Definition Flashcards
(168 cards)
1
Q
Binding of the phagocyte and pathogen using noncovalent interactions
A
Adhesion (Attachment)
2
Q
enhancement of phagocytosis due to better binding mediated by complement or antibody receptors on the phagocytes’ surface.
A
Opsonins
3
Q
Two types of opsonins
A
Complement and Immunoglobulin
4
Q
Give the three Complement under opsonins
A
C3b (best), C4b, C5b
5
Q
Give the three examples of immunoglobulin under opsonins
A
IgG1, IgG3 (Best), IgG2
6
Q
surround the pathogen then form a vacuole called phagosome
A
Pseudophilia
7
Q
are converted into phagolysosomes by fusion with lysosome (contains digestive enzymes) which release their contents into the newly-forming phagolysosomes
A
phagosomes
8
Q
Occurs inside the phagolysosome
A
Digestion or Killing
9
Q
Two types of OXYGEN-DEPENDENT
A
Reactive Oxygen Intermediates
Myeloperoxidase
10
Q
o Superoxide anion, hydrogen peroxide and hydroxyl
radicals
o Kills microbes directly by oxidizing their nucleic acid
and proteins
A
Reactive Oxygen Intermediates
11
Q
Activated by H2O2
A
Myeloperoxidase
12
Q
Two types of OXYGEN-INDEPENDENT
A
Defensins and Digestive Enzymes
13
Q
Antibody-like peptides made by phagocytes, especially PMNs
A
Defensins
14
Q
Present in the phagolysosomes that damage microbes
A
Digestive enzyme
15
Q
Considered as part of non-specific line of defense
Changes in capillary wall structure allow interstitial fluid and WBCs to leak out in tissue
Promotes macrophage activity
A
INFLAMATION
16
Q
Five CARDINAL SIGNS OF INFLAMMATION
A
Calor
Dolor
Tumor
Rubor
Functio laesa
17
Q
Specific immune responses exhibit three distinct characteristics:
o Self/non-self discrimination
o Memory
o Specificity
A
THIRD LINE OF DEFENSE
18
Q
Selectively respond to non-self-substances or antigens
Which leads to immune memory and a permanently altered pattern of response or adaptation in immunocompetent individual
A
Lymphocytes
19
Q
Give the three Cellular components:
A
T Cells, B Cells, Plasma Cells
20
Q
Give the two types of humoral components
A
Antibodies, Cytokines
21
Q
Natural: Injection
Artificial: Vaccination
A
ACTIVE IMMUNITY
22
Q
Natural: Maternal Antibodies
Artificial: Monoclonal antibodies
A
PASSIVE IMMUNITY
23
Q
Natural Infection Artificial vaccination
Permanent
ab produce by host
A
ACTIVE
24
Q
Natural transfer in vivo or colostrum
Artificial infusion of serum or plasma
Temporary
No Ab produce by host
A
Passive
25
Delayed (Type IV) hypersensitivity
Immunity to viral and fungal antigens, transplant rejection, intracellular organisms, tumor cells, contact sensitivity
Cell-Mediated Immunity
26
Found in Paracortical Areas
T-Cell Dependent Regions
27
Found in the cortex
B-Cell Dependent Regions
28
have small B Cells
Primary Follicles
29
contain many large, dividing lymphocytes and plasma cells (known as Germinal Centers)
Secondary Follicles:
30
Do not express CD glycoproteins
Contains terminal deoxynucleotidyl transferase (TdT)
Pre T-Cells/ Bone Marrow T-Cells
31
• Destroy host cells harboring anything foreign and thus bearing foreign antigen, such as body cells invaded by viruses, cancer cells that have mutated proteins resulting from the malignant transformation and xenografts (cells transplanted from another species)
CYTOTOXIC T-CELLS (CD8+ or Tc Cells)
32
The direct means used by cytotoxic T Cells is the same as used by NK cells by releasing perforin molecules which penetrate into the target cell’s surface membrane and join together to form large pore-like channels
PERFORIN MOLECULES
33
Will recognize and bind to the combination of antigen with MHC Class II molecules on the macrophage surface, resulting in the production of soluble factors called cytokines such as IL-2
HELPER T-CELLS (CD4+ or Th Cells
34
Do not have to be presented antigen to become active
Limit immune reactions → negative feedback
SUPRESSOR T-CELLS (CD8+ or Ts Cells)
35
Induced during the primary immune response
They recognize specific antigen and participate in anamnestic response
Most have Th functions and hence are CD4+
MEMORY (Tm) T-CELLS
36
Not stimulated by antigen yet
Synthesizes IgM heavy chains (not light chains) which is confined in the cytoplasm of cell and not secreted
Expresses: MHC Class II, complement receptors
Characterized by the presence of mu chains in cytoplasm
Pre B-Cell
37
Loses some of its cytoplasmic IgM heavy chains
Acquire surface IgM and then IgD
Migrate to Germinal Centers:
38
Loses some of its cytoplasmic IgM heavy chains
Acquire surface IgM and then IgD
