize and lyse infected cells carrying antigens bound to class I MHC

89
Q

helper T cell - receptor expressed

A

CD4+

90
Q

cytotoxic T cell - receptor expressed

A

CD8+

91
Q

cytotoxic T cell - mechanism of action

A

lyse infected cells using perforins and granzymes

92
Q

helper T cell - what does it recognize

A

antigens bound to MHC II

93
Q

cytotoxic T cell - what does it recognize

A

antigens bound to MHC I

94
Q

Th 1 - function

A

secrete cytokines that stimulate cell mediated lysis by cytotoxic T cells and macrophages

95
Q

Th 2 - function

A

secrete cytokines that stimulate antibody production (IgE)

96
Q

Th 17 - function

A

secrete IL-17, involved in recruiting neutrophils and macrophages at interfaces (skin, gut, etc.)

97
Q

autoimmune regulatory disorders often result from dysfunction in what cell

A

Th 17

98
Q

Treg cells - function

A

express Foxp3 as a transcriptional regulator - suppresses immune response when threat has passed

99
Q

antigen presenting cells - function

A

process antigen intracellularly and display epitopes on MHC molecules in cell membrane for recognition by immune cells

100
Q

major antigen presenting cells

A
  1. dendritic cells
  2. macrophages
  3. B lymphocytes
101
Q

major histocompatibility complex - function

A
  1. role in recognizing self from nonself

2. hold APC-processed antigens for recognition by immune cells

102
Q

MHC I - function

A

enable recognition of antigens by cytotoxic T cells

103
Q

MHC I - on which cells is it found?

A

found on most nucleated cells

104
Q

MHC II - function

A

enable recognition of antigens by helper T cells

105
Q

MHC II - on which cells is it found?

A

found on professional APCs (e.g. macrophages, dendritic cells, B lymphocytes)

106
Q

what enables cytotoxic T cell activation against viruses and tumors?

A

cross-presentation

107
Q

cross presentation - define

A

presentation of epitopes from exogenous antigens together with MHC I instead of MHC II

108
Q

cross presentation - on which cells is it found?

A

only in some APCs, esp. dendritic cells

109
Q

active immunization - define

A
  1. exposure to less potent version of antigen, eliciting endogenous immune response
  2. produces immunological memory
110
Q

passive immunization - define

A
  1. transfer of preformed immune factors from exogenous source (antibody transfer)
  2. rapid response but without immunologic memory
111
Q

which type of immunization is short-term?

A

passive immunization

112
Q

blood typing - define

A

assignment of individuals to various blood groups determined by antigens present in RBC plasma membrane

113
Q

ABO blood group - basis

A

presence or absence of oligosaccharide moieties (A & B antigens)

114
Q

ABO blood group - universal donor

A

Type O

115
Q

ABO blood group - universal receiver

A

Type AB

116
Q

Rh blood group - basis

A

presence or absence of RhD/Rh antigen

117
Q

erythroblastosis fetalis - mechanism

A
  1. Rh- mother and Rh+ first baby –> no adverse reaction to the fetus, but the mother will produce anti-RhD antibodies (IgG) that may cross the placental barrier in later pregnancies
  2. Rh- mother and Rh+ second baby –> anti-RhD antibodies cross the placenta and attack the RBCs of the fetus
118
Q

tissue typing - define

A

matching of tissues for predicting compatibility of donor and recipients of tissues and organs

119
Q

tissue typing - basis

A

blood group antigens, MHC (human leukocyte antigens)