Complement System (Exam III) Flashcards
1
Q
Component of the immune system that is genetically determines and nonspecific
A
Innate immune system
2
Q
Elements of this system include mucous secretions, complement proteins, certain WBCs (especially neutrophils, macrophages, and dendritic cells)
A
Innate immune system
3
Q
Component of the immune system involving lymphocytes (B cells and T cells) containing a small number of genetically encoded proteins that combine to produce an enormous variety of proteins capable of recognizing and deactivating specific antigens
A
Adaptive immune system
4
Q
What immune system are you born with?
What immune system do you acquire?
A
Innate
Adaptive
5
Q
First function of the complement system
A
Alter membrane pathogens and cellular debris
6
Q
The first function of the complement system is to alter membrane pathogens and cellular debris via
A
Opsonization
7
Q
What promotes removal of particles via complement receptors on host cells via a coating
A
Opsonization
8
Q
Opsonization leads to the assembly of _____ on pathogens and subsequent _____
A
MAC; lysis
9
Q
MAC
A
Membrane attack complex
10
Q
Second function of the complement system
A
Enhance the inflammatory response
11
Q
The complement system enhances the inflammatory response via
A
Release of anaphylatoxins that promote cell activation or migration to inflammatory site
12
Q
Migration to inflammatory site
A
Chemotaxis
13
Q
The complement system becomes activated in innate immunity when it senses:
A
Apoptotic cells, tissue debris or pathogens
14
Q
Innate immune system is always functioning at:
A
A very low level
15
Q
The body has mechanisms in place to prevent the innate immune system from:
A
Destroying all cells in our body
16
Q
The complement system can be activated in three ways:
A
- C3 turnover
- Natural antibodies
- Lectins
17
Q
Activation of the complement system by C3 turnover engages what pathway
A
The alternative pathway
18
Q
Activation of the complement system through natural antibodies engages what pathway
A
Classical pathway
19
Q
Activation of the complement system by binding of lectins engages what pathway
A
The lectin pathway
20
Q
In adaptive immunity naturally antibodies are replace by:
A
Specific antibodies
21
Q
The complement system triggers the following immune functions (3):
A
- Phagocytosis
- Inflammation
- Membrane attack
22
Q
phagocytosis in the complement system occurs by:
A
Opsonizing antigens
23
Q
has the most important opsonizing activity
A
C3B
24
Q
occurs by chemotactically attracting macrophages and neutrophils
A
Inflammation
25
What anaphylatoxins are involved in inflammation
C3a C5a
26
What process ruptures the cells wall of bacteria (punching hole in it)
Membrane attack
27
A local response to cellular injury that is marked by capillary dilatation, leukocytic infiltration, redness, heart, and pain
Inflammation
28
Serves as a mechanism initiating the elimination of noxious agents and of damaged tissue
Inflammation
29
Wheel and flare response is characteristic of:
Type I allergic reaction
30
Swelling produced by the release of serum into the tissues
Wheal
31
Redness of the skin resulting from the dilation of blood vessels
Flare
32
The classic pathway is triggered by the activation of:
C1-complex
33
The mannose-binding (lectin) pathway is homologous to the classical pathway, but uses the opsonins:
Mannose-binding lectin (MBL) and ficolin
34
What opsonins does the classical pathway use
C1q
35
The alternative pathway is continuously activated at a ______ level
Low
36
The alternative pathway is continuously activated at a low level as a result of:
Spontaneous C3 hydrolysis
37
In the alternative pathway spontaneous C3 hydrolysis occurs as a result of:
Breakdown of the internal thioester bond
38
The breakdown of the the internal thioester bond in C3 is due to C3 being mildly unstable in:
Aqueous environment
39
Pathway that does not rely on pathogen-binding antibodies like other pathways
Alternative pathway
40
Pathway that responds when you have antigen:antibody complexes (on pathogen surfaces)
Classical pathway
41
The classical pathway involve what molecules (3)
C1, C4, C2
42
The C1 molecule in the classical pathway breaks down into
C1q, C1r, C1s
43
Pathway involving mannose-binding lectin or ficolin binding carbohydrates on pathogen surfaces
Lectin pathway
44
The lectin pathway involves mannose-binding lectin or ficolin binding to _____ on pathogen surfaces
Carbohydrates
45
What molecules does the lectin pathway involve
MBL/ficolin,C4, C2
46
Enzymatic activity of the MBL/ficolin complex in the lectin pathway
MASP-2
47
What molecules do the lectin pathway and classical pathway have in common
C4 and C2
48
The alternative pathway occurs on
Pathogen surfaces
49
The molecules involves in the alternative pathway include
C3, B, D
50
All three pathways converge at the production of
C3 convertase
51
What two pathways are pretty much identical excepting for what triggers them
Classical and lectin pathways
52
A molecule that cleaves different members of the complement pathways
C3 convertase
53
C3 convertase cleaves C3 into
C3a and C3b
54
After c3 convertase cleaves C3 into C3a and C3b, the C3b will bind
