S2 [LEC]: Antibody & TCR Flashcards
The main humoral element of the adaptive response
Antibody
Approximately how many amino acids make up a domain?
110 amino acids
This component of the glycoprotein structure prevents degradation, makes the antibody more soluble, and enhances the functional activity
Carbohydrates
If an immunoglobulin acts with an antigen, it is considered an ___
Antibody
Primary function of an antibody
Antigen binding
The primary function of an antibody is done by which part?
Fab
The biological functions of an antibody is done by which part?
Fc
Opsonin receptors for phagocytosis
FcyR
Give the molecular weight:
IgG
150 000
Give the molecular weight:
IgM
900 000
Give the molecular weight:
Monomeric IgA
160 000
Give the molecular weight:
Dimeric IgA
170 000
Give the molecular weight:
IgD
180 000
Give the molecular weight:
IgE
190 000
A dimeric IgA is called ___
Secretory IgA
Cold-reacting antibody
IgM
Saline-reacting antibody
IgM
Warm-reacting antibody
IgG
Albumin-reacting antibody
IgG
Classify the antibody according to occurrence:
Appear without stimulus
Natural/ Naturally Occurring antibodies
Classify the antibody according to occurrence:
Appear after introduction to an antigen
Immune antibodies
Classify the antibody according to occurrence:
ABO antibodies
Natural antibodies
Classify the antibody according to occurrence:
Rh antibodies
Immune antibodies
Classify the antibody according to the species which produce them:
Produced after introduction of Ag of same species
Isoantibodies
Classify the antibody according to the species which produce them:
ABO, Rh antibodies
Isoantibodies
Classify the antibody according to the species which produce them:
Antibodies produced after introduction of Ag from another species
Heterophile antibodies
Classify the antibody according to their in-vitro behavior:
Bivalent, saline-acting
Complete
Classify the antibody according to their in-vitro behavior:
Univalent, blocking; conglutinating antibody; albumin acting
Incomplete
Classify the antibody according to their in-vitro behavior:
Thermo-labile
Complete
Classify the antibody according to their in-vitro behavior:
Thermo-stable
Incomplete
T/F: Antibodies can directly kill the pathogen
False
Complement pathway activated by antibodies
Classical pathway
Sedimentation coefficient:
IgG
7S
Sedimentation coefficient:
IgM
19S
Sedimentation coefficient:
Monomeric IgA
7S
Sedimentation coefficient:
Dimeric IgA
9S
Sedimentation coefficient:
IgD
7S
Sedimentation coefficient:
IgE
8S
IgM form present in the surface of the B cell
Monomeric
First breast milk of the mother where IgA is abundant
Colostrum
Other term for isoantibodies
Alloantibodies
Antibody type that can detect viral infections such as infectious mononucleosis
Heterophile antibodies
T/F: Agglutinins are soluble
False (insoluble)
T/F: Precipitins are soluble
True
Antibody class that is an excellent agglutinin
IgM
Antibody class that is associated with precipitation
IgG
Heat modified agglutinins
Agglutinoids
T/F: Agglutinoids can produce agglutination once it binds to the antigen
False: they can bind to the antigen but cannot agglutinate anymore
Antibody that causes lysis of antigenic cell
Lysin
Antibodies that combine with the antigen but not grossly detected unless they are shown to block a reaction, or unless the protein species of the antibody can be identified
Blocking or inhibitory antibodies
T/F: The reaction of the blocking or inhibitory antibody can be visibly seen
False
Basic structural unit of immunoglobulin
Monomer
Component of the immunoglobulin that stabilizes the 3D structure of immunoglobulin
Disulfide chains & Noncovalent bonds
Component of the immunoglobulin that stabilizes the domains within polypeptide chains
Intrachain
Component of the immunoglobulin that holds the variable region
Interchain
Globular/balloon-like region of polypeptide chain
Domain
Chain that is attached between heavy and light chain; heavy and heavy chain
Interchain
The structure of immunoglobulin consists of how many light and heavy chains?
2 heavy chains
2 light chains
The hinge region is rich in what specific amino acid?
Proline
The location of the hinge region
Between CH1 and CH2
The terminal end of the variable region
Aminoterminal end
The terminal end of the constant region
Carboxyl end
In which domain is the carbohydrate component attached?
