Chapter 6 - Immunogen and Immunoglobulin Flashcards
Macromolecules capable of triggering an adaptive immune response by inducing the formation of antibodies or sensitized T cells in an immunocompetent host.
Immunogen
A substance that reacts with antibody or sensitized T cells but may not be able to evoke an immune response in the first place.
Antigen
Which of the following is true?
A. All immunogens are antigens.
B. All antigens are immunogens.
A. All immunogens are antigens
Incomplete / partial antigen
Hapten
In order for a hapten to induce an immune response, what must be added?
Carrier
Which of the following is true?
A. Haptens are antigenic
B. Haptens are immunogenic
A. Haptens are antigenic
Best immunogens
Proteins, polysaccharide
Less immunogenic
Carbohydrates
Not immunogenic
Nucleic acids, lipids
Antigen derived from the same individual
Autoantigen
Antigen derived from different species
Heteroantigen / xenogeneic antigen
Antigen derived from different individual from same species
Alloantigen / homologous antigen
Graft derived from same individual
Autograft
Graft derived from different class but identical individual (identical twins)
Isograft / syngraft
Graft from different individual but same species
Allograft
Graft from different species
Heterograft / xanograft
Found in unrelated plan and animals, cross react with other antibodies.
Heterophile antigens
Old name for antibodies.
Gammaglobulins
Which Ig is not found on the gamma region when subjected to electrophoresis?
IgA
Products of antigenic stimulation
Antibodies / Immunoglobulins
Functions of immunoglobulins
Cell cytotoxicity
Neutralization
Opsonization
Determines Ig class
Heavy chain
The antigen binding region
A. Fc
B. Fab
B. Fab
What part makes the antibodies flexible?
Hinge
The amino group is found on ______.
A. Fc region
B. Fab region
B. Fab region
The carboxyl group is found on ______.
A. Fc region
B. Fab region
A. Fc region
Location of the hinge region.
Between CH1 and CH2
Which antibody part binds with complement, specifically C1q?
CH2
Which antibody part is responsible for cytotropic reaction involving macrophages?
CH3
The Fc receptor binding site
CH3
The hinge region is rich in which amino acid?
Proline
What connects the two heavy chains of antibodies together?
Disulfide bond
What connect the light chains and heavy chains of an antibody?
Disulfide bond
Heavy chain that determines Ig class.
Isotype
Variation in the variable region of both HC and LC
Isotype
Variation in the constant region of both HC and LC
Allotype
The first ____ or ____ amino acids are considered the variable region.
110 or 120
Which antibody isotype have an extra domain CH4?
IgM and IgE
How many domain does IgG have?
4
How many domains does IgE have?
5
How many domains does IgM have?
5
Sections or regions in an immunoglobulin molecule
Domains
Number of binding site in an antobody
Valence
Basic Ig structure
Monomer
Which antibody is a dimer?
IgA
IgA are found in _____.
Secretions
The 2 monomers of an IgA is linked by?
J chain
A polymeric antibody
IgM
Enumerate the antibody isotypes from most to least abundant.
IgG > IgA > IgM > IgD > IgE
A protein that contains light chain to light chain linkage (which is abnormal).
Bence-Jones protein
BJP is associated with the presence of _____ spike during electrophoresis.
Gamma
BJP precipitates at ____ to ____ degree Celsius.
40 to 60
Confirmatory test for BJP
Electrophoresis
BJP dissolves at ____ degree Celsius.
100
BJP is associated with what disease?
Multiple myeloma
Is BJP specific to multiple myeloma?
No
Massive proteinuria is associated with?
Nephrotic syndrome
What protein remains in circulation for patients with nephrotic syndrome? (This is also the largest protein)
Alpha-2-macroglobulin
Ig class with the hight molecular weight
IgM (900 000 daltons)
Next largest Ig class after IgM
IgE
Smallest Ig class
IgG
Sedimentation coefficient for IgG, IgA and IgD
7S
Sedimentation coefficient for IgM
19S
Sedimentation coefficient for IgE
8S
Ig class with the longest half life
IgG (23 days)
Ig class with the longest half life next to IgG
IgM (6 days)
How many domains does IgG have?
4
How many domains does IgE have?
5
How many domains does IgM have?
5
Ig isotype that is most efficient in complement fixation
IgM
Can IgG induce complement fixation?