Adult/ Mature B Cell
39
Most proficient antibody-forming cell
Terminally differentiated B Cell
Does not have the following B Cell features
Plasma Cell
40
Antibody generator”
• Any substance that is recognized as foreign and elicits specific activation of lymphocytes/ provokes an immune response
Antigens
41
Is the ability to induce a humoral and/or cell-mediated
immune response
IMMUNOGENICITY
42
Is the ability to induce a humoral and/or cell-mediated
immune response
IMMUNOGENICITY
43
Is the ability to combine specifically with the final products of the above responses (i.e., antibodies and/or cell-surface receptors)
ANTIGENICITY
44
Complex molecules
Capable of reacting with homologous antibodies
Can stimulate an immune response, antibody synthesis
COMPLETE ANTIGENS
45
Too small too behave as a complete Ag
Capable of reacting with homologous antibodies
Cannot stimulate an immune response
May bind themselves to protein and hence resulting haptenprotein complex is antigenic
HAPTENS/ INCOMPLETE ANTIGENS
46
Examples of Haptens:
Antibiotics: Penicillin, Gentamicin
Analgesics: Aspirin
Complex CHO: capsule of H. influenzae type B
47
CONTRIBUTION OF THE IMMUNOGEN
Size
Accessibility of determinant groups on the surface of the molecule
Degradability
Chemical Composition
Physical form
Foreignness
48
The greater the difference between the substance and the host, the more potent is its antigenic qualities
Foreigness
49
If immunodominant groups reside within the interior of protein molecule, they can neither stimulate an immune response nor react with homologous antibodies
Accessibility of determinant groups on the surface of the molecule
50
CONTRIBUTION OF THE BIOLOGICAL SYSTEMS
Genetic factor
Ages
51
Some substances are immunogenic in one species to another. Similarly, some substances are immunogenic in one individual but not in others
Genetic factor
52
Usually, the very young or very old have diminished ability to mount an immune response to an immunogen
Age
53
METHOD OF ADMINISTRATION
Dose
Route
Adjuvants
54
The dose of administration of an immunogen can influence its immunogenicity. There is a dose of antigen above or below which the immune response will not be optimal
Dose
55
Subcutaneous or Intramuscular Route > Intravenous or By Mouth
Route
56
Substances that enhances the immune response o Undesirable side effects: Fever and Inflammation
Adjuvants
57
CHEMICAL NATURE
Proteins
Polysaccharide
Lipids
Nucleic acid
58
Must be pure proteins or glycoproteins/ lipoproteins to become a good immunogens
Protein
59
Pure polysaccharide and lipopolysaccharides are good immunogens
Polysaccharide
60
Poorly immunogenic
Immunogenic when single stranded or complexed with proteins
Nucleic acids
61
Non-immunogenic (haptens
Lipids
62
Antigenic sites, antigenic determinants, antigenic factors, antigenic specificities
Small chemical groups or radicals attached to a larger protein or polysaccharide of the cell
Epitopes
63
Term applied to the number of combining sites on either an antibody or antigen
Immunologic Valence
64
single combining site
Monovalent
65
more than one determinant site
Polyvalent/ Multivalent
66
antibody formed as a result of immune stimulus (exposure to a foreign antigen
Immunoglobulin
67
antibody formed without prior exposure to foreign antigen
Naturally occuring
68
antibody formed to one’s own antigens (abnormal condition)
Autoantibody
69
antibody capable of causing agglutination when reacting with corresponding antigen
Agglutinin
70
antibody formed to foreign antigens, but within the same species
Alloantibody
71
name commonly given to blood groups antibodies Anti-A and Anti-B
Isoagglutinin
72
GENERAL FUNCTION OF IMMUNOGLOBULIN
Neutralize toxic substances
• Facilitate phagocytosis
• Kill microbes
• Combine with antigen on cellular surfaces and thereby cause destruction of cells
73
Variants present in all healthy members of a species
Isotypes
74
Variants that are inherited as alternatives (alleles)
Allotypes
75
Antigenic determinants associated with variable regions of immunoglobulin molecule
Idiotypes
76
▪ Gamma (IgG) ▪ Mu (IgM) ▪ Delta (IgD) ▪ Alpha (IgA) ▪ Epsilon (IgE
Heavy Chains
77
▪ Two identically defined types of light chains ▪ Kappa ▪ Lambda
Light Chains
78
▪ Capable of antigen binding
▪ Each is composed of one LC and ½ HC
o Fab Fragment
79
▪ Fragment crystalline ▪ Composed of the second half of two HC
Fc Fragment
80
Two types of peptide chains
Heavy chain and light chain
81
• F(ab)2
• Fc
oCapable of causing agglutination or precipitation