CH2
Meaning of Fc
Fragment crystallizable
Enzyme that can cleave the antibody into three fragments
Papain
Enzyme that can cleave the antibody into two fragments
Pepsin
Regions where the epitopes specifically bind
Hypervariable region/ Complementarity determining region (CDR)
Sequence of amino acid comprising polypeptide chain changes
Variable region
Sequence of amino acid comprising polypeptide chain is fixed and unchanging
Constant region
What comprises the variable region?
VH and VL
What comprises the constant region?
CH1, CH2, CH3
This component of the hinge region allows flexibility of the immunoglobulin
Proline
Flexible part of the antibody
Hinge
VH and VL are collectively termed as ___
Fab
___ amino acids comprises the hypervariable region
> 30
CH2 and CH3 are termed as ___
Fc
Binding site of C1q in classical complement pathway
CH2
Complement fragment that binds to the CH1
C4b
Determines the antibody isotype
Fc/ Constant region
Binding site of C4b
CH1
Fc is crystallized at what temperature?
4C
Recognition unit in classical complement pathway
C1q
Biggest complement molecule
C1
To enable the classical complement pathway, the C1q should bind with ___
CH2
Where B cells, CD8 cells, plasma cells, heterologous cells bind
CH3
Where Fc receptors in monocytes and macrophages binds
CH3
Fc receptors of mast cells
FcER
Discrete loops projecting outward from the terminal end of the light chain
Hypervariable region
Region where antigens will bind
CDR1, CDR2, CDR3 (Complementarity determining region)
Specific part of the paratope that recognize and bind with the epitope of the antigen
CDR1, CDR2, CDR3 (Complementarity determining region)
Arrangement of heavy and light chains
Immunoglobulin fold
How many binding site does a TCR has?
1
How many CDRs are there in one Fab region?
6
T/F: Sometimes, a secretory IgA can be in the form of a trimer
True
Person responsible for the discovery of the structure of immunoglobulin through ultracentrifugation
Edelman
Polypeptide chain that normally holds polymeric immunoglobulin
J chain (joining chain)
Substance attached to a polymeric Ig found in secretion
Secretory component
Site of cleavage of pepsin
Below the hinge region; before the disulfide bonds
Refer to the number of combining sites
Valence
After pepsin digestion, this reducing agent reduces further to produce 2 Fab and 1 Fc region
Mercaptoethylamine
Site of cleavage of papain
Above the hinge region; after the disulfide bond
Product of reduction by mercaptoethylamine after papain digestion
Fd (degradable fragment)
Amino terminal half of heavy chain that binds to antigen
Fd (degradable fragment)
When an immunoglobulin is added with mercaptoethylamine, the product will be ___
2 heavy chains
2 light chains
More predominant light chain
Kappa chain
Ratio of kappa: lambda light chain
2:1
Kappa chain is coded by what chromosome?
2
Lambda chain is coded by what chromosome?
22
A condition that overproduces Bence Jones protein made up of light chains
Multiple Myeloma
Person responsible for the discovery of that the diversity in the immunoglobulin molecule is generated as a result of somatic recombination of genes
Susumu Tonegawa
Chromosome that codes for the variable region on the heavy chain
Chromosome 14
The D and J segments are binded by ___ enzyme after the deletion of intervening DNA
Recombinase
Recombinase is coded by what gene?
RAG1, RAG2
The joining of V, D, and J segment is done at what level?