C3 convertase
55
When C3b combines with C3 convertase bind together, this leads to the cleavage of
C5 into C5a and C5b
56
What molecules are peptide mediators of inflamantion and phagocyte recruitment
C3a and c5b
57
What molecule binds to complement receptors on phagocytes and leads to the opsonization of pathogens and removal of immune complexes
C3b
58
What molecule triggers MAC formation along with lysis of certain pathogens and cells
C5b
59
1. Molecule important in opsonization
2. Molecule important in MAC formation
3. Molecules important in inflammation
1- C3b
2- c5b
3- C3a & C5a
60
In addition to the C3 being broken down into C3a and C3b during activation of the complement system our bodies also:
Constitutively hydrolyze C3 into c3a and C3b but at a very low level
61
The central component of the complement system:
Complement fixation
62
In fixation of complement what molecule tags the bacterium for destruction
C3b
63
In fixation of the complement system what molecule recruits phagocytes and functions in inflammation
C3a
64
Cleavage of c3 exposes a:
Thioester bond
65
when the thioester bond is exposed on c3 this allows _____ to strongly covalently bind
Nucleophiles
66
In the classical pathway of complement, you have antibodies coating to the surface and the ____ molecule is going to bind to that
C1 molecule (made of C1q, C1r, C1s)
67
What subunit of the C1 molecule will cleave C4 into C4a and C4b
C1s
68
The cleavage of c4 into c4a and c4b will induce the celaveage of:
C2 into C2a and C2b
69
C4b and C2a together will cleave C3 into
C3a and C3b
70
C4b + C2a together form
C3 convertase
71
C1 is a complex of c1q, c1r and c1s. The c1q portion is composed of:
Six identical subunits with globular heads and long collagen-like tails
72
The headlight structure of c1q function to:
Sit down and bind pathogen surfaces
73
Once the c1q globular heads are bound to the pathogen surface, the c1r portion undergoes conformational change which results in:
Cleaving and activating the c1s zymogen
74
C1s will bind the:
Receptors on the pathogen surface
75
What cleaves C4 into C4a and C4b
Activated c1s
76
When the C4b binds to C2, the C2 undergoes cleavage by ____ to form C2a and C2b
C1s
77
After the c2 is cleaved into c2a and C2b, ___ combine with the c4b to create _____
C2b; c3 complement (c4bc2a)
78
Because c4b2a is an activate c3 convertase it functions to cleave
C3 into c3a and C3B
79
After c3 is cleaved by the c3 convertase it will bind either:
Microbial surface or the convertase itself
80
One molecule of c4b2a can cleave up to _____ molecules of c3 into C3b
1000
81
The whole process starting with the c1s binding to the microbial surface and ending with the cleavage of c3 and all the in between steps are part of the:
Opsonizaiton process
82
When molecules get coated with _____ they are said to be opsonized
C3b
83
In the mannose-binding lectin pathway, instead of the antibody binding event it uses:
Lectin binding proteins
84
The Mannen-binding lectin forms a complex with ______ that resembles the complement c1 complex
Serine proteases
85
MLB forms cluster of two to six ____ heads around a central ____ like stalk
Carbohydrate-binding
Collagen-like
86
What are the two associated enzyme activities of the two serine proteases in mannan-binding lectin
MASP-1
MASP-2
87
The function of the MASP-1 and MASP-2 enzymes associated with Mannan-binding lectin allows for the cleavage of:
C4 and C2
88
Mannan-binding lectin and Ficolin both associated with:
MASP-1 and MASP-2
89
In the mannose-binding lectin pathway, the C4b2a is a c3 convertase; it will cleave the C3 into c3a and C3B and the C3b will bind the c4b2a complex generating:
C5 convertase
90
In the alternative pathway:
C3b is deposited by the classical pathway or lectin pathway’s:
C3 convertase
91
In the alternative pathway:
C3b binds:
Factor B
92
In the alternative pathway:
Bound factor B is cleaved by ________ into Ba and Bb
Plasma protease factor D
93
In the alternative pathway:
C3bBb complex is a:
C3 convertase
94
The alternative pathway of complement involves creating a C5 convertase that ultimately leads to the deposition of:
MAC complexes
95
In addition to the alternative pathway, the C5 convertase can also be generated in other pathways, the key is you need to generate a ____ in order to create a convertase that will cleave C5 into C5a and C5b
C3b complex
96
The alternative pathway is triggered by:
Covalent binding of C3b to pathogen or cell surface
97
In the alternative pathway- what forms the pore on the membrane surface
C9
98
The MAC complex is composed of molecules
C5b, C6, C7, C8, and a bunch of C9
99
All three of the pathway ultimately lead up to
MAC complex
100
What is the most direct pathway leading the the MAC complex
Alternative pathway
101
In order for phagocytosis to follow opsonization - the phagocytic cells must contain
A specific receptor for the complement molecules on their surface
102
If the phagocytic cells do not contain the receptors specific to the complement molecules coating the pathogen:
Phagocytosis will not occur
103
For phagocytosis to occur what specific molecules must be present and why?
