What is an antigen?
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Foreign molecular structures that the adaptive immune system can respond to.
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What is an antigen?
Foreign molecular structures that the adaptive immune system can respond to.
How long after vaccination can anti-X antibody be detected in the blood of the pig?
Approximately 7-10 days.
What does the B-cell need help from once it has 'seen' its antigen of interest?
Helper T-cell.
What is an antigen?
A substance that can induce an immune response.
What is required for the B-cell to receive help from a Helper T-cell?
The Helper T-cell must have also 'seen' the same antigen of interest.
What are examples of antigens?
Foreign substances like bacteria, viruses, and pollen.
What is the role of B-cells in recognizing antigens?
Recognizing antigens free in solution in the extracellular environment.
What is an antigen?
Antigens are molecules that can be recognized by the immune system as foreign and trigger an immune response.
What is usually generated against haptens?
Antibody.
How do T-cells recognize antigens?
T-cells must have their unique antigen presented to them by another cell.
How do RBC antigens differ between individuals?
RBC antigens may be foreign to another individual's immune system if they have different RBC antigens.
What type of response is not usually generated against haptens?
Cell-mediated response (CTLs).
What is a property of a good immunogen related to foreignness?
It should be foreign to the host (not self).
What makes mature B and T-lymphocytes antigen-specific?
Their unique B-cell or T-cell receptors for antigen.
What is a hapten?
A small molecule that, when combined with a larger molecule, can elicit an immune response.
Once antibody is generated against a hapten, what can bind to the hapten?
The antibody, even if the hapten is not bound to the larger molecule.
What type of proteins make the best antigens?
Foreign proteins.
What do mature B and T-lymphocytes need to interact with to be activated?
Their antigen.
Can haptens elicit an immune response by themselves?
No, haptens by themselves are not immunogenic in vivo.
How can the immune system 'see' haptens as foreign?
When haptens are bound to a larger molecule.
How does the acquired immune system prevent responding to 'self-antigens'?
It develops in a way to prevent responding to self-antigens.
What are MHC molecules essential for?
Antigen presentation by APCs and host infected/tumor cells to T-cells.
What are the products of the adaptive immune response that antigens can interact with?
Specific antibodies, specific T-lymphocytes, and specific B-lymphocytes.
What is the minimum molecular size required to be an immunogen?
Greater than 1000 Daltons (1kDa).
What is one mechanism for lysing RBCs coated with antibody?
Complement activation via the Classical Pathway.
What type of immune response is generated to haptens?
An adaptive immune response.
Why are lipids and nucleic acids generally poor immunogens?
They are simple molecules and are readily degraded.
Which molecule of the Sars2 Coronavirus is most associated with vaccines?
Spike protein.
What are epitopes also known as?
Antigenic determinant sites.
What is the importance of stability in an immunogen?
Stability ensures that the molecule exists long enough to be immunogenic.
What do MHC molecules present to T-cells?
Peptides of the larger protein antigen.
How does penicillin become 'seen' by the adaptive immune system?
By binding to RBCs.
How is the antigen recognized by specific antibodies?
The antigen that induced the response will be recognized by specific antibodies generated by the response.
Why are simple repeating units poor immunogens?
They are poor immunogens because they are polymers, like carbohydrates and plastics.
How many pathways of antigen presentation to T-lymphocytes are there in the Adaptive Immune System?
Two pathways.
How does complement activation via the Classical Pathway lead to lysis of RBCs?
Antibody bound to RBC can open up a site for C1 complement protein to bind and activate the Classical Complement pathway, leading to the formation of the MAC.
What are examples of haptens?
Drugs, hormones, toxins.
What makes prokaryotic nucleic acids able to stimulate a potent immune response in mammals?
CpG motifs of bacterial DNA.
What elements of protein structure may be involved in protein epitopes?
Primary, secondary, tertiary, or quaternary structure.
What drives the adaptive immune response?
Antigen.
What do epitopes bind with?
Antibody, TCR, or BCR.
What type of antigens do T-cells respond to?
Protein antigens.
Why are totally inert molecules not immunogenic?
Because they do not trigger an immune response.
What is produced in response to penicillin binding to RBCs?
Antibody to penicillin.
Which type of molecules are usually good immunogens?
Proteins and glycoproteins.
How is the antigen recognized by specific T-lymphocytes and B-lymphocytes?
The antigen can be recognized via the T-cell Receptor on T-cells and the B-cell Receptor on B-cells.