RNA
Nearest gene to the J chain
Mu gene
Components of the light chain production
V and J segment
Next chain to be formed after mu
Delta
Process whereby the cell is committed to the expression of a particular V region for its heavy chain and its light chain
Allelic exclusion
Occurs following a successful rearrangement of the Ig DNA segments
Allelic exclusion
CD marker for class switching in B cell
CD 40
CD marker for class switching in T helper cell
CD 40 ligand protein
T/F: When an antibody changes isotype, it changes specificity
False
Type of antibody diversity:
Difference in heavy chain
Isotype
Type of antibody diversity:
Represent classes of antibody
Isotype
Type of antibody diversity:
Same constant regions with minor, but immunologic differences
Allotype
Type of antibody diversity:
Recognize different specific epitopes
Idiotype
Type of antibody diversity:
Represents subclass
Allotype
Type of antibody diversity:
IgG, IgM, IgA
Isotype
Type of antibody diversity:
Differences in the antigenic region; same isotype but with slight or very minor differences in the constant region
Allotype
Type of antibody diversity:
Difference in the variable region
Idiotype
Most abundant Ig
IgG
Ig responsible in anamnestic response
IgG
Ig with the longest half life
IgG
CD marker responsible in activating ADCC through IgG
CD 16
IgG subclass:
Most abundant
IgG1
IgG subclass:
Least efficient in placental crossing
IgG2
IgG subclass:
Complement activator
IgG3
IgG subclass:
Has the largest hinge region and largest number of interchain disulfide bonds
IgG3
IgG subclass:
Least abundant
IgG4
IgG subclass that are good opsonins
IgG1 and IgG3
Ig that plays an important role in primary immune response
IgM
Ig that has a star-fish/ crab-like conformation
IgM
T/F: Plasma cells that produce IgM have no memory
True
Predominant antibody in the secretions
Secretory IgA
Antibody known as the antiseptic paint
IgA
IgA subclass that is found in serum and is mainly monomer
IgA1
IgA subclass that is found in secretions as dimer, with secretory component
IgA2
Antibody important in gut immunity
IgA
Which IgA subclass is more resistant to bacteria?
IgA2
The secretory component of the dimeric IgA
Poly-Ig receptor
Where the secretory IgA is released
Lumen
Antibody not capable of classical complement activation
IgA
T/F: IgA may activate the alternative pathway in aggregated form
True
Antibody that is extremely scarce in the serum
IgD
Antibody that is an important marker in B cell maturity
IgD
Antibody that is more susceptible to proteolysis due to unusually long hinge region
IgD
Least abundant antibody in the blood
IgE
Nuisance antibody
IgE
Reaginic antibody
IgE
Heat labile antibody
IgE
Antibody that participates in immediate hypersensitivity reactions
IgE
Antibody that has an additional constant region
IgE
Receptor that allows IgE to bind to mast cells and basophils
FcER
Antibody responsible in helminth reaction
IgE
According to this theory, antigen played a central role in determining the specificity of Ab molecules
Instructive theory by Haurowitz
A theory where a particular antigen or antigenic determinants would serve as a template against which antibodies would fold
Direct template by Breinl and Haurowitz
A theory where they suggested that the entry of antigenic determinants intro the antibody-producing cells induced a heritable change in these cells
Indirect template by Burnet and Fenner
According to this theory, the immunocompetent cells have a restricted immunological range
Selective theory
In this theory, the genes are already produced and antigens will choose which antibody they will bind
Selective theory
According to ___ in the ___ theory, the immuno-competent cells have surface receptors that are capable of reacting with antigens, which have complementary side chains to which the specific antigen fit complementarily
Ehrlich
Side chain theory
According to ___ in the ___ theory, millions of globulin molecules were formed against all possible range of antigens
Jerne
Natural selection
The most widely accepted theory and provides a framework for better understanding of the specificity, immunological memory, and the property of recognition of self and non-self by adoptive immunity
The clonal selection theory
Animal used in production of monoclonal antibodies
Mouse
Animal used in production of polyclonal antibodies
Rabbit
In the production of monoclonal antibody, the plasma cells are fused with what cell?
Myeloma cells
Allows the fusion of plasma cell with myeloma cell
Polyethylene glycol (PEG)
Medium used in the use of PEG for the fusion of plasma cell with myeloma cell
Hypoxhanthine-aminopterin-thymidine medium
Prevents nucleotide synthesis of myeloma cells
Aminopterin
TCR is made up of how many glycopeptides?