o Retains the ability to bind antigen
PEPSIN
82
Produces 3 fragments
• 2 Fab
• 1 Fc
83
No detectable antibod
Lag phase
84
Antibody titer increases logarithmically
Log phase
85
Antibody titer stabilizes
Plateau phase
86
Antibody is broken down (catabolized)
Decline
87
o When a foreign antigen is first introduced, the antibody cannot be detected immediately in the serum or plasma
o Antibodies are detected about 10-14 days after antigenic stimulation (greatest at 20 days)
o Subclass of antibody associated with this is IgM
Primary response
88
o A second exposure to the same antigen creates more a rapid response
o Detectable amounts of IgM appear first, followed by IgG
o Memory phenomenon elicited
o Produces a higher and longer lasting titer of IgG
Secondary response
89
o Major immunoglobulin in blood (about 75%) o Smallest molecular weight; longest half-life
o Major immunoglobulin during secondary immune response
o Major opsonizing immunoglobulin o Can pass through the placental barrier
o Important to the passive immunity of fetus and newborn baby
o Participates in precipitation and agglutination
IgG
90
dominant subtype in adult human
IgG1
91
cannot cross the placenta
IgG2
92
most effective binder for complement
IgG3
93
- least or unable to fix complement
IgG4
94
o Pentamer (5 subunits)
o Major antibody during the primary immune response
o Only antibody made to certain carbohydrate antigens (ABO Blood Group Antigen)
o Does not cross the placenta
o First effective antibody against bacteremia
o Excellent agglutinins but poor precipitins
o Excellent complement fixing antibody
o Wassermann antibodies, heterophile antibodies, rheumatoid factor, cold agglutinins
IgM
95
o Major immunoglobulin found in secretions o Secretory IgA: Dimer, Blood: Monomer
o Does not cross placenta nor does not activate complement
o Major immune factor in combating pathogens in the respiratory, urinary and intestinal tracts
o Monomeric forms do not appear to activate complement but dimeric can fix complement
IgA
96
o Present in lowest concentration
o Ability to attach to human skin (homocytotropism)
oMast cells and basophils carry a unique high affinity Fc receptors specific for IgE antibodies Formerly called Reagin
Synthesized mainly in respiratory and gastrointestinal tracts
Does not pass the placenta
Does not fix complement
IgE
97
• Produces a rapid, highly amplified response to a trigger stimulus mediated by a cascade phenomenon where the product of one reaction is the enzymatic catalyst of the next
COMPLEMENT SYSTEM
98
o C3a, C4a and C5a
o Substances that degranulate mast cells causing release of histamine (mediator of inflammation
Anaphylatoxins
99
Chemotaxins
o C5a o Attracts leukocytes to migrate up the concentration gradient
100
C4 greatly enhances neutralization of viruses by homologous antibodies
Virus Neutralization
101
o C3b
o Promotes attachment and ultimate ingestion of the foreign substances
Opsonization
102
MAC
Cell lysis
103
o Consists of recognition event, which initiates the complement cascade o The classical and alternative pathway differ in this phase
Initiation Phase
104
Activation of early complement components culminate in activation of C3, which is a critical component
o The classical and alternative pathway also differ in this phase
Amplification Phase
105
Culminates in target cell lysis
o The classical and alternative pathways share common final pathway for this phase
Membrane attack complex
106
• Attachment of antigen-antibody causes an allosteric structural change in the immunoglobulin, creating a complement receptor site.
• First complement molecule attached is C1
o Aka Recognition Unit
o Consists of C1q, C1r, C1s
o Held together by Calcium ion
Classical pathway
107
• The most important and most abundant component is C3
• C3a and C5a have both chemotactic and anaphylatoxic properties but does not interact with other complement component
Classical parthway
108
• Primitive defense system
• Bypass mechanism that does not require C1, C4, and C2
• Important in early protection against bacteria
PROPERDIN/ ALTERNATIVE PATHWAY
109
▪ By aggregated IgA or IgG4
▪ Can be activated in the absence of complement binding antibody
Immunologically
110
Bacterial Cell Products
• Lipopolysaccharides (Gram Neg)
• Teichoic Acid (Gram Pos)
• Zymosan (Yeast)
• Surface components of Parasites (S. mansoni)
Non-immunologically
111
Like C3b, it complexes with Bb
• Cobra Venom Factor (CVF
112
Classical and MBL C3 convertase.