Yes except IgG4
Known as the “coating antibody”
IgG
The first Ig to be produced after antigenic stimulation
IgM
Reaginic antibody
IgE
Major antibody on secretions
IgA
Antibody associated with anaphylaxis
IgA
Antibody that is sensitive to enzymatic degradation
IgD
This Ig’s main function is immunoregulation
IgD
The first antibody to appear in phylogeny and last to leave in senescence
IgM
Which Ig is the best complement fixer?
IgM
The only polymeric antibody
IgM
This antibody is postulated to be an anti-idiopathic antibody.
IgD
Which IgA subclass is found in secretions?
IgA2
True/False: IgM is always a pentamer in the body.
False. It is a monomer in B cell surface.
Agglutination is associated with which antibody?
IgM
Precipitation is associated with which antibody?
IgG
Ig found on the surface of B cells
IgD, IgM
Most heat labile Ig
IgE
When is a major basic protein secreted?
When an IgE attaches to an eosinophil
Which Ig provides immunity to newborns?
IgG
Which Ig can cross the placenta?
IgG
Which IgG subclass is the least effective in passing the placenta?
IgG2
Which Ig is associated with secondary immune response?
IgG
How are the subclasses of IgG differ?
They differ from their disulfide bonds
Which IgG subclass is the most abundant in circulation?
IgG1
Which Ig is high in allergy and in parasite infection?
IgE
The process of genetically pre-programming a lymphocyte to produce one type of Ig and that a particular cell capable of responding to it, causing it to proliferate.
Clonal selection
This theory states that certain cells had specific receptors for antigen that were present before contact with antigen occurred.
Ehrlich’s side chain theory
IgA subclass found in serum
IgA1
The process of transforming a polymeric antibody into a monomer.
Reduction
2 substances used to reduce an antibody.
Dithiothreitol (DIT) and 2-mercaptoethanol (2-ME)
Papain cuts antibodies into how many parts?
3 parts
This Ig’s main function is immunoregulation
IgD
The first antibody to appear in phylogeny and last to leave in senescence
IgM
Which Ig is the best complement fixer?
IgM
The only polymeric antibody
IgM
This antibody is postulated to be an anti-idiopathic antibody.
IgD
Which IgA subclass is found in secretions?
IgA2
True/False: IgM is always a pentamer in the body.
False. It is a monomer in B cell surface.
Agglutination is associated with which antibody?
IgM
Precipitation is associated with which antibody?
IgG
Ig found on the surface of B cells
IgD, IgM
Most heat labile Ig
IgE
When is a major basic protein secreted?
When an IgE attaches to an eosinophil
Which Ig provides immunity to newborns?
IgG
Which Ig can cross the placenta?
IgG
Which IgG subclass is the least effective in passing the placenta?
IgG2
Which Ig is associated with secondary immune response?
IgG
How are the subclasses of IgG differ?
They differ from their disulfide bonds
Which IgG subclass is the most abundant in circulation?
IgG1
Which Ig is high in allergy and in parasite infection?
IgE
The process of genetically pre-programming a lymphocyte to produce one type of Ig and that a particular cell capable of responding to it, causing it to proliferate.
Clonal selection
This theory states that certain cells had specific receptors for antigen that were present before contact with antigen occurred.
Ehrlich’s side chain theory
IgA subclass found in serum
IgA1
The process of transforming a polymeric antibody into a monomer.
Reduction
2 substances used to reduce an antibody.
Dithiothreitol (DIT) and 2-mercaptoethanol (2-ME)
Papain cuts an antibody into how many fragments?
3 parts
Which part of the antibody does papain cut?
It cuts the antibody directly in its hinge region.
Pepsin cuts an antibody into how many fragments?
2
Which part of the antibody does pepsin cut?
Below the hinge region
Which fragment of the antibody crystallizes at cold temperature?
Fc portion
This complex’s function is to bring out antigen into cell surface.
Major Histocompatibility Complex
The molecular basis of self from nonself
Major Histocompatibility Complex
MHC genes are located on the ____ (long/short) arm of chromosome _____.
Short arm of chromosome 6
Set of genes that controls tissue compatibility
MHC genes
What does MHC genes encode in humans?
Human Leukocyte Antigen Complex
Which cell has the most number of MHC?
Lymphocytes
MHC class associated with autoimmune diseases.
MHC II
Which MHC class process cytoplasmically derived antigens and presenta it to CD8 positive cells?
MHC I
Which MHC class process extracellularly derived antigens and presents it to CD4 positive cells?
MHC class II
MHC class 1 is present in all _____.
Nucleated cells
MHC class II is present in ______.
Immunocompetent cells (macrophages, B cells, dendritic cells, APCs)
MHC class I presents antigens to which cell?