What is an example of a molecule that can act as a hapten?
Penicillin.
What is another mechanism for lysing RBCs coated with antibody?
Host cells (phagocytic cells and NK cells) expressing receptors for the Fc part of antibody.
Which pathway of antigen presentation primarily results in antigen-specific Antibody production?
One pathway.
What makes bacterial LPS different from most lipid-carbohydrate molecules?
They are good immunogens.
What is the difference between conformational and denatured protein epitopes?
Conformational epitopes depend on recognizing proteins in their native state, while denatured epitopes are altered by denaturing or degradation.
What are the essential components of the acquired immune response?
Antigen, Antigen Presenting Cells (APCs), Major Histocompatibility Complex (MHC) molecules, B- and T-lymphocytes.
Can a single immunogenic molecule have multiple epitopes?
Yes, it may have several different epitopes.
How can proteins that are easily degraded be 'fixed' to improve immunogenicity?
They can be 'fixed' with heat or formaldehyde to slow down degradation.
What do antigens interact with and bind to?
Major Histocompatibility Complex (MHC) molecules.
What can result from the production of antibody to penicillin?
Lysis of the RBCs.
Why are lipids and nucleic acids generally poor immunogens?
They are generally poor immunogens due to their chemical composition.
What portion of the larger antigen molecule actually binds with the antibody or the T-cell Receptor or the B-cell Receptor?
Only a portion of the larger antigen molecule actually binds with the antibody or the T-cell Receptor or the B-cell Receptor.
Why is penicillin alone too small to elicit an immune response?
Because it might bind to albumin or RBCs, etc., and then elicit an immune response.
Which cells express receptors for the Fc part of antibody to lyse RBCs?
Phagocytic cells and NK cells.
What type of microbes is the pathway resulting in antigen-specific Antibody production best for responding to?
Extracellular microbes.
What is the role of Antigen Presenting Cells (APCs) in the immune response?
They capture, process, and present antigens to T-helper lymphocytes (Th-cells).
What happens to immunogenicity when protein structures are denatured or degraded?
It may be lost.
Why are some bacteria's polymer capsular coatings poorly immunogenic?
They are simple, repeating units that protect the bacteria from an immune response.
What are the cells responsible for presenting antigens to T-cells?
Antigen Presenting Cells (APCs).
What happens if an immunogenic molecule has different epitopes?
Each different epitope will be recognized by different antibody, BCR, and/or TCR.
What is the additional benefit of 'fixing' a molecule to improve immunogenicity?
It will also inactivate a toxin that one might want to use as an immunogen in a vaccine.
What is the condition called when the antibody is bound to the RBC?
Drug-induced hemolytic anemia.
What can result from an immune response to penicillin acting as a hapten?
An allergy or other immune-mediated conditions.
Which pathway of antigen presentation results in antigen-specific CTLs (cytotoxic T-lymphocytes)?
One pathway.
How are antigens made inside cells presented to Cytotoxic T-lymphocytes (CTLs)?
Host infected cells and tumor cells process and present internal antigens to CTLs.
What is an example of a molecule with many epitopes?
The SARS CoV 2 spike protein.
What molecules are involved in presenting antigens to T-cells?
Major Histocompatibility Complex (MHC) molecules.
What are two mechanisms that can destroy the RBCs once the antibody is bound to them?
What can stimulate an immune response?
Haptens.
What is the overall result of Th-cells in the immune response?
Th-cells help both B-cells and CTLs.
What is the pathway resulting in antigen-specific CTLs best for responding to?
Host virally infected cells and host tumor cells.
What does antigen interact with to bind to antibody?
Antibody.
Which types of lymphocytes are involved in the acquired immune response?
B- and T-lymphocytes.
What is the role of antigen-activated B-cells in the immune response?
They become plasma cells and make/secrete antibodies that target extracellular pathogens.
What drives B-cells to make antibody specific to the antigen that stimulated the B-cell?
Antigen.
What is the role of antigen-activated CTLs in the immune response?
They kill host infected cells and tumor cells.
What type of receptor do T-cells express that is specific to an antigen?
T-cell receptor (TCR).
What drives the proliferation of antigen-specific T-cells?
Antigen binding to TCR.
What must always present the antigen to the T-cell for interaction?
Another cell.
What type of receptor do B-cells express that is specific to an antigen?
B-cell receptor (BCR).
What drives the proliferation of antigen-specific B-cells?
Antigen binding to BCR.