2
Most common TCR type
alpha, beta
CD marker that is noncovalently associated with TCR
CD 3
CD marker that transduces signals that lead to activation of T cell
CD 3
Chromosome that codes for the alpha-chain of TCR
14
Chromosome that codes for the beta-chain of TCR
7
TCR that are commonly specific for unconventional antigens such as heat shock protein and phospholipid
gamma and delta
The basic structure of immunoglobulins was first discovered by ___
Edelman & Porter
Antibodies that have 4 constant domains
IgM, IgE
Which of the following is characteristic of variable domains of immunoglobulins?
i. They occur on both the H and L chains
ii. They represent the complement-binding site
iii. They are at the carboxy-terminal ends of the molecules
iv. They are found only on H chains
i
All of the following are true of IgM except that it:
i. Can cross the placenta
ii. Fixes the complement
iii. Has a J chain
iv. Is a primary response antibody
i
How does the structure of IgE differ from that of IgG?
i. IgG has a secretory component and IgE does not
ii. IgE has one more constant region than IgG
iii. IgG has more antigen-binding sites than IgE
iv. IgG has more light chains than IgE
ii
How many antigen-binding sites does a typical IgM molecule have?
i. 2
ii. 4
iii. 6
iv. 10
iv
Bence Jones proteins are identical to which of the following?
i. H chains
ii. L chains
iii. IgM molecules
iv. IgG molecules
ii
A Fab fragment consists of
i. two H chains
ii. two L chains
iii. one L chain and one-half of an H chain
iv. one L chain and an entire H chain
iii
Which antibody best protects mucosal surfaces?
IgA
Which of the following pairs represents two different immunoglobulin allotypes?
i. IgM and IgG
ii. IgM1 and IgM2
iii. Anti-human IgM and anti-human IgG
iv. IgG1m3 and IgG1m17
iv
The structure of a typical immunoglobulin consists of which of the following?
i. 2L and 2H chains
ii. 4L and 2H chains
iii. 4L and 4H chains
iv. 2L and 4H chains
i
Which of the following are L chains of antibody molecules?
i. Kappa
ii. Gamma
iii. Mu
iv. Alpha
i
If the results of serum protein electrophoresis show a significant decrease in the gamma band, which of the following is a likely possibility?
i. Normal response to active infection
ii. Multiple myeloma
iii. Immunodeficiency disorder
iv. Monoclonal gammopathy
iii
The subclass of IgG differ mainly in
i. the type of L chain
ii. the arrangement of disulfide bonds
iii. the ability to act as opsonins
iv. molecular weight
ii
Which best describes the role of the secretory component of IgA?
i. A transport mechanism across endothelial cells
ii. A means of joining two IgA monomers together
iii. An aid to trapping antigen
iv. Enhancement of complement fixation by the classical pathway
i
Which represents the main function of IgD?
i. Protection of the mucous membranes
ii. Removal of antigens by complement fixation
iii. Enhancing proliferation of B cells
iv. Destruction of parasitic worms
iii
Which antibody is best at agglutination and complement fixation?
IgM
Which of the following can be attributed to the clonal selection hypothesis of antibody formation?
i. Plasma cells make generalized antibody
ii. B cells are preprogrammed for specific antibody synthesis
iii. Proteins can alter their shape to conform to antigen
iv. Cell receptors break off and become circulating antibody
ii
All of the following are true of IgE except that is
i. fails to fix complement
ii. is heat stable
iii. attaches to tissue mast cells
iv. is found in the serum of allergic persons
ii
Which best describes coding for immunoglobulin molecules?
i. All genes are located on the same chromosome
ii. L chain rearrangement occurs before H chain rearrangement
iii. Four different regions are involved in coding of H chains
iv. Lambda rearrangement occurs before kappa rearrangement
iii
What is the purpose of HAT medium in the preparation of monoclonal antibody?
i. Fusion of the two cell types
ii. Restricting the growth of myeloma cells
iii. Restricting the growth of spleen cells
iv. Restricting antibody production to the IgM class
ii
Papain digestion of an IgG molecule results in which of the following?
i. 2 Fab’ and 1 Fc’ fragment
ii. F(ab’)2 and 1 Fc’ fragment
iii. 2 Fab and 2 Fc fragments
iv. 2 Fab and 1 Fc fragment
iv
Which antibody provides protection to the growing fetus because it is able to cross the placent?
IgG
Which best characterizes the secondary response?
i. Equal amounts of IgM and IgG are produced
ii. There is an increase in IgM only
iii. There is a large increase in IgG but not IgM
iv. The lag phase is the same as in the primary response
iii