C5a and has to internalize it
104
You can opsonize and coat the bacteria with C3b, bind them to the complement receptor on the phagocytic cell, but if _____ is not present then the bacteria will not be internalized by the phagocytic cell
C5a
105
All of the cells in our body carry different proteins on their surfaces designed to prevent the complement pathway:
From attacking self cells
106
Membrane protein that displaces Bb from C3b and C2b from C4b
Decay-accelerating factor (DAF)
107
Membrane protein that promotes C3b and C4b inactivation by I
Membrane cofactor protein (MCP)
108
DAF and MCP are both
Control proteins
109
We have spontaneous production of ____ at low levels
C3b
110
If you get C3b binding to autologous host membranes, it will interact with ______ which blocks the association of factor B with C3b thereby preventing the formation of ______
DAF
C3 convertase
111
On the cell membrane, DAF causes the C3 convertase to
Dissociate
112
MCP binding to the C3b Bb complex causes the release of the ____ portion and allows _____ to come in and bind to the C3b and cleaving it into an inactive form
Bb
Factor I molecule
113
DAF and MCP both involve the dissociation of the Bb portion, but MCP additionally makes the C3b susceptible to:
Cleavage by factor I
114
Factor I functions to:
Cleave C3b molecule into an inactive form
115
Innapropriate activation of the complement pathway leads to: (2)
Diseased state and destroying of self cells
116
Acquired disorder that results in premature death and impaired production of blood cells
Paroxysmal Nocturnal Hemoglobiuria
117
What cells does PNH affect
RBCs, leukocytes and platelets
118
Who does PNH affect and when does diagnosis typically occur
Both sexes equally
Diagnosed in young adulthood
119
Paroxysmal Nocturnal Hemoglobinuria results from
Deficiency of the DAF protein
120
Paroxysmal nocturnal hemoglobinuria gets its named based on it occuring mainly at:
Night
121
In PNH the deficiency of DAF protein:
Results in destruction of self cells
122
Results from chronic uncontrolled activation of the complement system
Atypical hemolytic uremic syndrome
123
Disease in which multiple blood clothes form throughout the body in small blood vessels, which can lead to stroke, heart attack, kidney failure and death
Atypical hemolytic uremic syndrome
124
Atypical hemolytic uremic syndrome is due to
Mutations in factor H, factor I, or membrane cofactor protein
125
The most common functional defect in atypical hemolytic uremic syndrome and age-related macular degeneration is:
Reduced cofactor activity (MCP or factor H) for C3b
126
Atypical hemolytic uremic syndrome is a very _____ disease in terms of which protein is affected which also determines:
Heterogeneous
The severity of the disease
127
In Atypical hemolytic uremic syndrome, the post commonly affected factor causing the disease is
Factor H
128
In normal conditions MCP or factor H will bind to C3b when C3b is created, this is when factor I comes in and cleaves C3b into an inactive form. If you don’t have a functional MCP or factor H:
Factor I will be unable to bind
129
If there is any spontaneous creation of C3b from C3 convertase or the hydrolysis that occurs naturally the molecules of our defense mechanism are there to prevent:
Initiation of the complement cascade which leads to cell death
130
Disease characterized by recurrent attacks of severe swelling
Hereditary angioedema
131
Angioedema caused by mutations in the gene that makes the C1 inhibitor
Type I & Type II
132
Hereditary angioedema caused by deficiency of C1
Type I
133
Hereditary angioedema caused by atypical C1 protein that is less capable of suppressing acitvation of complement system
Type II
134
Hereditary angioedema associated with mutations in Factor XIII gene
Type III
135
Factor-XII gets cleaved into Factor-XIIa also known as
Plasmin
136
Factor-XIIa (Plasmin) function to cleave:
Prekallikrein into Kallikrein
137
Factor-XIIa also functions in the conversion of the _____ pathway of the clotting cascade
Common
138
Kallekrein convertes a high-molecular-weight Kininogen into
Bradykinin
139
Bradykinin plays a role in (3)
1- vasodilation
2- smooth muscle contraction
3- edema
140
The classic pathways works through:
Antigen-antibody complexes and C1
141
The lectin pathway and alternative pathway function within the ____ immune system, whereas the classical pathway functions with _____ immune system
Lectin & alternative = innate immune system
Classical = both innate and adaptive immune system