C4b2a
113
• Structure is similar to C1q
• Binding of MBL to bacterium allows MASP 1 and MASP 2 to bind
• MASP 1 and 2, like C1r and C1s, cleave C4 and C2 → C4b2a complex binds to a particle surface
• MBL: Mannose-binding lectin
114
Enzymes that destroy the primary structure (amino acid sequence)
INACTIVATORS
115
Prevent their further interaction with other intermediates of the cascade
INHIBITORS
116
Enzymatically destroys the biologic activity of C3a, C4a, and C5a by removing the carboxy-terminal arginine
Anaphylatoxin Inactivator
117
▪ The C3b inactivator, is serine protease
▪ It cleaves C3b
Factor I
118
Acts with Factor I to bind C3b and allow Factor I to cleave the alpha chain of C3b
Factor H
119
A plasma alpha2-globulin, inhibits the enzymatic activity if C1 esterase by dissociating the subunits C1q, C1r, C1s
▪ Deficiency in C1 INH: Hereditary Angioneurotic Edema (HANE)
o C1 INH
120
Factor I
Anaphylatoxin Inactivator
Inactivators
121
Factor H
C1 INH
Inhibitors
122
• Is the initial force of attraction that an antibody for a
specific antigenic determinant or epitope
• How well the antibody fits to the shape of the antigen will
determine the stability of bond (goodness of fit)
• Antigens and antibodies with the perfect lock and key fit
will have the strongest affinity
AFFINITY
123
• Is the sum of all attractive forces
• between an antigen and antibody
• It is the force that stabilizes the antigen-antibody reaction,
keeping the molecules together
• The stronger the chemical bonds which form between the
antigen and antibody, the less likely that the reaction will
reverse
AVIDITY
124
• Term applied to aggregation
of PARTICULATE/ INSOLUBLE test antigens
AGGLUTINATION
125
Aggregation of SOLUBLE test antigens
PRECIPITATION
126
Participating antigen (e.g., RBC, bacteria)
Agglutinogen
127
Participating antibody
Agglutinin
128
o Sensitization (Antigen-Antibody Formation)
o Lattice Formation
Agglutination TWO STAGES
129
Represent the physical attachment of antibody molecules to antigen on the erythrocyte membrane
SENSITIZATION
130
P ▪ Binds to C4b and allows Factor I to cleave the alpha chain of C4b
C4bBP
131
Protects the target cell from lysis by binding to the developing fluid phase C5b67. The resulting complex cannot penetrate the cell membrane
S Protein (Vitronectin
132
•
Establishment of crosslinks between sensitized particles (e.g., erythrocytes) and antibodies resulting in aggregation
•
Slower process than sensitization phase
•
Formation depends on the ability of the cell with attached antibody on its surface to come close enough to another cell to permit
the antibody molecules to bridge the gap and combine with the antigen receptor site on the second cell
LATTICE FORMATION
133
• Insoluble particle which is in suspension is reacted with an antibody thus resulting to aggregation of particles
• The aggregation is brought about by antibody molecules with two or more combining sites linking the particles.
DIRECT AGGLUTINATION
134
Refers to antibodies reactive with antigens of the native particles.
• Antigen is naturally found in the
cell
DIRECT IMMUNE
135
Lectins (Phytohemagglutinins) are not antibodies hence the direct hemagglutination of blood group O cells by anti-H lectin is considered a non-immune reaction
Aggregations of red cells are not due to Ag-Ab reaction
DIRECT NON-IMMUNE
136
Instead of antibody that will bind to the antigen, it is viruses (Influenza and Rubella) that bind to epitope and agglutinate
o This is a non-immune type of agglutination
VIRAL HEMAGGLUTINATION
137
o Measures the ability of soluble antigen to inhibit the agglutination of antigen-coated RBC by antibodies
o Fixed amount of antibodies to the antigen in question is mixed with a fixed amount of RBC coated with the antigen
• HEMAGGLUTINATION INHIBITION
138
• Reactions wherein antigen is attached to a carrier particle and is used to detect antibody in biologic sample
• Involves the agglutination of cells or inert particle (passive carrier) coated with soluble antigen or antibody
INDIRECT/ PASSIVE AGGLUTINATION
139
▪ Many proteins adsorb poorly to cells, mild treatment with tannic acid or similar reagents may increase the amount of cell-bound antigen or antibody
Tannic Acids
140
Has similar applications to the tanned red cell technique. Protein antigen are chemically coupled by covalent bonds to red cell membrane using BDB
o BDB (Bidiazotized Benzidine) Method
141
Tannic acids
Bdb
Are.