Cytotoxic T cell
MHC class II presents antigens to ______.
T-helper cells
Enumerate the genetic loci of MHC Class I.
HLA-A,B,C
Enumerate the genetic loci of MHC Class II.
HLA-DP, DQ, DR
Which MHC Class has alpha and beta chain structure?
MHC Class II
Which MHC Class has alpha and B2 microglobulin chain structure?
MHC class I
Which MHC involves complement components C2, C4 and Factor B?
MHC Class III
What do you call the HLA on RBC?
Bennet-Goodspeed
Bennet-Goodspeed is of what MHC class?
MHC Class II
HLA genotyping test.
PCR-based amplification
The test for the phenotypic or genotypic ID of the HLA antigens or genes in a transplant candidate or donor.
HLA phenotyping
Limitations of HLA phenotyping.
Requires viable lymphocytes, requires separation of lymphocytes
Interpret the following HLA phenotyping grades:
- 1
- 2
- 4
- 6
- 8
- 0
- Negative
- Doubtful negative
- Weak positive
- Positive
- Strong positive
- Unreadable
Which HLA phenotyping grade has the most percentage of cell death?
8
Importance of HLA typing
Tissue / organ transplant, paternity testing, studies of racial ancestry & migration, for diagnostic & genetic counseling, disease association
Substance that can enhance immune response.
Adjuvants
Adjuvants came from the word “adjuvare”, which means?
To aid
Which lymphocyte contains both MHC class I and class II molecules?
B cells
T cells contain:
A. MHC class I
B. MHC class II
C. Both
D. Neither
A. MHC class I
What is used to separate B from T cells?
Nylon wool
HLA-B27 is associated with what disease?
Ankylosing spondylitis
HLA-DR3 is associated with what disease?
Multiple sclerosis
HLA DR2 and DR3 are associated with what disease?
SLE
HLA-DR4 is associated with what disease?
RA
HLA DR3 and DR4 is associated with what disease?
Type I DM
This classification of drug prevents transplant rejection by weakening the patient’s immune system.
Immunosuppressive agents
What immunosuppressive drug blocks the production and secretion of cytokines, inflammatory mediators, chemoattractant and adhesion molecules?
Corticosteroids
Which immunosuppressive agent interferes with the maturation of lymphocytes and kill proliferating cells?
Antimetabolites
Which immunosuppressive agent blocks signal transduction in T lymphocytes? (ex: cyclosporine)
Calcineurin inhibitors
Which immunosuppressive agent interferes in T cell activation?
Monoclonal antibodies
Which immunosuppressive agent depletes lymphocyte from the circulation? (Thymoglobulin)
Polyclonal antibodies
Basiliximab and daclizumab binds CD____ receptor.
25
Alemtuzumab binds CD_____.
52
Which type of graft rejection occurs after days of transplantation, preformed antibodies to ABO, HLA and certain endothelial bind to donor vascular endothelium, activating complement and clotting factors?
Accelerated
Which type of graft rejection occurs minutes to hours after transplantation, and is caused by preformed antibodies to ABO, HLA and certain endothelial bind to donor vascular endothelium, activating complement and clotting factors?
Hyperacute
Which type of graft rejection happens 100 days or more wherein the T cells in HSC, lung, or liver transplants reacts against foreign HLA proteins in the recipient’s cells, causing massive cytokine release, inflammation, and tissue destruction in various locations throughout the body.
GVHD (Graft Versus Host Disease)
Which type of graft rejection occurs days to months wherein there is a cell-mediated response to foreign MHC-expressing cells and CD4+ T cells produce cytokines and induce delayed type hypersensitivity?
Acute
Which type of graft rejection occurs 1 year or more with the presence of delayed type hypersensitivity response and possibly antibodies to foreign HLA antigens on graft?
Chronic
This test uses mitomycin C-treated or irradiated donor lymphocytes and live recipient lymphocytes.
Mixed lymphocyte reaction
Rh antibodies are of which Ig class and subclass?
IgG4
True/False: Rh antibodies can induce complement fixation.
False. It cannot.
Where do we get cyclosporine?
Fungi
Where do we get bacitracin?
Bacillus
The most commonly donated organs.
Kidney
The safest organ to transplant.
Cornea
Why is cornea the safest organ to transplant?
It is avascular, it has decreased MHC class I molecules and it has no MHC class II molecules
A part of IgA that prevents it from enzymatic degradation and facilitates in the transport of secretory IgA.
Secretory piece