Coupling reagents
142
Primarily designed to demonstrate incomplete antibody presence in the serum
ANTI-GLOBULIN TEST
143
• Incomplete antibody is already attached to red cells prior to the reaction with
• Anti-Globulin
Anti-D Test for Rh HDN
Direct
144
Is still to be attached to an analyte (to be added in the reaction)
Rose Waaler Test for RF Detection
Indirect
145
to detect the capsular antigen of anthrax bacilli
Ascoll
146
Lancefield serological typing is for
Streptococci
147
identification of species origin for a blood stain
Forensic
148
behaves as a precipitinogen when mixed with anti-CRP
CRP
149
Antigen is diluted and added to constant amount of antibody
Prozone: Ag excess
Postzone: Ab excess
Detects smallest amount of antigen that can give a visible
•
reaction with a given amount of antibody
DEAN and WEBB (ALPHA) PROCEDURE
150
Antibody is diluted and added to constant amount of a
Precipitation occurs in a much narrower range of reactant dilutions
Detects smallest amount of antibody that can give a visible reaction with a given amount of antigen
Prozone: Ab excess Postzone: Ag
RAMON (BETA) PROCEDURE
151
Precipitation reactions which are conducted in semisolid medium circumvent the problem of zoning and ambiguity in the number of antigen and antibody system
PRECIPITIN TEST
152
Soluble antigen and/or antibody can diffuse through the pores of the gel until their concentration reaches the optimum ratio and there form a stable immunoprecipitate Molecules of different sizes tend to diffuse through gels at different rates (the higher the MW, the slower the rate of diffusion)
Precipitin texpst
153
Only one reactant (usually antigen) is moving
SINGLE DIFFUSION TEST
154
Both antigen and antibody are moving through the medium
DOUBLE DIFFUSION TEST
155
. Reaction in tubes - Antigen and antibody migrate up and down
SINGLE DIMENSION TEST
156
Petri Dish- Antigen and antibody diffuse rapidly
DOUBLE DIMENSION TEST
157
Single diffusion- single dimension
Single diffusion- double dimension
oDouble diffusion- single dimension
Double diffusion- double dimension
FOUR COMBINATIONS FOR IMMUNODIFFUSION TESTS
158
o Commonly called as Radial Immunodiffusion (RID) or Mancini Test
o Popular method for quantitating a variety of proteins normally found in serum (Ig classes, complement component, lysozyme)
o Quantitating antibody titers
• SINGLE DIFFUSION - DOUBLE DIMENSION
159
Measure the disc while it is expanding (usually at 18 hours) or taken before point of equivalence is reached
Results obtained in a shorter period of time
Diameter is proportional to the logarithm of concentration
KINETIC (FAHEY) METHOD
160
Measure it when it essentially has stopped expanding; allow maximal precipitation or completion
Produce a more reliable result
Diameter is proportional to the square of concentration
END-POINT (MANCINI) METHOD
161
Movement of charged molecules through an electrical field
• Negative-charged ion (Cathode) → Positive-charged ion (Anode)
ELECTROPHORESIS
162
o Also known as Ouchterlony and Elek
o Ability to detect serologic identity (or lack thereof) in two or more antigen-antibody systems
DOUBLE DIFFUSION – DOUBLE DIMENSION
163
o Principle is the same with immunodiffusion except for the use of electrical current to enhance the movement of reactants and possibly shorten the time of reaction
IMMUNOELECTROPHORESIS
164
o Rocket Technique of Laurell
o Electrophoretic counterpart of Oudin
Single reagent (antigen) migrating electrophoretically
SINGLE REACTANT MOVING IN ONE DIMENSION
165
Platelets
Quantitative
Employs electrophoresis
ROCKET TECHNIQUE OF LAUREL
166
Tube
Qualitative
Diffusion
Oudin
167
This is because of smaller amounts of
precipitates exist on either side of equivalence
Fuzzy edges
R-TYPE PRECIPITATION
168
Clean edge
Because flocculation is complete within the equivalence zone
H-TYPE PRECIPITATION
